diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp --- a/llvm/lib/Analysis/ConstantFolding.cpp +++ b/llvm/lib/Analysis/ConstantFolding.cpp @@ -1460,6 +1460,7 @@ case Intrinsic::convert_to_fp16: case Intrinsic::bitreverse: case Intrinsic::amdgcn_fmul_legacy: + case Intrinsic::amdgcn_fract: case Intrinsic::x86_sse_cvtss2si: case Intrinsic::x86_sse_cvtss2si64: case Intrinsic::x86_sse_cvttss2si: @@ -1786,10 +1787,23 @@ return ConstantFP::get(Ty->getContext(), U); } + if (IntrinsicID == Intrinsic::amdgcn_fract) { + // The v_fract instruction behaves like the OpenCL spec, which defines + // fract(x) as fmin(x - floor(x), 0x1.fffffep-1f): "The min() operator is + // there to prevent fract(-small) from returning 1.0. It returns the + // largest positive floating-point number less than 1.0." + APFloat FloorU(U); + FloorU.roundToIntegral(APFloat::rmTowardNegative); + APFloat FractU(U - FloorU); + APFloat AlmostOne(U.getSemantics(), 1); + AlmostOne.next(/*nextDown*/ true); + return ConstantFP::get(Ty->getContext(), minimum(FractU, AlmostOne)); + } + /// We only fold functions with finite arguments. Folding NaN and inf is /// likely to be aborted with an exception anyway, and some host libms /// have known errors raising exceptions. - if (Op->getValueAPF().isNaN() || Op->getValueAPF().isInfinity()) + if (!U.isFinite()) return nullptr; /// Currently APFloat versions of these functions do not exist, so we use diff --git a/llvm/test/Analysis/ConstantFolding/AMDGPU/fract.ll b/llvm/test/Analysis/ConstantFolding/AMDGPU/fract.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Analysis/ConstantFolding/AMDGPU/fract.ll @@ -0,0 +1,126 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -instsimplify -S | FileCheck %s + +declare half @llvm.amdgcn.fract.f16(half) +declare float @llvm.amdgcn.fract.f32(float) +declare double @llvm.amdgcn.fract.f64(double) + +define void @test_f16(half* %p) { +; CHECK-LABEL: @test_f16( +; CHECK-NEXT: store volatile half 0xH0000, half* [[P:%.*]] +; CHECK-NEXT: store volatile half 0xH0000, half* [[P]] +; CHECK-NEXT: store volatile half 0xH0000, half* [[P]] +; CHECK-NEXT: store volatile half 0xH0000, half* [[P]] +; CHECK-NEXT: store volatile half 0xH3400, half* [[P]] +; CHECK-NEXT: store volatile half 0xH3B00, half* [[P]] +; CHECK-NEXT: store volatile half 0xH0400, half* [[P]] +; CHECK-NEXT: store volatile half 0xH3BFF, half* [[P]] +; CHECK-NEXT: store volatile half 0xH7E00, half* [[P]] +; CHECK-NEXT: store volatile half 0xH7E00, half* [[P]] +; CHECK-NEXT: store volatile half 0xH7E00, half* [[P]] +; CHECK-NEXT: ret void +; + %p0 = call half @llvm.amdgcn.fract.f16(half +0.0) + store volatile half %p0, half* %p + %n0 = call half @llvm.amdgcn.fract.f16(half -0.0) + store volatile half %n0, half* %p + %p1 = call half @llvm.amdgcn.fract.f16(half +1.0) + store volatile half %p1, half* %p + %n1 = call half @llvm.amdgcn.fract.f16(half -1.0) + store volatile half %n1, half* %p + %p225 = call half @llvm.amdgcn.fract.f16(half +2.25) + store volatile half %p225, half* %p + %n6125 = call half @llvm.amdgcn.fract.f16(half -6.125) + store volatile half %n6125, half* %p + %ptiny = call half @llvm.amdgcn.fract.f16(half 0xH0400) ; +min normal + store volatile half %ptiny, half* %p + %ntiny = call half @llvm.amdgcn.fract.f16(half 0xH8400) ; -min normal + store volatile half %ntiny, half* %p + %pinf = call half @llvm.amdgcn.fract.f16(half 0xH7C00) ; +inf + store volatile half %pinf, half* %p + %ninf = call half @llvm.amdgcn.fract.f16(half 0xHFC00) ; -inf + store volatile half %ninf, half* %p + %nan = call half @llvm.amdgcn.fract.f16(half 0xH7E00) ; nan + store volatile half %nan, half* %p + ret void +} + +define void @test_f32(float* %p) { +; CHECK-LABEL: @test_f32( +; CHECK-NEXT: store volatile float 0.000000e+00, float* [[P:%.*]] +; CHECK-NEXT: store volatile float 0.000000e+00, float* [[P]] +; CHECK-NEXT: store volatile float 0.000000e+00, float* [[P]] +; CHECK-NEXT: store volatile float 0.000000e+00, float* [[P]] +; CHECK-NEXT: store volatile float 2.500000e-01, float* [[P]] +; CHECK-NEXT: store volatile float 8.750000e-01, float* [[P]] +; CHECK-NEXT: store volatile float 0x3810000000000000, float* [[P]] +; CHECK-NEXT: store volatile float 0x3FEFFFFFE0000000, float* [[P]] +; CHECK-NEXT: store volatile float 0x7FF8000000000000, float* [[P]] +; CHECK-NEXT: store volatile float 0x7FF8000000000000, float* [[P]] +; CHECK-NEXT: store volatile float 0x7FF8000000000000, float* [[P]] +; CHECK-NEXT: ret void +; + %p0 = call float @llvm.amdgcn.fract.f32(float +0.0) + store volatile float %p0, float* %p + %n0 = call float @llvm.amdgcn.fract.f32(float -0.0) + store volatile float %n0, float* %p + %p1 = call float @llvm.amdgcn.fract.f32(float +1.0) + store volatile float %p1, float* %p + %n1 = call float @llvm.amdgcn.fract.f32(float -1.0) + store volatile float %n1, float* %p + %p225 = call float @llvm.amdgcn.fract.f32(float +2.25) + store volatile float %p225, float* %p + %n6125 = call float @llvm.amdgcn.fract.f32(float -6.125) + store volatile float %n6125, float* %p + %ptiny = call float @llvm.amdgcn.fract.f32(float 0x3810000000000000) ; +min normal + store volatile float %ptiny, float* %p + %ntiny = call float @llvm.amdgcn.fract.f32(float 0xB810000000000000) ; -min normal + store volatile float %ntiny, float* %p + %pinf = call float @llvm.amdgcn.fract.f32(float 0x7FF0000000000000) ; +inf + store volatile float %pinf, float* %p + %ninf = call float @llvm.amdgcn.fract.f32(float 0xFFF0000000000000) ; -inf + store volatile float %ninf, float* %p + %nan = call float @llvm.amdgcn.fract.f32(float 0x7FF8000000000000) ; nan + store volatile float %nan, float* %p + ret void +} + +define void @test_f64(double* %p) { +; CHECK-LABEL: @test_f64( +; CHECK-NEXT: store volatile double 0.000000e+00, double* [[P:%.*]] +; CHECK-NEXT: store volatile double 0.000000e+00, double* [[P]] +; CHECK-NEXT: store volatile double 0.000000e+00, double* [[P]] +; CHECK-NEXT: store volatile double 0.000000e+00, double* [[P]] +; CHECK-NEXT: store volatile double 2.500000e-01, double* [[P]] +; CHECK-NEXT: store volatile double 8.750000e-01, double* [[P]] +; CHECK-NEXT: store volatile double 2.000000e-308, double* [[P]] +; CHECK-NEXT: store volatile double 0x3FEFFFFFFFFFFFFF, double* [[P]] +; CHECK-NEXT: store volatile double 0x7FF8000000000000, double* [[P]] +; CHECK-NEXT: store volatile double 0x7FF8000000000000, double* [[P]] +; CHECK-NEXT: store volatile double 0x7FF8000000000000, double* [[P]] +; CHECK-NEXT: ret void +; + %p0 = call double @llvm.amdgcn.fract.f64(double +0.0) + store volatile double %p0, double* %p + %n0 = call double @llvm.amdgcn.fract.f64(double -0.0) + store volatile double %n0, double* %p + %p1 = call double @llvm.amdgcn.fract.f64(double +1.0) + store volatile double %p1, double* %p + %n1 = call double @llvm.amdgcn.fract.f64(double -1.0) + store volatile double %n1, double* %p + %p225 = call double @llvm.amdgcn.fract.f64(double +2.25) + store volatile double %p225, double* %p + %n6125 = call double @llvm.amdgcn.fract.f64(double -6.125) + store volatile double %n6125, double* %p + %ptiny = call double @llvm.amdgcn.fract.f64(double +2.0e-308) ; +min normal + store volatile double %ptiny, double* %p + %ntiny = call double @llvm.amdgcn.fract.f64(double -2.0e-308) ; -min normal + store volatile double %ntiny, double* %p + %pinf = call double @llvm.amdgcn.fract.f64(double 0x7FF0000000000000) ; +inf + store volatile double %pinf, double* %p + %ninf = call double @llvm.amdgcn.fract.f64(double 0xFFF0000000000000) ; -inf + store volatile double %ninf, double* %p + %nan = call double @llvm.amdgcn.fract.f64(double 0x7FF8000000000000) ; nan + store volatile double %nan, double* %p + ret void +}