Index: llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp =================================================================== --- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -211,12 +211,12 @@ /// of each scalar operation (VL) that will be converted into a vector (I). /// Flag set: NSW, NUW, exact, and all of fast-math. static void propagateIRFlags(Value *I, ArrayRef VL) { - if (auto *VecOp = dyn_cast(I)) { - if (auto *Intersection = dyn_cast(VL[0])) { + if (auto *VecOp = dyn_cast(I)) { + if (auto *Intersection = dyn_cast(VL[0])) { // Intersection is initialized to the 0th scalar, // so start counting from index '1'. for (int i = 1, e = VL.size(); i < e; ++i) { - if (auto *Scalar = dyn_cast(VL[i])) + if (auto *Scalar = dyn_cast(VL[i])) Intersection->andIRFlags(Scalar); } VecOp->copyIRFlags(Intersection); @@ -2430,6 +2430,7 @@ V = Builder.CreateICmp(P0, L, R); E->VectorizedValue = V; + propagateIRFlags(E->VectorizedValue, E->Scalars); ++NumVectorInstructions; return V; } Index: llvm/trunk/test/Transforms/SLPVectorizer/X86/propagate_ir_flags.ll =================================================================== --- llvm/trunk/test/Transforms/SLPVectorizer/X86/propagate_ir_flags.ll +++ llvm/trunk/test/Transforms/SLPVectorizer/X86/propagate_ir_flags.ll @@ -348,3 +348,55 @@ ret void } +; CHECK-LABEL: @fcmp_fast +; CHECK: fcmp fast oge <2 x double> +; CHECK: sub fast <2 x double> +define void @fcmp_fast(double* %x) #1 { + %idx1 = getelementptr inbounds double, double* %x, i64 0 + %idx2 = getelementptr inbounds double, double* %x, i64 1 + + %load1 = load double, double* %idx1, align 8 + %load2 = load double, double* %idx2, align 8 + + %cmp1 = fcmp fast oge double %load1, 0.000000e+00 + %cmp2 = fcmp fast oge double %load2, 0.000000e+00 + + %sub1 = fsub fast double -0.000000e+00, %load1 + %sub2 = fsub fast double -0.000000e+00, %load2 + + %sel1 = select i1 %cmp1, double %load1, double %sub1 + %sel2 = select i1 %cmp2, double %load2, double %sub2 + + store double %sel1, double* %idx1, align 8 + store double %sel2, double* %idx2, align 8 + + ret void +} + +; CHECK-LABEL: @fcmp_no_fast +; CHECK: fcmp oge <2 x double> +; CHECK: sub <2 x double> +define void @fcmp_no_fast(double* %x) #1 { + %idx1 = getelementptr inbounds double, double* %x, i64 0 + %idx2 = getelementptr inbounds double, double* %x, i64 1 + + %load1 = load double, double* %idx1, align 8 + %load2 = load double, double* %idx2, align 8 + + %cmp1 = fcmp fast oge double %load1, 0.000000e+00 + %cmp2 = fcmp oge double %load2, 0.000000e+00 + + %sub1 = fsub fast double -0.000000e+00, %load1 + %sub2 = fsub double -0.000000e+00, %load2 + + %sel1 = select i1 %cmp1, double %load1, double %sub1 + %sel2 = select i1 %cmp2, double %load2, double %sub2 + + store double %sel1, double* %idx1, align 8 + store double %sel2, double* %idx2, align 8 + + ret void +} + +attributes #1 = { "target-features"="+avx" } +