llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-codegen Author: Shivam Gupta (xgupta) <details> <summary>Changes</summary> Apply expression-specific floating-point options when emitting fneg and call instructions. This prevents these instructions from retaining fast-math flags disabled by local FP pragmas, such as #pragma clang fp reassociate(off). Builtin calls are excluded because their lowering handles floating-point options separately. Fixes #<!-- -->51905 --- Full diff: https://github.com/llvm/llvm-project/pull/212141.diff 2 Files Affected: - (modified) clang/lib/CodeGen/CGExprScalar.cpp (+9-1) - (modified) clang/test/CodeGen/fp-reassoc-pragma.cpp (+16) ``````````diff diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp index 8783b43846434..1d26fde39885f 100644 --- a/clang/lib/CodeGen/CGExprScalar.cpp +++ b/clang/lib/CodeGen/CGExprScalar.cpp @@ -682,6 +682,12 @@ class ScalarExprEmitter if (E->getCallReturnType(CGF.getContext())->isReferenceType()) return EmitLoadOfLValue(E); + std::optional<CodeGenFunction::CGFPOptionsRAII> FPOptsRAII; + const FunctionDecl *FD = E->getDirectCallee(); + bool IsBuiltin = FD && FD->getBuiltinID() != 0; + if (!IsBuiltin && E->getType()->hasFloatingRepresentation()) + FPOptsRAII.emplace(CGF, E); + Value *V = CGF.EmitCallExpr(E).getScalarVal(); EmitLValueAlignmentAssumption(E, V); @@ -3707,8 +3713,10 @@ Value *ScalarExprEmitter::VisitMinus(const UnaryOperator *E, Op = Visit(E->getSubExpr()); // Generate a unary FNeg for FP ops. - if (Op->getType()->isFPOrFPVectorTy()) + if (Op->getType()->isFPOrFPVectorTy()) { + CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, E); return Builder.CreateFNeg(Op, "fneg"); + } // Emit unary minus with EmitSub so we handle overflow cases etc. BinOpInfo BinOp; diff --git a/clang/test/CodeGen/fp-reassoc-pragma.cpp b/clang/test/CodeGen/fp-reassoc-pragma.cpp index 8b9329c40174b..45d5ecde34484 100644 --- a/clang/test/CodeGen/fp-reassoc-pragma.cpp +++ b/clang/test/CodeGen/fp-reassoc-pragma.cpp @@ -1,4 +1,6 @@ // RUN: %clang_cc1 -O3 -triple %itanium_abi_triple -emit-llvm -o - %s | FileCheck %s +// RUN: %clang_cc1 -O0 -triple %itanium_abi_triple -funsafe-math-optimizations -emit-llvm -o - %s | FileCheck %s --check-prefix=UNSAFE + // Simple case float fp_reassoc_simple(float a, float b, float c) { // CHECK: _Z17fp_reassoc_simplefff @@ -90,3 +92,17 @@ float fp_reassoc_call_helper(float a, float b, float c) { #pragma clang fp reassociate(on) return helper_func(a, b, c); } + + +double fp_reassoc_call_helper(bool flag, double x, double y) { + return flag ? x : y; +} + +#pragma clang fp reassociate(off) +double fp_reassoc_off_fneg_call(double x) { + // UNSAFE-LABEL: _Z24fp_reassoc_off_fneg_calld + // UNSAFE: fcmp nsz arcp afn + // UNSAFE: fneg nsz arcp afn + // UNSAFE: call nsz arcp afn + return fp_reassoc_call_helper(x < 0, -x, x); +} `````````` </details> https://github.com/llvm/llvm-project/pull/212141 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
