Auto merge of #143337 - matthiaskrgr:rollup-lqwhe0i, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang/rust#141847 (Explain `TOCTOU` on the top of `std::fs`, and reference it in functions)
 - rust-lang/rust#142138 (Add `Vec::into_chunks`)
 - rust-lang/rust#142321 (Expose elf abi on ppc64 targets)
 - rust-lang/rust#142886 (ci: aarch64-gnu: Stop skipping `panic_abort_doc_tests`)
 - rust-lang/rust#143194 (fix bitcast of single-element SIMD vectors)
 - rust-lang/rust#143231 (Suggest use another lifetime specifier instead of underscore lifetime)
 - rust-lang/rust#143232 ([COMPILETEST-UNTANGLE 3/N] Use "directives" consistently within compiletest)
 - rust-lang/rust#143258 (Don't recompute `DisambiguatorState` for every RPITIT in trait definition)
 - rust-lang/rust#143274 (ci: support optional jobs)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 2 insertions, 8 deletions

diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
index 7ef04213d32..60cf4e28b5a 100644
--- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -1117,7 +1117,7 @@ pub(super) fn transmute_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     // While optimizations will remove no-op transmutes, they might still be
     // there in debug or things that aren't no-op in MIR because they change
     // the Rust type but not the underlying layout/niche.
-    if from_scalar == to_scalar {
+    if from_scalar == to_scalar && from_backend_ty == to_backend_ty {
         return imm;
     }
 
@@ -1136,13 +1136,7 @@ pub(super) fn transmute_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     assume_scalar_range(bx, imm, from_scalar, from_backend_ty);
 
     imm = match (from_scalar.primitive(), to_scalar.primitive()) {
-        (Int(..) | Float(_), Int(..) | Float(_)) => {
-            if from_backend_ty == to_backend_ty {
-                imm
-            } else {
-                bx.bitcast(imm, to_backend_ty)
-            }
-        }
+        (Int(..) | Float(_), Int(..) | Float(_)) => bx.bitcast(imm, to_backend_ty),
         (Pointer(..), Pointer(..)) => bx.pointercast(imm, to_backend_ty),
         (Int(..), Pointer(..)) => bx.ptradd(bx.const_null(bx.type_ptr()), imm),
         (Pointer(..), Int(..)) => {