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[Transforms] Add more cos combinations to SimplifyLibCalls and InstCombine #79699

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Merged
merged 2 commits into from
Feb 5, 2024
Merged

[Transforms] Add more cos combinations to SimplifyLibCalls and InstCombine #79699

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448b280
[Transforms] Add pre-commit tests (NFC)
AZero13 Jan 29, 2024
9148d60
[Transforms] Add more cos combinations to SimplifyLibCalls and InstCo…
AZero13 Jan 27, 2024
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10 changes: 6 additions & 4 deletions llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2488,11 +2488,13 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
}
case Intrinsic::cos:
case Intrinsic::amdgcn_cos: {
Value *X;
Value *X, *Sign;
Value *Src = II->getArgOperand(0);
if (match(Src, m_FNeg(m_Value(X))) || match(Src, m_FAbs(m_Value(X)))) {
// cos(-x) -> cos(x)
// cos(fabs(x)) -> cos(x)
if (match(Src, m_FNeg(m_Value(X))) || match(Src, m_FAbs(m_Value(X))) ||
match(Src, m_CopySign(m_Value(X), m_Value(Sign)))) {
// cos(-x) --> cos(x)
// cos(fabs(x)) --> cos(x)
// cos(copysign(x, y)) --> cos(x)
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I think this could be broken out into an optimizeEvenFunction helper method.

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I'll do that in another PR. I think this is good for now.

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In InstCombineAndOrXor we have stripSignOnlyFPOps

return replaceOperand(*II, 0, X);
}
break;
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12 changes: 9 additions & 3 deletions llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
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Expand Up @@ -1933,12 +1933,18 @@ static Value *optimizeTrigReflections(CallInst *Call, LibFunc Func,
break;
case LibFunc_cos:
case LibFunc_cosf:
case LibFunc_cosl:
// cos(-X) --> cos(X)
if (match(Call->getArgOperand(0), m_FNeg(m_Value(X))))
case LibFunc_cosl: {
// cos(-x) --> cos(x)
// cos(fabs(x)) --> cos(x)
// cos(copysign(x, y)) --> cos(x)
Value *Sign;
Value *Src = Call->getArgOperand(0);
if (match(Src, m_FNeg(m_Value(X))) || match(Src, m_FAbs(m_Value(X))) ||
match(Src, m_CopySign(m_Value(X), m_Value(Sign))))
return copyFlags(*Call,
B.CreateCall(Call->getCalledFunction(), X, "cos"));
break;
}
default:
break;
}
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73 changes: 73 additions & 0 deletions llvm/test/Transforms/InstCombine/cos-1.ll
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Expand Up @@ -17,6 +17,14 @@ declare float @llvm.sin.f32(float)
declare double @tan(double)
declare fp128 @tanl(fp128)

declare double @fabs(double)
declare double @llvm.fabs.f64(double)
declare float @fabsf(float)
declare float @llvm.fabs.f32(float)

declare double @llvm.copysign(double, double)
declare float @llvm.copysign.f32(float, float)

; cos(-x) -> cos(x);

define double @cos_negated_arg(double %x) {
Expand Down Expand Up @@ -100,6 +108,71 @@ define float @cosf_unary_negated_arg_FMF(float %x) {
ret float %r
}

; cos(fabs(x)) -> cos(x)

define double @cos_unary_fabs_arg(double %x) {
; ANY-LABEL: @cos_unary_fabs_arg(
; ANY-NEXT: [[COS:%.*]] = call double @cos(double [[X:%.*]])
; ANY-NEXT: ret double [[COS]]
;
%fabs = tail call double @llvm.fabs.f64(double %x)
%r = call double @cos(double %fabs)
ret double %r
}

define float @cosf_unary_fabs_arg(float %x) {
; ANY-LABEL: @cosf_unary_fabs_arg(
; ANY-NEXT: [[COS:%.*]] = call float @cosf(float [[X:%.*]])
; ANY-NEXT: ret float [[COS]]
;
%fabs = tail call float @llvm.fabs.f32(float %x)
%r = call float @cosf(float %fabs)
ret float %r
}

define float @cosf_unary_fabs_arg_FMF(float %x) {
; ANY-LABEL: @cosf_unary_fabs_arg_FMF(
; ANY-NEXT: [[COS:%.*]] = call reassoc nnan float @cosf(float [[X:%.*]])
; ANY-NEXT: ret float [[COS]]
;
%fabs = tail call float @llvm.fabs.f32(float %x)
%r = call nnan reassoc float @cosf(float %fabs)
ret float %r
}

; cos(copysign(x, y)) -> cos(x)

define double @cos_copysign_arg(double %x, double %y) {
; ANY-LABEL: @cos_copysign_arg(
; ANY-NEXT: [[COS:%.*]] = call double @cos(double [[X:%.*]])
; ANY-NEXT: ret double [[COS]]
;
%copysign = tail call double @llvm.copysign(double %x, double %y)
%r = call double @cos(double %copysign)
ret double %r
}


define float @cosf_unary_copysign_arg(float %x) {
; ANY-LABEL: @cosf_unary_copysign_arg(
; ANY-NEXT: [[COS:%.*]] = call float @cosf(float [[X:%.*]])
; ANY-NEXT: ret float [[COS]]
;
%copysign = tail call float @llvm.copysign.f32(float %x, float 1.0)
%r = call float @cosf(float %copysign)
ret float %r
}

define float @cosf_copysign_arg_FMF(float %x, float %y) {
; ANY-LABEL: @cosf_copysign_arg_FMF(
; ANY-NEXT: [[COS:%.*]] = call reassoc nnan float @cosf(float [[X:%.*]])
; ANY-NEXT: ret float [[COS]]
;
%copysign = tail call float @llvm.copysign.f32(float %x, float %y)
%r = call nnan reassoc float @cosf(float %copysign)
ret float %r
}

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test a vector intrinsic case?

; sin(-x) -> -sin(x);

define double @sin_negated_arg(double %x) {
Expand Down