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[InstCombine] Remove unnecessary one-use-check #66419

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Merged
nikic merged 1 commit into from
Sep 15, 2023
Merged

[InstCombine] Remove unnecessary one-use-check #66419

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7 changes: 3 additions & 4 deletions llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3646,10 +3646,9 @@ Instruction *InstCombinerImpl::visitOr(BinaryOperator &I) {
// ((A & B) ^ B) | ((A & B) ^ A) -> A ^ B
// (B ^ (A & B)) | (A ^ (A & B)) -> A ^ B
const auto TryXorOpt = [&](Value *Lhs, Value *Rhs) -> Instruction * {
if (match(Lhs, m_OneUse(m_c_Xor(m_And(m_Value(A), m_Value(B)),
m_Deferred(A)))) &&
match(Rhs, m_OneUse(m_c_Xor(m_And(m_Specific(A), m_Specific(B)),
m_Deferred(B))))) {
if (match(Lhs, m_c_Xor(m_And(m_Value(A), m_Value(B)), m_Deferred(A))) &&
match(Rhs,
m_c_Xor(m_And(m_Specific(A), m_Specific(B)), m_Deferred(B)))) {
return BinaryOperator::CreateXor(A, B);
}
return nullptr;
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14 changes: 6 additions & 8 deletions llvm/test/Transforms/InstCombine/or-xor-xor.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -97,11 +97,10 @@ define i3 @or_xor_xor_normal_multiple_uses_and(i3 %a, i3 %b) {

define i32 @or_xor_xor_negative_multiple_uses_xor1(i32 %a, i32 %b) {
; CHECK-LABEL: @or_xor_xor_negative_multiple_uses_xor1(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[AND]], [[B]]
; CHECK-NEXT: [[AND1:%.*]] = xor i32 [[A:%.*]], -1
; CHECK-NEXT: [[XOR1:%.*]] = and i32 [[AND1]], [[B:%.*]]
; CHECK-NEXT: call void @use.i32(i32 [[XOR1]])
; CHECK-NEXT: [[XOR2:%.*]] = xor i32 [[AND]], [[A]]
; CHECK-NEXT: [[OR:%.*]] = or i32 [[XOR1]], [[XOR2]]
; CHECK-NEXT: [[OR:%.*]] = xor i32 [[A]], [[B]]
; CHECK-NEXT: ret i32 [[OR]]
;
%and = and i32 %a, %b
Expand All @@ -114,11 +113,10 @@ define i32 @or_xor_xor_negative_multiple_uses_xor1(i32 %a, i32 %b) {

define i5 @or_xor_xor_negative_multiple_uses_xor2(i5 %a, i5 %b) {
; CHECK-LABEL: @or_xor_xor_negative_multiple_uses_xor2(
; CHECK-NEXT: [[AND:%.*]] = and i5 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[XOR1:%.*]] = xor i5 [[AND]], [[B]]
; CHECK-NEXT: [[XOR2:%.*]] = xor i5 [[AND]], [[A]]
; CHECK-NEXT: [[A1:%.*]] = xor i5 [[B:%.*]], -1
; CHECK-NEXT: [[XOR2:%.*]] = and i5 [[A1]], [[A:%.*]]
; CHECK-NEXT: call void @use.i5(i5 [[XOR2]])
; CHECK-NEXT: [[OR:%.*]] = or i5 [[XOR1]], [[XOR2]]
; CHECK-NEXT: [[OR:%.*]] = xor i5 [[A]], [[B]]
; CHECK-NEXT: ret i5 [[OR]]
;
%and = and i5 %a, %b
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