From 1276764736eee61bd56daa5f6330f4c7b51de9c0 Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Tue, 25 Apr 2017 15:19:04 +0000 Subject: [PATCH] [InstCombine] Add missing commute handling to (A | B) & (B ^ (~A)) -> (A & B) The matching here wasn't able to handle all the possible commutes. It always assumed the not would be on the left of the xor, but that's not guaranteed. Differential Revision: https://reviews.llvm.org/D32474 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301316 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 11 ++++++++--- test/Transforms/InstCombine/and.ll | 10 ++-------- 2 files changed, 10 insertions(+), 11 deletions(-) diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 8cf48dc5b77..a97b5a9ec0b 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1425,13 +1425,18 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { return BinaryOperator::CreateAnd(Op1, Builder->CreateNot(C)); // (A | B) & ((~A) ^ B) -> (A & B) - if (match(Op0, m_Or(m_Value(A), m_Value(B))) && - match(Op1, m_Xor(m_Not(m_Specific(A)), m_Specific(B)))) + // (A | B) & (B ^ (~A)) -> (A & B) + // (B | A) & ((~A) ^ B) -> (A & B) + // (B | A) & (B ^ (~A)) -> (A & B) + if (match(Op1, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) && + match(Op0, m_c_Or(m_Specific(A), m_Specific(B)))) return BinaryOperator::CreateAnd(A, B); // ((~A) ^ B) & (A | B) -> (A & B) // ((~A) ^ B) & (B | A) -> (A & B) - if (match(Op0, m_Xor(m_Not(m_Value(A)), m_Value(B))) && + // (B ^ (~A)) & (A | B) -> (A & B) + // (B ^ (~A)) & (B | A) -> (A & B) + if (match(Op0, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) && match(Op1, m_c_Or(m_Specific(A), m_Specific(B)))) return BinaryOperator::CreateAnd(A, B); } diff --git a/test/Transforms/InstCombine/and.ll b/test/Transforms/InstCombine/and.ll index 1816b2402e3..a2715c12fa8 100644 --- a/test/Transforms/InstCombine/and.ll +++ b/test/Transforms/InstCombine/and.ll @@ -617,10 +617,7 @@ final: define i32 @test42(i32 %a, i32 %c, i32 %d) { ; CHECK-LABEL: @test42( ; CHECK-NEXT: [[FORCE:%.*]] = mul i32 [[C:%.*]], [[D:%.*]] -; CHECK-NEXT: [[OR:%.*]] = or i32 [[FORCE]], [[A:%.*]] -; CHECK-NEXT: [[NOTA:%.*]] = xor i32 [[A]], -1 -; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[FORCE]], [[NOTA]] -; CHECK-NEXT: [[AND:%.*]] = and i32 [[XOR]], [[OR]] +; CHECK-NEXT: [[AND:%.*]] = and i32 [[FORCE]], [[A:%.*]] ; CHECK-NEXT: ret i32 [[AND]] ; %force = mul i32 %c, %d ; forces the complexity sorting @@ -634,10 +631,7 @@ define i32 @test42(i32 %a, i32 %c, i32 %d) { define i32 @test43(i32 %a, i32 %c, i32 %d) { ; CHECK-LABEL: @test43( ; CHECK-NEXT: [[FORCE:%.*]] = mul i32 [[C:%.*]], [[D:%.*]] -; CHECK-NEXT: [[OR:%.*]] = or i32 [[FORCE]], [[A:%.*]] -; CHECK-NEXT: [[NOTA:%.*]] = xor i32 [[A]], -1 -; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[FORCE]], [[NOTA]] -; CHECK-NEXT: [[AND:%.*]] = and i32 [[OR]], [[XOR]] +; CHECK-NEXT: [[AND:%.*]] = and i32 [[FORCE]], [[A:%.*]] ; CHECK-NEXT: ret i32 [[AND]] ; %force = mul i32 %c, %d ; forces the complexity sorting -- 2.50.1