diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -2863,14 +2863,12 @@ } // Canonicalize select with fcmp to fabs(). -0.0 makes this tricky. We need - // fast-math-flags (nsz) or fsub with +0.0 (not fneg) for this to work. We - // also require nnan because we do not want to unintentionally change the - // sign of a NaN value. + // fast-math-flags (nsz) or fsub with +0.0 (not fneg) for this to work. // (X <= +/-0.0) ? (0.0 - X) : X --> fabs(X) Instruction *FSub; if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) && match(TrueVal, m_FSub(m_PosZeroFP(), m_Specific(FalseVal))) && - match(TrueVal, m_Instruction(FSub)) && FSub->hasNoNaNs() && + match(TrueVal, m_Instruction(FSub)) && (Pred == FCmpInst::FCMP_OLE || Pred == FCmpInst::FCMP_ULE)) { Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI); return replaceInstUsesWith(SI, Fabs); @@ -2878,7 +2876,7 @@ // (X > +/-0.0) ? X : (0.0 - X) --> fabs(X) if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) && match(FalseVal, m_FSub(m_PosZeroFP(), m_Specific(TrueVal))) && - match(FalseVal, m_Instruction(FSub)) && FSub->hasNoNaNs() && + match(FalseVal, m_Instruction(FSub)) && (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_UGT)) { Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI); return replaceInstUsesWith(SI, Fabs); @@ -2889,8 +2887,7 @@ Instruction *FNeg; if (match(CondVal, m_FCmp(Pred, m_Specific(FalseVal), m_AnyZeroFP())) && match(TrueVal, m_FNeg(m_Specific(FalseVal))) && - match(TrueVal, m_Instruction(FNeg)) && FNeg->hasNoNaNs() && - FNeg->hasNoSignedZeros() && SI.hasNoSignedZeros() && + match(TrueVal, m_Instruction(FNeg)) && SI.hasNoSignedZeros() && (Pred == FCmpInst::FCMP_OLT || Pred == FCmpInst::FCMP_OLE || Pred == FCmpInst::FCMP_ULT || Pred == FCmpInst::FCMP_ULE)) { Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, FalseVal, &SI); @@ -2901,8 +2898,7 @@ // (X >= +/-0.0) ? X : -X --> fabs(X) if (match(CondVal, m_FCmp(Pred, m_Specific(TrueVal), m_AnyZeroFP())) && match(FalseVal, m_FNeg(m_Specific(TrueVal))) && - match(FalseVal, m_Instruction(FNeg)) && FNeg->hasNoNaNs() && - FNeg->hasNoSignedZeros() && SI.hasNoSignedZeros() && + match(FalseVal, m_Instruction(FNeg)) && SI.hasNoSignedZeros() && (Pred == FCmpInst::FCMP_OGT || Pred == FCmpInst::FCMP_OGE || Pred == FCmpInst::FCMP_UGT || Pred == FCmpInst::FCMP_UGE)) { Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, TrueVal, &SI); diff --git a/llvm/test/Transforms/InstCombine/fabs.ll b/llvm/test/Transforms/InstCombine/fabs.ll --- a/llvm/test/Transforms/InstCombine/fabs.ll +++ b/llvm/test/Transforms/InstCombine/fabs.ll @@ -254,10 +254,8 @@ define double @select_fcmp_ole_zero(double %x) { ; CHECK-LABEL: @select_fcmp_ole_zero( -; CHECK-NEXT: [[LEZERO:%.*]] = fcmp ole double [[X:%.*]], 0.000000e+00 -; CHECK-NEXT: [[NEGX:%.*]] = fsub double 0.000000e+00, [[X]] -; CHECK-NEXT: [[FABS:%.*]] = select i1 [[LEZERO]], double [[NEGX]], double [[X]] -; CHECK-NEXT: ret double [[FABS]] +; CHECK-NEXT: [[TMP1:%.*]] = call double @llvm.fabs.f64(double [[X:%.*]]) +; CHECK-NEXT: ret double [[TMP1]] ; %lezero = fcmp ole double %x, 0.0 %negx = fsub double 0.0, %x @@ -345,10 +343,8 @@ define fp128 @select_fcmp_ogt_zero(fp128 %x) { ; CHECK-LABEL: @select_fcmp_ogt_zero( -; CHECK-NEXT: [[GTZERO:%.*]] = fcmp ogt fp128 [[X:%.*]], 0xL00000000000000000000000000000000 -; CHECK-NEXT: [[NEGX:%.*]] = fsub fp128 0xL00000000000000000000000000000000, [[X]] -; CHECK-NEXT: [[FABS:%.*]] = select i1 [[GTZERO]], fp128 [[X]], fp128 [[NEGX]] -; CHECK-NEXT: ret fp128 [[FABS]] +; CHECK-NEXT: [[TMP1:%.*]] = call fp128 @llvm.fabs.f128(fp128 [[X:%.*]]) +; CHECK-NEXT: ret fp128 [[TMP1]] ; %gtzero = fcmp ogt fp128 %x, zeroinitializer %negx = fsub fp128 zeroinitializer, %x @@ -434,10 +430,8 @@ define double @select_fcmp_olt_zero_unary_fneg(double %x) { ; CHECK-LABEL: @select_fcmp_olt_zero_unary_fneg( -; CHECK-NEXT: [[LTZERO:%.*]] = fcmp olt double [[X:%.*]], 0.000000e+00 -; CHECK-NEXT: [[NEGX:%.*]] = fneg double [[X]] -; CHECK-NEXT: [[FABS:%.*]] = select nsz i1 [[LTZERO]], double [[NEGX]], double [[X]] -; CHECK-NEXT: ret double [[FABS]] +; CHECK-NEXT: [[TMP1:%.*]] = call nsz double @llvm.fabs.f64(double [[X:%.*]]) +; CHECK-NEXT: ret double [[TMP1]] ; %ltzero = fcmp olt double %x, 0.0 %negx = fneg double %x @@ -723,10 +717,8 @@ define <2 x float> @select_fcmp_ogt_zero_unary_fneg(<2 x float> %x) { ; CHECK-LABEL: @select_fcmp_ogt_zero_unary_fneg( -; CHECK-NEXT: [[GTZERO:%.*]] = fcmp ogt <2 x float> [[X:%.*]], zeroinitializer -; CHECK-NEXT: [[NEGX:%.*]] = fneg <2 x float> [[X]] -; CHECK-NEXT: [[FABS:%.*]] = select nsz <2 x i1> [[GTZERO]], <2 x float> [[X]], <2 x float> [[NEGX]] -; CHECK-NEXT: ret <2 x float> [[FABS]] +; CHECK-NEXT: [[TMP1:%.*]] = call nsz <2 x float> @llvm.fabs.v2f32(<2 x float> [[X:%.*]]) +; CHECK-NEXT: ret <2 x float> [[TMP1]] ; %gtzero = fcmp ogt <2 x float> %x, zeroinitializer %negx = fneg <2 x float> %x