Merge from rustc

117 files changed, 1588 insertions, 1657 deletions

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 959cf9fa513..cf735815fd2 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -2959,21 +2959,27 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             }
         }
 
-        let mut err = self.path_does_not_live_long_enough(borrow_span, &format!("`{name}`"));
+        let name = if borrow_span.in_external_macro(self.infcx.tcx.sess.source_map()) {
+            // Don't name local variables in external macros.
+            "value".to_string()
+        } else {
+            format!("`{name}`")
+        };
+
+        let mut err = self.path_does_not_live_long_enough(borrow_span, &name);
 
         if let Some(annotation) = self.annotate_argument_and_return_for_borrow(borrow) {
             let region_name = annotation.emit(self, &mut err);
 
             err.span_label(
                 borrow_span,
-                format!("`{name}` would have to be valid for `{region_name}`..."),
+                format!("{name} would have to be valid for `{region_name}`..."),
             );
 
             err.span_label(
                 drop_span,
                 format!(
-                    "...but `{}` will be dropped here, when the {} returns",
-                    name,
+                    "...but {name} will be dropped here, when the {} returns",
                     self.infcx
                         .tcx
                         .opt_item_name(self.mir_def_id().to_def_id())
@@ -3011,7 +3017,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             }
         } else {
             err.span_label(borrow_span, "borrowed value does not live long enough");
-            err.span_label(drop_span, format!("`{name}` dropped here while still borrowed"));
+            err.span_label(drop_span, format!("{name} dropped here while still borrowed"));
 
             borrow_spans.args_subdiag(&mut err, |args_span| {
                 crate::session_diagnostics::CaptureArgLabel::Capture {
diff --git a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
index f77dda0d386..a845431faca 100644
--- a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
@@ -95,7 +95,9 @@ impl<'tcx> BorrowExplanation<'tcx> {
                         && let hir::def::Res::Local(hir_id) = p.res
                         && let hir::Node::Pat(pat) = tcx.hir_node(hir_id)
                     {
-                        err.span_label(pat.span, format!("binding `{ident}` declared here"));
+                        if !ident.span.in_external_macro(tcx.sess.source_map()) {
+                            err.span_label(pat.span, format!("binding `{ident}` declared here"));
+                        }
                     }
                 }
             }
diff --git a/compiler/rustc_codegen_gcc/.github/workflows/ci.yml b/compiler/rustc_codegen_gcc/.github/workflows/ci.yml
index f96912e6b7a..ef024258ffc 100644
--- a/compiler/rustc_codegen_gcc/.github/workflows/ci.yml
+++ b/compiler/rustc_codegen_gcc/.github/workflows/ci.yml
@@ -1,8 +1,10 @@
 name: CI
 
 on:
-  - push
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
 
 permissions:
   contents: read
@@ -121,3 +123,22 @@ jobs:
         run: |
           cd build_system
           cargo test
+
+  # Summary job for the merge queue.
+  # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+  success:
+    needs: [build, duplicates, build_system]
+    # We need to ensure this job does *not* get skipped if its dependencies fail,
+    # because a skipped job is considered a success by GitHub. So we have to
+    # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
+    # when the workflow is canceled manually.
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      # Manually check the status of all dependencies. `if: failure()` does not work.
+      - name: Conclusion
+        run: |
+          # Print the dependent jobs to see them in the CI log
+          jq -C <<< '${{ toJson(needs) }}'
+          # Check if all jobs that we depend on (in the needs array) were successful.
+          jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
diff --git a/compiler/rustc_codegen_gcc/.github/workflows/failures.yml b/compiler/rustc_codegen_gcc/.github/workflows/failures.yml
index d080bbfe91f..bc42eb1468e 100644
--- a/compiler/rustc_codegen_gcc/.github/workflows/failures.yml
+++ b/compiler/rustc_codegen_gcc/.github/workflows/failures.yml
@@ -2,7 +2,10 @@
 name: Failures
 
 on:
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
 
 permissions:
   contents: read
@@ -108,3 +111,22 @@ jobs:
           echo "Error: 'the compiler unexpectedly panicked' found in output logs. CI Error!!"
           exit 1
         fi
+
+  # Summary job for the merge queue.
+  # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+  success_failures:
+    needs: [build]
+    # We need to ensure this job does *not* get skipped if its dependencies fail,
+    # because a skipped job is considered a success by GitHub. So we have to
+    # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
+    # when the workflow is canceled manually.
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      # Manually check the status of all dependencies. `if: failure()` does not work.
+      - name: Conclusion
+        run: |
+          # Print the dependent jobs to see them in the CI log
+          jq -C <<< '${{ toJson(needs) }}'
+          # Check if all jobs that we depend on (in the needs array) were successful.
+          jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
diff --git a/compiler/rustc_codegen_gcc/.github/workflows/gcc12.yml b/compiler/rustc_codegen_gcc/.github/workflows/gcc12.yml
index bb9e020dc6a..da9a1506855 100644
--- a/compiler/rustc_codegen_gcc/.github/workflows/gcc12.yml
+++ b/compiler/rustc_codegen_gcc/.github/workflows/gcc12.yml
@@ -1,8 +1,10 @@
 name: CI libgccjit 12
 
 on:
-  - push
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
 
 permissions:
   contents: read
@@ -85,3 +87,22 @@ jobs:
     #- name: Run tests
       #run: |
         #./y.sh test --release --clean --build-sysroot ${{ matrix.commands }} --no-default-features
+
+  # Summary job for the merge queue.
+  # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+  success_gcc12:
+    needs: [build]
+    # We need to ensure this job does *not* get skipped if its dependencies fail,
+    # because a skipped job is considered a success by GitHub. So we have to
+    # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
+    # when the workflow is canceled manually.
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      # Manually check the status of all dependencies. `if: failure()` does not work.
+      - name: Conclusion
+        run: |
+          # Print the dependent jobs to see them in the CI log
+          jq -C <<< '${{ toJson(needs) }}'
+          # Check if all jobs that we depend on (in the needs array) were successful.
+          jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
diff --git a/compiler/rustc_codegen_gcc/.github/workflows/m68k.yml b/compiler/rustc_codegen_gcc/.github/workflows/m68k.yml
index ed1fc02bd91..21731f7087e 100644
--- a/compiler/rustc_codegen_gcc/.github/workflows/m68k.yml
+++ b/compiler/rustc_codegen_gcc/.github/workflows/m68k.yml
@@ -3,8 +3,10 @@
 name: m68k CI
 
 on:
-  - push
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
 
 permissions:
   contents: read
@@ -105,3 +107,22 @@ jobs:
     - name: Run tests
       run: |
         ./y.sh test --release --clean --build-sysroot --sysroot-features compiler_builtins/no-f16-f128 ${{ matrix.commands }}
+
+  # Summary job for the merge queue.
+  # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+  success_m68k:
+    needs: [build]
+    # We need to ensure this job does *not* get skipped if its dependencies fail,
+    # because a skipped job is considered a success by GitHub. So we have to
+    # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
+    # when the workflow is canceled manually.
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      # Manually check the status of all dependencies. `if: failure()` does not work.
+      - name: Conclusion
+        run: |
+          # Print the dependent jobs to see them in the CI log
+          jq -C <<< '${{ toJson(needs) }}'
+          # Check if all jobs that we depend on (in the needs array) were successful.
+          jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
diff --git a/compiler/rustc_codegen_gcc/.github/workflows/release.yml b/compiler/rustc_codegen_gcc/.github/workflows/release.yml
index 886ce90b471..47a40286554 100644
--- a/compiler/rustc_codegen_gcc/.github/workflows/release.yml
+++ b/compiler/rustc_codegen_gcc/.github/workflows/release.yml
@@ -1,8 +1,10 @@
 name: CI with sysroot compiled in release mode
 
 on:
-  - push
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
 
 permissions:
   contents: read
@@ -82,3 +84,22 @@ jobs:
           echo "Test is done with LTO enabled, hence inlining should occur across crates"
           exit 1
         fi
+
+  # Summary job for the merge queue.
+  # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+  success_release:
+    needs: [build]
+    # We need to ensure this job does *not* get skipped if its dependencies fail,
+    # because a skipped job is considered a success by GitHub. So we have to
+    # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
+    # when the workflow is canceled manually.
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      # Manually check the status of all dependencies. `if: failure()` does not work.
+      - name: Conclusion
+        run: |
+          # Print the dependent jobs to see them in the CI log
+          jq -C <<< '${{ toJson(needs) }}'
+          # Check if all jobs that we depend on (in the needs array) were successful.
+          jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
diff --git a/compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml b/compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml
index d5ae6144496..4b9f48e7b18 100644
--- a/compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml
+++ b/compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml
@@ -1,8 +1,10 @@
 name: stdarch tests with sysroot compiled in release mode
 
 on:
-  - push
-  - pull_request
+  push:
+    branches:
+      - master
+  pull_request:
 
 permissions:
   contents: read
@@ -102,3 +104,22 @@ jobs:
         # TODO: remove --skip test_mm512_stream_ps when stdarch is updated in rustc.
         # TODO: remove --skip test_tile_ when it's implemented.
         STDARCH_TEST_EVERYTHING=1 CHANNEL=release CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER="${{ matrix.cargo_runner }}" TARGET=x86_64-unknown-linux-gnu CG_RUSTFLAGS="-Ainternal_features --cfg stdarch_intel_sde" ./y.sh cargo test --manifest-path build/build_sysroot/sysroot_src/library/stdarch/Cargo.toml -- --skip rtm --skip tbm --skip sse4a --skip test_mm512_stream_ps --skip test_tile_
+
+  # Summary job for the merge queue.
+  # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+  success_stdarch:
+    needs: [build]
+    # We need to ensure this job does *not* get skipped if its dependencies fail,
+    # because a skipped job is considered a success by GitHub. So we have to
+    # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
+    # when the workflow is canceled manually.
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      # Manually check the status of all dependencies. `if: failure()` does not work.
+      - name: Conclusion
+        run: |
+          # Print the dependent jobs to see them in the CI log
+          jq -C <<< '${{ toJson(needs) }}'
+          # Check if all jobs that we depend on (in the needs array) were successful.
+          jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
diff --git a/compiler/rustc_codegen_gcc/Cargo.lock b/compiler/rustc_codegen_gcc/Cargo.lock
index 636e75b94a3..832603aa792 100644
--- a/compiler/rustc_codegen_gcc/Cargo.lock
+++ b/compiler/rustc_codegen_gcc/Cargo.lock
@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.4.0"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72fd91f4adbf02b53cfc73c97bc33c5f253009043f30c56a5ec08dd5c8094dc8"
+checksum = "2895ddec764de7ac76fe6c056050c4801a80109c066f177a00a9cc8dee02b29b"
 dependencies = [
  "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.5.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0fb7b8f48a75e2cfe78c3d9a980b32771c34ffd12d196021ab3f98c49fbd2f0d"
+checksum = "ac133db68db8a6a8b2c51ef4b18d8ea16682d5814c4641272fe37bbbc223d5f3"
 dependencies = [
  "libc",
 ]
diff --git a/compiler/rustc_codegen_gcc/Cargo.toml b/compiler/rustc_codegen_gcc/Cargo.toml
index 63d37358561..b50f2a626d5 100644
--- a/compiler/rustc_codegen_gcc/Cargo.toml
+++ b/compiler/rustc_codegen_gcc/Cargo.toml
@@ -22,7 +22,7 @@ master = ["gccjit/master"]
 default = ["master"]
 
 [dependencies]
-gccjit = "2.4"
+gccjit = "2.5"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.
diff --git a/compiler/rustc_codegen_gcc/Readme.md b/compiler/rustc_codegen_gcc/Readme.md
index e92c16ece2f..d0e4dbba6d3 100644
--- a/compiler/rustc_codegen_gcc/Readme.md
+++ b/compiler/rustc_codegen_gcc/Readme.md
@@ -23,7 +23,7 @@ A secondary goal is to check if using the gcc backend will provide any run-time
 ## Building
 
 **This requires a patched libgccjit in order to work.
-You need to use my [fork of gcc](https://github.com/antoyo/gcc) which already includes these patches.**
+You need to use my [fork of gcc](https://github.com/rust-lang/gcc) which already includes these patches.**
 
 ```bash
 $ cp config.example.toml config.toml
@@ -40,7 +40,7 @@ to do a few more things.
 To build it (most of these instructions come from [here](https://gcc.gnu.org/onlinedocs/jit/internals/index.html), so don't hesitate to take a look there if you encounter an issue):
 
 ```bash
-$ git clone https://github.com/antoyo/gcc
+$ git clone https://github.com/rust-lang/gcc
 $ sudo apt install flex libmpfr-dev libgmp-dev libmpc3 libmpc-dev
 $ mkdir gcc-build gcc-install
 $ cd gcc-build
diff --git a/compiler/rustc_codegen_gcc/build_system/src/clone_gcc.rs b/compiler/rustc_codegen_gcc/build_system/src/clone_gcc.rs
index e28ee873eb6..b49dd47f352 100644
--- a/compiler/rustc_codegen_gcc/build_system/src/clone_gcc.rs
+++ b/compiler/rustc_codegen_gcc/build_system/src/clone_gcc.rs
@@ -61,7 +61,7 @@ pub fn run() -> Result<(), String> {
         return Ok(());
     };
 
-    let result = git_clone("https://github.com/antoyo/gcc", Some(&args.out_path), false)?;
+    let result = git_clone("https://github.com/rust-lang/gcc", Some(&args.out_path), false)?;
     if result.ran_clone {
         let gcc_commit = args.config_info.get_gcc_commit()?;
         println!("Checking out GCC commit `{}`...", gcc_commit);
diff --git a/compiler/rustc_codegen_gcc/build_system/src/test.rs b/compiler/rustc_codegen_gcc/build_system/src/test.rs
index 6c29c7d1825..df4ac85233b 100644
--- a/compiler/rustc_codegen_gcc/build_system/src/test.rs
+++ b/compiler/rustc_codegen_gcc/build_system/src/test.rs
@@ -529,20 +529,21 @@ fn asm_tests(env: &Env, args: &TestArg) -> Result<(), String> {
 
     env.insert("COMPILETEST_FORCE_STAGE0".to_string(), "1".to_string());
 
-    let extra =
-        if args.is_using_gcc_master_branch() { "" } else { " -Csymbol-mangling-version=v0" };
-
-    let rustc_args = &format!(
-        r#"-Zpanic-abort-tests \
-            -Zcodegen-backend="{pwd}/target/{channel}/librustc_codegen_gcc.{dylib_ext}" \
-            --sysroot "{sysroot_dir}" -Cpanic=abort{extra}"#,
+    let codegen_backend_path = format!(
+        "{pwd}/target/{channel}/librustc_codegen_gcc.{dylib_ext}",
         pwd = std::env::current_dir()
             .map_err(|error| format!("`current_dir` failed: {:?}", error))?
             .display(),
         channel = args.config_info.channel.as_str(),
         dylib_ext = args.config_info.dylib_ext,
-        sysroot_dir = args.config_info.sysroot_path,
-        extra = extra,
+    );
+
+    let extra =
+        if args.is_using_gcc_master_branch() { "" } else { " -Csymbol-mangling-version=v0" };
+
+    let rustc_args = format!(
+        "-Zpanic-abort-tests -Zcodegen-backend={codegen_backend_path} --sysroot {} -Cpanic=abort{extra}",
+        args.config_info.sysroot_path
     );
 
     run_command_with_env(
@@ -677,7 +678,7 @@ fn test_projects(env: &Env, args: &TestArg) -> Result<(), String> {
 fn test_libcore(env: &Env, args: &TestArg) -> Result<(), String> {
     // FIXME: create a function "display_if_not_quiet" or something along the line.
     println!("[TEST] libcore");
-    let path = get_sysroot_dir().join("sysroot_src/library/core/tests");
+    let path = get_sysroot_dir().join("sysroot_src/library/coretests");
     let _ = remove_dir_all(path.join("target"));
     run_cargo_command(&[&"test"], Some(&path), env, args)?;
     Ok(())
diff --git a/compiler/rustc_codegen_gcc/doc/add-attribute.md b/compiler/rustc_codegen_gcc/doc/add-attribute.md
index ae3bcc5e2eb..267c1819525 100644
--- a/compiler/rustc_codegen_gcc/doc/add-attribute.md
+++ b/compiler/rustc_codegen_gcc/doc/add-attribute.md
@@ -14,4 +14,4 @@ Finally, you need to update this repository by calling the relevant API you adde
 
 To test it, build `gcc`, run `cargo update -p gccjit` and then you can test the generated output for a given Rust crate.
 
-[gccjit.rs]: https://github.com/antoyo/gccjit.rs
+[gccjit.rs]: https://github.com/rust-lang/gccjit.rs
diff --git a/compiler/rustc_codegen_gcc/example/mini_core.rs b/compiler/rustc_codegen_gcc/example/mini_core.rs
index 5544aee9eaf..c554a87b825 100644
--- a/compiler/rustc_codegen_gcc/example/mini_core.rs
+++ b/compiler/rustc_codegen_gcc/example/mini_core.rs
@@ -51,6 +51,10 @@ impl<T: ?Sized> LegacyReceiver for &T {}
 impl<T: ?Sized> LegacyReceiver for &mut T {}
 impl<T: ?Sized, A: Allocator> LegacyReceiver for Box<T, A> {}
 
+#[lang = "receiver"]
+trait Receiver {
+}
+
 #[lang = "copy"]
 pub trait Copy {}
 
@@ -134,6 +138,14 @@ impl Mul for u8 {
     }
 }
 
+impl Mul for i32 {
+    type Output = Self;
+
+    fn mul(self, rhs: Self) -> Self::Output {
+        self * rhs
+    }
+}
+
 impl Mul for usize {
     type Output = Self;
 
@@ -142,6 +154,14 @@ impl Mul for usize {
     }
 }
 
+impl Mul for isize {
+    type Output = Self;
+
+    fn mul(self, rhs: Self) -> Self::Output {
+        self * rhs
+    }
+}
+
 #[lang = "add"]
 pub trait Add<RHS = Self> {
     type Output;
@@ -165,6 +185,14 @@ impl Add for i8 {
     }
 }
 
+impl Add for i32 {
+    type Output = Self;
+
+    fn add(self, rhs: Self) -> Self {
+        self + rhs
+    }
+}
+
 impl Add for usize {
     type Output = Self;
 
@@ -196,6 +224,14 @@ impl Sub for usize {
     }
 }
 
+impl Sub for isize {
+    type Output = Self;
+
+    fn sub(self, rhs: Self) -> Self {
+        self - rhs
+    }
+}
+
 impl Sub for u8 {
     type Output = Self;
 
@@ -220,6 +256,14 @@ impl Sub for i16 {
     }
 }
 
+impl Sub for i32 {
+    type Output = Self;
+
+    fn sub(self, rhs: Self) -> Self {
+        self - rhs
+    }
+}
+
 #[lang = "rem"]
 pub trait Rem<RHS = Self> {
     type Output;
@@ -628,6 +672,10 @@ pub mod libc {
         pub fn memcpy(dst: *mut u8, src: *const u8, size: usize);
         pub fn memmove(dst: *mut u8, src: *const u8, size: usize);
         pub fn strncpy(dst: *mut u8, src: *const u8, size: usize);
+        pub fn fflush(stream: *mut i32) -> i32;
+        pub fn exit(status: i32);
+
+        pub static stdout: *mut i32;
     }
 }
 
diff --git a/compiler/rustc_codegen_gcc/libgccjit.version b/compiler/rustc_codegen_gcc/libgccjit.version
index 417fd5b0393..125b04004b0 100644
--- a/compiler/rustc_codegen_gcc/libgccjit.version
+++ b/compiler/rustc_codegen_gcc/libgccjit.version
@@ -1 +1 @@
-e607be166673a8de9fc07f6f02c60426e556c5f2
+0ea98a1365b81f7488073512c850e8ee951a4afd
diff --git a/compiler/rustc_codegen_gcc/patches/0022-core-Disable-not-compiling-tests.patch b/compiler/rustc_codegen_gcc/patches/0022-core-Disable-not-compiling-tests.patch
deleted file mode 100644
index 70e3e2ba7fe..00000000000
--- a/compiler/rustc_codegen_gcc/patches/0022-core-Disable-not-compiling-tests.patch
+++ /dev/null
@@ -1,44 +0,0 @@
-From af0e237f056fa838c77463381a19b0dc993c0a35 Mon Sep 17 00:00:00 2001
-From: None <none@example.com>
-Date: Sun, 1 Sep 2024 11:42:17 -0400
-Subject: [PATCH] Disable not compiling tests
-
----
- library/core/tests/Cargo.toml | 14 ++++++++++++++
- library/core/tests/lib.rs     |  1 +
- 2 files changed, 15 insertions(+)
- create mode 100644 library/core/tests/Cargo.toml
-
-diff --git a/library/core/tests/Cargo.toml b/library/core/tests/Cargo.toml
-new file mode 100644
-index 0000000..ca326ac
---- /dev/null
-+++ b/library/core/tests/Cargo.toml
-@@ -0,0 +1,14 @@
-+[workspace]
-+
-+[package]
-+name = "coretests"
-+version = "0.0.0"
-+edition = "2021"
-+
-+[lib]
-+name = "coretests"
-+path = "lib.rs"
-+
-+[dependencies]
-+rand = { version = "0.8.5", default-features = false }
-+rand_xorshift = { version = "0.3.0", default-features = false }
-diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
-index a4a7946..ecfe43f 100644
---- a/library/core/tests/lib.rs
-+++ b/library/core/tests/lib.rs
-@@ -1,4 +1,5 @@
- // tidy-alphabetical-start
-+#![cfg(test)]
- #![cfg_attr(target_has_atomic = "128", feature(integer_atomics))]
- #![cfg_attr(test, feature(cfg_match))]
- #![feature(alloc_layout_extra)]
--- 
-2.47.1
-
diff --git a/compiler/rustc_codegen_gcc/patches/0028-core-Disable-long-running-tests.patch b/compiler/rustc_codegen_gcc/patches/0028-core-Disable-long-running-tests.patch
index dc1beae6d2e..20df4245cfd 100644
--- a/compiler/rustc_codegen_gcc/patches/0028-core-Disable-long-running-tests.patch
+++ b/compiler/rustc_codegen_gcc/patches/0028-core-Disable-long-running-tests.patch
@@ -1,17 +1,17 @@
-From eb703e627e7a84f1cd8d0d87f0f69da1f0acf765 Mon Sep 17 00:00:00 2001
-From: bjorn3 <bjorn3@users.noreply.github.com>
-Date: Fri, 3 Dec 2021 12:16:30 +0100
+From ec2d0dc77fb484d926b45bb626b0db6a4bb0ab5c Mon Sep 17 00:00:00 2001
+From: None <none@example.com>
+Date: Thu, 27 Mar 2025 09:20:41 -0400
 Subject: [PATCH] Disable long running tests
 
 ---
- library/core/tests/slice.rs | 2 ++
+ library/coretests/tests/slice.rs | 2 ++
  1 file changed, 2 insertions(+)
 
-diff --git a/library/core/tests/slice.rs b/library/core/tests/slice.rs
-index 8402833..84592e0 100644
---- a/library/core/tests/slice.rs
-+++ b/library/core/tests/slice.rs
-@@ -2462,6 +2462,7 @@ take_tests! {
+diff --git a/library/coretests/tests/slice.rs b/library/coretests/tests/slice.rs
+index d17e681..fba5cd6 100644
+--- a/library/coretests/tests/slice.rs
++++ b/library/coretests/tests/slice.rs
+@@ -2486,6 +2486,7 @@ split_off_tests! {
  #[cfg(not(miri))] // unused in Miri
  const EMPTY_MAX: &'static [()] = &[(); usize::MAX];
  
@@ -19,14 +19,14 @@ index 8402833..84592e0 100644
  // can't be a constant due to const mutability rules
  #[cfg(not(miri))] // unused in Miri
  macro_rules! empty_max_mut {
-@@ -2485,6 +2486,7 @@ take_tests! {
-     (take_mut_oob_max_range_to_inclusive, (..=usize::MAX), None, empty_max_mut!()),
-     (take_mut_in_bounds_max_range_from, (usize::MAX..), Some(&mut [] as _), empty_max_mut!()),
+@@ -2509,6 +2510,7 @@ split_off_tests! {
+     (split_off_mut_oob_max_range_to_inclusive, (..=usize::MAX), None, empty_max_mut!()),
+     (split_off_mut_in_bounds_max_range_from, (usize::MAX..), Some(&mut [] as _), empty_max_mut!()),
  }
 +*/
  
  #[test]
  fn test_slice_from_ptr_range() {
 -- 
-2.26.2.7.g19db9cfb68
+2.49.0
 
diff --git a/compiler/rustc_codegen_gcc/patches/cross_patches/0001-Disable-libstd-and-libtest-dylib.patch b/compiler/rustc_codegen_gcc/patches/cross_patches/0001-Disable-libstd-and-libtest-dylib.patch
index c220f53040f..fa360fe9e74 100644
--- a/compiler/rustc_codegen_gcc/patches/cross_patches/0001-Disable-libstd-and-libtest-dylib.patch
+++ b/compiler/rustc_codegen_gcc/patches/cross_patches/0001-Disable-libstd-and-libtest-dylib.patch
@@ -1,19 +1,18 @@
-From 966beefe08be6045bfcca26079b76a7a80413080 Mon Sep 17 00:00:00 2001
+From b2911e732d1bf0e28872495c4c47af1dad3c7911 Mon Sep 17 00:00:00 2001
 From: None <none@example.com>
-Date: Thu, 28 Sep 2023 17:37:38 -0400
+Date: Thu, 27 Mar 2025 14:30:10 -0400
 Subject: [PATCH] Disable libstd and libtest dylib
 
 ---
- library/std/Cargo.toml  | 2 +-
- library/test/Cargo.toml | 2 +-
- 2 files changed, 2 insertions(+), 2 deletions(-)
+ library/std/Cargo.toml | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
 
 diff --git a/library/std/Cargo.toml b/library/std/Cargo.toml
-index 5b21355..cb0c49b 100644
+index 176da60..c183cdb 100644
 --- a/library/std/Cargo.toml
 +++ b/library/std/Cargo.toml
-@@ -9,7 +9,7 @@ description = "The Rust Standard Library"
- edition = "2021"
+@@ -10,7 +10,7 @@ edition = "2024"
+ autobenches = false
  
  [lib]
 -crate-type = ["dylib", "rlib"]
@@ -21,3 +20,6 @@ index 5b21355..cb0c49b 100644
  
  [dependencies]
  alloc = { path = "../alloc", public = true }
+-- 
+2.49.0
+
diff --git a/compiler/rustc_codegen_gcc/patches/libgccjit12/0001-core-Disable-portable-simd-test.patch b/compiler/rustc_codegen_gcc/patches/libgccjit12/0001-core-Disable-portable-simd-test.patch
index 9ef5e0e4f46..9d5b2dc537d 100644
--- a/compiler/rustc_codegen_gcc/patches/libgccjit12/0001-core-Disable-portable-simd-test.patch
+++ b/compiler/rustc_codegen_gcc/patches/libgccjit12/0001-core-Disable-portable-simd-test.patch
@@ -1,25 +1,17 @@
-From 124a11ce086952a5794d5cfbaa45175809497b81 Mon Sep 17 00:00:00 2001
+From 1a8f6b8e39f343959d4d2e6b6957a6d780ac3fc0 Mon Sep 17 00:00:00 2001
 From: None <none@example.com>
-Date: Sat, 18 Nov 2023 10:50:36 -0500
-Subject: [PATCH] [core] Disable portable-simd test
+Date: Thu, 27 Mar 2025 14:32:14 -0400
+Subject: [PATCH] Disable portable-simd test
 
 ---
- library/core/tests/lib.rs | 2 --
- 1 file changed, 2 deletions(-)
+ library/coretests/tests/lib.rs | 1 -
+ 1 file changed, 1 deletion(-)
 
-diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
-index b71786c..cf484d5 100644
---- a/library/core/tests/lib.rs
-+++ b/library/core/tests/lib.rs
-@@ -87,7 +87,6 @@
- #![feature(numfmt)]
- #![feature(pattern)]
- #![feature(pointer_is_aligned_to)]
--#![feature(portable_simd)]
- #![feature(ptr_metadata)]
- #![feature(slice_from_ptr_range)]
- #![feature(slice_internals)]
-@@ -155,7 +154,6 @@ mod pin;
+diff --git a/library/coretests/tests/lib.rs b/library/coretests/tests/lib.rs
+index 79022fe..9223b2f 100644
+--- a/library/coretests/tests/lib.rs
++++ b/library/coretests/tests/lib.rs
+@@ -165,7 +165,6 @@ mod pin;
  mod pin_macro;
  mod ptr;
  mod result;
@@ -27,4 +19,6 @@ index b71786c..cf484d5 100644
  mod slice;
  mod str;
  mod str_lossy;
--- 2.45.2
+-- 
+2.49.0
+
diff --git a/compiler/rustc_codegen_gcc/rust-toolchain b/compiler/rustc_codegen_gcc/rust-toolchain
index 940b3de9f74..fd898c59707 100644
--- a/compiler/rustc_codegen_gcc/rust-toolchain
+++ b/compiler/rustc_codegen_gcc/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2025-01-12"
+channel = "nightly-2025-04-17"
 components = ["rust-src", "rustc-dev", "llvm-tools-preview"]
diff --git a/compiler/rustc_codegen_gcc/src/abi.rs b/compiler/rustc_codegen_gcc/src/abi.rs
index 9fe6baa3d25..a96b18e01c0 100644
--- a/compiler/rustc_codegen_gcc/src/abi.rs
+++ b/compiler/rustc_codegen_gcc/src/abi.rs
@@ -9,6 +9,8 @@ use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::LayoutOf;
 #[cfg(feature = "master")]
 use rustc_session::config;
+#[cfg(feature = "master")]
+use rustc_target::callconv::Conv;
 use rustc_target::callconv::{ArgAttributes, CastTarget, FnAbi, PassMode};
 
 use crate::builder::Builder;
@@ -105,6 +107,8 @@ pub trait FnAbiGccExt<'gcc, 'tcx> {
     // TODO(antoyo): return a function pointer type instead?
     fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> FnAbiGcc<'gcc>;
     fn ptr_to_gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc>;
+    #[cfg(feature = "master")]
+    fn gcc_cconv(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Option<FnAttribute<'gcc>>;
 }
 
 impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
@@ -227,4 +231,47 @@ impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
         );
         pointer_type
     }
+
+    #[cfg(feature = "master")]
+    fn gcc_cconv(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Option<FnAttribute<'gcc>> {
+        conv_to_fn_attribute(self.conv, &cx.tcx.sess.target.arch)
+    }
+}
+
+#[cfg(feature = "master")]
+pub fn conv_to_fn_attribute<'gcc>(conv: Conv, arch: &str) -> Option<FnAttribute<'gcc>> {
+    // TODO: handle the calling conventions returning None.
+    let attribute = match conv {
+        Conv::C
+        | Conv::Rust
+        | Conv::CCmseNonSecureCall
+        | Conv::CCmseNonSecureEntry
+        | Conv::RiscvInterrupt { .. } => return None,
+        Conv::Cold => return None,
+        Conv::PreserveMost => return None,
+        Conv::PreserveAll => return None,
+        Conv::GpuKernel => {
+            // TODO(antoyo): remove clippy allow attribute when this is implemented.
+            #[allow(clippy::if_same_then_else)]
+            if arch == "amdgpu" {
+                return None;
+            } else if arch == "nvptx64" {
+                return None;
+            } else {
+                panic!("Architecture {} does not support GpuKernel calling convention", arch);
+            }
+        }
+        Conv::AvrInterrupt => return None,
+        Conv::AvrNonBlockingInterrupt => return None,
+        Conv::ArmAapcs => return None,
+        Conv::Msp430Intr => return None,
+        Conv::X86Fastcall => return None,
+        Conv::X86Intr => return None,
+        Conv::X86Stdcall => return None,
+        Conv::X86ThisCall => return None,
+        Conv::X86VectorCall => return None,
+        Conv::X86_64SysV => FnAttribute::SysvAbi,
+        Conv::X86_64Win64 => FnAttribute::MsAbi,
+    };
+    Some(attribute)
 }
diff --git a/compiler/rustc_codegen_gcc/src/asm.rs b/compiler/rustc_codegen_gcc/src/asm.rs
index 415f8affab9..dbdf37ee6c9 100644
--- a/compiler/rustc_codegen_gcc/src/asm.rs
+++ b/compiler/rustc_codegen_gcc/src/asm.rs
@@ -36,7 +36,8 @@ use crate::type_of::LayoutGccExt;
 //
 // 3. Clobbers. GCC has a separate list of clobbers, and clobbers don't have indexes.
 //    Contrary, Rust expresses clobbers through "out" operands that aren't tied to
-//    a variable (`_`),  and such "clobbers" do have index.
+//    a variable (`_`),  and such "clobbers" do have index. Input operands cannot also
+//    be clobbered.
 //
 // 4. Furthermore, GCC Extended Asm does not support explicit register constraints
 //    (like `out("eax")`) directly, offering so-called "local register variables"
@@ -161,6 +162,16 @@ impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
         // Also, we don't emit any asm operands immediately; we save them to
         // the one of the buffers to be emitted later.
 
+        let mut input_registers = vec![];
+
+        for op in rust_operands {
+            if let InlineAsmOperandRef::In { reg, .. } = *op {
+                if let ConstraintOrRegister::Register(reg_name) = reg_to_gcc(reg) {
+                    input_registers.push(reg_name);
+                }
+            }
+        }
+
         // 1. Normal variables (and saving operands to buffers).
         for (rust_idx, op) in rust_operands.iter().enumerate() {
             match *op {
@@ -183,25 +194,39 @@ impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
                             continue;
                         }
                         (Register(reg_name), None) => {
-                            // `clobber_abi` can add lots of clobbers that are not supported by the target,
-                            // such as AVX-512 registers, so we just ignore unsupported registers
-                            let is_target_supported =
-                                reg.reg_class().supported_types(asm_arch, true).iter().any(
-                                    |&(_, feature)| {
-                                        if let Some(feature) = feature {
-                                            self.tcx
-                                                .asm_target_features(instance.def_id())
-                                                .contains(&feature)
-                                        } else {
-                                            true // Register class is unconditionally supported
-                                        }
-                                    },
-                                );
-
-                            if is_target_supported && !clobbers.contains(&reg_name) {
-                                clobbers.push(reg_name);
+                            if input_registers.contains(&reg_name) {
+                                // the `clobber_abi` operand is converted into a series of
+                                // `lateout("reg") _` operands. Of course, a user could also
+                                // explicitly define such an output operand.
+                                //
+                                // GCC does not allow input registers to be clobbered, so if this out register
+                                // is also used as an in register, do not add it to the clobbers list.
+                                // it will be treated as a lateout register with `out_place: None`
+                                if !late {
+                                    bug!("input registers can only be used as lateout regisers");
+                                }
+                                ("r", dummy_output_type(self.cx, reg.reg_class()))
+                            } else {
+                                // `clobber_abi` can add lots of clobbers that are not supported by the target,
+                                // such as AVX-512 registers, so we just ignore unsupported registers
+                                let is_target_supported =
+                                    reg.reg_class().supported_types(asm_arch, true).iter().any(
+                                        |&(_, feature)| {
+                                            if let Some(feature) = feature {
+                                                self.tcx
+                                                    .asm_target_features(instance.def_id())
+                                                    .contains(&feature)
+                                            } else {
+                                                true // Register class is unconditionally supported
+                                            }
+                                        },
+                                    );
+
+                                if is_target_supported && !clobbers.contains(&reg_name) {
+                                    clobbers.push(reg_name);
+                                }
+                                continue;
                             }
-                            continue;
                         }
                     };
 
@@ -230,13 +255,10 @@ impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
                 }
 
                 InlineAsmOperandRef::InOut { reg, late, in_value, out_place } => {
-                    let constraint =
-                        if let ConstraintOrRegister::Constraint(constraint) = reg_to_gcc(reg) {
-                            constraint
-                        } else {
-                            // left for the next pass
-                            continue;
-                        };
+                    let ConstraintOrRegister::Constraint(constraint) = reg_to_gcc(reg) else {
+                        // left for the next pass
+                        continue;
+                    };
 
                     // Rustc frontend guarantees that input and output types are "compatible",
                     // so we can just use input var's type for the output variable.
@@ -589,114 +611,127 @@ fn estimate_template_length(
 }
 
 /// Converts a register class to a GCC constraint code.
-fn reg_to_gcc(reg: InlineAsmRegOrRegClass) -> ConstraintOrRegister {
-    let constraint = match reg {
-        // For vector registers LLVM wants the register name to match the type size.
+fn reg_to_gcc(reg_or_reg_class: InlineAsmRegOrRegClass) -> ConstraintOrRegister {
+    match reg_or_reg_class {
         InlineAsmRegOrRegClass::Reg(reg) => {
-            match reg {
-                InlineAsmReg::X86(_) => {
-                    // TODO(antoyo): add support for vector register.
-                    //
-                    // // For explicit registers, we have to create a register variable: https://stackoverflow.com/a/31774784/389119
-                    return ConstraintOrRegister::Register(match reg.name() {
-                        // Some of registers' names does not map 1-1 from rust to gcc
-                        "st(0)" => "st",
+            ConstraintOrRegister::Register(explicit_reg_to_gcc(reg))
+        }
+        InlineAsmRegOrRegClass::RegClass(reg_class) => {
+            ConstraintOrRegister::Constraint(reg_class_to_gcc(reg_class))
+        }
+    }
+}
 
-                        name => name,
-                    });
+fn explicit_reg_to_gcc(reg: InlineAsmReg) -> &'static str {
+    // For explicit registers, we have to create a register variable: https://stackoverflow.com/a/31774784/389119
+    match reg {
+        InlineAsmReg::X86(reg) => {
+            // TODO(antoyo): add support for vector register.
+            match reg.reg_class() {
+                X86InlineAsmRegClass::reg_byte => {
+                    // GCC does not support the `b` suffix, so we just strip it
+                    // see https://github.com/rust-lang/rustc_codegen_gcc/issues/485
+                    reg.name().trim_end_matches('b')
                 }
+                _ => match reg.name() {
+                    // Some of registers' names does not map 1-1 from rust to gcc
+                    "st(0)" => "st",
 
-                _ => unimplemented!(),
+                    name => name,
+                },
             }
         }
-        // They can be retrieved from https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html
-        InlineAsmRegOrRegClass::RegClass(reg) => match reg {
-            InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg) => "w",
-            InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => "x",
-            InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => {
-                unreachable!("clobber-only")
-            }
-            InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
-            | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low16)
-            | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low8)
-            | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16)
-            | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low8)
-            | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low4)
-            | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg)
-            | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg) => "t",
-            InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_upper) => "d",
-            InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_pair) => "r",
-            InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_iw) => "w",
-            InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_ptr) => "e",
-            InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::wreg) => "w",
-            InlineAsmRegClass::Hexagon(HexagonInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::Hexagon(HexagonInlineAsmRegClass::preg) => {
-                unreachable!("clobber-only")
-            }
-            InlineAsmRegClass::LoongArch(LoongArchInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::LoongArch(LoongArchInlineAsmRegClass::freg) => "f",
-            InlineAsmRegClass::M68k(M68kInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::M68k(M68kInlineAsmRegClass::reg_addr) => "a",
-            InlineAsmRegClass::M68k(M68kInlineAsmRegClass::reg_data) => "d",
-            InlineAsmRegClass::CSKY(CSKYInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::CSKY(CSKYInlineAsmRegClass::freg) => "f",
-            InlineAsmRegClass::Mips(MipsInlineAsmRegClass::reg) => "d", // more specific than "r"
-            InlineAsmRegClass::Mips(MipsInlineAsmRegClass::freg) => "f",
-            InlineAsmRegClass::Msp430(Msp430InlineAsmRegClass::reg) => "r",
-            // https://github.com/gcc-mirror/gcc/blob/master/gcc/config/nvptx/nvptx.md -> look for
-            // "define_constraint".
-            InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg16) => "h",
-            InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg32) => "r",
-            InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg64) => "l",
-
-            InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => "b",
-            InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::freg) => "f",
-            InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::vreg) => "v",
-            InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr)
-            | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => {
-                unreachable!("clobber-only")
-            }
-            InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::freg) => "f",
-            InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => {
-                unreachable!("clobber-only")
-            }
-            InlineAsmRegClass::X86(X86InlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => "Q",
-            InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => "q",
-            InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg)
-            | InlineAsmRegClass::X86(X86InlineAsmRegClass::ymm_reg) => "x",
-            InlineAsmRegClass::X86(X86InlineAsmRegClass::zmm_reg) => "v",
-            InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => "Yk",
-            InlineAsmRegClass::X86(
-                X86InlineAsmRegClass::kreg0
-                | X86InlineAsmRegClass::x87_reg
-                | X86InlineAsmRegClass::mmx_reg
-                | X86InlineAsmRegClass::tmm_reg,
-            ) => unreachable!("clobber-only"),
-            InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => {
-                bug!("GCC backend does not support SPIR-V")
-            }
-            InlineAsmRegClass::Wasm(WasmInlineAsmRegClass::local) => "r",
-            InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg_addr) => "a",
-            InlineAsmRegClass::S390x(S390xInlineAsmRegClass::freg) => "f",
-            InlineAsmRegClass::S390x(S390xInlineAsmRegClass::vreg) => "v",
-            InlineAsmRegClass::S390x(S390xInlineAsmRegClass::areg) => {
-                unreachable!("clobber-only")
-            }
-            InlineAsmRegClass::Sparc(SparcInlineAsmRegClass::reg) => "r",
-            InlineAsmRegClass::Sparc(SparcInlineAsmRegClass::yreg) => unreachable!("clobber-only"),
-            InlineAsmRegClass::Err => unreachable!(),
-        },
-    };
 
-    ConstraintOrRegister::Constraint(constraint)
+        _ => unimplemented!(),
+    }
+}
+
+/// They can be retrieved from https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html
+fn reg_class_to_gcc(reg_class: InlineAsmRegClass) -> &'static str {
+    match reg_class {
+        InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg) => "w",
+        InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => "x",
+        InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => {
+            unreachable!("clobber-only")
+        }
+        InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
+        | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low16)
+        | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low8)
+        | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16)
+        | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low8)
+        | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low4)
+        | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg)
+        | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg) => "t",
+        InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_upper) => "d",
+        InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_pair) => "r",
+        InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_iw) => "w",
+        InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_ptr) => "e",
+        InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::wreg) => "w",
+        InlineAsmRegClass::Hexagon(HexagonInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::Hexagon(HexagonInlineAsmRegClass::preg) => {
+            unreachable!("clobber-only")
+        }
+        InlineAsmRegClass::LoongArch(LoongArchInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::LoongArch(LoongArchInlineAsmRegClass::freg) => "f",
+        InlineAsmRegClass::M68k(M68kInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::M68k(M68kInlineAsmRegClass::reg_addr) => "a",
+        InlineAsmRegClass::M68k(M68kInlineAsmRegClass::reg_data) => "d",
+        InlineAsmRegClass::CSKY(CSKYInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::CSKY(CSKYInlineAsmRegClass::freg) => "f",
+        InlineAsmRegClass::Mips(MipsInlineAsmRegClass::reg) => "d", // more specific than "r"
+        InlineAsmRegClass::Mips(MipsInlineAsmRegClass::freg) => "f",
+        InlineAsmRegClass::Msp430(Msp430InlineAsmRegClass::reg) => "r",
+        // https://github.com/gcc-mirror/gcc/blob/master/gcc/config/nvptx/nvptx.md -> look for
+        // "define_constraint".
+        InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg16) => "h",
+        InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg32) => "r",
+        InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg64) => "l",
+
+        InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => "b",
+        InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::freg) => "f",
+        InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::vreg) => "v",
+        InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr)
+        | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => {
+            unreachable!("clobber-only")
+        }
+        InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::freg) => "f",
+        InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => {
+            unreachable!("clobber-only")
+        }
+        InlineAsmRegClass::X86(X86InlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => "Q",
+        InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => "q",
+        InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg)
+        | InlineAsmRegClass::X86(X86InlineAsmRegClass::ymm_reg) => "x",
+        InlineAsmRegClass::X86(X86InlineAsmRegClass::zmm_reg) => "v",
+        InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => "Yk",
+        InlineAsmRegClass::X86(
+            X86InlineAsmRegClass::kreg0
+            | X86InlineAsmRegClass::x87_reg
+            | X86InlineAsmRegClass::mmx_reg
+            | X86InlineAsmRegClass::tmm_reg,
+        ) => unreachable!("clobber-only"),
+        InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => {
+            bug!("GCC backend does not support SPIR-V")
+        }
+        InlineAsmRegClass::Wasm(WasmInlineAsmRegClass::local) => "r",
+        InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg_addr) => "a",
+        InlineAsmRegClass::S390x(S390xInlineAsmRegClass::freg) => "f",
+        InlineAsmRegClass::S390x(S390xInlineAsmRegClass::vreg) => "v",
+        InlineAsmRegClass::S390x(S390xInlineAsmRegClass::areg) => {
+            unreachable!("clobber-only")
+        }
+        InlineAsmRegClass::Sparc(SparcInlineAsmRegClass::reg) => "r",
+        InlineAsmRegClass::Sparc(SparcInlineAsmRegClass::yreg) => unreachable!("clobber-only"),
+        InlineAsmRegClass::Err => unreachable!(),
+    }
 }
 
 /// Type to use for outputs that are discarded. It doesn't really matter what
diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs
index 6573b5b165e..5c70f4a7df9 100644
--- a/compiler/rustc_codegen_gcc/src/builder.rs
+++ b/compiler/rustc_codegen_gcc/src/builder.rs
@@ -368,16 +368,8 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
         let previous_arg_count = args.len();
         let orig_args = args;
         let args = {
-            let function_address_names = self.function_address_names.borrow();
-            let original_function_name = function_address_names.get(&func_ptr);
             func_ptr = llvm::adjust_function(self.context, &func_name, func_ptr, args);
-            llvm::adjust_intrinsic_arguments(
-                self,
-                gcc_func,
-                args.into(),
-                &func_name,
-                original_function_name,
-            )
+            llvm::adjust_intrinsic_arguments(self, gcc_func, args.into(), &func_name)
         };
         let args_adjusted = args.len() != previous_arg_count;
         let args = self.check_ptr_call("call", func_ptr, &args);
@@ -1271,7 +1263,50 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     }
 
     fn fcmp(&mut self, op: RealPredicate, lhs: RValue<'gcc>, rhs: RValue<'gcc>) -> RValue<'gcc> {
-        self.context.new_comparison(self.location, op.to_gcc_comparison(), lhs, rhs)
+        // LLVM has a concept of "unordered compares", where eg ULT returns true if either the two
+        // arguments are unordered (i.e. either is NaN), or the lhs is less than the rhs. GCC does
+        // not natively have this concept, so in some cases we must manually handle NaNs
+        let must_handle_nan = match op {
+            RealPredicate::RealPredicateFalse => unreachable!(),
+            RealPredicate::RealOEQ => false,
+            RealPredicate::RealOGT => false,
+            RealPredicate::RealOGE => false,
+            RealPredicate::RealOLT => false,
+            RealPredicate::RealOLE => false,
+            RealPredicate::RealONE => false,
+            RealPredicate::RealORD => unreachable!(),
+            RealPredicate::RealUNO => unreachable!(),
+            RealPredicate::RealUEQ => false,
+            RealPredicate::RealUGT => true,
+            RealPredicate::RealUGE => true,
+            RealPredicate::RealULT => true,
+            RealPredicate::RealULE => true,
+            RealPredicate::RealUNE => false,
+            RealPredicate::RealPredicateTrue => unreachable!(),
+        };
+
+        let cmp = self.context.new_comparison(self.location, op.to_gcc_comparison(), lhs, rhs);
+
+        if must_handle_nan {
+            let is_nan = self.context.new_binary_op(
+                self.location,
+                BinaryOp::LogicalOr,
+                self.cx.bool_type,
+                // compare a value to itself to check whether it is NaN
+                self.context.new_comparison(self.location, ComparisonOp::NotEquals, lhs, lhs),
+                self.context.new_comparison(self.location, ComparisonOp::NotEquals, rhs, rhs),
+            );
+
+            self.context.new_binary_op(
+                self.location,
+                BinaryOp::LogicalOr,
+                self.cx.bool_type,
+                is_nan,
+                cmp,
+            )
+        } else {
+            cmp
+        }
     }
 
     /* Miscellaneous instructions */
diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs
index 1e1f577bb3a..73718994e64 100644
--- a/compiler/rustc_codegen_gcc/src/context.rs
+++ b/compiler/rustc_codegen_gcc/src/context.rs
@@ -23,6 +23,8 @@ use rustc_target::spec::{
     HasTargetSpec, HasWasmCAbiOpt, HasX86AbiOpt, Target, TlsModel, WasmCAbi, X86Abi,
 };
 
+#[cfg(feature = "master")]
+use crate::abi::conv_to_fn_attribute;
 use crate::callee::get_fn;
 use crate::common::SignType;
 
@@ -213,33 +215,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         let bool_type = context.new_type::<bool>();
 
         let mut functions = FxHashMap::default();
-        let builtins = [
-            "__builtin_unreachable",
-            "abort",
-            "__builtin_expect", /*"__builtin_expect_with_probability",*/
-            "__builtin_constant_p",
-            "__builtin_add_overflow",
-            "__builtin_mul_overflow",
-            "__builtin_saddll_overflow",
-            /*"__builtin_sadd_overflow",*/
-            "__builtin_smulll_overflow", /*"__builtin_smul_overflow",*/
-            "__builtin_ssubll_overflow",
-            /*"__builtin_ssub_overflow",*/ "__builtin_sub_overflow",
-            "__builtin_uaddll_overflow",
-            "__builtin_uadd_overflow",
-            "__builtin_umulll_overflow",
-            "__builtin_umul_overflow",
-            "__builtin_usubll_overflow",
-            "__builtin_usub_overflow",
-            "__builtin_powif",
-            "__builtin_powi",
-            "fabsf",
-            "fabs",
-            "copysignf",
-            "copysign",
-            "nearbyintf",
-            "nearbyint",
-        ];
+        let builtins = ["abort"];
 
         for builtin in builtins.iter() {
             functions.insert(builtin.to_string(), context.get_builtin_function(builtin));
@@ -509,7 +485,11 @@ impl<'gcc, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     fn declare_c_main(&self, fn_type: Self::Type) -> Option<Self::Function> {
         let entry_name = self.sess().target.entry_name.as_ref();
         if !self.functions.borrow().contains_key(entry_name) {
-            Some(self.declare_entry_fn(entry_name, fn_type, ()))
+            #[cfg(feature = "master")]
+            let conv = conv_to_fn_attribute(self.sess().target.entry_abi, &self.sess().target.arch);
+            #[cfg(not(feature = "master"))]
+            let conv = None;
+            Some(self.declare_entry_fn(entry_name, fn_type, conv))
         } else {
             // If the symbol already exists, it is an error: for example, the user wrote
             // #[no_mangle] extern "C" fn main(..) {..}
@@ -605,7 +585,10 @@ impl<'b, 'tcx> CodegenCx<'b, 'tcx> {
         let mut name = String::with_capacity(prefix.len() + 6);
         name.push_str(prefix);
         name.push('.');
-        name.push_str(&(idx as u64).to_base(ALPHANUMERIC_ONLY));
+        // Offset the index by the base so that always at least two characters
+        // are generated. This avoids cases where the suffix is interpreted as
+        // size by the assembler (for m68k: .b, .w, .l).
+        name.push_str(&(idx as u64 + ALPHANUMERIC_ONLY as u64).to_base(ALPHANUMERIC_ONLY));
         name
     }
 }
diff --git a/compiler/rustc_codegen_gcc/src/declare.rs b/compiler/rustc_codegen_gcc/src/declare.rs
index 7cdbe3c0c62..c1ca3eb849e 100644
--- a/compiler/rustc_codegen_gcc/src/declare.rs
+++ b/compiler/rustc_codegen_gcc/src/declare.rs
@@ -58,7 +58,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         variadic: bool,
     ) -> Function<'gcc> {
         self.linkage.set(FunctionType::Extern);
-        declare_raw_fn(self, name, () /*llvm::CCallConv*/, return_type, params, variadic)
+        declare_raw_fn(self, name, None, return_type, params, variadic)
     }
 
     pub fn declare_global(
@@ -92,7 +92,8 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         &self,
         name: &str,
         _fn_type: Type<'gcc>,
-        callconv: (), /*llvm::CCallConv*/
+        #[cfg(feature = "master")] callconv: Option<FnAttribute<'gcc>>,
+        #[cfg(not(feature = "master"))] callconv: Option<()>,
     ) -> RValue<'gcc> {
         // TODO(antoyo): use the fn_type parameter.
         let const_string = self.context.new_type::<u8>().make_pointer().make_pointer();
@@ -123,14 +124,11 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             #[cfg(feature = "master")]
             fn_attributes,
         } = fn_abi.gcc_type(self);
-        let func = declare_raw_fn(
-            self,
-            name,
-            (), /*fn_abi.llvm_cconv()*/
-            return_type,
-            &arguments_type,
-            is_c_variadic,
-        );
+        #[cfg(feature = "master")]
+        let conv = fn_abi.gcc_cconv(self);
+        #[cfg(not(feature = "master"))]
+        let conv = None;
+        let func = declare_raw_fn(self, name, conv, return_type, &arguments_type, is_c_variadic);
         self.on_stack_function_params.borrow_mut().insert(func, on_stack_param_indices);
         #[cfg(feature = "master")]
         for fn_attr in fn_attributes {
@@ -162,7 +160,8 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
 fn declare_raw_fn<'gcc>(
     cx: &CodegenCx<'gcc, '_>,
     name: &str,
-    _callconv: (), /*llvm::CallConv*/
+    #[cfg(feature = "master")] callconv: Option<FnAttribute<'gcc>>,
+    #[cfg(not(feature = "master"))] _callconv: Option<()>,
     return_type: Type<'gcc>,
     param_types: &[Type<'gcc>],
     variadic: bool,
@@ -192,6 +191,10 @@ fn declare_raw_fn<'gcc>(
         let name = &mangle_name(name);
         let func =
             cx.context.new_function(None, cx.linkage.get(), return_type, &params, name, variadic);
+        #[cfg(feature = "master")]
+        if let Some(attribute) = callconv {
+            func.add_attribute(attribute);
+        }
         cx.functions.borrow_mut().insert(name.to_string(), func);
 
         #[cfg(feature = "master")]
diff --git a/compiler/rustc_codegen_gcc/src/gcc_util.rs b/compiler/rustc_codegen_gcc/src/gcc_util.rs
index 6eae0c24f48..202764d5649 100644
--- a/compiler/rustc_codegen_gcc/src/gcc_util.rs
+++ b/compiler/rustc_codegen_gcc/src/gcc_util.rs
@@ -194,6 +194,7 @@ pub fn to_gcc_features<'a>(sess: &Session, s: &'a str) -> SmallVec<[&'a str; 2]>
 
 fn arch_to_gcc(name: &str) -> &str {
     match name {
+        "M68000" => "68000",
         "M68020" => "68020",
         _ => name,
     }
diff --git a/compiler/rustc_codegen_gcc/src/int.rs b/compiler/rustc_codegen_gcc/src/int.rs
index f3552d9b12f..9b5b0fde6e2 100644
--- a/compiler/rustc_codegen_gcc/src/int.rs
+++ b/compiler/rustc_codegen_gcc/src/int.rs
@@ -404,7 +404,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
         let ret_indirect = matches!(fn_abi.ret.mode, PassMode::Indirect { .. });
 
-        let result = if ret_indirect {
+        let call = if ret_indirect {
             let res_value = self.current_func().new_local(self.location, res_type, "result_value");
             let res_addr = res_value.get_address(self.location);
             let res_param_type = res_type.make_pointer();
@@ -432,8 +432,17 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
             );
             self.context.new_call(self.location, func, &[lhs, rhs, overflow_addr])
         };
-
-        (result, self.context.new_cast(self.location, overflow_value, self.bool_type).to_rvalue())
+        // NOTE: we must assign the result of the operation to a variable at this point to make
+        // sure it will be evaluated by libgccjit now.
+        // Otherwise, it will only be evaluated when the rvalue for the call is used somewhere else
+        // and overflow_value will not be initialized at the correct point in the program.
+        let result = self.current_func().new_local(self.location, res_type, "result");
+        self.block.add_assignment(self.location, result, call);
+
+        (
+            result.to_rvalue(),
+            self.context.new_cast(self.location, overflow_value, self.bool_type).to_rvalue(),
+        )
     }
 
     pub fn gcc_icmp(
@@ -865,6 +874,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         let value_type = value.get_type();
         if self.is_native_int_type_or_bool(dest_typ) && self.is_native_int_type_or_bool(value_type)
         {
+            // TODO: use self.location.
             self.context.new_cast(None, value, dest_typ)
         } else if self.is_native_int_type_or_bool(dest_typ) {
             self.context.new_cast(None, self.low(value), dest_typ)
@@ -905,6 +915,7 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         let name_suffix = match self.type_kind(dest_typ) {
             TypeKind::Float => "tisf",
             TypeKind::Double => "tidf",
+            TypeKind::FP128 => "tixf",
             kind => panic!("cannot cast a non-native integer to type {:?}", kind),
         };
         let sign = if signed { "" } else { "un" };
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/llvm.rs b/compiler/rustc_codegen_gcc/src/intrinsic/llvm.rs
index 2d731f88d7d..0eebd21001a 100644
--- a/compiler/rustc_codegen_gcc/src/intrinsic/llvm.rs
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/llvm.rs
@@ -1,11 +1,90 @@
 use std::borrow::Cow;
 
-use gccjit::{CType, Context, Function, FunctionPtrType, RValue, ToRValue, UnaryOp};
+use gccjit::{CType, Context, Field, Function, FunctionPtrType, RValue, ToRValue, Type};
 use rustc_codegen_ssa::traits::BuilderMethods;
 
 use crate::builder::Builder;
 use crate::context::CodegenCx;
 
+fn encode_key_128_type<'a, 'gcc, 'tcx>(
+    builder: &Builder<'a, 'gcc, 'tcx>,
+) -> (Type<'gcc>, Field<'gcc>, Field<'gcc>) {
+    let m128i = builder.context.new_vector_type(builder.i64_type, 2);
+    let field1 = builder.context.new_field(None, builder.u32_type, "field1");
+    let field2 = builder.context.new_field(None, m128i, "field2");
+    let field3 = builder.context.new_field(None, m128i, "field3");
+    let field4 = builder.context.new_field(None, m128i, "field4");
+    let field5 = builder.context.new_field(None, m128i, "field5");
+    let field6 = builder.context.new_field(None, m128i, "field6");
+    let field7 = builder.context.new_field(None, m128i, "field7");
+    let encode_type = builder.context.new_struct_type(
+        None,
+        "EncodeKey128Output",
+        &[field1, field2, field3, field4, field5, field6, field7],
+    );
+    #[cfg(feature = "master")]
+    encode_type.as_type().set_packed();
+    (encode_type.as_type(), field1, field2)
+}
+
+fn encode_key_256_type<'a, 'gcc, 'tcx>(
+    builder: &Builder<'a, 'gcc, 'tcx>,
+) -> (Type<'gcc>, Field<'gcc>, Field<'gcc>) {
+    let m128i = builder.context.new_vector_type(builder.i64_type, 2);
+    let field1 = builder.context.new_field(None, builder.u32_type, "field1");
+    let field2 = builder.context.new_field(None, m128i, "field2");
+    let field3 = builder.context.new_field(None, m128i, "field3");
+    let field4 = builder.context.new_field(None, m128i, "field4");
+    let field5 = builder.context.new_field(None, m128i, "field5");
+    let field6 = builder.context.new_field(None, m128i, "field6");
+    let field7 = builder.context.new_field(None, m128i, "field7");
+    let field8 = builder.context.new_field(None, m128i, "field8");
+    let encode_type = builder.context.new_struct_type(
+        None,
+        "EncodeKey256Output",
+        &[field1, field2, field3, field4, field5, field6, field7, field8],
+    );
+    #[cfg(feature = "master")]
+    encode_type.as_type().set_packed();
+    (encode_type.as_type(), field1, field2)
+}
+
+fn aes_output_type<'a, 'gcc, 'tcx>(
+    builder: &Builder<'a, 'gcc, 'tcx>,
+) -> (Type<'gcc>, Field<'gcc>, Field<'gcc>) {
+    let m128i = builder.context.new_vector_type(builder.i64_type, 2);
+    let field1 = builder.context.new_field(None, builder.u8_type, "field1");
+    let field2 = builder.context.new_field(None, m128i, "field2");
+    let aes_output_type = builder.context.new_struct_type(None, "AesOutput", &[field1, field2]);
+    let typ = aes_output_type.as_type();
+    #[cfg(feature = "master")]
+    typ.set_packed();
+    (typ, field1, field2)
+}
+
+fn wide_aes_output_type<'a, 'gcc, 'tcx>(
+    builder: &Builder<'a, 'gcc, 'tcx>,
+) -> (Type<'gcc>, Field<'gcc>, Field<'gcc>) {
+    let m128i = builder.context.new_vector_type(builder.i64_type, 2);
+    let field1 = builder.context.new_field(None, builder.u8_type, "field1");
+    let field2 = builder.context.new_field(None, m128i, "field2");
+    let field3 = builder.context.new_field(None, m128i, "field3");
+    let field4 = builder.context.new_field(None, m128i, "field4");
+    let field5 = builder.context.new_field(None, m128i, "field5");
+    let field6 = builder.context.new_field(None, m128i, "field6");
+    let field7 = builder.context.new_field(None, m128i, "field7");
+    let field8 = builder.context.new_field(None, m128i, "field8");
+    let field9 = builder.context.new_field(None, m128i, "field9");
+    let aes_output_type = builder.context.new_struct_type(
+        None,
+        "WideAesOutput",
+        &[field1, field2, field3, field4, field5, field6, field7, field8, field9],
+    );
+    #[cfg(feature = "master")]
+    aes_output_type.as_type().set_packed();
+    (aes_output_type.as_type(), field1, field2)
+}
+
 #[cfg_attr(not(feature = "master"), allow(unused_variables))]
 pub fn adjust_function<'gcc>(
     context: &'gcc Context<'gcc>,
@@ -43,7 +122,6 @@ pub fn adjust_intrinsic_arguments<'a, 'b, 'gcc, 'tcx>(
     gcc_func: FunctionPtrType<'gcc>,
     mut args: Cow<'b, [RValue<'gcc>]>,
     func_name: &str,
-    original_function_name: Option<&String>,
 ) -> Cow<'b, [RValue<'gcc>]> {
     // TODO: this might not be a good way to workaround the missing tile builtins.
     if func_name == "__builtin_trap" {
@@ -504,6 +582,72 @@ pub fn adjust_intrinsic_arguments<'a, 'b, 'gcc, 'tcx>(
                 let arg4 = builder.context.new_rvalue_from_int(arg4_type, -1);
                 args = vec![a, b, c, arg4, new_args[3]].into();
             }
+            "__builtin_ia32_encodekey128_u32" => {
+                let mut new_args = args.to_vec();
+                let m128i = builder.context.new_vector_type(builder.i64_type, 2);
+                let array_type = builder.context.new_array_type(None, m128i, 6);
+                let result = builder.current_func().new_local(None, array_type, "result");
+                new_args.push(result.get_address(None));
+                args = new_args.into();
+            }
+            "__builtin_ia32_encodekey256_u32" => {
+                let mut new_args = args.to_vec();
+                let m128i = builder.context.new_vector_type(builder.i64_type, 2);
+                let array_type = builder.context.new_array_type(None, m128i, 7);
+                let result = builder.current_func().new_local(None, array_type, "result");
+                new_args.push(result.get_address(None));
+                args = new_args.into();
+            }
+            "__builtin_ia32_aesenc128kl_u8"
+            | "__builtin_ia32_aesdec128kl_u8"
+            | "__builtin_ia32_aesenc256kl_u8"
+            | "__builtin_ia32_aesdec256kl_u8" => {
+                let mut new_args = vec![];
+                let m128i = builder.context.new_vector_type(builder.i64_type, 2);
+                let result = builder.current_func().new_local(None, m128i, "result");
+                new_args.push(result.get_address(None));
+                new_args.extend(args.to_vec());
+                args = new_args.into();
+            }
+            "__builtin_ia32_aesencwide128kl_u8"
+            | "__builtin_ia32_aesdecwide128kl_u8"
+            | "__builtin_ia32_aesencwide256kl_u8"
+            | "__builtin_ia32_aesdecwide256kl_u8" => {
+                let mut new_args = vec![];
+
+                let mut old_args = args.to_vec();
+                let handle = old_args.swap_remove(0); // Called __P in GCC.
+                let first_value = old_args.swap_remove(0);
+
+                let element_type = first_value.get_type();
+                let array_type = builder.context.new_array_type(None, element_type, 8);
+                let result = builder.current_func().new_local(None, array_type, "result");
+                new_args.push(result.get_address(None));
+
+                let array = builder.current_func().new_local(None, array_type, "array");
+                let input = builder.context.new_array_constructor(
+                    None,
+                    array_type,
+                    &[
+                        first_value,
+                        old_args.swap_remove(0),
+                        old_args.swap_remove(0),
+                        old_args.swap_remove(0),
+                        old_args.swap_remove(0),
+                        old_args.swap_remove(0),
+                        old_args.swap_remove(0),
+                        old_args.swap_remove(0),
+                    ],
+                );
+                builder.llbb().add_assignment(None, array, input);
+                let input_ptr = array.get_address(None);
+                let arg2_type = gcc_func.get_param_type(1);
+                let input_ptr = builder.context.new_cast(None, input_ptr, arg2_type);
+                new_args.push(input_ptr);
+
+                new_args.push(handle);
+                args = new_args.into();
+            }
             _ => (),
         }
     } else {
@@ -541,33 +685,6 @@ pub fn adjust_intrinsic_arguments<'a, 'b, 'gcc, 'tcx>(
                 let c = builder.context.new_rvalue_from_vector(None, arg3_type, &[new_args[2]; 2]);
                 args = vec![a, b, c, new_args[3]].into();
             }
-            "__builtin_ia32_vfmaddsubpd256"
-            | "__builtin_ia32_vfmaddsubps"
-            | "__builtin_ia32_vfmaddsubps256"
-            | "__builtin_ia32_vfmaddsubpd" => {
-                if let Some(original_function_name) = original_function_name {
-                    match &**original_function_name {
-                        "llvm.x86.fma.vfmsubadd.pd.256"
-                        | "llvm.x86.fma.vfmsubadd.ps"
-                        | "llvm.x86.fma.vfmsubadd.ps.256"
-                        | "llvm.x86.fma.vfmsubadd.pd" => {
-                            // NOTE: since both llvm.x86.fma.vfmsubadd.ps and llvm.x86.fma.vfmaddsub.ps maps to
-                            // __builtin_ia32_vfmaddsubps, only add minus if this comes from a
-                            // subadd LLVM intrinsic, e.g. _mm256_fmsubadd_pd.
-                            let mut new_args = args.to_vec();
-                            let arg3 = &mut new_args[2];
-                            *arg3 = builder.context.new_unary_op(
-                                None,
-                                UnaryOp::Minus,
-                                arg3.get_type(),
-                                *arg3,
-                            );
-                            args = new_args.into();
-                        }
-                        _ => (),
-                    }
-                }
-            }
             "__builtin_ia32_ldmxcsr" => {
                 // The builtin __builtin_ia32_ldmxcsr takes an integer value while llvm.x86.sse.ldmxcsr takes a pointer,
                 // so dereference the pointer.
@@ -728,6 +845,96 @@ pub fn adjust_intrinsic_return_value<'a, 'gcc, 'tcx>(
             let f16_type = builder.context.new_c_type(CType::Float16);
             return_value = builder.context.new_cast(None, return_value, f16_type);
         }
+        "__builtin_ia32_encodekey128_u32" => {
+            // The builtin __builtin_ia32_encodekey128_u32 writes the result in its pointer argument while
+            // llvm.x86.encodekey128 returns a value.
+            // We added a result pointer argument and now need to assign its value to the return_value expected by
+            // the LLVM intrinsic.
+            let (encode_type, field1, field2) = encode_key_128_type(builder);
+            let result = builder.current_func().new_local(None, encode_type, "result");
+            let field1 = result.access_field(None, field1);
+            builder.llbb().add_assignment(None, field1, return_value);
+            let field2 = result.access_field(None, field2);
+            let field2_type = field2.to_rvalue().get_type();
+            let array_type = builder.context.new_array_type(None, field2_type, 6);
+            let ptr = builder.context.new_cast(None, args[2], array_type.make_pointer());
+            let field2_ptr =
+                builder.context.new_cast(None, field2.get_address(None), array_type.make_pointer());
+            builder.llbb().add_assignment(
+                None,
+                field2_ptr.dereference(None),
+                ptr.dereference(None),
+            );
+            return_value = result.to_rvalue();
+        }
+        "__builtin_ia32_encodekey256_u32" => {
+            // The builtin __builtin_ia32_encodekey256_u32 writes the result in its pointer argument while
+            // llvm.x86.encodekey256 returns a value.
+            // We added a result pointer argument and now need to assign its value to the return_value expected by
+            // the LLVM intrinsic.
+            let (encode_type, field1, field2) = encode_key_256_type(builder);
+            let result = builder.current_func().new_local(None, encode_type, "result");
+            let field1 = result.access_field(None, field1);
+            builder.llbb().add_assignment(None, field1, return_value);
+            let field2 = result.access_field(None, field2);
+            let field2_type = field2.to_rvalue().get_type();
+            let array_type = builder.context.new_array_type(None, field2_type, 7);
+            let ptr = builder.context.new_cast(None, args[3], array_type.make_pointer());
+            let field2_ptr =
+                builder.context.new_cast(None, field2.get_address(None), array_type.make_pointer());
+            builder.llbb().add_assignment(
+                None,
+                field2_ptr.dereference(None),
+                ptr.dereference(None),
+            );
+            return_value = result.to_rvalue();
+        }
+        "__builtin_ia32_aesdec128kl_u8"
+        | "__builtin_ia32_aesenc128kl_u8"
+        | "__builtin_ia32_aesdec256kl_u8"
+        | "__builtin_ia32_aesenc256kl_u8" => {
+            // The builtin for aesdec/aesenc writes the result in its pointer argument while
+            // llvm.x86.aesdec128kl returns a value.
+            // We added a result pointer argument and now need to assign its value to the return_value expected by
+            // the LLVM intrinsic.
+            let (aes_output_type, field1, field2) = aes_output_type(builder);
+            let result = builder.current_func().new_local(None, aes_output_type, "result");
+            let field1 = result.access_field(None, field1);
+            builder.llbb().add_assignment(None, field1, return_value);
+            let field2 = result.access_field(None, field2);
+            let ptr = builder.context.new_cast(
+                None,
+                args[0],
+                field2.to_rvalue().get_type().make_pointer(),
+            );
+            builder.llbb().add_assignment(None, field2, ptr.dereference(None));
+            return_value = result.to_rvalue();
+        }
+        "__builtin_ia32_aesencwide128kl_u8"
+        | "__builtin_ia32_aesdecwide128kl_u8"
+        | "__builtin_ia32_aesencwide256kl_u8"
+        | "__builtin_ia32_aesdecwide256kl_u8" => {
+            // The builtin for aesdecwide/aesencwide writes the result in its pointer argument while
+            // llvm.x86.aesencwide128kl returns a value.
+            // We added a result pointer argument and now need to assign its value to the return_value expected by
+            // the LLVM intrinsic.
+            let (aes_output_type, field1, field2) = wide_aes_output_type(builder);
+            let result = builder.current_func().new_local(None, aes_output_type, "result");
+            let field1 = result.access_field(None, field1);
+            builder.llbb().add_assignment(None, field1, return_value);
+            let field2 = result.access_field(None, field2);
+            let field2_type = field2.to_rvalue().get_type();
+            let array_type = builder.context.new_array_type(None, field2_type, 8);
+            let ptr = builder.context.new_cast(None, args[0], array_type.make_pointer());
+            let field2_ptr =
+                builder.context.new_cast(None, field2.get_address(None), array_type.make_pointer());
+            builder.llbb().add_assignment(
+                None,
+                field2_ptr.dereference(None),
+                ptr.dereference(None),
+            );
+            return_value = result.to_rvalue();
+        }
         _ => (),
     }
 
@@ -915,16 +1122,6 @@ pub fn intrinsic<'gcc, 'tcx>(name: &str, cx: &CodegenCx<'gcc, 'tcx>) -> Function
         "llvm.ctlz.v4i64" => "__builtin_ia32_vplzcntq_256_mask",
         "llvm.ctlz.v2i64" => "__builtin_ia32_vplzcntq_128_mask",
         "llvm.ctpop.v32i16" => "__builtin_ia32_vpopcountw_v32hi",
-        "llvm.x86.fma.vfmsub.sd" => "__builtin_ia32_vfmsubsd3",
-        "llvm.x86.fma.vfmsub.ss" => "__builtin_ia32_vfmsubss3",
-        "llvm.x86.fma.vfmsubadd.pd" => "__builtin_ia32_vfmaddsubpd",
-        "llvm.x86.fma.vfmsubadd.pd.256" => "__builtin_ia32_vfmaddsubpd256",
-        "llvm.x86.fma.vfmsubadd.ps" => "__builtin_ia32_vfmaddsubps",
-        "llvm.x86.fma.vfmsubadd.ps.256" => "__builtin_ia32_vfmaddsubps256",
-        "llvm.x86.fma.vfnmadd.sd" => "__builtin_ia32_vfnmaddsd3",
-        "llvm.x86.fma.vfnmadd.ss" => "__builtin_ia32_vfnmaddss3",
-        "llvm.x86.fma.vfnmsub.sd" => "__builtin_ia32_vfnmsubsd3",
-        "llvm.x86.fma.vfnmsub.ss" => "__builtin_ia32_vfnmsubss3",
         "llvm.x86.avx512.conflict.d.512" => "__builtin_ia32_vpconflictsi_512_mask",
         "llvm.x86.avx512.conflict.d.256" => "__builtin_ia32_vpconflictsi_256_mask",
         "llvm.x86.avx512.conflict.d.128" => "__builtin_ia32_vpconflictsi_128_mask",
@@ -1002,8 +1199,6 @@ pub fn intrinsic<'gcc, 'tcx>(name: &str, cx: &CodegenCx<'gcc, 'tcx>) -> Function
         "llvm.fshr.v32i16" => "__builtin_ia32_vpshrdv_v32hi",
         "llvm.fshr.v16i16" => "__builtin_ia32_vpshrdv_v16hi",
         "llvm.fshr.v8i16" => "__builtin_ia32_vpshrdv_v8hi",
-        "llvm.x86.fma.vfmadd.sd" => "__builtin_ia32_vfmaddsd3",
-        "llvm.x86.fma.vfmadd.ss" => "__builtin_ia32_vfmaddss3",
         "llvm.x86.rdrand.64" => "__builtin_ia32_rdrand64_step",
 
         // The above doc points to unknown builtins for the following, so override them:
@@ -1324,6 +1519,16 @@ pub fn intrinsic<'gcc, 'tcx>(name: &str, cx: &CodegenCx<'gcc, 'tcx>) -> Function
         "llvm.x86.avx512fp16.mask.vfmadd.cph.256" => "__builtin_ia32_vfmaddcph256_mask3",
         "llvm.x86.avx512fp16.mask.vfcmadd.cph.128" => "__builtin_ia32_vfcmaddcph128_mask3",
         "llvm.x86.avx512fp16.mask.vfmadd.cph.128" => "__builtin_ia32_vfmaddcph128_mask3",
+        "llvm.x86.encodekey128" => "__builtin_ia32_encodekey128_u32",
+        "llvm.x86.encodekey256" => "__builtin_ia32_encodekey256_u32",
+        "llvm.x86.aesenc128kl" => "__builtin_ia32_aesenc128kl_u8",
+        "llvm.x86.aesdec128kl" => "__builtin_ia32_aesdec128kl_u8",
+        "llvm.x86.aesenc256kl" => "__builtin_ia32_aesenc256kl_u8",
+        "llvm.x86.aesdec256kl" => "__builtin_ia32_aesdec256kl_u8",
+        "llvm.x86.aesencwide128kl" => "__builtin_ia32_aesencwide128kl_u8",
+        "llvm.x86.aesdecwide128kl" => "__builtin_ia32_aesdecwide128kl_u8",
+        "llvm.x86.aesencwide256kl" => "__builtin_ia32_aesencwide256kl_u8",
+        "llvm.x86.aesdecwide256kl" => "__builtin_ia32_aesdecwide256kl_u8",
 
         // TODO: support the tile builtins:
         "llvm.x86.ldtilecfg" => "__builtin_trap",
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
index f38622074f1..d22f4229e23 100644
--- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
@@ -78,6 +78,7 @@ fn get_simple_intrinsic<'gcc, 'tcx>(
         sym::maxnumf64 => "fmax",
         sym::copysignf32 => "copysignf",
         sym::copysignf64 => "copysign",
+        sym::copysignf128 => "copysignl",
         sym::floorf32 => "floorf",
         sym::floorf64 => "floor",
         sym::ceilf32 => "ceilf",
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/simd.rs b/compiler/rustc_codegen_gcc/src/intrinsic/simd.rs
index 8b454ab2a42..6d40d5297f1 100644
--- a/compiler/rustc_codegen_gcc/src/intrinsic/simd.rs
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/simd.rs
@@ -399,7 +399,7 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
     }
 
     #[cfg(feature = "master")]
-    if name == sym::simd_insert {
+    if name == sym::simd_insert || name == sym::simd_insert_dyn {
         require!(
             in_elem == arg_tys[2],
             InvalidMonomorphization::InsertedType {
@@ -410,6 +410,8 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
                 out_ty: arg_tys[2]
             }
         );
+
+        // TODO(antoyo): For simd_insert, check if the index is a constant of the correct size.
         let vector = args[0].immediate();
         let index = args[1].immediate();
         let value = args[2].immediate();
@@ -422,13 +424,15 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
     }
 
     #[cfg(feature = "master")]
-    if name == sym::simd_extract {
+    if name == sym::simd_extract || name == sym::simd_extract_dyn {
         require!(
             ret_ty == in_elem,
             InvalidMonomorphization::ReturnType { span, name, in_elem, in_ty, ret_ty }
         );
+        // TODO(antoyo): For simd_extract, check if the index is a constant of the correct size.
         let vector = args[0].immediate();
-        return Ok(bx.context.new_vector_access(None, vector, args[1].immediate()).to_rvalue());
+        let index = args[1].immediate();
+        return Ok(bx.context.new_vector_access(None, vector, index).to_rvalue());
     }
 
     if name == sym::simd_select {
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index bfa23174a19..624fdb4043c 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -188,10 +188,10 @@ impl CodegenBackend for GccCodegenBackend {
         crate::DEFAULT_LOCALE_RESOURCE
     }
 
-    fn init(&self, sess: &Session) {
+    fn init(&self, _sess: &Session) {
         #[cfg(feature = "master")]
         {
-            let target_cpu = target_cpu(sess);
+            let target_cpu = target_cpu(_sess);
 
             // Get the second TargetInfo with the correct CPU features by setting the arch.
             let context = Context::default();
diff --git a/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt b/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt
index 082958bfe1f..499c1a96231 100644
--- a/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt
+++ b/compiler/rustc_codegen_gcc/tests/failing-ui-tests.txt
@@ -1,11 +1,9 @@
 tests/ui/allocator/no_std-alloc-error-handler-custom.rs
 tests/ui/allocator/no_std-alloc-error-handler-default.rs
 tests/ui/asm/may_unwind.rs
-tests/ui/asm/x86_64/multiple-clobber-abi.rs
 tests/ui/functions-closures/parallel-codegen-closures.rs
 tests/ui/linkage-attr/linkage1.rs
 tests/ui/lto/dylib-works.rs
-tests/ui/numbers-arithmetic/saturating-float-casts.rs
 tests/ui/sepcomp/sepcomp-cci.rs
 tests/ui/sepcomp/sepcomp-extern.rs
 tests/ui/sepcomp/sepcomp-fns-backwards.rs
@@ -33,7 +31,6 @@ tests/ui/unwind-no-uwtable.rs
 tests/ui/parser/unclosed-delimiter-in-dep.rs
 tests/ui/consts/missing_span_in_backtrace.rs
 tests/ui/drop/dynamic-drop.rs
-tests/ui/issues/issue-40883.rs
 tests/ui/issues/issue-43853.rs
 tests/ui/issues/issue-47364.rs
 tests/ui/macros/rfc-2011-nicer-assert-messages/assert-without-captures-does-not-create-unnecessary-code.rs
@@ -102,14 +99,12 @@ tests/ui/codegen/equal-pointers-unequal/as-cast/basic.rs
 tests/ui/codegen/equal-pointers-unequal/as-cast/inline1.rs
 tests/ui/codegen/equal-pointers-unequal/as-cast/print.rs
 tests/ui/codegen/equal-pointers-unequal/as-cast/inline2.rs
-tests/ui/codegen/equal-pointers-unequal/as-cast/print3.rs
 tests/ui/codegen/equal-pointers-unequal/as-cast/segfault.rs
 tests/ui/codegen/equal-pointers-unequal/exposed-provenance/function.rs
 tests/ui/codegen/equal-pointers-unequal/exposed-provenance/basic.rs
 tests/ui/codegen/equal-pointers-unequal/as-cast/zero.rs
 tests/ui/codegen/equal-pointers-unequal/exposed-provenance/inline1.rs
 tests/ui/codegen/equal-pointers-unequal/exposed-provenance/print.rs
-tests/ui/codegen/equal-pointers-unequal/exposed-provenance/print3.rs
 tests/ui/codegen/equal-pointers-unequal/exposed-provenance/inline2.rs
 tests/ui/codegen/equal-pointers-unequal/exposed-provenance/segfault.rs
 tests/ui/codegen/equal-pointers-unequal/exposed-provenance/zero.rs
@@ -117,8 +112,9 @@ tests/ui/codegen/equal-pointers-unequal/strict-provenance/basic.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/function.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/print.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/inline1.rs
-tests/ui/codegen/equal-pointers-unequal/strict-provenance/print3.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/inline2.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/segfault.rs
 tests/ui/codegen/equal-pointers-unequal/strict-provenance/zero.rs
 tests/ui/simd/simd-bitmask-notpow2.rs
+tests/ui/codegen/StackColoring-not-blowup-stack-issue-40883.rs
+tests/ui/uninhabited/uninhabited-transparent-return-abi.rs
diff --git a/compiler/rustc_codegen_gcc/tests/run/abort1.rs b/compiler/rustc_codegen_gcc/tests/run/abort1.rs
index fe46d9ae418..ff2bb75ece2 100644
--- a/compiler/rustc_codegen_gcc/tests/run/abort1.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/abort1.rs
@@ -3,45 +3,13 @@
 // Run-time:
 //   status: signal
 
-#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-mod intrinsics {
-    use super::Sized;
-
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    pub fn abort() -> !;
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 fn test_fail() -> ! {
     unsafe { intrinsics::abort() };
diff --git a/compiler/rustc_codegen_gcc/tests/run/abort2.rs b/compiler/rustc_codegen_gcc/tests/run/abort2.rs
index 4123f4f4bee..781f518e0b2 100644
--- a/compiler/rustc_codegen_gcc/tests/run/abort2.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/abort2.rs
@@ -3,45 +3,13 @@
 // Run-time:
 //   status: signal
 
-#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-mod intrinsics {
-    use super::Sized;
-
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    pub fn abort() -> !;
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 fn fail() -> i32 {
     unsafe { intrinsics::abort() };
diff --git a/compiler/rustc_codegen_gcc/tests/run/array.rs b/compiler/rustc_codegen_gcc/tests/run/array.rs
index e18a4ced6bc..3ab0c309fde 100644
--- a/compiler/rustc_codegen_gcc/tests/run/array.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/array.rs
@@ -8,20 +8,12 @@
 //     10
 
 #![feature(no_core)]
-
 #![no_std]
 #![no_core]
 #![no_main]
 
 extern crate mini_core;
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-        pub fn puts(s: *const u8) -> i32;
-    }
-}
+use mini_core::*;
 
 static mut ONE: usize = 1;
 
diff --git a/compiler/rustc_codegen_gcc/tests/run/asm.rs b/compiler/rustc_codegen_gcc/tests/run/asm.rs
index 4e05d026868..2dbf43be664 100644
--- a/compiler/rustc_codegen_gcc/tests/run/asm.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/asm.rs
@@ -174,6 +174,59 @@ fn asm() {
         mem_cpy(array2.as_mut_ptr(), array1.as_ptr(), 3);
     }
     assert_eq!(array1, array2);
+
+    // in and clobber registers cannot overlap. This tests that the lateout register without an
+    // output place (indicated by the `_`) is not added to the list of clobbered registers
+    let x = 8;
+    let y: i32;
+    unsafe {
+        asm!(
+            "mov rax, rdi",
+            in("rdi") x,
+            lateout("rdi") _,
+            out("rax") y,
+        );
+    }
+    assert_eq!((x, y), (8, 8));
+
+    // sysv64 is the default calling convention on unix systems. The rdi register is
+    // used to pass arguments in the sysv64 calling convention, so this register will be clobbered
+    #[cfg(unix)]
+    {
+        let x = 16;
+        let y: i32;
+        unsafe {
+            asm!(
+                "mov rax, rdi",
+                in("rdi") x,
+                out("rax") y,
+                clobber_abi("sysv64"),
+            );
+        }
+        assert_eq!((x, y), (16, 16));
+    }
+
+    // the `b` suffix for registers in the `reg_byte` register class is not supported in GCC
+    // and needs to be stripped in order to use these registers.
+    unsafe {
+        core::arch::asm!(
+            "",
+            out("al") _,
+            out("bl") _,
+            out("cl") _,
+            out("dl") _,
+            out("sil") _,
+            out("dil") _,
+            out("r8b") _,
+            out("r9b") _,
+            out("r10b") _,
+            out("r11b") _,
+            out("r12b") _,
+            out("r13b") _,
+            out("r14b") _,
+            out("r15b") _,
+        );
+    }
 }
 
 #[cfg(not(target_arch = "x86_64"))]
diff --git a/compiler/rustc_codegen_gcc/tests/run/assign.rs b/compiler/rustc_codegen_gcc/tests/run/assign.rs
index 286155852d5..4535ab5778e 100644
--- a/compiler/rustc_codegen_gcc/tests/run/assign.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/assign.rs
@@ -5,130 +5,13 @@
 //     7 8
 //     10
 
-#![allow(internal_features, unused_attributes)]
-#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs, track_caller)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for *mut i32 {}
-impl Copy for usize {}
-impl Copy for u8 {}
-impl Copy for i8 {}
-impl Copy for i32 {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn puts(s: *const u8) -> i32;
-        pub fn fflush(stream: *mut i32) -> i32;
-        pub fn printf(format: *const i8, ...) -> i32;
-
-        pub static stdout: *mut i32;
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    pub fn abort() -> !;
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        libc::fflush(libc::stdout);
-        intrinsics::abort();
-    }
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[track_caller]
-#[lang = "panic_const_add_overflow"]
-pub fn panic_const_add_overflow() -> ! {
-    panic("attempt to add with overflow");
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 fn inc_ref(num: &mut isize) -> isize {
     *num = *num + 5;
@@ -139,9 +22,8 @@ fn inc(num: isize) -> isize {
     num + 1
 }
 
-
 #[no_mangle]
-extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
+extern "C" fn main(mut argc: isize, _argv: *const *const u8) -> i32 {
     argc = inc(argc);
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, argc);
diff --git a/compiler/rustc_codegen_gcc/tests/run/closure.rs b/compiler/rustc_codegen_gcc/tests/run/closure.rs
index c7a236f74f9..a8a3fadfed4 100644
--- a/compiler/rustc_codegen_gcc/tests/run/closure.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/closure.rs
@@ -9,55 +9,38 @@
 //     Both args: 11
 
 #![feature(no_core)]
-
 #![no_std]
 #![no_core]
 #![no_main]
 
 extern crate mini_core;
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
+use mini_core::*;
 
 #[no_mangle]
-extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
+extern "C" fn main(argc: isize, _argv: *const *const u8) -> i32 {
     let string = "Arg: %d\n\0";
-    let mut closure = || {
-        unsafe {
-            libc::printf(string as *const str as *const i8, argc);
-        }
+    let mut closure = || unsafe {
+        libc::printf(string as *const str as *const i8, argc);
     };
     closure();
 
-    let mut closure = || {
-        unsafe {
-            libc::printf("Argument: %d\n\0" as *const str as *const i8, argc);
-        }
+    let mut closure = || unsafe {
+        libc::printf("Argument: %d\n\0" as *const str as *const i8, argc);
     };
     closure();
 
-    let mut closure = |string| {
-        unsafe {
-            libc::printf(string as *const str as *const i8, argc);
-        }
+    let mut closure = |string| unsafe {
+        libc::printf(string as *const str as *const i8, argc);
     };
     closure("String arg: %d\n\0");
 
-    let mut closure = |arg: isize| {
-        unsafe {
-            libc::printf("Int argument: %d\n\0" as *const str as *const i8, arg);
-        }
+    let mut closure = |arg: isize| unsafe {
+        libc::printf("Int argument: %d\n\0" as *const str as *const i8, arg);
     };
     closure(argc + 1);
 
-    let mut closure = |string, arg: isize| {
-        unsafe {
-            libc::printf(string as *const str as *const i8, arg);
-        }
+    let mut closure = |string, arg: isize| unsafe {
+        libc::printf(string as *const str as *const i8, arg);
     };
     closure("Both args: %d\n\0", argc + 10);
 
diff --git a/compiler/rustc_codegen_gcc/tests/run/condition.rs b/compiler/rustc_codegen_gcc/tests/run/condition.rs
index b02359702ed..bd3b6f7497f 100644
--- a/compiler/rustc_codegen_gcc/tests/run/condition.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/condition.rs
@@ -6,19 +6,12 @@
 //     1
 
 #![feature(no_core)]
-
 #![no_std]
 #![no_core]
 #![no_main]
 
 extern crate mini_core;
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
+use mini_core::*;
 
 #[no_mangle]
 extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
@@ -27,15 +20,14 @@ extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
             libc::printf(b"true\n\0" as *const u8 as *const i8);
         }
 
-        let string =
-            match argc {
-                1 => b"1\n\0",
-                2 => b"2\n\0",
-                3 => b"3\n\0",
-                4 => b"4\n\0",
-                5 => b"5\n\0",
-                _ => b"_\n\0",
-            };
+        let string = match argc {
+            1 => b"1\n\0",
+            2 => b"2\n\0",
+            3 => b"3\n\0",
+            4 => b"4\n\0",
+            5 => b"5\n\0",
+            _ => b"_\n\0",
+        };
         libc::printf(string as *const u8 as *const i8);
     }
     0
diff --git a/compiler/rustc_codegen_gcc/tests/run/empty_main.rs b/compiler/rustc_codegen_gcc/tests/run/empty_main.rs
index 042e44080c5..fe3df5a2389 100644
--- a/compiler/rustc_codegen_gcc/tests/run/empty_main.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/empty_main.rs
@@ -3,37 +3,13 @@
 // Run-time:
 //   status: 0
 
-#![feature(auto_traits, lang_items, no_core)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 #[no_mangle]
 extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
diff --git a/compiler/rustc_codegen_gcc/tests/run/exit.rs b/compiler/rustc_codegen_gcc/tests/run/exit.rs
index 9a7c91c0adb..e0a59174bd3 100644
--- a/compiler/rustc_codegen_gcc/tests/run/exit.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/exit.rs
@@ -3,44 +3,13 @@
 // Run-time:
 //   status: 2
 
-#![feature(auto_traits, lang_items, no_core, intrinsics)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn exit(status: i32);
-    }
-}
-
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 #[no_mangle]
 extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
diff --git a/compiler/rustc_codegen_gcc/tests/run/exit_code.rs b/compiler/rustc_codegen_gcc/tests/run/exit_code.rs
index c50d2b0d710..376824da845 100644
--- a/compiler/rustc_codegen_gcc/tests/run/exit_code.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/exit_code.rs
@@ -3,37 +3,13 @@
 // Run-time:
 //   status: 1
 
-#![feature(auto_traits, lang_items, no_core)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 #[no_mangle]
 extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
diff --git a/compiler/rustc_codegen_gcc/tests/run/float.rs b/compiler/rustc_codegen_gcc/tests/run/float.rs
new file mode 100644
index 00000000000..424fa1cf4ad
--- /dev/null
+++ b/compiler/rustc_codegen_gcc/tests/run/float.rs
@@ -0,0 +1,28 @@
+// Compiler:
+//
+// Run-time:
+//   status: 0
+
+#![feature(const_black_box)]
+
+fn main() {
+    use std::hint::black_box;
+
+    macro_rules! check {
+        ($ty:ty, $expr:expr) => {{
+            const EXPECTED: $ty = $expr;
+            assert_eq!($expr, EXPECTED);
+        }};
+    }
+
+    check!(i32, (black_box(0.0f32) as i32));
+
+    check!(u64, (black_box(f32::NAN) as u64));
+    check!(u128, (black_box(f32::NAN) as u128));
+
+    check!(i64, (black_box(f64::NAN) as i64));
+    check!(u64, (black_box(f64::NAN) as u64));
+
+    check!(i16, (black_box(f32::MIN) as i16));
+    check!(i16, (black_box(f32::MAX) as i16));
+}
diff --git a/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs b/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs
index 98b351e5044..93b9baee1b2 100644
--- a/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/fun_ptr.rs
@@ -5,19 +5,12 @@
 //   stdout: 1
 
 #![feature(no_core)]
-
 #![no_std]
 #![no_core]
 #![no_main]
 
 extern crate mini_core;
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
+use mini_core::*;
 
 fn i16_as_i8(a: i16) -> i8 {
     a as i8
diff --git a/compiler/rustc_codegen_gcc/tests/run/int.rs b/compiler/rustc_codegen_gcc/tests/run/int.rs
index 58a26801b67..47b5dea46f8 100644
--- a/compiler/rustc_codegen_gcc/tests/run/int.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/int.rs
@@ -3,9 +3,7 @@
 // Run-time:
 //   status: 0
 
-/*
- * Code
- */
+#![feature(const_black_box)]
 
 fn main() {
     use std::hint::black_box;
diff --git a/compiler/rustc_codegen_gcc/tests/run/mut_ref.rs b/compiler/rustc_codegen_gcc/tests/run/mut_ref.rs
index b0215860406..fa50d5bc5d3 100644
--- a/compiler/rustc_codegen_gcc/tests/run/mut_ref.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/mut_ref.rs
@@ -1,4 +1,3 @@
-
 // Compiler:
 //
 // Run-time:
@@ -7,139 +6,20 @@
 //     6
 //     11
 
-#![allow(internal_features, unused_attributes)]
-#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs, track_caller)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for *mut i32 {}
-impl Copy for usize {}
-impl Copy for u8 {}
-impl Copy for i8 {}
-impl Copy for i32 {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn puts(s: *const u8) -> i32;
-        pub fn fflush(stream: *mut i32) -> i32;
-        pub fn printf(format: *const i8, ...) -> i32;
-
-        pub static stdout: *mut i32;
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    pub fn abort() -> !;
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        libc::fflush(libc::stdout);
-        intrinsics::abort();
-    }
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[track_caller]
-#[lang = "panic_const_add_overflow"]
-pub fn panic_const_add_overflow() -> ! {
-    panic("attempt to add with overflow");
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 struct Test {
     field: isize,
 }
 
 fn test(num: isize) -> Test {
-    Test {
-        field: num + 1,
-    }
+    Test { field: num + 1 }
 }
 
 fn update_num(num: &mut isize) {
@@ -147,7 +27,7 @@ fn update_num(num: &mut isize) {
 }
 
 #[no_mangle]
-extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
+extern "C" fn main(mut argc: isize, _argv: *const *const u8) -> i32 {
     let mut test = test(argc);
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, test.field);
diff --git a/compiler/rustc_codegen_gcc/tests/run/operations.rs b/compiler/rustc_codegen_gcc/tests/run/operations.rs
index 8ba7a4c5ed8..a1b0772f76b 100644
--- a/compiler/rustc_codegen_gcc/tests/run/operations.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/operations.rs
@@ -5,229 +5,13 @@
 //     39
 //     10
 
-#![allow(internal_features, unused_attributes)]
-#![feature(auto_traits, lang_items, no_core, intrinsics, arbitrary_self_types, rustc_attrs)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl Copy for *mut i32 {}
-impl Copy for usize {}
-impl Copy for u8 {}
-impl Copy for i8 {}
-impl Copy for i16 {}
-impl Copy for i32 {}
-
-#[lang = "deref"]
-pub trait Deref {
-    type Target: ?Sized;
-
-    fn deref(&self) -> &Self::Target;
-}
-
-#[lang = "legacy_receiver"]
-trait LegacyReceiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-#[lang = "panic_location"]
-struct PanicLocation {
-    file: &'static str,
-    line: u32,
-    column: u32,
-}
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-        pub fn puts(s: *const u8) -> i32;
-        pub fn fflush(stream: *mut i32) -> i32;
-
-        pub static stdout: *mut i32;
-    }
-}
-
-mod intrinsics {
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    pub fn abort() -> !;
-}
-
-#[lang = "panic"]
-#[track_caller]
-#[no_mangle]
-pub fn panic(_msg: &'static str) -> ! {
-    unsafe {
-        libc::puts("Panicking\0" as *const str as *const u8);
-        libc::fflush(libc::stdout);
-        intrinsics::abort();
-    }
-}
-
-#[lang = "add"]
-trait Add<RHS = Self> {
-    type Output;
-
-    fn add(self, rhs: RHS) -> Self::Output;
-}
-
-impl Add for u8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i8 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for i32 {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for usize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-impl Add for isize {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        self + rhs
-    }
-}
-
-#[lang = "sub"]
-pub trait Sub<RHS = Self> {
-    type Output;
-
-    fn sub(self, rhs: RHS) -> Self::Output;
-}
-
-impl Sub for usize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for isize {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for u8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for i8 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-impl Sub for i16 {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        self - rhs
-    }
-}
-
-#[lang = "mul"]
-pub trait Mul<RHS = Self> {
-    type Output;
-
-    #[must_use]
-    fn mul(self, rhs: RHS) -> Self::Output;
-}
-
-impl Mul for u8 {
-    type Output = Self;
-
-    fn mul(self, rhs: Self) -> Self::Output {
-        self * rhs
-    }
-}
-
-impl Mul for usize {
-    type Output = Self;
-
-    fn mul(self, rhs: Self) -> Self::Output {
-        self * rhs
-    }
-}
-
-impl Mul for isize {
-    type Output = Self;
-
-    fn mul(self, rhs: Self) -> Self::Output {
-        self * rhs
-    }
-}
-
-#[track_caller]
-#[lang = "panic_const_add_overflow"]
-pub fn panic_const_add_overflow() -> ! {
-    panic("attempt to add with overflow");
-}
-
-#[track_caller]
-#[lang = "panic_const_sub_overflow"]
-pub fn panic_const_sub_overflow() -> ! {
-    panic("attempt to subtract with overflow");
-}
-
-#[track_caller]
-#[lang = "panic_const_mul_overflow"]
-pub fn panic_const_mul_overflow() -> ! {
-    panic("attempt to multiply with overflow");
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 #[no_mangle]
 extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
diff --git a/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs b/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs
index 0ba49e7187f..c1254c51ce9 100644
--- a/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/ptr_cast.rs
@@ -2,35 +2,32 @@
 //
 // Run-time:
 //   status: 0
-//   stdout: 1
+//   stdout: 10
+//     10
+//     42
 
 #![feature(no_core)]
-
 #![no_std]
 #![no_core]
 #![no_main]
 
 extern crate mini_core;
+use mini_core::*;
 
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
-
-static mut ONE: usize = 1;
-
-fn make_array() -> [u8; 3] {
-    [42, 10, 5]
+fn int_cast(a: u16, b: i16) -> (u8, u16, u32, usize, i8, i16, i32, isize, u8, u32) {
+    (
+        a as u8, a as u16, a as u32, a as usize, a as i8, a as i16, a as i32, a as isize, b as u8,
+        b as u32,
+    )
 }
 
 #[no_mangle]
 extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
+    let (a, b, c, d, e, f, g, h, i, j) = int_cast(10, 42);
     unsafe {
-        let ptr = ONE as *mut usize;
-        let value = ptr as usize;
-        libc::printf(b"%ld\n\0" as *const u8 as *const i8, value);
+        libc::printf(b"%d\n\0" as *const u8 as *const i8, c);
+        libc::printf(b"%ld\n\0" as *const u8 as *const i8, d);
+        libc::printf(b"%ld\n\0" as *const u8 as *const i8, j);
     }
     0
 }
diff --git a/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs b/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs
index 3cc1e274001..c1254c51ce9 100644
--- a/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/return-tuple.rs
@@ -6,54 +6,13 @@
 //     10
 //     42
 
-#![feature(auto_traits, lang_items, no_core, intrinsics)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-#[lang = "copy"]
-pub unsafe trait Copy {}
-
-impl Copy for bool {}
-impl Copy for u8 {}
-impl Copy for u16 {}
-impl Copy for u32 {}
-impl Copy for u64 {}
-impl Copy for usize {}
-impl Copy for i8 {}
-impl Copy for i16 {}
-impl Copy for i32 {}
-impl Copy for isize {}
-impl Copy for f32 {}
-impl Copy for char {}
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
-
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "legacy_receiver"]
-trait LegacyReceiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 fn int_cast(a: u16, b: i16) -> (u8, u16, u32, usize, i8, i16, i32, isize, u8, u32) {
     (
diff --git a/compiler/rustc_codegen_gcc/tests/run/slice.rs b/compiler/rustc_codegen_gcc/tests/run/slice.rs
index 825fcb8a081..449ccabef7f 100644
--- a/compiler/rustc_codegen_gcc/tests/run/slice.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/slice.rs
@@ -5,26 +5,17 @@
 //   stdout: 5
 
 #![feature(no_core)]
-
 #![no_std]
 #![no_core]
 #![no_main]
 
 extern crate mini_core;
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
+use mini_core::*;
 
 static mut TWO: usize = 2;
 
 fn index_slice(s: &[u32]) -> u32 {
-    unsafe {
-        s[TWO]
-    }
+    unsafe { s[TWO] }
 }
 
 #[no_mangle]
diff --git a/compiler/rustc_codegen_gcc/tests/run/static.rs b/compiler/rustc_codegen_gcc/tests/run/static.rs
index c3c8121b1e1..1e36cf4f3d3 100644
--- a/compiler/rustc_codegen_gcc/tests/run/static.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/static.rs
@@ -9,70 +9,13 @@
 //      12
 //      1
 
-#![feature(auto_traits, lang_items, no_core, intrinsics, rustc_attrs)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "destruct"]
-pub trait Destruct {}
-
-#[lang = "drop"]
-pub trait Drop {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-impl<T: ?Sized> Copy for *mut T {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-mod intrinsics {
-    use super::Sized;
-
-    #[rustc_nounwind]
-    #[rustc_intrinsic]
-    pub fn abort() -> !;
-}
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
-
-#[lang = "structural_peq"]
-pub trait StructuralPartialEq {}
-
-#[lang = "drop_in_place"]
-#[allow(unconditional_recursion)]
-pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
-    // Code here does not matter - this is replaced by the
-    // real drop glue by the compiler.
-    drop_in_place(to_drop);
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 struct Test {
     field: isize,
@@ -84,20 +27,14 @@ struct WithRef {
 
 static mut CONSTANT: isize = 10;
 
-static mut TEST: Test = Test {
-    field: 12,
-};
+static mut TEST: Test = Test { field: 12 };
 
-static mut TEST2: Test = Test {
-    field: 14,
-};
+static mut TEST2: Test = Test { field: 14 };
 
-static mut WITH_REF: WithRef = WithRef {
-    refe: unsafe { &TEST },
-};
+static mut WITH_REF: WithRef = WithRef { refe: unsafe { &TEST } };
 
 #[no_mangle]
-extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
+extern "C" fn main(argc: isize, _argv: *const *const u8) -> i32 {
     unsafe {
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, CONSTANT);
         libc::printf(b"%ld\n\0" as *const u8 as *const i8, TEST2.field);
diff --git a/compiler/rustc_codegen_gcc/tests/run/structs.rs b/compiler/rustc_codegen_gcc/tests/run/structs.rs
index 59b8f358863..da73cbed9ae 100644
--- a/compiler/rustc_codegen_gcc/tests/run/structs.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/structs.rs
@@ -5,44 +5,13 @@
 //   stdout: 1
 //     2
 
-#![feature(auto_traits, lang_items, no_core, intrinsics)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 struct Test {
     field: isize,
diff --git a/compiler/rustc_codegen_gcc/tests/run/tuple.rs b/compiler/rustc_codegen_gcc/tests/run/tuple.rs
index ed60a56a68c..e0f2e95f628 100644
--- a/compiler/rustc_codegen_gcc/tests/run/tuple.rs
+++ b/compiler/rustc_codegen_gcc/tests/run/tuple.rs
@@ -4,44 +4,13 @@
 //   status: 0
 //   stdout: 3
 
-#![feature(auto_traits, lang_items, no_core, intrinsics)]
-#![allow(internal_features)]
-
+#![feature(no_core)]
 #![no_std]
 #![no_core]
 #![no_main]
 
-/*
- * Core
- */
-
-// Because we don't have core yet.
-#[lang = "sized"]
-pub trait Sized {}
-
-#[lang = "copy"]
-trait Copy {
-}
-
-impl Copy for isize {}
-
-#[lang = "receiver"]
-trait Receiver {
-}
-
-#[lang = "freeze"]
-pub(crate) unsafe auto trait Freeze {}
-
-mod libc {
-    #[link(name = "c")]
-    extern "C" {
-        pub fn printf(format: *const i8, ...) -> i32;
-    }
-}
-
-/*
- * Code
- */
+extern crate mini_core;
+use mini_core::*;
 
 #[no_mangle]
 extern "C" fn main(argc: i32, _argv: *const *const u8) -> i32 {
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index d405d044cae..5c8c51c8bbc 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -818,8 +818,8 @@ fn test_unstable_options_tracking_hash() {
     tracked!(min_function_alignment, Some(Align::EIGHT));
     tracked!(mir_emit_retag, true);
     tracked!(mir_enable_passes, vec![("DestProp".to_string(), false)]);
-    tracked!(mir_keep_place_mention, true);
     tracked!(mir_opt_level, Some(4));
+    tracked!(mir_preserve_ub, true);
     tracked!(move_size_limit, Some(4096));
     tracked!(mutable_noalias, false);
     tracked!(next_solver, NextSolverConfig { coherence: true, globally: true });
diff --git a/compiler/rustc_middle/src/ty/adt.rs b/compiler/rustc_middle/src/ty/adt.rs
index 66517c97a68..d92b4f9c06b 100644
--- a/compiler/rustc_middle/src/ty/adt.rs
+++ b/compiler/rustc_middle/src/ty/adt.rs
@@ -55,8 +55,6 @@ bitflags::bitflags! {
         const IS_UNSAFE_CELL              = 1 << 9;
         /// Indicates whether the type is `UnsafePinned`.
         const IS_UNSAFE_PINNED              = 1 << 10;
-        /// Indicates whether the type is anonymous.
-        const IS_ANONYMOUS                = 1 << 11;
     }
 }
 rustc_data_structures::external_bitflags_debug! { AdtFlags }
diff --git a/compiler/rustc_mir_transform/src/early_otherwise_branch.rs b/compiler/rustc_mir_transform/src/early_otherwise_branch.rs
index d49f5d9f9c3..c7feb9e949b 100644
--- a/compiler/rustc_mir_transform/src/early_otherwise_branch.rs
+++ b/compiler/rustc_mir_transform/src/early_otherwise_branch.rs
@@ -223,7 +223,7 @@ impl<'tcx> crate::MirPass<'tcx> for EarlyOtherwiseBranch {
         // Since this optimization adds new basic blocks and invalidates others,
         // clean up the cfg to make it nicer for other passes
         if should_cleanup {
-            simplify_cfg(body);
+            simplify_cfg(tcx, body);
         }
     }
 
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index 69e80ed54ea..c5732194424 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -63,7 +63,7 @@ impl<'tcx> crate::MirPass<'tcx> for Inline {
         let _guard = span.enter();
         if inline::<NormalInliner<'tcx>>(tcx, body) {
             debug!("running simplify cfg on {:?}", body.source);
-            simplify_cfg(body);
+            simplify_cfg(tcx, body);
             deref_finder(tcx, body);
         }
     }
@@ -99,7 +99,7 @@ impl<'tcx> crate::MirPass<'tcx> for ForceInline {
         let _guard = span.enter();
         if inline::<ForceInliner<'tcx>>(tcx, body) {
             debug!("running simplify cfg on {:?}", body.source);
-            simplify_cfg(body);
+            simplify_cfg(tcx, body);
             deref_finder(tcx, body);
         }
     }
diff --git a/compiler/rustc_mir_transform/src/jump_threading.rs b/compiler/rustc_mir_transform/src/jump_threading.rs
index 8b4b214a3d4..9732225e48d 100644
--- a/compiler/rustc_mir_transform/src/jump_threading.rs
+++ b/compiler/rustc_mir_transform/src/jump_threading.rs
@@ -90,11 +90,7 @@ impl<'tcx> crate::MirPass<'tcx> for JumpThreading {
         };
 
         for bb in body.basic_blocks.indices() {
-            let old_len = finder.opportunities.len();
-            // If we have any const-eval errors discard any opportunities found
-            if finder.start_from_switch(bb).is_none() {
-                finder.opportunities.truncate(old_len);
-            }
+            finder.start_from_switch(bb);
         }
 
         let opportunities = finder.opportunities;
@@ -201,28 +197,26 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
 
     /// Recursion entry point to find threading opportunities.
     #[instrument(level = "trace", skip(self))]
-    fn start_from_switch(&mut self, bb: BasicBlock) -> Option<()> {
+    fn start_from_switch(&mut self, bb: BasicBlock) {
         let bbdata = &self.body[bb];
         if bbdata.is_cleanup || self.loop_headers.contains(bb) {
-            return Some(());
+            return;
         }
-        let Some((discr, targets)) = bbdata.terminator().kind.as_switch() else { return Some(()) };
-        let Some(discr) = discr.place() else { return Some(()) };
+        let Some((discr, targets)) = bbdata.terminator().kind.as_switch() else { return };
+        let Some(discr) = discr.place() else { return };
         debug!(?discr, ?bb);
 
         let discr_ty = discr.ty(self.body, self.tcx).ty;
-        let Ok(discr_layout) = self.ecx.layout_of(discr_ty) else {
-            return Some(());
-        };
+        let Ok(discr_layout) = self.ecx.layout_of(discr_ty) else { return };
 
-        let Some(discr) = self.map.find(discr.as_ref()) else { return Some(()) };
+        let Some(discr) = self.map.find(discr.as_ref()) else { return };
         debug!(?discr);
 
         let cost = CostChecker::new(self.tcx, self.typing_env, None, self.body);
         let mut state = State::new_reachable();
 
         let conds = if let Some((value, then, else_)) = targets.as_static_if() {
-            let value = ScalarInt::try_from_uint(value, discr_layout.size)?;
+            let Some(value) = ScalarInt::try_from_uint(value, discr_layout.size) else { return };
             self.arena.alloc_from_iter([
                 Condition { value, polarity: Polarity::Eq, target: then },
                 Condition { value, polarity: Polarity::Ne, target: else_ },
@@ -248,10 +242,10 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
         mut state: State<ConditionSet<'a>>,
         mut cost: CostChecker<'_, 'tcx>,
         depth: usize,
-    ) -> Option<()> {
+    ) {
         // Do not thread through loop headers.
         if self.loop_headers.contains(bb) {
-            return Some(());
+            return;
         }
 
         debug!(cost = ?cost.cost());
@@ -259,16 +253,16 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
             self.body.basic_blocks[bb].statements.iter().enumerate().rev()
         {
             if self.is_empty(&state) {
-                return Some(());
+                return;
             }
 
             cost.visit_statement(stmt, Location { block: bb, statement_index });
             if cost.cost() > MAX_COST {
-                return Some(());
+                return;
             }
 
             // Attempt to turn the `current_condition` on `lhs` into a condition on another place.
-            self.process_statement(bb, stmt, &mut state)?;
+            self.process_statement(bb, stmt, &mut state);
 
             // When a statement mutates a place, assignments to that place that happen
             // above the mutation cannot fulfill a condition.
@@ -280,7 +274,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
         }
 
         if self.is_empty(&state) || depth >= MAX_BACKTRACK {
-            return Some(());
+            return;
         }
 
         let last_non_rec = self.opportunities.len();
@@ -293,9 +287,9 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
             match term.kind {
                 TerminatorKind::SwitchInt { ref discr, ref targets } => {
                     self.process_switch_int(discr, targets, bb, &mut state);
-                    self.find_opportunity(pred, state, cost, depth + 1)?;
+                    self.find_opportunity(pred, state, cost, depth + 1);
                 }
-                _ => self.recurse_through_terminator(pred, || state, &cost, depth)?,
+                _ => self.recurse_through_terminator(pred, || state, &cost, depth),
             }
         } else if let &[ref predecessors @ .., last_pred] = &predecessors[..] {
             for &pred in predecessors {
@@ -320,13 +314,12 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
             let first = &mut new_tos[0];
             *first = ThreadingOpportunity { chain: vec![bb], target: first.target };
             self.opportunities.truncate(last_non_rec + 1);
-            return Some(());
+            return;
         }
 
         for op in self.opportunities[last_non_rec..].iter_mut() {
             op.chain.push(bb);
         }
-        Some(())
     }
 
     /// Extract the mutated place from a statement.
@@ -440,23 +433,23 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
         lhs: PlaceIndex,
         rhs: &Operand<'tcx>,
         state: &mut State<ConditionSet<'a>>,
-    ) -> Option<()> {
+    ) {
         match rhs {
             // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`.
             Operand::Constant(constant) => {
-                let constant = self
-                    .ecx
-                    .eval_mir_constant(&constant.const_, constant.span, None)
-                    .discard_err()?;
+                let Some(constant) =
+                    self.ecx.eval_mir_constant(&constant.const_, constant.span, None).discard_err()
+                else {
+                    return;
+                };
                 self.process_constant(bb, lhs, constant, state);
             }
             // Transfer the conditions on the copied rhs.
             Operand::Move(rhs) | Operand::Copy(rhs) => {
-                let Some(rhs) = self.map.find(rhs.as_ref()) else { return Some(()) };
+                let Some(rhs) = self.map.find(rhs.as_ref()) else { return };
                 state.insert_place_idx(rhs, lhs, &self.map);
             }
         }
-        Some(())
     }
 
     #[instrument(level = "trace", skip(self))]
@@ -466,18 +459,14 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
         lhs_place: &Place<'tcx>,
         rhs: &Rvalue<'tcx>,
         state: &mut State<ConditionSet<'a>>,
-    ) -> Option<()> {
-        let Some(lhs) = self.map.find(lhs_place.as_ref()) else {
-            return Some(());
-        };
+    ) {
+        let Some(lhs) = self.map.find(lhs_place.as_ref()) else { return };
         match rhs {
-            Rvalue::Use(operand) => self.process_operand(bb, lhs, operand, state)?,
+            Rvalue::Use(operand) => self.process_operand(bb, lhs, operand, state),
             // Transfer the conditions on the copy rhs.
-            Rvalue::CopyForDeref(rhs) => {
-                self.process_operand(bb, lhs, &Operand::Copy(*rhs), state)?
-            }
+            Rvalue::CopyForDeref(rhs) => self.process_operand(bb, lhs, &Operand::Copy(*rhs), state),
             Rvalue::Discriminant(rhs) => {
-                let Some(rhs) = self.map.find_discr(rhs.as_ref()) else { return Some(()) };
+                let Some(rhs) = self.map.find_discr(rhs.as_ref()) else { return };
                 state.insert_place_idx(rhs, lhs, &self.map);
             }
             // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`.
@@ -485,7 +474,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
                 let agg_ty = lhs_place.ty(self.body, self.tcx).ty;
                 let lhs = match kind {
                     // Do not support unions.
-                    AggregateKind::Adt(.., Some(_)) => return Some(()),
+                    AggregateKind::Adt(.., Some(_)) => return,
                     AggregateKind::Adt(_, variant_index, ..) if agg_ty.is_enum() => {
                         if let Some(discr_target) = self.map.apply(lhs, TrackElem::Discriminant)
                             && let Some(discr_value) = self
@@ -498,23 +487,23 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
                         if let Some(idx) = self.map.apply(lhs, TrackElem::Variant(*variant_index)) {
                             idx
                         } else {
-                            return Some(());
+                            return;
                         }
                     }
                     _ => lhs,
                 };
                 for (field_index, operand) in operands.iter_enumerated() {
                     if let Some(field) = self.map.apply(lhs, TrackElem::Field(field_index)) {
-                        self.process_operand(bb, field, operand, state)?;
+                        self.process_operand(bb, field, operand, state);
                     }
                 }
             }
             // Transfer the conditions on the copy rhs, after inverting the value of the condition.
             Rvalue::UnaryOp(UnOp::Not, Operand::Move(place) | Operand::Copy(place)) => {
                 let layout = self.ecx.layout_of(place.ty(self.body, self.tcx).ty).unwrap();
-                let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return Some(()) };
-                let Some(place) = self.map.find(place.as_ref()) else { return Some(()) };
-                let conds = conditions.map(self.arena, |mut cond| {
+                let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return };
+                let Some(place) = self.map.find(place.as_ref()) else { return };
+                let Some(conds) = conditions.map(self.arena, |mut cond| {
                     cond.value = self
                         .ecx
                         .unary_op(UnOp::Not, &ImmTy::from_scalar_int(cond.value, layout))
@@ -522,7 +511,9 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
                         .to_scalar_int()
                         .discard_err()?;
                     Some(cond)
-                })?;
+                }) else {
+                    return;
+                };
                 state.insert_value_idx(place, conds, &self.map);
             }
             // We expect `lhs ?= A`. We found `lhs = Eq(rhs, B)`.
@@ -532,34 +523,38 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
                 box (Operand::Move(place) | Operand::Copy(place), Operand::Constant(value))
                 | box (Operand::Constant(value), Operand::Move(place) | Operand::Copy(place)),
             ) => {
-                let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return Some(()) };
-                let Some(place) = self.map.find(place.as_ref()) else { return Some(()) };
+                let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return };
+                let Some(place) = self.map.find(place.as_ref()) else { return };
                 let equals = match op {
                     BinOp::Eq => ScalarInt::TRUE,
                     BinOp::Ne => ScalarInt::FALSE,
-                    _ => return Some(()),
+                    _ => return,
                 };
                 if value.const_.ty().is_floating_point() {
                     // Floating point equality does not follow bit-patterns.
                     // -0.0 and NaN both have special rules for equality,
                     // and therefore we cannot use integer comparisons for them.
                     // Avoid handling them, though this could be extended in the future.
-                    return Some(());
+                    return;
                 }
-                let value = value.const_.try_eval_scalar_int(self.tcx, self.typing_env)?;
-                let conds = conditions.map(self.arena, |c| {
+                let Some(value) = value.const_.try_eval_scalar_int(self.tcx, self.typing_env)
+                else {
+                    return;
+                };
+                let Some(conds) = conditions.map(self.arena, |c| {
                     Some(Condition {
                         value,
                         polarity: if c.matches(equals) { Polarity::Eq } else { Polarity::Ne },
                         ..c
                     })
-                })?;
+                }) else {
+                    return;
+                };
                 state.insert_value_idx(place, conds, &self.map);
             }
 
             _ => {}
         }
-        Some(())
     }
 
     #[instrument(level = "trace", skip(self))]
@@ -568,7 +563,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
         bb: BasicBlock,
         stmt: &Statement<'tcx>,
         state: &mut State<ConditionSet<'a>>,
-    ) -> Option<()> {
+    ) {
         let register_opportunity = |c: Condition| {
             debug!(?bb, ?c.target, "register");
             self.opportunities.push(ThreadingOpportunity { chain: vec![bb], target: c.target })
@@ -581,32 +576,30 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
             // If we expect `discriminant(place) ?= A`,
             // we have an opportunity if `variant_index ?= A`.
             StatementKind::SetDiscriminant { box place, variant_index } => {
-                let Some(discr_target) = self.map.find_discr(place.as_ref()) else {
-                    return Some(());
-                };
+                let Some(discr_target) = self.map.find_discr(place.as_ref()) else { return };
                 let enum_ty = place.ty(self.body, self.tcx).ty;
                 // `SetDiscriminant` guarantees that the discriminant is now `variant_index`.
                 // Even if the discriminant write does nothing due to niches, it is UB to set the
                 // discriminant when the data does not encode the desired discriminant.
-                let discr =
-                    self.ecx.discriminant_for_variant(enum_ty, *variant_index).discard_err()?;
-                self.process_immediate(bb, discr_target, discr, state);
+                let Some(discr) =
+                    self.ecx.discriminant_for_variant(enum_ty, *variant_index).discard_err()
+                else {
+                    return;
+                };
+                self.process_immediate(bb, discr_target, discr, state)
             }
             // If we expect `lhs ?= true`, we have an opportunity if we assume `lhs == true`.
             StatementKind::Intrinsic(box NonDivergingIntrinsic::Assume(
                 Operand::Copy(place) | Operand::Move(place),
             )) => {
-                let Some(conditions) = state.try_get(place.as_ref(), &self.map) else {
-                    return Some(());
-                };
-                conditions.iter_matches(ScalarInt::TRUE).for_each(register_opportunity);
+                let Some(conditions) = state.try_get(place.as_ref(), &self.map) else { return };
+                conditions.iter_matches(ScalarInt::TRUE).for_each(register_opportunity)
             }
             StatementKind::Assign(box (lhs_place, rhs)) => {
-                self.process_assign(bb, lhs_place, rhs, state)?;
+                self.process_assign(bb, lhs_place, rhs, state)
             }
             _ => {}
         }
-        Some(())
     }
 
     #[instrument(level = "trace", skip(self, state, cost))]
@@ -617,7 +610,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
         state: impl FnOnce() -> State<ConditionSet<'a>>,
         cost: &CostChecker<'_, 'tcx>,
         depth: usize,
-    ) -> Option<()> {
+    ) {
         let term = self.body.basic_blocks[bb].terminator();
         let place_to_flood = match term.kind {
             // We come from a target, so those are not possible.
@@ -632,9 +625,9 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
             | TerminatorKind::FalseUnwind { .. }
             | TerminatorKind::Yield { .. } => bug!("{term:?} invalid"),
             // Cannot reason about inline asm.
-            TerminatorKind::InlineAsm { .. } => return Some(()),
+            TerminatorKind::InlineAsm { .. } => return,
             // `SwitchInt` is handled specially.
-            TerminatorKind::SwitchInt { .. } => return Some(()),
+            TerminatorKind::SwitchInt { .. } => return,
             // We can recurse, no thing particular to do.
             TerminatorKind::Goto { .. } => None,
             // Flood the overwritten place, and progress through.
diff --git a/compiler/rustc_mir_transform/src/match_branches.rs b/compiler/rustc_mir_transform/src/match_branches.rs
index 5059837328e..b37241185c9 100644
--- a/compiler/rustc_mir_transform/src/match_branches.rs
+++ b/compiler/rustc_mir_transform/src/match_branches.rs
@@ -43,7 +43,7 @@ impl<'tcx> crate::MirPass<'tcx> for MatchBranchSimplification {
         }
 
         if should_cleanup {
-            simplify_cfg(body);
+            simplify_cfg(tcx, body);
         }
     }
 
diff --git a/compiler/rustc_mir_transform/src/remove_place_mention.rs b/compiler/rustc_mir_transform/src/remove_place_mention.rs
index 15fe77d5319..cb598ceb4df 100644
--- a/compiler/rustc_mir_transform/src/remove_place_mention.rs
+++ b/compiler/rustc_mir_transform/src/remove_place_mention.rs
@@ -8,7 +8,7 @@ pub(super) struct RemovePlaceMention;
 
 impl<'tcx> crate::MirPass<'tcx> for RemovePlaceMention {
     fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
-        !sess.opts.unstable_opts.mir_keep_place_mention
+        !sess.opts.unstable_opts.mir_preserve_ub
     }
 
     fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
diff --git a/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs b/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs
index 8a8cdafc690..43f80508e4a 100644
--- a/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs
+++ b/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs
@@ -35,7 +35,7 @@ impl<'tcx> crate::MirPass<'tcx> for RemoveUnneededDrops {
         // if we applied optimizations, we potentially have some cfg to cleanup to
         // make it easier for further passes
         if should_simplify {
-            simplify_cfg(body);
+            simplify_cfg(tcx, body);
         }
     }
 
diff --git a/compiler/rustc_mir_transform/src/simplify.rs b/compiler/rustc_mir_transform/src/simplify.rs
index 5947637cded..4f2cce8ac10 100644
--- a/compiler/rustc_mir_transform/src/simplify.rs
+++ b/compiler/rustc_mir_transform/src/simplify.rs
@@ -26,6 +26,13 @@
 //! Here the block (`{ return; }`) has the return type `char`, rather than `()`, but the MIR we
 //! naively generate still contains the `_a = ()` write in the unreachable block "after" the
 //! return.
+//!
+//! **WARNING**: This is one of the few optimizations that runs on built and analysis MIR, and
+//! so its effects may affect the type-checking, borrow-checking, and other analysis of MIR.
+//! We must be extremely careful to only apply optimizations that preserve UB and all
+//! non-determinism, since changes here can affect which programs compile in an insta-stable way.
+//! The normal logic that a program with UB can be changed to do anything does not apply to
+//! pre-"runtime" MIR!
 
 use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_middle::mir::visit::{MutVisitor, MutatingUseContext, PlaceContext, Visitor};
@@ -66,8 +73,8 @@ impl SimplifyCfg {
     }
 }
 
-pub(super) fn simplify_cfg(body: &mut Body<'_>) {
-    CfgSimplifier::new(body).simplify();
+pub(super) fn simplify_cfg<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    CfgSimplifier::new(tcx, body).simplify();
     remove_dead_blocks(body);
 
     // FIXME: Should probably be moved into some kind of pass manager
@@ -79,9 +86,9 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyCfg {
         self.name()
     }
 
-    fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         debug!("SimplifyCfg({:?}) - simplifying {:?}", self.name(), body.source);
-        simplify_cfg(body);
+        simplify_cfg(tcx, body);
     }
 
     fn is_required(&self) -> bool {
@@ -90,12 +97,13 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyCfg {
 }
 
 struct CfgSimplifier<'a, 'tcx> {
+    preserve_switch_reads: bool,
     basic_blocks: &'a mut IndexSlice<BasicBlock, BasicBlockData<'tcx>>,
     pred_count: IndexVec<BasicBlock, u32>,
 }
 
 impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
-    fn new(body: &'a mut Body<'tcx>) -> Self {
+    fn new(tcx: TyCtxt<'tcx>, body: &'a mut Body<'tcx>) -> Self {
         let mut pred_count = IndexVec::from_elem(0u32, &body.basic_blocks);
 
         // we can't use mir.predecessors() here because that counts
@@ -110,9 +118,12 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
             }
         }
 
+        // Preserve `SwitchInt` reads on built and analysis MIR, or if `-Zmir-preserve-ub`.
+        let preserve_switch_reads = matches!(body.phase, MirPhase::Built | MirPhase::Analysis(_))
+            || tcx.sess.opts.unstable_opts.mir_preserve_ub;
         let basic_blocks = body.basic_blocks_mut();
 
-        CfgSimplifier { basic_blocks, pred_count }
+        CfgSimplifier { preserve_switch_reads, basic_blocks, pred_count }
     }
 
     fn simplify(mut self) {
@@ -253,9 +264,15 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
 
     // turn a branch with all successors identical to a goto
     fn simplify_branch(&mut self, terminator: &mut Terminator<'tcx>) -> bool {
-        match terminator.kind {
-            TerminatorKind::SwitchInt { .. } => {}
-            _ => return false,
+        // Removing a `SwitchInt` terminator may remove reads that result in UB,
+        // so we must not apply this optimization before borrowck or when
+        // `-Zmir-preserve-ub` is set.
+        if self.preserve_switch_reads {
+            return false;
+        }
+
+        let TerminatorKind::SwitchInt { .. } = terminator.kind else {
+            return false;
         };
 
         let first_succ = {
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index df44b3cc23c..71cc814cb50 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1884,13 +1884,15 @@ impl<'a> Parser<'a> {
             let mut expr = self.parse_expr_opt()?;
             if let Some(expr) = &mut expr {
                 if label.is_some()
-                    && matches!(
-                        expr.kind,
+                    && match &expr.kind {
                         ExprKind::While(_, _, None)
-                            | ExprKind::ForLoop { label: None, .. }
-                            | ExprKind::Loop(_, None, _)
-                            | ExprKind::Block(_, None)
-                    )
+                        | ExprKind::ForLoop { label: None, .. }
+                        | ExprKind::Loop(_, None, _) => true,
+                        ExprKind::Block(block, None) => {
+                            matches!(block.rules, BlockCheckMode::Default)
+                        }
+                        _ => false,
+                    }
                 {
                     self.psess.buffer_lint(
                         BREAK_WITH_LABEL_AND_LOOP,
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 1b0794f79d3..36eee5f3086 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -2322,12 +2322,12 @@ options! {
     mir_include_spans: MirIncludeSpans = (MirIncludeSpans::default(), parse_mir_include_spans, [UNTRACKED],
         "include extra comments in mir pretty printing, like line numbers and statement indices, \
          details about types, etc. (boolean for all passes, 'nll' to enable in NLL MIR only, default: 'nll')"),
-    mir_keep_place_mention: bool = (false, parse_bool, [TRACKED],
-        "keep place mention MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 \
-        (default: no)"),
     #[rustc_lint_opt_deny_field_access("use `Session::mir_opt_level` instead of this field")]
     mir_opt_level: Option<usize> = (None, parse_opt_number, [TRACKED],
         "MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)"),
+    mir_preserve_ub: bool = (false, parse_bool, [TRACKED],
+        "keep place mention statements and reads in trivial SwitchInt terminators, which are interpreted \
+        e.g., by miri; implies -Zmir-opt-level=0 (default: no)"),
     mir_strip_debuginfo: MirStripDebugInfo = (MirStripDebugInfo::None, parse_mir_strip_debuginfo, [TRACKED],
         "Whether to remove some of the MIR debug info from methods.  Default: None"),
     move_size_limit: Option<usize> = (None, parse_opt_number, [TRACKED],
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 1bc08e60098..2ec25a85297 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -2218,7 +2218,6 @@ symbols! {
         unsafe_extern_blocks,
         unsafe_fields,
         unsafe_no_drop_flag,
-        unsafe_pin_internals,
         unsafe_pinned,
         unsafe_unpin,
         unsize,
diff --git a/compiler/rustc_target/src/spec/targets/i686_win7_windows_msvc.rs b/compiler/rustc_target/src/spec/targets/i686_win7_windows_msvc.rs
index 233a1c4fd7a..91ab3111097 100644
--- a/compiler/rustc_target/src/spec/targets/i686_win7_windows_msvc.rs
+++ b/compiler/rustc_target/src/spec/targets/i686_win7_windows_msvc.rs
@@ -7,6 +7,12 @@ pub(crate) fn target() -> Target {
     base.cpu = "pentium4".into();
     base.max_atomic_width = Some(64);
     base.supported_sanitizers = SanitizerSet::ADDRESS;
+    // On Windows 7 32-bit, the alignment characteristic of the TLS Directory
+    // don't appear to be respected by the PE Loader, leading to crashes. As
+    // a result, let's disable has_thread_local to make sure TLS goes through
+    // the emulation layer.
+    // See https://github.com/rust-lang/rust/issues/138903
+    base.has_thread_local = false;
 
     base.add_pre_link_args(
         LinkerFlavor::Msvc(Lld::No),
diff --git a/library/alloc/src/ffi/c_str.rs b/library/alloc/src/ffi/c_str.rs
index f6743c65710..ef8548d2429 100644
--- a/library/alloc/src/ffi/c_str.rs
+++ b/library/alloc/src/ffi/c_str.rs
@@ -1116,7 +1116,7 @@ impl CStr {
     /// with the corresponding <code>&[str]</code> slice. Otherwise, it will
     /// replace any invalid UTF-8 sequences with
     /// [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD] and return a
-    /// <code>[Cow]::[Owned]\(&[str])</code> with the result.
+    /// <code>[Cow]::[Owned]\([String])</code> with the result.
     ///
     /// [str]: prim@str "str"
     /// [Borrowed]: Cow::Borrowed
diff --git a/library/core/src/iter/adapters/enumerate.rs b/library/core/src/iter/adapters/enumerate.rs
index bd093e279c3..f7b9f0b7a5e 100644
--- a/library/core/src/iter/adapters/enumerate.rs
+++ b/library/core/src/iter/adapters/enumerate.rs
@@ -23,6 +23,39 @@ impl<I> Enumerate<I> {
     pub(in crate::iter) fn new(iter: I) -> Enumerate<I> {
         Enumerate { iter, count: 0 }
     }
+
+    /// Retrieve the current position of the iterator.
+    ///
+    /// If the iterator has not advanced, the position returned will be 0.
+    ///
+    /// The position may also exceed the bounds of the iterator to allow for calculating
+    /// the displacement of the iterator from following calls to [`Iterator::next`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(next_index)]
+    ///
+    /// let arr = ['a', 'b'];
+    ///
+    /// let mut iter = arr.iter().enumerate();
+    ///
+    /// assert_eq!(iter.next_index(), 0);
+    /// assert_eq!(iter.next(), Some((0, &'a')));
+    ///
+    /// assert_eq!(iter.next_index(), 1);
+    /// assert_eq!(iter.next_index(), 1);
+    /// assert_eq!(iter.next(), Some((1, &'b')));
+    ///
+    /// assert_eq!(iter.next_index(), 2);
+    /// assert_eq!(iter.next(), None);
+    /// assert_eq!(iter.next_index(), 2);
+    /// ```
+    #[inline]
+    #[unstable(feature = "next_index", issue = "130711")]
+    pub fn next_index(&self) -> usize {
+        self.count
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
index 48ed5ae451e..9e6acf04bf7 100644
--- a/library/core/src/pin.rs
+++ b/library/core/src/pin.rs
@@ -1092,24 +1092,15 @@ pub use self::unsafe_pinned::UnsafePinned;
 #[rustc_pub_transparent]
 #[derive(Copy, Clone)]
 pub struct Pin<Ptr> {
-    // FIXME(#93176): this field is made `#[unstable] #[doc(hidden)] pub` to:
-    //   - deter downstream users from accessing it (which would be unsound!),
-    //   - let the `pin!` macro access it (such a macro requires using struct
-    //     literal syntax in order to benefit from lifetime extension).
-    //
-    // However, if the `Deref` impl exposes a field with the same name as this
-    // field, then the two will collide, resulting in a confusing error when the
-    // user attempts to access the field through a `Pin<Ptr>`. Therefore, the
-    // name `__pointer` is designed to be unlikely to collide with any other
-    // field. Long-term, macro hygiene is expected to offer a more robust
-    // alternative, alongside `unsafe` fields.
-    #[unstable(feature = "unsafe_pin_internals", issue = "none")]
-    #[doc(hidden)]
-    pub __pointer: Ptr,
+    /// Only public for bootstrap.
+    #[cfg(bootstrap)]
+    pub pointer: Ptr,
+    #[cfg(not(bootstrap))]
+    pointer: Ptr,
 }
 
 // The following implementations aren't derived in order to avoid soundness
-// issues. `&self.__pointer` should not be accessible to untrusted trait
+// issues. `&self.pointer` should not be accessible to untrusted trait
 // implementations.
 //
 // See <https://internals.rust-lang.org/t/unsoundness-in-pin/11311/73> for more details.
@@ -1223,7 +1214,7 @@ impl<Ptr: Deref<Target: Unpin>> Pin<Ptr> {
     #[rustc_const_stable(feature = "const_pin", since = "1.84.0")]
     #[stable(feature = "pin_into_inner", since = "1.39.0")]
     pub const fn into_inner(pin: Pin<Ptr>) -> Ptr {
-        pin.__pointer
+        pin.pointer
     }
 }
 
@@ -1360,7 +1351,7 @@ impl<Ptr: Deref> Pin<Ptr> {
     #[rustc_const_stable(feature = "const_pin", since = "1.84.0")]
     #[stable(feature = "pin", since = "1.33.0")]
     pub const unsafe fn new_unchecked(pointer: Ptr) -> Pin<Ptr> {
-        Pin { __pointer: pointer }
+        Pin { pointer }
     }
 
     /// Gets a shared reference to the pinned value this [`Pin`] points to.
@@ -1374,7 +1365,7 @@ impl<Ptr: Deref> Pin<Ptr> {
     #[inline(always)]
     pub fn as_ref(&self) -> Pin<&Ptr::Target> {
         // SAFETY: see documentation on this function
-        unsafe { Pin::new_unchecked(&*self.__pointer) }
+        unsafe { Pin::new_unchecked(&*self.pointer) }
     }
 }
 
@@ -1418,7 +1409,7 @@ impl<Ptr: DerefMut> Pin<Ptr> {
     #[inline(always)]
     pub fn as_mut(&mut self) -> Pin<&mut Ptr::Target> {
         // SAFETY: see documentation on this function
-        unsafe { Pin::new_unchecked(&mut *self.__pointer) }
+        unsafe { Pin::new_unchecked(&mut *self.pointer) }
     }
 
     /// Gets `Pin<&mut T>` to the underlying pinned value from this nested `Pin`-pointer.
@@ -1485,7 +1476,7 @@ impl<Ptr: DerefMut> Pin<Ptr> {
     where
         Ptr::Target: Sized,
     {
-        *(self.__pointer) = value;
+        *(self.pointer) = value;
     }
 }
 
@@ -1513,7 +1504,7 @@ impl<Ptr: Deref> Pin<Ptr> {
     #[rustc_const_stable(feature = "const_pin", since = "1.84.0")]
     #[stable(feature = "pin_into_inner", since = "1.39.0")]
     pub const unsafe fn into_inner_unchecked(pin: Pin<Ptr>) -> Ptr {
-        pin.__pointer
+        pin.pointer
     }
 }
 
@@ -1539,7 +1530,7 @@ impl<'a, T: ?Sized> Pin<&'a T> {
         U: ?Sized,
         F: FnOnce(&T) -> &U,
     {
-        let pointer = &*self.__pointer;
+        let pointer = &*self.pointer;
         let new_pointer = func(pointer);
 
         // SAFETY: the safety contract for `new_unchecked` must be
@@ -1569,7 +1560,7 @@ impl<'a, T: ?Sized> Pin<&'a T> {
     #[rustc_const_stable(feature = "const_pin", since = "1.84.0")]
     #[stable(feature = "pin", since = "1.33.0")]
     pub const fn get_ref(self) -> &'a T {
-        self.__pointer
+        self.pointer
     }
 }
 
@@ -1580,7 +1571,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     #[rustc_const_stable(feature = "const_pin", since = "1.84.0")]
     #[stable(feature = "pin", since = "1.33.0")]
     pub const fn into_ref(self) -> Pin<&'a T> {
-        Pin { __pointer: self.__pointer }
+        Pin { pointer: self.pointer }
     }
 
     /// Gets a mutable reference to the data inside of this `Pin`.
@@ -1600,7 +1591,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     where
         T: Unpin,
     {
-        self.__pointer
+        self.pointer
     }
 
     /// Gets a mutable reference to the data inside of this `Pin`.
@@ -1618,7 +1609,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     #[stable(feature = "pin", since = "1.33.0")]
     #[rustc_const_stable(feature = "const_pin", since = "1.84.0")]
     pub const unsafe fn get_unchecked_mut(self) -> &'a mut T {
-        self.__pointer
+        self.pointer
     }
 
     /// Constructs a new pin by mapping the interior value.
@@ -1705,21 +1696,21 @@ impl<Ptr: LegacyReceiver> LegacyReceiver for Pin<Ptr> {}
 #[stable(feature = "pin", since = "1.33.0")]
 impl<Ptr: fmt::Debug> fmt::Debug for Pin<Ptr> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Debug::fmt(&self.__pointer, f)
+        fmt::Debug::fmt(&self.pointer, f)
     }
 }
 
 #[stable(feature = "pin", since = "1.33.0")]
 impl<Ptr: fmt::Display> fmt::Display for Pin<Ptr> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(&self.__pointer, f)
+        fmt::Display::fmt(&self.pointer, f)
     }
 }
 
 #[stable(feature = "pin", since = "1.33.0")]
 impl<Ptr: fmt::Pointer> fmt::Pointer for Pin<Ptr> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Pointer::fmt(&self.__pointer, f)
+        fmt::Pointer::fmt(&self.pointer, f)
     }
 }
 
@@ -1945,80 +1936,22 @@ unsafe impl<T: ?Sized> PinCoerceUnsized for *mut T {}
 /// constructor.
 ///
 /// [`Box::pin`]: ../../std/boxed/struct.Box.html#method.pin
+#[cfg(not(bootstrap))]
 #[stable(feature = "pin_macro", since = "1.68.0")]
 #[rustc_macro_transparency = "semitransparent"]
-#[allow_internal_unstable(unsafe_pin_internals)]
-#[rustc_macro_edition_2021]
+#[allow_internal_unstable(super_let)]
 pub macro pin($value:expr $(,)?) {
-    // This is `Pin::new_unchecked(&mut { $value })`, so, for starters, let's
-    // review such a hypothetical macro (that any user-code could define):
-    //
-    // ```rust
-    // macro_rules! pin {( $value:expr ) => (
-    //     match &mut { $value } { at_value => unsafe { // Do not wrap `$value` in an `unsafe` block.
-    //         $crate::pin::Pin::<&mut _>::new_unchecked(at_value)
-    //     }}
-    // )}
-    // ```
-    //
-    // Safety:
-    //   - `type P = &mut _`. There are thus no pathological `Deref{,Mut}` impls
-    //     that would break `Pin`'s invariants.
-    //   - `{ $value }` is braced, making it a _block expression_, thus **moving**
-    //     the given `$value`, and making it _become an **anonymous** temporary_.
-    //     By virtue of being anonymous, it can no longer be accessed, thus
-    //     preventing any attempts to `mem::replace` it or `mem::forget` it, _etc._
-    //
-    // This gives us a `pin!` definition that is sound, and which works, but only
-    // in certain scenarios:
-    //   - If the `pin!(value)` expression is _directly_ fed to a function call:
-    //     `let poll = pin!(fut).poll(cx);`
-    //   - If the `pin!(value)` expression is part of a scrutinee:
-    //     ```rust
-    //     match pin!(fut) { pinned_fut => {
-    //         pinned_fut.as_mut().poll(...);
-    //         pinned_fut.as_mut().poll(...);
-    //     }} // <- `fut` is dropped here.
-    //     ```
-    // Alas, it doesn't work for the more straight-forward use-case: `let` bindings.
-    // ```rust
-    // let pinned_fut = pin!(fut); // <- temporary value is freed at the end of this statement
-    // pinned_fut.poll(...) // error[E0716]: temporary value dropped while borrowed
-    //                      // note: consider using a `let` binding to create a longer lived value
-    // ```
-    //   - Issues such as this one are the ones motivating https://github.com/rust-lang/rfcs/pull/66
-    //
-    // This makes such a macro incredibly unergonomic in practice, and the reason most macros
-    // out there had to take the path of being a statement/binding macro (_e.g._, `pin!(future);`)
-    // instead of featuring the more intuitive ergonomics of an expression macro.
-    //
-    // Luckily, there is a way to avoid the problem. Indeed, the problem stems from the fact that a
-    // temporary is dropped at the end of its enclosing statement when it is part of the parameters
-    // given to function call, which has precisely been the case with our `Pin::new_unchecked()`!
-    // For instance,
-    // ```rust
-    // let p = Pin::new_unchecked(&mut <temporary>);
-    // ```
-    // becomes:
-    // ```rust
-    // let p = { let mut anon = <temporary>; &mut anon };
-    // ```
-    //
-    // However, when using a literal braced struct to construct the value, references to temporaries
-    // can then be taken. This makes Rust change the lifespan of such temporaries so that they are,
-    // instead, dropped _at the end of the enscoping block_.
-    // For instance,
-    // ```rust
-    // let p = Pin { __pointer: &mut <temporary> };
-    // ```
-    // becomes:
-    // ```rust
-    // let mut anon = <temporary>;
-    // let p = Pin { __pointer: &mut anon };
-    // ```
-    // which is *exactly* what we want.
-    //
-    // See https://doc.rust-lang.org/1.58.1/reference/destructors.html#temporary-lifetime-extension
-    // for more info.
-    $crate::pin::Pin::<&mut _> { __pointer: &mut { $value } }
+    {
+        super let mut pinned = $value;
+        // SAFETY: The value is pinned: it is the local above which cannot be named outside this macro.
+        unsafe { $crate::pin::Pin::new_unchecked(&mut pinned) }
+    }
+}
+
+/// Only for bootstrap.
+#[cfg(bootstrap)]
+#[stable(feature = "pin_macro", since = "1.68.0")]
+#[rustc_macro_transparency = "semitransparent"]
+pub macro pin($value:expr $(,)?) {
+    $crate::pin::Pin::<&mut _> { pointer: &mut { $value } }
 }
diff --git a/library/core/src/ptr/const_ptr.rs b/library/core/src/ptr/const_ptr.rs
index 0854e31c199..2d869958b85 100644
--- a/library/core/src/ptr/const_ptr.rs
+++ b/library/core/src/ptr/const_ptr.rs
@@ -1739,3 +1739,11 @@ impl<T: ?Sized> PartialOrd for *const T {
         *self >= *other
     }
 }
+
+#[stable(feature = "raw_ptr_default", since = "CURRENT_RUSTC_VERSION")]
+impl<T: ?Sized + Thin> Default for *const T {
+    /// Returns the default value of [`null()`][crate::ptr::null].
+    fn default() -> Self {
+        crate::ptr::null()
+    }
+}
diff --git a/library/core/src/ptr/mut_ptr.rs b/library/core/src/ptr/mut_ptr.rs
index e29774963db..df49eedb350 100644
--- a/library/core/src/ptr/mut_ptr.rs
+++ b/library/core/src/ptr/mut_ptr.rs
@@ -2156,3 +2156,11 @@ impl<T: ?Sized> PartialOrd for *mut T {
         *self >= *other
     }
 }
+
+#[stable(feature = "raw_ptr_default", since = "CURRENT_RUSTC_VERSION")]
+impl<T: ?Sized + Thin> Default for *mut T {
+    /// Returns the default value of [`null_mut()`][crate::ptr::null_mut].
+    fn default() -> Self {
+        crate::ptr::null_mut()
+    }
+}
diff --git a/library/coretests/tests/iter/adapters/enumerate.rs b/library/coretests/tests/iter/adapters/enumerate.rs
index b57d51c077e..2294f856b58 100644
--- a/library/coretests/tests/iter/adapters/enumerate.rs
+++ b/library/coretests/tests/iter/adapters/enumerate.rs
@@ -120,3 +120,13 @@ fn test_double_ended_enumerate() {
     assert_eq!(it.next_back(), Some((2, 3)));
     assert_eq!(it.next(), None);
 }
+
+#[test]
+fn test_empty_iterator_enumerate_next_index() {
+    let mut it = empty::<i32>().enumerate();
+    assert_eq!(it.next_index(), 0);
+    assert_eq!(it.next_index(), 0);
+    assert_eq!(it.next(), None);
+    assert_eq!(it.next_index(), 0);
+    assert_eq!(it.next_index(), 0);
+}
diff --git a/library/coretests/tests/lib.rs b/library/coretests/tests/lib.rs
index 1c43bfe0ed4..ac111575938 100644
--- a/library/coretests/tests/lib.rs
+++ b/library/coretests/tests/lib.rs
@@ -63,6 +63,7 @@
 #![feature(maybe_uninit_write_slice)]
 #![feature(min_specialization)]
 #![feature(never_type)]
+#![feature(next_index)]
 #![feature(numfmt)]
 #![feature(pattern)]
 #![feature(pointer_is_aligned_to)]
diff --git a/library/coretests/tests/pin_macro.rs b/library/coretests/tests/pin_macro.rs
index bfbfa8d280f..3174c91a649 100644
--- a/library/coretests/tests/pin_macro.rs
+++ b/library/coretests/tests/pin_macro.rs
@@ -38,6 +38,7 @@ fn rust_2024_expr() {
 }
 
 #[test]
+#[cfg(not(bootstrap))]
 fn temp_lifetime() {
     // Check that temporary lifetimes work as in Rust 2021.
     // Regression test for https://github.com/rust-lang/rust/issues/138596
diff --git a/library/coretests/tests/ptr.rs b/library/coretests/tests/ptr.rs
index cc5f7946863..7d6e4eac1e2 100644
--- a/library/coretests/tests/ptr.rs
+++ b/library/coretests/tests/ptr.rs
@@ -1020,3 +1020,20 @@ fn test_ptr_swap_nonoverlapping_is_untyped() {
     ptr_swap_nonoverlapping_is_untyped_inner();
     const { ptr_swap_nonoverlapping_is_untyped_inner() };
 }
+
+#[test]
+fn test_ptr_default() {
+    #[derive(Default)]
+    struct PtrDefaultTest {
+        ptr: *const u64,
+    }
+    let default = PtrDefaultTest::default();
+    assert!(default.ptr.is_null());
+
+    #[derive(Default)]
+    struct PtrMutDefaultTest {
+        ptr: *mut u64,
+    }
+    let default = PtrMutDefaultTest::default();
+    assert!(default.ptr.is_null());
+}
diff --git a/library/std/src/sys/fs/unix.rs b/library/std/src/sys/fs/unix.rs
index 687fc322e59..bc8817bac70 100644
--- a/library/std/src/sys/fs/unix.rs
+++ b/library/std/src/sys/fs/unix.rs
@@ -12,10 +12,11 @@ use libc::c_char;
     all(target_os = "linux", not(target_env = "musl")),
     target_os = "android",
     target_os = "fuchsia",
-    target_os = "hurd"
+    target_os = "hurd",
+    target_os = "illumos",
 ))]
 use libc::dirfd;
-#[cfg(target_os = "fuchsia")]
+#[cfg(any(target_os = "fuchsia", target_os = "illumos"))]
 use libc::fstatat as fstatat64;
 #[cfg(any(all(target_os = "linux", not(target_env = "musl")), target_os = "hurd"))]
 use libc::fstatat64;
@@ -892,7 +893,8 @@ impl DirEntry {
             all(target_os = "linux", not(target_env = "musl")),
             target_os = "android",
             target_os = "fuchsia",
-            target_os = "hurd"
+            target_os = "hurd",
+            target_os = "illumos",
         ),
         not(miri) // no dirfd on Miri
     ))]
@@ -922,6 +924,7 @@ impl DirEntry {
             target_os = "android",
             target_os = "fuchsia",
             target_os = "hurd",
+            target_os = "illumos",
         )),
         miri
     ))]
diff --git a/src/bootstrap/src/core/build_steps/compile.rs b/src/bootstrap/src/core/build_steps/compile.rs
index 6a5b38dd504..68fa42ee9e6 100644
--- a/src/bootstrap/src/core/build_steps/compile.rs
+++ b/src/bootstrap/src/core/build_steps/compile.rs
@@ -1194,8 +1194,7 @@ pub fn rustc_cargo(
         let enzyme_dir = builder.build.out.join(arch).join("enzyme").join("lib");
         cargo.rustflag("-L").rustflag(enzyme_dir.to_str().expect("Invalid path"));
 
-        if !builder.config.dry_run() {
-            let llvm_config = builder.llvm_config(builder.config.build).unwrap();
+        if let Some(llvm_config) = builder.llvm_config(builder.config.build) {
             let llvm_version_major = llvm::get_llvm_version_major(builder, &llvm_config);
             cargo.rustflag("-l").rustflag(&format!("Enzyme-{llvm_version_major}"));
         }
diff --git a/src/bootstrap/src/core/build_steps/setup.rs b/src/bootstrap/src/core/build_steps/setup.rs
index 80d92135dd3..83083e12ef1 100644
--- a/src/bootstrap/src/core/build_steps/setup.rs
+++ b/src/bootstrap/src/core/build_steps/setup.rs
@@ -584,6 +584,7 @@ Select which editor you would like to set up [default: None]: ";
                 "51068d4747a13732440d1a8b8f432603badb1864fa431d83d0fd4f8fa57039e0",
                 "d29af4d949bbe2371eac928a3c31cf9496b1701aa1c45f11cd6c759865ad5c45",
                 "b5dd299b93dca3ceeb9b335f929293cb3d4bf4977866fbe7ceeac2a8a9f99088",
+                "631c837b0e98ae35fd48b0e5f743b1ca60adadf2d0a2b23566ba25df372cf1a9",
             ],
             EditorKind::Helix => &[
                 "2d3069b8cf1b977e5d4023965eb6199597755e6c96c185ed5f2854f98b83d233",
@@ -602,10 +603,12 @@ Select which editor you would like to set up [default: None]: ";
                 "4eecb58a2168b252077369da446c30ed0e658301efe69691979d1ef0443928f4",
                 "c394386e6133bbf29ffd32c8af0bb3d4aac354cba9ee051f29612aa9350f8f8d",
                 "e53e9129ca5ee5dcbd6ec8b68c2d87376474eb154992deba3c6d9ab1703e0717",
+                "f954316090936c7e590c253ca9d524008375882fa13c5b41d7e2547a896ff893",
             ],
             EditorKind::Zed => &[
                 "bbce727c269d1bd0c98afef4d612eb4ce27aea3c3a8968c5f10b31affbc40b6c",
                 "a5380cf5dd9328731aecc5dfb240d16dac46ed272126b9728006151ef42f5909",
+                "2e96bf0d443852b12f016c8fc9840ab3d0a2b4fe0b0fb3a157e8d74d5e7e0e26",
             ],
         }
     }
diff --git a/src/etc/natvis/libcore.natvis b/src/etc/natvis/libcore.natvis
index 8a441cf2093..8fe87a99989 100644
--- a/src/etc/natvis/libcore.natvis
+++ b/src/etc/natvis/libcore.natvis
@@ -69,9 +69,9 @@
   </Type>
 
   <Type Name="core::pin::Pin&lt;*&gt;">
-    <DisplayString>Pin({(void*)__pointer}: {__pointer})</DisplayString>
+    <DisplayString>Pin({(void*)pointer}: {pointer})</DisplayString>
     <Expand>
-      <ExpandedItem>__pointer</ExpandedItem>
+      <ExpandedItem>pointer</ExpandedItem>
     </Expand>
   </Type>
 
diff --git a/src/etc/rust_analyzer_eglot.el b/src/etc/rust_analyzer_eglot.el
index 6b40371d9af..90bd38aa894 100644
--- a/src/etc/rust_analyzer_eglot.el
+++ b/src/etc/rust_analyzer_eglot.el
@@ -8,10 +8,11 @@
                                                          "check"
                                                          "--json-output"])
                  :linkedProjects ["Cargo.toml"
-                                  "src/bootstrap/Cargo.toml"
-                                  "src/tools/rust-analyzer/Cargo.toml"
                                   "compiler/rustc_codegen_cranelift/Cargo.toml"
-                                  "compiler/rustc_codegen_gcc/Cargo.toml"]
+                                  "compiler/rustc_codegen_gcc/Cargo.toml"
+                                  "library/Cargo.toml"
+                                  "src/bootstrap/Cargo.toml"
+                                  "src/tools/rust-analyzer/Cargo.toml"]
                  :rustfmt ( :overrideCommand ["build/host/rustfmt/bin/rustfmt"
                                               "--edition=2021"])
                  :procMacro ( :server "build/host/stage0/libexec/rust-analyzer-proc-macro-srv"
diff --git a/src/etc/rust_analyzer_settings.json b/src/etc/rust_analyzer_settings.json
index da7d326a512..5ce886a9b65 100644
--- a/src/etc/rust_analyzer_settings.json
+++ b/src/etc/rust_analyzer_settings.json
@@ -9,11 +9,11 @@
     ],
     "rust-analyzer.linkedProjects": [
         "Cargo.toml",
+        "compiler/rustc_codegen_cranelift/Cargo.toml",
+        "compiler/rustc_codegen_gcc/Cargo.toml",
         "library/Cargo.toml",
         "src/bootstrap/Cargo.toml",
-        "src/tools/rust-analyzer/Cargo.toml",
-        "compiler/rustc_codegen_cranelift/Cargo.toml",
-        "compiler/rustc_codegen_gcc/Cargo.toml"
+        "src/tools/rust-analyzer/Cargo.toml"
     ],
     "rust-analyzer.rustfmt.overrideCommand": [
         "${workspaceFolder}/build/host/rustfmt/bin/rustfmt",
@@ -36,5 +36,10 @@
     },
     "rust-analyzer.server.extraEnv": {
         "RUSTUP_TOOLCHAIN": "nightly"
+    },
+    "files.associations": {
+        "*.fixed": "rust",
+        "*.pp": "rust",
+        "*.mir": "rust"
     }
 }
diff --git a/src/etc/rust_analyzer_zed.json b/src/etc/rust_analyzer_zed.json
index abc6ddbc213..3461ff887d9 100644
--- a/src/etc/rust_analyzer_zed.json
+++ b/src/etc/rust_analyzer_zed.json
@@ -21,15 +21,15 @@
         },
         "linkedProjects": [
           "Cargo.toml",
+          "compiler/rustc_codegen_cranelift/Cargo.toml",
+          "compiler/rustc_codegen_gcc/Cargo.toml",
           "library/Cargo.toml",
           "src/bootstrap/Cargo.toml",
-          "src/tools/rust-analyzer/Cargo.toml",
-          "compiler/rustc_codegen_cranelift/Cargo.toml",
-          "compiler/rustc_codegen_gcc/Cargo.toml"
+          "src/tools/rust-analyzer/Cargo.toml"
         ],
         "procMacro": {
-            "enable": true,
-            "server": "${workspaceFolder}/build/host/stage0/libexec/rust-analyzer-proc-macro-srv"
+          "enable": true,
+          "server": "${workspaceFolder}/build/host/stage0/libexec/rust-analyzer-proc-macro-srv"
         },
         "rustc": {
           "source": "./Cargo.toml"
@@ -47,5 +47,8 @@
         }
       }
     }
+  },
+  "file_types": {
+    "Rust": ["fixed", "pp", "mir"]
   }
 }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 034ecb2f6c1..6ecb67c776c 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2773,10 +2773,35 @@ fn clean_maybe_renamed_item<'tcx>(
 ) -> Vec<Item> {
     use hir::ItemKind;
 
-    let def_id = item.owner_id.to_def_id();
-    let mut name = if renamed.is_some() { renamed } else { cx.tcx.hir_opt_name(item.hir_id()) };
+    fn get_name(
+        cx: &DocContext<'_>,
+        item: &hir::Item<'_>,
+        renamed: Option<Symbol>,
+    ) -> Option<Symbol> {
+        renamed.or_else(|| cx.tcx.hir_opt_name(item.hir_id()))
+    }
 
+    let def_id = item.owner_id.to_def_id();
     cx.with_param_env(def_id, |cx| {
+        // These kinds of item either don't need a `name` or accept a `None` one so we handle them
+        // before.
+        match item.kind {
+            ItemKind::Impl(impl_) => return clean_impl(impl_, item.owner_id.def_id, cx),
+            ItemKind::Use(path, kind) => {
+                return clean_use_statement(
+                    item,
+                    get_name(cx, item, renamed),
+                    path,
+                    kind,
+                    cx,
+                    &mut FxHashSet::default(),
+                );
+            }
+            _ => {}
+        }
+
+        let mut name = get_name(cx, item, renamed).unwrap();
+
         let kind = match item.kind {
             ItemKind::Static(_, ty, mutability, body_id) => StaticItem(Static {
                 type_: Box::new(clean_ty(ty, cx)),
@@ -2815,7 +2840,7 @@ fn clean_maybe_renamed_item<'tcx>(
                         item_type: Some(type_),
                     })),
                     item.owner_id.def_id.to_def_id(),
-                    name.unwrap(),
+                    name,
                     import_id,
                     renamed,
                 ));
@@ -2838,17 +2863,14 @@ fn clean_maybe_renamed_item<'tcx>(
                 generics: clean_generics(generics, cx),
                 fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(),
             }),
-            ItemKind::Impl(impl_) => return clean_impl(impl_, item.owner_id.def_id, cx),
             ItemKind::Macro(_, macro_def, MacroKind::Bang) => MacroItem(Macro {
-                source: display_macro_source(cx, name.unwrap(), macro_def),
+                source: display_macro_source(cx, name, macro_def),
                 macro_rules: macro_def.macro_rules,
             }),
-            ItemKind::Macro(_, _, macro_kind) => {
-                clean_proc_macro(item, name.as_mut().unwrap(), macro_kind, cx)
-            }
+            ItemKind::Macro(_, _, macro_kind) => clean_proc_macro(item, &mut name, macro_kind, cx),
             // proc macros can have a name set by attributes
             ItemKind::Fn { ref sig, generics, body: body_id, .. } => {
-                clean_fn_or_proc_macro(item, sig, generics, body_id, name.as_mut().unwrap(), cx)
+                clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
             }
             ItemKind::Trait(_, _, _, generics, bounds, item_ids) => {
                 let items = item_ids
@@ -2864,10 +2886,7 @@ fn clean_maybe_renamed_item<'tcx>(
                 }))
             }
             ItemKind::ExternCrate(orig_name, _) => {
-                return clean_extern_crate(item, name.unwrap(), orig_name, cx);
-            }
-            ItemKind::Use(path, kind) => {
-                return clean_use_statement(item, name, path, kind, cx, &mut FxHashSet::default());
+                return clean_extern_crate(item, name, orig_name, cx);
             }
             _ => span_bug!(item.span, "not yet converted"),
         };
@@ -2876,7 +2895,7 @@ fn clean_maybe_renamed_item<'tcx>(
             cx,
             kind,
             item.owner_id.def_id.to_def_id(),
-            name.unwrap(),
+            name,
             import_id,
             renamed,
         )]
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index dab23f8e42a..f446c9fbbd8 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -84,8 +84,8 @@ impl JsonRenderer<'_> {
                     let lo = span.lo(self.sess());
                     Some(Span {
                         filename: local_path,
-                        begin: (lo.line, lo.col.to_usize()),
-                        end: (hi.line, hi.col.to_usize()),
+                        begin: (lo.line, lo.col.to_usize() + 1),
+                        end: (hi.line, hi.col.to_usize() + 1),
                     })
                 } else {
                     None
diff --git a/src/rustdoc-json-types/lib.rs b/src/rustdoc-json-types/lib.rs
index 7247950545a..64223b5b758 100644
--- a/src/rustdoc-json-types/lib.rs
+++ b/src/rustdoc-json-types/lib.rs
@@ -30,7 +30,7 @@ pub type FxHashMap<K, V> = HashMap<K, V>; // re-export for use in src/librustdoc
 /// This integer is incremented with every breaking change to the API,
 /// and is returned along with the JSON blob as [`Crate::format_version`].
 /// Consuming code should assert that this value matches the format version(s) that it supports.
-pub const FORMAT_VERSION: u32 = 44;
+pub const FORMAT_VERSION: u32 = 45;
 
 /// The root of the emitted JSON blob.
 ///
@@ -205,9 +205,9 @@ pub struct Item {
 pub struct Span {
     /// The path to the source file for this span relative to the path `rustdoc` was invoked with.
     pub filename: PathBuf,
-    /// Zero indexed Line and Column of the first character of the `Span`
+    /// One indexed Line and Column of the first character of the `Span`.
     pub begin: (usize, usize),
-    /// Zero indexed Line and Column of the last character of the `Span`
+    /// One indexed Line and Column of the last character of the `Span`.
     pub end: (usize, usize),
 }
 
diff --git a/src/tools/miri/src/lib.rs b/src/tools/miri/src/lib.rs
index 5921ba86639..b6b2684dc6d 100644
--- a/src/tools/miri/src/lib.rs
+++ b/src/tools/miri/src/lib.rs
@@ -169,7 +169,7 @@ pub const MIRI_DEFAULT_ARGS: &[&str] = &[
     "-Zalways-encode-mir",
     "-Zextra-const-ub-checks",
     "-Zmir-emit-retag",
-    "-Zmir-keep-place-mention",
+    "-Zmir-preserve-ub",
     "-Zmir-opt-level=0",
     "-Zmir-enable-passes=-CheckAlignment,-CheckNull",
     // Deduplicating diagnostics means we miss events when tracking what happens during an
diff --git a/src/tools/miri/tests/fail/read_from_trivial_switch.rs b/src/tools/miri/tests/fail/read_from_trivial_switch.rs
new file mode 100644
index 00000000000..d34b1cd5820
--- /dev/null
+++ b/src/tools/miri/tests/fail/read_from_trivial_switch.rs
@@ -0,0 +1,14 @@
+// Ensure that we don't optimize out `SwitchInt` reads even if that terminator
+// branches to the same basic block on every target, since the operand may have
+// side-effects that affect analysis of the MIR.
+//
+// See <https://github.com/rust-lang/miri/issues/4237>.
+
+use std::mem::MaybeUninit;
+
+fn main() {
+    let uninit: MaybeUninit<i32> = MaybeUninit::uninit();
+    let bad_ref: &i32 = unsafe { uninit.assume_init_ref() };
+    let &(0 | _) = bad_ref;
+    //~^ ERROR: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+}
diff --git a/src/tools/miri/tests/fail/read_from_trivial_switch.stderr b/src/tools/miri/tests/fail/read_from_trivial_switch.stderr
new file mode 100644
index 00000000000..6b3d4539b96
--- /dev/null
+++ b/src/tools/miri/tests/fail/read_from_trivial_switch.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+  --> tests/fail/read_from_trivial_switch.rs:LL:CC
+   |
+LL |     let &(0 | _) = bad_ref;
+   |         ^^^^^^^^ using uninitialized data, but this operation requires initialized memory
+   |
+   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
+   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
+   = note: BACKTRACE:
+   = note: inside `main` at tests/fail/read_from_trivial_switch.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+
diff --git a/src/tools/nix-dev-shell/flake.nix b/src/tools/nix-dev-shell/flake.nix
index 1b838bd2f7b..b8287de5fcf 100644
--- a/src/tools/nix-dev-shell/flake.nix
+++ b/src/tools/nix-dev-shell/flake.nix
@@ -1,32 +1,24 @@
 {
   description = "rustc dev shell";
 
-  inputs = {
-    nixpkgs.url      = "github:NixOS/nixpkgs/nixos-unstable";
-    flake-utils.url  = "github:numtide/flake-utils";
-  };
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
 
-  outputs = { self, nixpkgs, flake-utils, ... }:
-	flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        x = import ./x { inherit pkgs; };
-      in
-      {
-        devShells.default = with pkgs; mkShell {
-          name = "rustc-dev-shell";
-          nativeBuildInputs = with pkgs; [
-            binutils cmake ninja pkg-config python3 git curl cacert patchelf nix
-          ];
-          buildInputs = with pkgs; [
-            openssl glibc.out glibc.static x
-          ];
-          # Avoid creating text files for ICEs.
-          RUSTC_ICE = "0";
-          # Provide `libstdc++.so.6` for the self-contained lld.
-          # Provide `libz.so.1`.
-          LD_LIBRARY_PATH = "${with pkgs; lib.makeLibraryPath [stdenv.cc.cc.lib zlib]}";
-        };
-      }
-    );
+  outputs =
+    {
+      self,
+      nixpkgs,
+    }:
+    let
+      inherit (nixpkgs) lib;
+      forEachSystem = lib.genAttrs lib.systems.flakeExposed;
+    in
+    {
+      devShells = forEachSystem (system: {
+        default = nixpkgs.legacyPackages.${system}.callPackage ./shell.nix { };
+      });
+
+      packages = forEachSystem (system: {
+        default = nixpkgs.legacyPackages.${system}.callPackage ./x { };
+      });
+    };
 }
diff --git a/src/tools/nix-dev-shell/shell.nix b/src/tools/nix-dev-shell/shell.nix
index a3f5969bd81..0adbacf7e8d 100644
--- a/src/tools/nix-dev-shell/shell.nix
+++ b/src/tools/nix-dev-shell/shell.nix
@@ -1,18 +1,26 @@
-{ pkgs ? import <nixpkgs> {} }:
-let 
-  x = import ./x { inherit pkgs; };
+{
+  pkgs ? import <nixpkgs> { },
+}:
+let
+  inherit (pkgs.lib) lists attrsets;
+
+  x = pkgs.callPackage ./x { };
+  inherit (x.passthru) cacert env;
 in
 pkgs.mkShell {
-  name = "rustc";
-  nativeBuildInputs = with pkgs; [
-    binutils cmake ninja pkg-config python3 git curl cacert patchelf nix
-  ];
-  buildInputs = with pkgs; [
-    openssl glibc.out glibc.static x
-  ];
-  # Avoid creating text files for ICEs.
-  RUSTC_ICE = "0";
-  # Provide `libstdc++.so.6` for the self-contained lld.
-  # Provide `libz.so.1`
-  LD_LIBRARY_PATH = "${with pkgs; lib.makeLibraryPath [stdenv.cc.cc.lib zlib]}";
+  name = "rustc-shell";
+
+  inputsFrom = [ x ];
+  packages = [
+    pkgs.git
+    pkgs.nix
+    x
+    # Get the runtime deps of the x wrapper
+  ] ++ lists.flatten (attrsets.attrValues env);
+
+  env = {
+    # Avoid creating text files for ICEs.
+    RUSTC_ICE = 0;
+    SSL_CERT_FILE = cacert;
+  };
 }
diff --git a/src/tools/nix-dev-shell/x/default.nix b/src/tools/nix-dev-shell/x/default.nix
index e6dfbad6f19..422c1c4a2ae 100644
--- a/src/tools/nix-dev-shell/x/default.nix
+++ b/src/tools/nix-dev-shell/x/default.nix
@@ -1,22 +1,83 @@
 {
-  pkgs ? import <nixpkgs> { },
+  pkgs,
+  lib,
+  stdenv,
+  rustc,
+  python3,
+  makeBinaryWrapper,
+  # Bootstrap
+  curl,
+  pkg-config,
+  libiconv,
+  openssl,
+  patchelf,
+  cacert,
+  zlib,
+  # LLVM Deps
+  ninja,
+  cmake,
+  glibc,
 }:
-pkgs.stdenv.mkDerivation {
-  name = "x";
+stdenv.mkDerivation (self: {
+  strictDeps = true;
+  name = "x-none";
+
+  outputs = [
+    "out"
+    "unwrapped"
+  ];
 
   src = ./x.rs;
   dontUnpack = true;
 
-  nativeBuildInputs = with pkgs; [ rustc ];
+  nativeBuildInputs = [
+    rustc
+    makeBinaryWrapper
+  ];
 
+  env.PYTHON = python3.interpreter;
   buildPhase = ''
-    PYTHON=${pkgs.lib.getExe pkgs.python3} rustc -Copt-level=3 --crate-name x $src --out-dir $out/bin
+    rustc -Copt-level=3 --crate-name x $src --out-dir $unwrapped/bin
   '';
 
-  meta = with pkgs.lib; {
+  installPhase =
+    let
+      inherit (self.passthru) cacert env;
+    in
+    ''
+      makeWrapper $unwrapped/bin/x $out/bin/x \
+        --set-default SSL_CERT_FILE ${cacert} \
+        --prefix CPATH ";" "${lib.makeSearchPath "include" env.cpath}" \
+        --prefix PATH : ${lib.makeBinPath env.path} \
+        --prefix LD_LIBRARY_PATH : ${lib.makeLibraryPath env.ldLib}
+    '';
+
+  # For accessing them in the devshell
+  passthru = {
+    env = {
+      cpath = [ libiconv ];
+      path = [
+        python3
+        patchelf
+        curl
+        pkg-config
+        cmake
+        ninja
+        stdenv.cc
+      ];
+      ldLib = [
+        openssl
+        zlib
+        stdenv.cc.cc.lib
+      ];
+    };
+    cacert = "${cacert}/etc/ssl/certs/ca-bundle.crt";
+  };
+
+  meta = {
     description = "Helper for rust-lang/rust x.py";
     homepage = "https://github.com/rust-lang/rust/blob/master/src/tools/x";
-    license = licenses.mit;
+    license = lib.licenses.mit;
     mainProgram = "x";
   };
-}
+})
diff --git a/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir b/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir
index d52241b459e..2a965fe67b9 100644
--- a/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir
+++ b/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir
@@ -24,43 +24,47 @@ fn match_tuple(_1: (u32, bool, Option<i32>, u32)) -> u32 {
 
     bb1: {
         _0 = const 0_u32;
-        goto -> bb10;
+        goto -> bb11;
     }
 
     bb2: {
-        _2 = discriminant((_1.2: std::option::Option<i32>));
-        switchInt(move _2) -> [0: bb4, 1: bb3, otherwise: bb1];
+        switchInt(copy (_1.1: bool)) -> [0: bb3, otherwise: bb3];
     }
 
     bb3: {
-        switchInt(copy (((_1.2: std::option::Option<i32>) as Some).0: i32)) -> [1: bb4, 8: bb4, otherwise: bb1];
+        _2 = discriminant((_1.2: std::option::Option<i32>));
+        switchInt(move _2) -> [0: bb5, 1: bb4, otherwise: bb1];
     }
 
     bb4: {
-        _5 = Le(const 6_u32, copy (_1.3: u32));
-        switchInt(move _5) -> [0: bb5, otherwise: bb7];
+        switchInt(copy (((_1.2: std::option::Option<i32>) as Some).0: i32)) -> [1: bb5, 8: bb5, otherwise: bb1];
     }
 
     bb5: {
-        _3 = Le(const 13_u32, copy (_1.3: u32));
-        switchInt(move _3) -> [0: bb1, otherwise: bb6];
+        _5 = Le(const 6_u32, copy (_1.3: u32));
+        switchInt(move _5) -> [0: bb6, otherwise: bb8];
     }
 
     bb6: {
-        _4 = Le(copy (_1.3: u32), const 16_u32);
-        switchInt(move _4) -> [0: bb1, otherwise: bb8];
+        _3 = Le(const 13_u32, copy (_1.3: u32));
+        switchInt(move _3) -> [0: bb1, otherwise: bb7];
     }
 
     bb7: {
-        _6 = Le(copy (_1.3: u32), const 9_u32);
-        switchInt(move _6) -> [0: bb5, otherwise: bb8];
+        _4 = Le(copy (_1.3: u32), const 16_u32);
+        switchInt(move _4) -> [0: bb1, otherwise: bb9];
     }
 
     bb8: {
-        falseEdge -> [real: bb9, imaginary: bb1];
+        _6 = Le(copy (_1.3: u32), const 9_u32);
+        switchInt(move _6) -> [0: bb6, otherwise: bb9];
     }
 
     bb9: {
+        falseEdge -> [real: bb10, imaginary: bb1];
+    }
+
+    bb10: {
         StorageLive(_7);
         _7 = copy (_1.0: u32);
         StorageLive(_8);
@@ -74,10 +78,10 @@ fn match_tuple(_1: (u32, bool, Option<i32>, u32)) -> u32 {
         StorageDead(_9);
         StorageDead(_8);
         StorageDead(_7);
-        goto -> bb10;
+        goto -> bb11;
     }
 
-    bb10: {
+    bb11: {
         return;
     }
 }
diff --git a/tests/mir-opt/dead-store-elimination/place_mention.rs b/tests/mir-opt/dead-store-elimination/place_mention.rs
index 5e4a286a208..1848a028297 100644
--- a/tests/mir-opt/dead-store-elimination/place_mention.rs
+++ b/tests/mir-opt/dead-store-elimination/place_mention.rs
@@ -2,7 +2,7 @@
 // and don't remove it as a dead store.
 //
 //@ test-mir-pass: DeadStoreElimination-initial
-//@ compile-flags: -Zmir-keep-place-mention
+//@ compile-flags: -Zmir-preserve-ub
 
 // EMIT_MIR place_mention.main.DeadStoreElimination-initial.diff
 fn main() {
diff --git a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff
index 56d4d50e967..151580da19e 100644
--- a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff
+++ b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-abort.diff
@@ -33,7 +33,7 @@
 -         _4 = g() -> [return: bb1, unwind unreachable];
 +         _4 = {coroutine@$DIR/inline_coroutine.rs:20:5: 20:8 (#0)};
 +         _3 = &mut _4;
-+         _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:20:5: 20:8}> { __pointer: copy _3 };
++         _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:20:5: 20:8}> { pointer: copy _3 };
 +         StorageDead(_3);
 +         StorageLive(_5);
 +         _5 = const false;
diff --git a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff
index 751916a00f1..6196fc0d0c6 100644
--- a/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff
+++ b/tests/mir-opt/inline/inline_coroutine.main.Inline.panic-unwind.diff
@@ -33,7 +33,7 @@
 -         _4 = g() -> [return: bb1, unwind continue];
 +         _4 = {coroutine@$DIR/inline_coroutine.rs:20:5: 20:8 (#0)};
 +         _3 = &mut _4;
-+         _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:20:5: 20:8}> { __pointer: copy _3 };
++         _2 = Pin::<&mut {coroutine@$DIR/inline_coroutine.rs:20:5: 20:8}> { pointer: copy _3 };
 +         StorageDead(_3);
 +         StorageLive(_5);
 +         _5 = const false;
diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff
index e49d7cea28e..1e9a6dd4f5c 100644
--- a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff
+++ b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff
@@ -121,7 +121,7 @@
 -     }
 - 
 -     bb2: {
-+         _4 = Pin::<&mut {async fn body of ActionPermit<'_, T>::perform()}> { __pointer: copy _5 };
++         _4 = Pin::<&mut {async fn body of ActionPermit<'_, T>::perform()}> { pointer: copy _5 };
           StorageDead(_5);
           StorageLive(_6);
           StorageLive(_7);
@@ -218,7 +218,7 @@
 +         _37 = deref_copy (_8.0: &mut {async fn body of ActionPermit<'_, T>::perform()});
 +         _21 = &mut (((*_37) as variant#3).1: std::future::Ready<()>);
 +         _20 = &mut (*_21);
-+         _19 = Pin::<&mut std::future::Ready<()>> { __pointer: copy _20 };
++         _19 = Pin::<&mut std::future::Ready<()>> { pointer: copy _20 };
 +         StorageDead(_20);
 +         StorageLive(_22);
 +         StorageLive(_23);
@@ -239,7 +239,7 @@
 +         _48 = &mut (_19.0: &mut std::future::Ready<()>);
 +         _45 = copy (_19.0: &mut std::future::Ready<()>);
 +         StorageDead(_48);
-+         _47 = Pin::<&mut std::future::Ready<()>> { __pointer: copy _45 };
++         _47 = Pin::<&mut std::future::Ready<()>> { pointer: copy _45 };
 +         StorageDead(_47);
 +         _44 = &mut ((*_45).0: std::option::Option<()>);
 +         StorageLive(_49);
diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff
index e7aed556f2d..94b89a310ba 100644
--- a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff
+++ b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff
@@ -123,7 +123,7 @@
 -     }
 - 
 -     bb2: {
-+         _4 = Pin::<&mut {async fn body of ActionPermit<'_, T>::perform()}> { __pointer: copy _5 };
++         _4 = Pin::<&mut {async fn body of ActionPermit<'_, T>::perform()}> { pointer: copy _5 };
           StorageDead(_5);
           StorageLive(_6);
           StorageLive(_7);
@@ -235,7 +235,7 @@
 +         _37 = deref_copy (_8.0: &mut {async fn body of ActionPermit<'_, T>::perform()});
 +         _21 = &mut (((*_37) as variant#3).1: std::future::Ready<()>);
 +         _20 = &mut (*_21);
-+         _19 = Pin::<&mut std::future::Ready<()>> { __pointer: copy _20 };
++         _19 = Pin::<&mut std::future::Ready<()>> { pointer: copy _20 };
 +         StorageDead(_20);
 +         StorageLive(_22);
 +         StorageLive(_23);
@@ -256,7 +256,7 @@
 +         _50 = &mut (_19.0: &mut std::future::Ready<()>);
 +         _47 = copy (_19.0: &mut std::future::Ready<()>);
 +         StorageDead(_50);
-+         _49 = Pin::<&mut std::future::Ready<()>> { __pointer: copy _47 };
++         _49 = Pin::<&mut std::future::Ready<()>> { pointer: copy _47 };
 +         StorageDead(_49);
 +         _46 = &mut ((*_47).0: std::option::Option<()>);
 +         StorageLive(_51);
diff --git a/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir b/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir
index 889ff6f9f5e..be0931eaa61 100644
--- a/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir
+++ b/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir
@@ -14,7 +14,7 @@ fn single_switchint() -> () {
     }
 
     bb1: {
-        switchInt(copy (_2.0: i32)) -> [3: bb8, 4: bb8, otherwise: bb7];
+        switchInt(copy (_2.0: i32)) -> [3: bb9, 4: bb9, otherwise: bb8];
     }
 
     bb2: {
@@ -22,7 +22,7 @@ fn single_switchint() -> () {
     }
 
     bb3: {
-        falseEdge -> [real: bb12, imaginary: bb4];
+        falseEdge -> [real: bb14, imaginary: bb4];
     }
 
     bb4: {
@@ -30,43 +30,51 @@ fn single_switchint() -> () {
     }
 
     bb5: {
-        falseEdge -> [real: bb11, imaginary: bb6];
+        falseEdge -> [real: bb13, imaginary: bb6];
     }
 
     bb6: {
-        falseEdge -> [real: bb10, imaginary: bb1];
+        switchInt(copy (_2.1: bool)) -> [0: bb7, otherwise: bb7];
     }
 
     bb7: {
-        _1 = const 5_i32;
-        goto -> bb13;
+        falseEdge -> [real: bb12, imaginary: bb1];
     }
 
     bb8: {
-        falseEdge -> [real: bb9, imaginary: bb7];
+        _1 = const 5_i32;
+        goto -> bb15;
     }
 
     bb9: {
-        _1 = const 4_i32;
-        goto -> bb13;
+        switchInt(copy (_2.1: bool)) -> [0: bb10, otherwise: bb10];
     }
 
     bb10: {
-        _1 = const 3_i32;
-        goto -> bb13;
+        falseEdge -> [real: bb11, imaginary: bb8];
     }
 
     bb11: {
-        _1 = const 2_i32;
-        goto -> bb13;
+        _1 = const 4_i32;
+        goto -> bb15;
     }
 
     bb12: {
-        _1 = const 1_i32;
-        goto -> bb13;
+        _1 = const 3_i32;
+        goto -> bb15;
     }
 
     bb13: {
+        _1 = const 2_i32;
+        goto -> bb15;
+    }
+
+    bb14: {
+        _1 = const 1_i32;
+        goto -> bb15;
+    }
+
+    bb15: {
         StorageDead(_2);
         StorageDead(_1);
         _0 = const ();
diff --git a/tests/mir-opt/read_from_trivial_switch.main.SimplifyCfg-initial.diff b/tests/mir-opt/read_from_trivial_switch.main.SimplifyCfg-initial.diff
new file mode 100644
index 00000000000..87758408a1c
--- /dev/null
+++ b/tests/mir-opt/read_from_trivial_switch.main.SimplifyCfg-initial.diff
@@ -0,0 +1,49 @@
+- // MIR for `main` before SimplifyCfg-initial
++ // MIR for `main` after SimplifyCfg-initial
+  
+  fn main() -> () {
+      let mut _0: ();
+      let _1: &i32;
+      let _2: i32;
+      scope 1 {
+          debug ref_ => _1;
+          scope 2 {
+          }
+      }
+  
+      bb0: {
+          StorageLive(_1);
+          StorageLive(_2);
+          _2 = const 1_i32;
+          _1 = &_2;
+          FakeRead(ForLet(None), _1);
+          PlaceMention(_1);
+-         switchInt(copy (*_1)) -> [0: bb2, otherwise: bb1];
++         switchInt(copy (*_1)) -> [0: bb1, otherwise: bb1];
+      }
+  
+      bb1: {
+-         goto -> bb5;
+-     }
+- 
+-     bb2: {
+-         goto -> bb5;
+-     }
+- 
+-     bb3: {
+-         goto -> bb1;
+-     }
+- 
+-     bb4: {
+-         FakeRead(ForMatchedPlace(None), _1);
+-         unreachable;
+-     }
+- 
+-     bb5: {
+          _0 = const ();
+          StorageDead(_2);
+          StorageDead(_1);
+          return;
+      }
+  }
+  
diff --git a/tests/mir-opt/read_from_trivial_switch.rs b/tests/mir-opt/read_from_trivial_switch.rs
new file mode 100644
index 00000000000..1c64c1d45e8
--- /dev/null
+++ b/tests/mir-opt/read_from_trivial_switch.rs
@@ -0,0 +1,15 @@
+// Ensure that we don't optimize out `SwitchInt` reads even if that terminator
+// branches to the same basic block on every target, since the operand may have
+// side-effects that affect analysis of the MIR.
+//
+// See <https://github.com/rust-lang/miri/issues/4237>.
+
+//@ test-mir-pass: SimplifyCfg-initial
+//@ compile-flags: -Zmir-preserve-ub
+
+// EMIT_MIR read_from_trivial_switch.main.SimplifyCfg-initial.diff
+fn main() {
+    let ref_ = &1i32;
+    // CHECK: switchInt
+    let &(0 | _) = ref_;
+}
diff --git a/tests/pretty/postfix-yield.rs b/tests/pretty/postfix-yield.rs
index f76e8142ae8..60380a4071c 100644
--- a/tests/pretty/postfix-yield.rs
+++ b/tests/pretty/postfix-yield.rs
@@ -2,7 +2,8 @@
 //@ edition: 2024
 //@ pp-exact
 
-#![feature(gen_blocks, coroutines, coroutine_trait, yield_expr)]
+#![feature(gen_blocks, coroutines, coroutine_trait, yield_expr,
+stmt_expr_attributes)]
 
 use std::ops::{Coroutine, CoroutineState};
 use std::pin::pin;
diff --git a/tests/rustdoc-json/impls/auto.rs b/tests/rustdoc-json/impls/auto.rs
index f94f7338480..ce47d1be690 100644
--- a/tests/rustdoc-json/impls/auto.rs
+++ b/tests/rustdoc-json/impls/auto.rs
@@ -15,8 +15,8 @@ impl Foo {
 }
 
 // Testing spans, so all tests below code
-//@ is "$.index[?(@.docs=='has span')].span.begin" "[13, 0]"
-//@ is "$.index[?(@.docs=='has span')].span.end" "[15, 1]"
+//@ is "$.index[?(@.docs=='has span')].span.begin" "[13, 1]"
+//@ is "$.index[?(@.docs=='has span')].span.end" "[15, 2]"
 // FIXME: this doesn't work due to https://github.com/freestrings/jsonpath/issues/91
 // is "$.index[?(@.inner.impl.is_synthetic==true)].span" null
 pub struct Foo;
diff --git a/tests/rustdoc-json/span.rs b/tests/rustdoc-json/span.rs
new file mode 100644
index 00000000000..c96879d0e68
--- /dev/null
+++ b/tests/rustdoc-json/span.rs
@@ -0,0 +1,4 @@
+pub mod bar {}
+// This test ensures that spans are 1-indexed.
+//@ is "$.index[?(@.name=='span')].span.begin" "[1, 1]"
+//@ is "$.index[?(@.name=='bar')].span.begin" "[1, 1]"
diff --git a/tests/ui/async-await/pin-ergonomics/reborrow-once.stderr b/tests/ui/async-await/pin-ergonomics/reborrow-once.stderr
index a1ea2b4a57a..dc8e424ad2a 100644
--- a/tests/ui/async-await/pin-ergonomics/reborrow-once.stderr
+++ b/tests/ui/async-await/pin-ergonomics/reborrow-once.stderr
@@ -1,4 +1,4 @@
-error[E0499]: cannot borrow `*x.__pointer` as mutable more than once at a time
+error[E0499]: cannot borrow `*x.pointer` as mutable more than once at a time
   --> $DIR/reborrow-once.rs:12:14
    |
 LL |     twice(x, x);
diff --git a/tests/ui/coroutine/postfix-yield.rs b/tests/ui/coroutine/postfix-yield.rs
index ff843138c8c..f2fdcebdaa9 100644
--- a/tests/ui/coroutine/postfix-yield.rs
+++ b/tests/ui/coroutine/postfix-yield.rs
@@ -3,7 +3,7 @@
 //@ run-pass
 //@ edition: 2024
 
-#![feature(gen_blocks, coroutines, coroutine_trait, yield_expr)]
+#![feature(gen_blocks, coroutines, coroutine_trait, yield_expr, stmt_expr_attributes)]
 
 use std::ops::{Coroutine, CoroutineState};
 use std::pin::pin;
diff --git a/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.rs b/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.rs
deleted file mode 100644
index deb5a2f691b..00000000000
--- a/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-//@ edition:2018
-#![forbid(internal_features, unsafe_code)]
-#![feature(unsafe_pin_internals)]
-//~^ ERROR the feature `unsafe_pin_internals` is internal to the compiler or standard library
-
-use core::{marker::PhantomPinned, pin::Pin};
-
-/// The `unsafe_pin_internals` is indeed unsound.
-fn non_unsafe_pin_new_unchecked<T>(pointer: &mut T) -> Pin<&mut T> {
-    Pin { __pointer: pointer }
-}
-
-fn main() {
-    let mut self_referential = PhantomPinned;
-    let _: Pin<&mut PhantomPinned> = non_unsafe_pin_new_unchecked(&mut self_referential);
-}
diff --git a/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.stderr b/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.stderr
deleted file mode 100644
index fc9bcd90e52..00000000000
--- a/tests/ui/feature-gates/feature-gate-unsafe_pin_internals.stderr
+++ /dev/null
@@ -1,15 +0,0 @@
-error: the feature `unsafe_pin_internals` is internal to the compiler or standard library
-  --> $DIR/feature-gate-unsafe_pin_internals.rs:3:12
-   |
-LL | #![feature(unsafe_pin_internals)]
-   |            ^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: using it is strongly discouraged
-note: the lint level is defined here
-  --> $DIR/feature-gate-unsafe_pin_internals.rs:2:11
-   |
-LL | #![forbid(internal_features, unsafe_code)]
-   |           ^^^^^^^^^^^^^^^^^
-
-error: aborting due to 1 previous error
-
diff --git a/tests/ui/lint/break-with-label-and-unsafe-block.rs b/tests/ui/lint/break-with-label-and-unsafe-block.rs
new file mode 100644
index 00000000000..a76a5761475
--- /dev/null
+++ b/tests/ui/lint/break-with-label-and-unsafe-block.rs
@@ -0,0 +1,11 @@
+//@ check-pass
+
+#![deny(break_with_label_and_loop)]
+
+unsafe fn foo() -> i32 { 42 }
+
+fn main () {
+    'label: loop {
+        break 'label unsafe { foo() }
+    };
+}
diff --git a/tests/ui/pattern/uninit-trivial.rs b/tests/ui/pattern/uninit-trivial.rs
new file mode 100644
index 00000000000..6ea6796c1c1
--- /dev/null
+++ b/tests/ui/pattern/uninit-trivial.rs
@@ -0,0 +1,8 @@
+// Regression test for the semantic changes in
+// <https://github.com/rust-lang/rust/pull/139042>.
+
+fn main() {
+    let x;
+    let (0 | _) = x;
+    //~^ ERROR used binding `x` isn't initialized
+}
diff --git a/tests/ui/pattern/uninit-trivial.stderr b/tests/ui/pattern/uninit-trivial.stderr
new file mode 100644
index 00000000000..2ff8557c945
--- /dev/null
+++ b/tests/ui/pattern/uninit-trivial.stderr
@@ -0,0 +1,16 @@
+error[E0381]: used binding `x` isn't initialized
+  --> $DIR/uninit-trivial.rs:6:10
+   |
+LL |     let x;
+   |         - binding declared here but left uninitialized
+LL |     let (0 | _) = x;
+   |          ^^^^^ `x` used here but it isn't initialized
+   |
+help: consider assigning a value
+   |
+LL |     let x = 42;
+   |           ++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0381`.
diff --git a/tests/ui/pin-macro/cant_access_internals.rs b/tests/ui/pin-macro/cant_access_internals.rs
deleted file mode 100644
index 36a47d0fdf9..00000000000
--- a/tests/ui/pin-macro/cant_access_internals.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-//@ edition:2018
-
-use core::{
-    marker::PhantomPinned,
-    mem,
-    pin::{pin, Pin},
-};
-
-fn main() {
-    let mut phantom_pinned = pin!(PhantomPinned);
-    mem::take(phantom_pinned.__pointer); //~ ERROR use of unstable library feature `unsafe_pin_internals`
-}
diff --git a/tests/ui/pin-macro/cant_access_internals.stderr b/tests/ui/pin-macro/cant_access_internals.stderr
deleted file mode 100644
index 8ad897bbbb9..00000000000
--- a/tests/ui/pin-macro/cant_access_internals.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0658]: use of unstable library feature `unsafe_pin_internals`
-  --> $DIR/cant_access_internals.rs:11:15
-   |
-LL |     mem::take(phantom_pinned.__pointer);
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: add `#![feature(unsafe_pin_internals)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.rs b/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.rs
index 8a0244e8145..e505fe43520 100644
--- a/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.rs
+++ b/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.rs
@@ -9,14 +9,14 @@ use core::{
 
 fn function_call_stops_borrow_extension() {
     let phantom_pinned = identity(pin!(PhantomPinned));
-    //~^ ERROR temporary value dropped while borrowed
+    //~^ ERROR does not live long enough
     stuff(phantom_pinned)
 }
 
 fn promotion_only_works_for_the_innermost_block() {
     let phantom_pinned = {
         let phantom_pinned = pin!(PhantomPinned);
-        //~^ ERROR temporary value dropped while borrowed
+        //~^ ERROR does not live long enough
         phantom_pinned
     };
     stuff(phantom_pinned)
diff --git a/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.stderr b/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.stderr
index 9df7f0ffd0c..43fb82be7c2 100644
--- a/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.stderr
+++ b/tests/ui/pin-macro/lifetime_errors_on_promotion_misusage.stderr
@@ -1,35 +1,29 @@
-error[E0716]: temporary value dropped while borrowed
+error[E0597]: value does not live long enough
   --> $DIR/lifetime_errors_on_promotion_misusage.rs:11:35
    |
 LL |     let phantom_pinned = identity(pin!(PhantomPinned));
-   |                                   ^^^^^^^^^^^^^^^^^^^ - temporary value is freed at the end of this statement
+   |                                   ^^^^^^^^^^^^^^^^^^^ - value dropped here while still borrowed
    |                                   |
-   |                                   creates a temporary value which is freed while still in use
+   |                                   borrowed value does not live long enough
 LL |
 LL |     stuff(phantom_pinned)
    |           -------------- borrow later used here
    |
    = note: this error originates in the macro `pin` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider using a `let` binding to create a longer lived value
-   |
-LL ~     let binding = pin!(PhantomPinned);
-LL ~     let phantom_pinned = identity(binding);
-   |
 
-error[E0716]: temporary value dropped while borrowed
+error[E0597]: value does not live long enough
   --> $DIR/lifetime_errors_on_promotion_misusage.rs:18:30
    |
 LL |     let phantom_pinned = {
    |         -------------- borrow later stored here
 LL |         let phantom_pinned = pin!(PhantomPinned);
-   |                              ^^^^^^^^^^^^^^^^^^^ creates a temporary value which is freed while still in use
+   |                              ^^^^^^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...
 LL |     };
-   |     - temporary value is freed at the end of this statement
+   |     - value dropped here while still borrowed
    |
-   = note: consider using a `let` binding to create a longer lived value
    = note: this error originates in the macro `pin` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0716`.
+For more information about this error, try `rustc --explain E0597`.
diff --git a/tests/ui/pin-macro/pin_move.stderr b/tests/ui/pin-macro/pin_move.stderr
index c9b8ad9b202..3f466020988 100644
--- a/tests/ui/pin-macro/pin_move.stderr
+++ b/tests/ui/pin-macro/pin_move.stderr
@@ -31,6 +31,11 @@ LL |     struct NotCopy<T>(T);
 LL |     let mut pointee = NotCopy(PhantomPinned);
 LL |     pin!(*&mut pointee);
    |          ------------- you could clone this value
+help: consider removing the dereference here
+   |
+LL -     pin!(*&mut pointee);
+LL +     pin!(&mut pointee);
+   |
 
 error: aborting due to 2 previous errors
 
diff --git a/triagebot.toml b/triagebot.toml
index 226f024c156..0f17d022fbb 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -659,6 +659,7 @@ message_on_add = [
     """\
 /poll Approve stable backport of #{number}?
 approve
+approve (but does not justify new dot release on its own)
 decline
 don't know
 """,