diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/consts.rs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_llvm/src/consts.rs b/compiler/rustc_codegen_llvm/src/consts.rs index a1ab6714d37..75b4ff1b6bb 100644 --- a/compiler/rustc_codegen_llvm/src/consts.rs +++ b/compiler/rustc_codegen_llvm/src/consts.rs @@ -128,6 +128,11 @@ pub(crate) fn const_alloc_to_llvm<'ll>( append_chunks_of_init_and_uninit_bytes(&mut llvals, cx, alloc, range); } + // Avoid wrapping in a struct if there is only a single value. This ensures + // that LLVM is able to perform the string merging optimization if the constant + // is a valid C string. LLVM only considers bare arrays for this optimization, + // not arrays wrapped in a struct. LLVM handles this at: + // https://github.com/rust-lang/llvm-project/blob/acaea3d2bb8f351b740db7ebce7d7a40b9e21488/llvm/lib/Target/TargetLoweringObjectFile.cpp#L249-L280 if let &[data] = &*llvals { data } else { cx.const_struct(&llvals, true) } } |