Rollup merge of #145690 - sayantn:integer-funnel-shift, r=tgross35

Implement Integer funnel shifts

Tracking issue: rust-lang/rust#145686
ACP: https://github.com/rust-lang/libs-team/issues/642

This implements funnel shifts on primitive integer types. Implements this for cg_llvm, with a fallback impl for everything else

Thanks `@folkertdev` for the fixes and tests

cc `@rust-lang/libs-api`

5 files changed, 51 insertions, 1 deletions

diff --git a/src/tools/miri/tests/fail/intrinsics/funnel_shl.rs b/src/tools/miri/tests/fail/intrinsics/funnel_shl.rs
new file mode 100644
index 00000000000..40b61f65ebe
--- /dev/null
+++ b/src/tools/miri/tests/fail/intrinsics/funnel_shl.rs
@@ -0,0 +1,7 @@
+#![feature(core_intrinsics, funnel_shifts)]
+
+fn main() {
+    unsafe {
+        std::intrinsics::unchecked_funnel_shl(1_u32, 2, 32); //~ ERROR: Undefined Behavior
+    }
+}
diff --git a/src/tools/miri/tests/fail/intrinsics/funnel_shl.stderr b/src/tools/miri/tests/fail/intrinsics/funnel_shl.stderr
new file mode 100644
index 00000000000..fc828021b13
--- /dev/null
+++ b/src/tools/miri/tests/fail/intrinsics/funnel_shl.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: `assume` called with `false`
+  --> tests/fail/intrinsics/funnel_shl.rs:LL:CC
+   |
+LL |         std::intrinsics::unchecked_funnel_shl(1_u32, 2, 32);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Undefined Behavior occurred here
+   |
+   = 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/intrinsics/funnel_shl.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/miri/tests/fail/intrinsics/funnel_shr.rs b/src/tools/miri/tests/fail/intrinsics/funnel_shr.rs
new file mode 100644
index 00000000000..95822656397
--- /dev/null
+++ b/src/tools/miri/tests/fail/intrinsics/funnel_shr.rs
@@ -0,0 +1,7 @@
+#![feature(core_intrinsics, funnel_shifts)]
+
+fn main() {
+    unsafe {
+        std::intrinsics::unchecked_funnel_shr(1_u32, 2, 32); //~ ERROR: Undefined Behavior
+    }
+}
diff --git a/src/tools/miri/tests/fail/intrinsics/funnel_shr.stderr b/src/tools/miri/tests/fail/intrinsics/funnel_shr.stderr
new file mode 100644
index 00000000000..7361df1b4c7
--- /dev/null
+++ b/src/tools/miri/tests/fail/intrinsics/funnel_shr.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: `assume` called with `false`
+  --> tests/fail/intrinsics/funnel_shr.rs:LL:CC
+   |
+LL |         std::intrinsics::unchecked_funnel_shr(1_u32, 2, 32);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Undefined Behavior occurred here
+   |
+   = 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/intrinsics/funnel_shr.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/miri/tests/pass/intrinsics/integer.rs b/src/tools/miri/tests/pass/intrinsics/integer.rs
index 13e7bd8e1b9..8727b6d3c87 100644
--- a/src/tools/miri/tests/pass/intrinsics/integer.rs
+++ b/src/tools/miri/tests/pass/intrinsics/integer.rs
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 // SPDX-FileCopyrightText: The Rust Project Developers (see https://thanks.rust-lang.org)
 
-#![feature(core_intrinsics)]
+#![feature(core_intrinsics, funnel_shifts)]
 use std::intrinsics::*;
 
 pub fn main() {
@@ -143,5 +143,11 @@ pub fn main() {
 
         assert_eq!(unchecked_mul(6u8, 7), 42);
         assert_eq!(unchecked_mul(13, -5), -65);
+
+        assert_eq!(unchecked_funnel_shl(1_u32, 2, 5), 32);
+        assert_eq!(unchecked_funnel_shl(1_u32, 2, 31), 0x80000001);
+
+        assert_eq!(unchecked_funnel_shr(1_u32, 2, 5), 0x08000000);
+        assert_eq!(unchecked_funnel_shr(1_u32, 2, 31), 2);
     }
 }