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InstCombine: Avoid counting uses of constants #136566

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Merged
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Apr 23, 2025
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InstCombine: Avoid counting uses of constants #136566

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4 changes: 2 additions & 2 deletions llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5034,8 +5034,8 @@ static Instruction *foldICmpOrXX(ICmpInst &I, const SimplifyQuery &Q,

if (ICmpInst::isEquality(Pred) && Op0->hasOneUse()) {
// icmp (X | Y) eq/ne Y --> (X & ~Y) eq/ne 0 if Y is freely invertible
if (Value *NotOp1 =
IC.getFreelyInverted(Op1, !Op1->hasNUsesOrMore(3), &IC.Builder))
if (Value *NotOp1 = IC.getFreelyInverted(
Op1, !isa<Constant>(Op1) && !Op1->hasNUsesOrMore(3), &IC.Builder))
return new ICmpInst(Pred, IC.Builder.CreateAnd(A, NotOp1),
Constant::getNullValue(Op1->getType()));
// icmp (X | Y) eq/ne Y --> (~X | Y) eq/ne -1 if X is freely invertible.
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93 changes: 93 additions & 0 deletions llvm/test/Transforms/InstCombine/icmp.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -2954,6 +2954,99 @@ define i1 @or1_eq1(i32 %x) {
ret i1 %t1
}

define <2 x i1> @or1_eq1_vec(<2 x i32> %x) {
; CHECK-LABEL: @or1_eq1_vec(
; CHECK-NEXT: [[T1:%.*]] = icmp ult <2 x i32> [[X:%.*]], splat (i32 2)
; CHECK-NEXT: ret <2 x i1> [[T1]]
;
%t0 = or <2 x i32> %x, splat (i32 1)
%t1 = icmp eq <2 x i32> %t0, splat (i32 1)
ret <2 x i1> %t1
}

define <2 x i1> @or_eq_vec_nonsplat(<2 x i32> %x) {
; CHECK-LABEL: @or_eq_vec_nonsplat(
; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i32> [[X:%.*]], <i32 -2, i32 -3>
; CHECK-NEXT: [[T1:%.*]] = icmp eq <2 x i32> [[TMP1]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[T1]]
;
%t0 = or <2 x i32> %x, <i32 1, i32 2>
%t1 = icmp eq <2 x i32> %t0, <i32 1, i32 2>
ret <2 x i1> %t1
}

define void @or_eq_vec_multiple_nonsplat(<2 x i32> %x, <2 x i32> %y, <2 x i32> %z, ptr %ptr0, ptr %ptr1, ptr %ptr2) {
; CHECK-LABEL: @or_eq_vec_multiple_nonsplat(
; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i32> [[X:%.*]], <i32 -2, i32 -3>
; CHECK-NEXT: [[CMP0:%.*]] = icmp eq <2 x i32> [[TMP1]], zeroinitializer
; CHECK-NEXT: store <2 x i1> [[CMP0]], ptr [[PTR0:%.*]], align 1
; CHECK-NEXT: [[TMP2:%.*]] = and <2 x i32> [[Y:%.*]], <i32 -2, i32 -3>
; CHECK-NEXT: [[CMP1:%.*]] = icmp eq <2 x i32> [[TMP2]], zeroinitializer
; CHECK-NEXT: store <2 x i1> [[CMP1]], ptr [[PTR1:%.*]], align 1
; CHECK-NEXT: [[TMP3:%.*]] = and <2 x i32> [[Z:%.*]], <i32 -2, i32 -3>
; CHECK-NEXT: [[CMP2:%.*]] = icmp eq <2 x i32> [[TMP3]], zeroinitializer
; CHECK-NEXT: store <2 x i1> [[CMP2]], ptr [[PTR2:%.*]], align 1
; CHECK-NEXT: ret void
;
%t0 = or <2 x i32> %x, <i32 1, i32 2>
%cmp0 = icmp eq <2 x i32> %t0, <i32 1, i32 2>
store <2 x i1> %cmp0, ptr %ptr0

%t1 = or <2 x i32> %y, <i32 1, i32 2>
%cmp1 = icmp eq <2 x i32> %t1, <i32 1, i32 2>
store <2 x i1> %cmp1, ptr %ptr1

%t2 = or <2 x i32> %z, <i32 1, i32 2>
%cmp2 = icmp eq <2 x i32> %t2, <i32 1, i32 2>
store <2 x i1> %cmp2, ptr %ptr2
ret void
}

; Make sure use count of 1 doesn't matter
define i1 @or1_eq1_multiple(i32 %x, i32 %y, i32 %z, ptr %ptr0, ptr %ptr1) {
; CHECK-LABEL: @or1_eq1_multiple(
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], 2
; CHECK-NEXT: store i1 [[CMP1]], ptr [[PTR:%.*]], align 1
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i32 [[Y:%.*]], 2
; CHECK-NEXT: store i1 [[CMP2]], ptr [[PTR1:%.*]], align 1
; CHECK-NEXT: [[CMP3:%.*]] = icmp ult i32 [[Z:%.*]], 2
; CHECK-NEXT: ret i1 [[CMP3]]
;
%t0 = or i32 %x, 1
%cmp0 = icmp eq i32 %t0, 1
store i1 %cmp0, ptr %ptr0

%t1 = or i32 %y, 1
%cmp1 = icmp eq i32 %t1, 1
store i1 %cmp1, ptr %ptr1

%t2 = or i32 %z, 1
%cmp2 = icmp eq i32 %t2, 1
ret i1 %cmp2
}

define <2 x i1> @or1_eq1_multiple_vec(<2 x i32> %x, <2 x i32> %y, <2 x i32> %z, ptr %ptr0, ptr %ptr1) {
; CHECK-LABEL: @or1_eq1_multiple_vec(
; CHECK-NEXT: [[CMP0:%.*]] = icmp ult <2 x i32> [[X:%.*]], splat (i32 2)
; CHECK-NEXT: store <2 x i1> [[CMP0]], ptr [[PTR0:%.*]], align 1
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult <2 x i32> [[Y:%.*]], splat (i32 2)
; CHECK-NEXT: store <2 x i1> [[CMP1]], ptr [[PTR1:%.*]], align 1
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult <2 x i32> [[Z:%.*]], splat (i32 2)
; CHECK-NEXT: ret <2 x i1> [[CMP2]]
;
%t0 = or <2 x i32> %x, splat (i32 1)
%cmp0 = icmp eq <2 x i32> %t0, splat (i32 1)
store <2 x i1> %cmp0, ptr %ptr0

%t1 = or <2 x i32> %y, splat (i32 1)
%cmp1 = icmp eq <2 x i32> %t1, splat (i32 1)
store <2 x i1> %cmp1, ptr %ptr1

%t2 = or <2 x i32> %z, splat (i32 1)
%cmp2 = icmp eq <2 x i32> %t2, splat (i32 1)
ret <2 x i1> %cmp2
}

; X | C == C --> X <=u C (when C+1 is PowerOf2).

define <2 x i1> @or3_eq3_vec(<2 x i8> %x) {
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