diff options
Diffstat (limited to 'compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp')
| -rw-r--r-- | compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp index 7326f2e8e2a..af2353fbb19 100644 --- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp +++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp @@ -450,6 +450,20 @@ extern "C" void LLVMRustSetAlgebraicMath(LLVMValueRef V) { } } +// Enable the reassoc fast-math flag, allowing transformations that pretend +// floating-point addition and multiplication are associative. +// +// Note that this does NOT enable any flags which can cause a floating-point operation on +// well-defined inputs to return poison, and therefore this function can be used to build +// safe Rust intrinsics (such as fadd_algebraic). +// +// https://llvm.org/docs/LangRef.html#fast-math-flags +extern "C" void LLVMRustSetAllowReassoc(LLVMValueRef V) { + if (auto I = dyn_cast<Instruction>(unwrap<Value>(V))) { + I->setHasAllowReassoc(true); + } +} + extern "C" LLVMValueRef LLVMRustBuildAtomicLoad(LLVMBuilderRef B, LLVMTypeRef Ty, LLVMValueRef Source, const char *Name, LLVMAtomicOrdering Order) { |