Auto merge of #128371 - andjo403:rangeAttribute, r=nikic

Add range attribute to scalar function results and arguments

as LLVM 19 adds the range attribute this starts to use it for better optimization.
hade been interesting to see a perf run with the https://github.com/rust-lang/rust/pull/127513

closes https://github.com/rust-lang/rust/issues/50156
cc https://github.com/rust-lang/rust/issues/49572 shall be fixed but not possible to see as there is asserts that already trigger the optimization.

1 files changed, 12 insertions, 0 deletions

diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index 2ff7335a0fc..79a68b2ff0e 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -397,6 +397,18 @@ LLVMRustCreateAllocSizeAttr(LLVMContextRef C, uint32_t ElementSizeArg) {
                                               std::nullopt));
 }
 
+extern "C" LLVMAttributeRef
+LLVMRustCreateRangeAttribute(LLVMContextRef C, unsigned NumBits,
+                             const uint64_t LowerWords[],
+                             const uint64_t UpperWords[]) {
+#if LLVM_VERSION_GE(19, 0)
+  return LLVMCreateConstantRangeAttribute(C, Attribute::Range, NumBits,
+                                          LowerWords, UpperWords);
+#else
+  report_fatal_error("LLVM 19.0 is required for Range Attribute");
+#endif
+}
+
 // These values **must** match ffi::AllocKindFlags.
 // It _happens_ to match the LLVM values of llvm::AllocFnKind,
 // but that's happenstance and we do explicit conversions before