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Tweak my last commit to be less conservative about uses. 

We still save an instruction when just the "and" part is replaced.
Also change the code to match comments more closely.

llvm-svn: 147753
This commit is contained in:
Benjamin Kramer 2012-01-08 21:12:51 +00:00
parent 4882e488f7
commit 6609f741b9
2 changed files with 35 additions and 37 deletions
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48
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
View File

@ -745,18 +745,17 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
}
// (X & C) == 0 & X > -1 -> (X & (C | SignBit)) == 0
if (LHS->hasOneUse() && RHS->hasOneUse() &&
((LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero() &&
RHSCC == ICmpInst::ICMP_SGT && RHSCst->isAllOnesValue()) ||
(RHSCC == ICmpInst::ICMP_EQ && RHSCst->isZero() &&
LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue()))) {
BinaryOperator *BO =
dyn_cast<BinaryOperator>(LHSCC == ICmpInst::ICMP_EQ ? Val : Val2);
ConstantInt *AndCst;
if (BO && match(BO, m_OneUse(m_And(m_Value(), m_ConstantInt(AndCst))))) {
APInt New = AndCst->getValue() | APInt::getSignBit(AndCst->getBitWidth());
BO->setOperand(1, ConstantInt::get(AndCst->getContext(), New));
return BO == Val ? LHS : RHS;
if ((LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero() &&
RHSCC == ICmpInst::ICMP_SGT && RHSCst->isAllOnesValue()) ||
(RHSCC == ICmpInst::ICMP_EQ && RHSCst->isZero() &&
LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue())) {
ICmpInst *I = LHSCC == ICmpInst::ICMP_EQ ? LHS : RHS;
Value *X; ConstantInt *C;
if (I->hasOneUse() &&
match(I->getOperand(0), m_OneUse(m_And(m_Value(X), m_ConstantInt(C))))){
APInt New = C->getValue() | APInt::getSignBit(C->getBitWidth());
return Builder->CreateICmpEQ(Builder->CreateAnd(X, Builder->getInt(New)),
I->getOperand(1));
}
}
@ -1458,19 +1457,18 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
}
}
// (X & C) != 0 & X < 0 -> (X & (C | SignBit)) != 0
if (LHS->hasOneUse() && RHS->hasOneUse() &&
((LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero() &&
RHSCC == ICmpInst::ICMP_SLT && RHSCst->isZero()) ||
(RHSCC == ICmpInst::ICMP_NE && RHSCst->isZero() &&
LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero()))) {
BinaryOperator *BO =
dyn_cast<BinaryOperator>(LHSCC == ICmpInst::ICMP_NE ? Val : Val2);
ConstantInt *AndCst;
if (BO && match(BO, m_OneUse(m_And(m_Value(), m_ConstantInt(AndCst))))) {
APInt New = AndCst->getValue() | APInt::getSignBit(AndCst->getBitWidth());
BO->setOperand(1, ConstantInt::get(AndCst->getContext(), New));
return BO == Val ? LHS : RHS;
// (X & C) != 0 | X < 0 -> (X & (C | SignBit)) != 0
if ((LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero() &&
RHSCC == ICmpInst::ICMP_SLT && RHSCst->isZero()) ||
(RHSCC == ICmpInst::ICMP_NE && RHSCst->isZero() &&
LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero())) {
ICmpInst *I = LHSCC == ICmpInst::ICMP_NE ? LHS : RHS;
Value *X; ConstantInt *C;
if (I->hasOneUse() &&
match(I->getOperand(0), m_OneUse(m_And(m_Value(X), m_ConstantInt(C))))){
APInt New = C->getValue() | APInt::getSignBit(C->getBitWidth());
return Builder->CreateICmpNE(Builder->CreateAnd(X, Builder->getInt(New)),
I->getOperand(1));
}
}

24
llvm/test/Transforms/InstCombine/sign-test-and-or.ll
View File

@ -86,9 +86,9 @@ define void @test5(i32 %a) nounwind {
br i1 %or.cond, label %if.then, label %if.end
; CHECK: @test5
; CHECK-NEXT: %and = and i32 %a, -2013265920
; CHECK-NEXT: %1 = icmp eq i32 %and, 0
; CHECK-NEXT: br i1 %1, label %if.then, label %if.end
; CHECK-NEXT: %1 = and i32 %a, -2013265920
; CHECK-NEXT: %2 = icmp eq i32 %1, 0
; CHECK-NEXT: br i1 %2, label %if.then, label %if.end
if.then:
tail call void @foo() nounwind
@ -106,9 +106,9 @@ define void @test6(i32 %a) nounwind {
br i1 %or.cond, label %if.then, label %if.end
; CHECK: @test6
; CHECK-NEXT: %and = and i32 %a, -2013265920
; CHECK-NEXT: %1 = icmp eq i32 %and, 0
; CHECK-NEXT: br i1 %1, label %if.then, label %if.end
; CHECK-NEXT: %1 = and i32 %a, -2013265920
; CHECK-NEXT: %2 = icmp eq i32 %1, 0
; CHECK-NEXT: br i1 %2, label %if.then, label %if.end
if.then:
tail call void @foo() nounwind
@ -126,9 +126,9 @@ define void @test7(i32 %a) nounwind {
br i1 %or.cond, label %if.then, label %if.end
; CHECK: @test7
; CHECK-NEXT: %and = and i32 %a, -2013265920
; CHECK-NEXT: %1 = icmp eq i32 %and, 0
; CHECK-NEXT: br i1 %1, label %if.end, label %if.the
; CHECK-NEXT: %1 = and i32 %a, -2013265920
; CHECK-NEXT: %2 = icmp eq i32 %1, 0
; CHECK-NEXT: br i1 %2, label %if.end, label %if.the
if.then:
tail call void @foo() nounwind
@ -146,9 +146,9 @@ define void @test8(i32 %a) nounwind {
br i1 %or.cond, label %if.then, label %if.end
; CHECK: @test8
; CHECK-NEXT: %and = and i32 %a, -2013265920
; CHECK-NEXT: %1 = icmp eq i32 %and, 0
; CHECK-NEXT: br i1 %1, label %if.end, label %if.the
; CHECK-NEXT: %1 = and i32 %a, -2013265920
; CHECK-NEXT: %2 = icmp eq i32 %1, 0
; CHECK-NEXT: br i1 %2, label %if.end, label %if.the
if.then:
tail call void @foo() nounwind