Merge from rustc

6 files changed, 214 insertions, 15 deletions

diff --git a/tests/codegen/common_prim_int_ptr.rs b/tests/codegen/common_prim_int_ptr.rs
new file mode 100644
index 00000000000..87fa89abb86
--- /dev/null
+++ b/tests/codegen/common_prim_int_ptr.rs
@@ -0,0 +1,51 @@
+//@ compile-flags: -O
+
+#![crate_type = "lib"]
+#![feature(core_intrinsics)]
+
+// Tests that codegen works properly when enums like `Result<usize, Box<()>>`
+// are represented as `{ u64, ptr }`, i.e., for `Ok(123)`, `123` is stored
+// as a pointer.
+
+// CHECK-LABEL: @insert_int
+#[no_mangle]
+pub fn insert_int(x: usize) -> Result<usize, Box<()>> {
+    // CHECK: start:
+    // CHECK-NEXT: inttoptr i{{[0-9]+}} %x to ptr
+    // CHECK-NEXT: insertvalue
+    // CHECK-NEXT: ret { i{{[0-9]+}}, ptr }
+    Ok(x)
+}
+
+// CHECK-LABEL: @insert_box
+#[no_mangle]
+pub fn insert_box(x: Box<()>) -> Result<usize, Box<()>> {
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i{{[0-9]+}}, ptr }
+    // CHECK-NEXT: ret
+    Err(x)
+}
+
+// CHECK-LABEL: @extract_int
+// CHECK-NOT: nonnull
+// CHECK-SAME: (i{{[0-9]+}} {{[^,]+}} [[DISCRIMINANT:%[0-9]+]], ptr {{[^,]+}} [[PAYLOAD:%[0-9]+]])
+#[no_mangle]
+pub unsafe fn extract_int(x: Result<usize, Box<()>>) -> usize {
+    // CHECK: [[TEMP:%.+]] = ptrtoint ptr [[PAYLOAD]] to [[USIZE:i[0-9]+]]
+    // CHECK: ret [[USIZE]] [[TEMP]]
+    match x {
+        Ok(v) => v,
+        Err(_) => std::intrinsics::unreachable(),
+    }
+}
+
+// CHECK-LABEL: @extract_box
+// CHECK-SAME: (i{{[0-9]+}} {{[^,]+}} [[DISCRIMINANT:%[0-9]+]], ptr {{[^,]+}} [[PAYLOAD:%[0-9]+]])
+#[no_mangle]
+pub unsafe fn extract_box(x: Result<usize, Box<i32>>) -> Box<i32> {
+    // CHECK: ret ptr [[PAYLOAD]]
+    match x {
+        Ok(_) => std::intrinsics::unreachable(),
+        Err(e) => e,
+    }
+}
diff --git a/tests/codegen/intrinsics/transmute.rs b/tests/codegen/intrinsics/transmute.rs
index 5a503e86010..f858562b5f1 100644
--- a/tests/codegen/intrinsics/transmute.rs
+++ b/tests/codegen/intrinsics/transmute.rs
@@ -296,7 +296,7 @@ pub unsafe fn check_pair_with_bool(x: (u8, bool)) -> (bool, i8) {
 pub unsafe fn check_float_to_pointer(x: f64) -> *const () {
     // CHECK-NOT: alloca
     // CHECK: %0 = bitcast double %x to i64
-    // CHECK: %_0 = inttoptr i64 %0 to ptr
+    // CHECK: %_0 = getelementptr i8, ptr null, i64 %0
     // CHECK: ret ptr %_0
     transmute(x)
 }
@@ -371,7 +371,7 @@ pub unsafe fn check_issue_110005(x: (usize, bool)) -> Option<Box<[u8]>> {
 // CHECK-LABEL: @check_pair_to_dst_ref(
 #[no_mangle]
 pub unsafe fn check_pair_to_dst_ref<'a>(x: (usize, usize)) -> &'a [u8] {
-    // CHECK: %_0.0 = inttoptr i64 %x.0 to ptr
+    // CHECK: %_0.0 = getelementptr i8, ptr null, i64 %x.0
     // CHECK: %0 = insertvalue { ptr, i64 } poison, ptr %_0.0, 0
     // CHECK: %1 = insertvalue { ptr, i64 } %0, i64 %x.1, 1
     // CHECK: ret { ptr, i64 } %1
diff --git a/tests/codegen/precondition-checks.rs b/tests/codegen/precondition-checks.rs
new file mode 100644
index 00000000000..19149445003
--- /dev/null
+++ b/tests/codegen/precondition-checks.rs
@@ -0,0 +1,27 @@
+//@ compile-flags: -Cno-prepopulate-passes -Copt-level=0 -Cdebug-assertions=no
+
+// This test ensures that in a debug build which turns off debug assertions, we do not monomorphize
+// any of the standard library's unsafe precondition checks.
+// The naive codegen of those checks contains the actual check underneath an `if false`, which
+// could be optimized out if optimizations are enabled. But if we rely on optimizations to remove
+// panic branches, then we can't link compiler_builtins without optimizing it, which means that
+// -Zbuild-std doesn't work with -Copt-level=0.
+//
+// In other words, this tests for a mandatory optimization.
+
+#![crate_type = "lib"]
+
+use std::ptr::NonNull;
+
+// CHECK-LABEL: ; core::ptr::non_null::NonNull<T>::new_unchecked
+// CHECK-NOT: call
+// CHECK: }
+
+// CHECK-LABEL: @nonnull_new
+#[no_mangle]
+pub unsafe fn nonnull_new(ptr: *mut u8) -> NonNull<u8> {
+    // CHECK: ; call core::ptr::non_null::NonNull<T>::new_unchecked
+    unsafe {
+        NonNull::new_unchecked(ptr)
+    }
+}
diff --git a/tests/codegen/skip-mono-inside-if-false.rs b/tests/codegen/skip-mono-inside-if-false.rs
new file mode 100644
index 00000000000..8b95de99dd3
--- /dev/null
+++ b/tests/codegen/skip-mono-inside-if-false.rs
@@ -0,0 +1,41 @@
+//@ compile-flags: -Cno-prepopulate-passes -Copt-level=0
+
+#![crate_type = "lib"]
+
+#[no_mangle]
+pub fn demo_for_i32() {
+    generic_impl::<i32>();
+}
+
+// Two important things here:
+// - We replace the "then" block with `unreachable` to avoid linking problems
+// - We neither declare nor define the `big_impl` that said block "calls".
+
+// CHECK-LABEL: ; skip_mono_inside_if_false::generic_impl
+// CHECK: start:
+// CHECK-NEXT: br label %[[ELSE_BRANCH:bb[0-9]+]]
+// CHECK: [[ELSE_BRANCH]]:
+// CHECK-NEXT: call skip_mono_inside_if_false::small_impl
+// CHECK: bb{{[0-9]+}}:
+// CHECK-NEXT: ret void
+// CHECK: bb{{[0-9+]}}:
+// CHECK-NEXT: unreachable
+
+fn generic_impl<T>() {
+    trait MagicTrait {
+        const IS_BIG: bool;
+    }
+    impl<T> MagicTrait for T {
+        const IS_BIG: bool = std::mem::size_of::<T>() > 10;
+    }
+    if T::IS_BIG {
+        big_impl::<T>();
+    } else {
+        small_impl::<T>();
+    }
+}
+
+#[inline(never)]
+fn small_impl<T>() {}
+#[inline(never)]
+fn big_impl<T>() {}
diff --git a/tests/codegen/transmute-scalar.rs b/tests/codegen/transmute-scalar.rs
index 7a5eb4dfcd5..caaa70962d5 100644
--- a/tests/codegen/transmute-scalar.rs
+++ b/tests/codegen/transmute-scalar.rs
@@ -49,7 +49,7 @@ pub fn ptr_to_int(p: *mut u16) -> usize {
 }
 
 // CHECK: define{{.*}}ptr @int_to_ptr([[USIZE]] %i)
-// CHECK: %_0 = inttoptr [[USIZE]] %i to ptr
+// CHECK: %_0 = getelementptr i8, ptr null, [[USIZE]] %i
 // CHECK-NEXT: ret ptr %_0
 #[no_mangle]
 pub fn int_to_ptr(i: usize) -> *mut u16 {
diff --git a/tests/codegen/try_question_mark_nop.rs b/tests/codegen/try_question_mark_nop.rs
index 58cd6ff233a..f6cdf955209 100644
--- a/tests/codegen/try_question_mark_nop.rs
+++ b/tests/codegen/try_question_mark_nop.rs
@@ -4,17 +4,41 @@
 #![crate_type = "lib"]
 #![feature(try_blocks)]
 
-// These are now NOPs in LLVM 15, presumably thanks to nikic's change mentioned in
-// <https://github.com/rust-lang/rust/issues/85133#issuecomment-1072168354>.
-// Unfortunately, as of 2022-08-17 they're not yet nops for `u64`s nor `Option`.
-
 use std::ops::ControlFlow::{self, Continue, Break};
+use std::ptr::NonNull;
+
+// CHECK-LABEL: @option_nop_match_32
+#[no_mangle]
+pub fn option_nop_match_32(x: Option<u32>) -> Option<u32> {
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: ret { i32, i32 }
+    match x {
+        Some(x) => Some(x),
+        None => None,
+    }
+}
+
+// CHECK-LABEL: @option_nop_traits_32
+#[no_mangle]
+pub fn option_nop_traits_32(x: Option<u32>) -> Option<u32> {
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: ret { i32, i32 }
+    try {
+        x?
+    }
+}
 
 // CHECK-LABEL: @result_nop_match_32
 #[no_mangle]
 pub fn result_nop_match_32(x: Result<i32, u32>) -> Result<i32, u32> {
-    // CHECK: start
-    // CHECK-NEXT: ret i64 %0
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: ret { i32, i32 }
     match x {
         Ok(x) => Ok(x),
         Err(x) => Err(x),
@@ -24,8 +48,60 @@ pub fn result_nop_match_32(x: Result<i32, u32>) -> Result<i32, u32> {
 // CHECK-LABEL: @result_nop_traits_32
 #[no_mangle]
 pub fn result_nop_traits_32(x: Result<i32, u32>) -> Result<i32, u32> {
-    // CHECK: start
-    // CHECK-NEXT: ret i64 %0
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: ret { i32, i32 }
+    try {
+        x?
+    }
+}
+
+// CHECK-LABEL: @result_nop_match_64
+#[no_mangle]
+pub fn result_nop_match_64(x: Result<i64, u64>) -> Result<i64, u64> {
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i64, i64 }
+    // CHECK-NEXT: insertvalue { i64, i64 }
+    // CHECK-NEXT: ret { i64, i64 }
+    match x {
+        Ok(x) => Ok(x),
+        Err(x) => Err(x),
+    }
+}
+
+// CHECK-LABEL: @result_nop_traits_64
+#[no_mangle]
+pub fn result_nop_traits_64(x: Result<i64, u64>) -> Result<i64, u64> {
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i64, i64 }
+    // CHECK-NEXT: insertvalue { i64, i64 }
+    // CHECK-NEXT: ret { i64, i64 }
+    try {
+        x?
+    }
+}
+
+// CHECK-LABEL: @result_nop_match_ptr
+#[no_mangle]
+pub fn result_nop_match_ptr(x: Result<usize, Box<()>>) -> Result<usize, Box<()>> {
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i{{[0-9]+}}, ptr }
+    // CHECK-NEXT: insertvalue { i{{[0-9]+}}, ptr }
+    // CHECK-NEXT: ret
+    match x {
+        Ok(x) => Ok(x),
+        Err(x) => Err(x),
+    }
+}
+
+// CHECK-LABEL: @result_nop_traits_ptr
+#[no_mangle]
+pub fn result_nop_traits_ptr(x: Result<u64, NonNull<()>>) -> Result<u64, NonNull<()>> {
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i{{[0-9]+}}, ptr }
+    // CHECK-NEXT: insertvalue { i{{[0-9]+}}, ptr }
+    // CHECK-NEXT: ret
     try {
         x?
     }
@@ -34,8 +110,10 @@ pub fn result_nop_traits_32(x: Result<i32, u32>) -> Result<i32, u32> {
 // CHECK-LABEL: @control_flow_nop_match_32
 #[no_mangle]
 pub fn control_flow_nop_match_32(x: ControlFlow<i32, u32>) -> ControlFlow<i32, u32> {
-    // CHECK: start
-    // CHECK-NEXT: ret i64 %0
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: ret { i32, i32 }
     match x {
         Continue(x) => Continue(x),
         Break(x) => Break(x),
@@ -45,8 +123,10 @@ pub fn control_flow_nop_match_32(x: ControlFlow<i32, u32>) -> ControlFlow<i32, u
 // CHECK-LABEL: @control_flow_nop_traits_32
 #[no_mangle]
 pub fn control_flow_nop_traits_32(x: ControlFlow<i32, u32>) -> ControlFlow<i32, u32> {
-    // CHECK: start
-    // CHECK-NEXT: ret i64 %0
+    // CHECK: start:
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: insertvalue { i32, i32 }
+    // CHECK-NEXT: ret { i32, i32 }
     try {
         x?
     }