This patch implements transform for pattern "(A | B) & ((~A) ^ B) -> (A & B)".

Differential Revision: http://reviews.llvm.org/D4628



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214478 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Suyog Sarda 2014-08-01 04:59:26 +00:00
parent d05b6c6f2c
commit 78061f4db4
2 changed files with 34 additions and 0 deletions

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@ -1295,6 +1295,16 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
if (Op0->hasOneUse() || cast<BinaryOperator>(Op0)->hasOneUse())
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))))
return BinaryOperator::CreateAnd(A, B);
// ((~A) ^ B) & (A | B) -> (A & B)
if (match(Op0, m_Xor(m_Not(m_Value(A)), m_Value(B))) &&
match(Op1, m_Or(m_Specific(A), m_Specific(B))))
return BinaryOperator::CreateAnd(A, B);
}
if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1))

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@ -112,3 +112,27 @@ define i32 @test11(i32 %A, i32 %B) {
; CHECK-LABEL: @test11(
; CHECK-NEXT: ret i32 -1
}
; (x | y) & ((~x) ^ y) -> (x & y)
define i32 @test12(i32 %x, i32 %y) {
%or = or i32 %x, %y
%neg = xor i32 %x, -1
%xor = xor i32 %neg, %y
%and = and i32 %or, %xor
ret i32 %and
; CHECK-LABEL: @test12(
; CHECK-NEXT: %and = and i32 %x, %y
; CHECK-NEXT: ret i32 %and
}
; ((~x) ^ y) & (x | y) -> (x & y)
define i32 @test13(i32 %x, i32 %y) {
%neg = xor i32 %x, -1
%xor = xor i32 %neg, %y
%or = or i32 %x, %y
%and = and i32 %xor, %or
ret i32 %and
; CHECK-LABEL: @test13(
; CHECK-NEXT: %and = and i32 %x, %y
; CHECK-NEXT: ret i32 %and
}