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Differential D27937

InstCombine: Fold fabs on select of constants
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Authored by arsenm on Dec 19 2016, 1:01 PM.

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majnemer

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arsenm updated this revision to Diff 81986.Dec 19 2016, 1:01 PM

arsenm retitled this revision from to InstCombine: Fold fabs on select of constants.

arsenm updated this object.

arsenm added a subscriber: llvm-commits.

Herald added a subscriber: wdng. · View Herald TranscriptDec 19 2016, 1:01 PM

ping

LGTM

This revision is now accepted and ready to land.Jan 2 2017, 2:14 PM

r290860

Revision Contents

Path

Size

lib/

Transforms/

InstCombine/

InstCombineCalls.cpp

12 lines

test/

Transforms/

InstCombine/

fabs.ll

48 lines

Diff 81986

lib/Transforms/InstCombine/InstCombineCalls.cpp

Show First 20 Lines • Show All 1,593 Lines • ▼ Show 20 Lines	case Intrinsic::fmuladd: {
if (match(Src1, m_FPOne())) {		if (match(Src1, m_FPOne())) {
Instruction *RI = BinaryOperator::CreateFAdd(Src0, II->getArgOperand(2));		Instruction *RI = BinaryOperator::CreateFAdd(Src0, II->getArgOperand(2));
RI->copyFastMathFlags(II);		RI->copyFastMathFlags(II);
return RI;		return RI;
}		}

break;		break;
}		}
		case Intrinsic::fabs: {
		Value *Cond;
		Constant LHS, RHS;
		if (match(II->getArgOperand(0),
		m_Select(m_Value(Cond), m_Constant(LHS), m_Constant(RHS)))) {
		CallInst *Call0 = Builder->CreateCall(II->getCalledFunction(), {LHS});
		CallInst *Call1 = Builder->CreateCall(II->getCalledFunction(), {RHS});
		return SelectInst::Create(Cond, Call0, Call1);
		}

		break;
		}
case Intrinsic::ppc_altivec_lvx:		case Intrinsic::ppc_altivec_lvx:
case Intrinsic::ppc_altivec_lvxl:		case Intrinsic::ppc_altivec_lvxl:
// Turn PPC lvx -> load if the pointer is known aligned.		// Turn PPC lvx -> load if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, DL, II, &AC,		if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, DL, II, &AC,
&DT) >= 16) {		&DT) >= 16) {
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),		Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
PointerType::getUnqual(II->getType()));		PointerType::getUnqual(II->getType()));
return new LoadInst(Ptr);		return new LoadInst(Ptr);
▲ Show 20 Lines • Show All 1,711 Lines • Show Last 20 Lines

test/Transforms/InstCombine/fabs.ll

Show First 20 Lines • Show All 92 Lines • ▼ Show 20 Lines	define float @square_fabs_shrink_call2(float %x) {
%trunc = fptrunc double %fabs to float		%trunc = fptrunc double %fabs to float
ret float %trunc		ret float %trunc

; CHECK-LABEL: square_fabs_shrink_call2(		; CHECK-LABEL: square_fabs_shrink_call2(
; CHECK-NEXT: %sq = fmul float %x, %x		; CHECK-NEXT: %sq = fmul float %x, %x
; CHECK-NEXT: ret float %sq		; CHECK-NEXT: ret float %sq
}		}

		; CHECK-LABEL: @fabs_select_constant_negative_positive(
		; CHECK: %fabs = select i1 %cmp, float 1.000000e+00, float 2.000000e+00
		; CHECK-NEXT: ret float %fabs
		define float @fabs_select_constant_negative_positive(i32 %c) {
		%cmp = icmp eq i32 %c, 0
		%select = select i1 %cmp, float -1.0, float 2.0
		%fabs = call float @llvm.fabs.f32(float %select)
		ret float %fabs
		}

		; CHECK-LABEL: @fabs_select_constant_positive_negative(
		; CHECK: %fabs = select i1 %cmp, float 1.000000e+00, float 2.000000e+00
		; CHECK-NEXT: ret float %fabs
		define float @fabs_select_constant_positive_negative(i32 %c) {
		%cmp = icmp eq i32 %c, 0
		%select = select i1 %cmp, float 1.0, float -2.0
		%fabs = call float @llvm.fabs.f32(float %select)
		ret float %fabs
		}

		; CHECK-LABEL: @fabs_select_constant_negative_negative(
		; CHECK: %fabs = select i1 %cmp, float 1.000000e+00, float 2.000000e+00
		; CHECK-NEXT: ret float %fabs
		define float @fabs_select_constant_negative_negative(i32 %c) {
		%cmp = icmp eq i32 %c, 0
		%select = select i1 %cmp, float -1.0, float -2.0
		%fabs = call float @llvm.fabs.f32(float %select)
		ret float %fabs
		}

		; CHECK-LABEL: @fabs_select_constant_neg0(
		; CHECK-NEXT: ret float 0.0
		define float @fabs_select_constant_neg0(i32 %c) {
		%cmp = icmp eq i32 %c, 0
		%select = select i1 %cmp, float -0.0, float 0.0
		%fabs = call float @llvm.fabs.f32(float %select)
		ret float %fabs
		}

		; CHECK-LABEL: @fabs_select_var_constant_negative(
		; CHECK: %select = select i1 %cmp, float %x, float -1.000000e+00
		; CHECK: %fabs = call float @llvm.fabs.f32(float %select)
		define float @fabs_select_var_constant_negative(i32 %c, float %x) {
		%cmp = icmp eq i32 %c, 0
		%select = select i1 %cmp, float %x, float -1.0
		%fabs = call float @llvm.fabs.f32(float %select)
		ret float %fabs
		}