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[InstCombine] Handle (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2) when the one of the Ands is commuted relative to the other

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Currently we expect A to be on the same side in both Ands but nothing guarantees that.

While there also switch to using matchers for some of the code.

Differential Revision: https://reviews.llvm.org/D34230

llvm-svn: 305487
This commit is contained in:
Craig Topper 2017-06-15 17:55:20 +00:00
parent 030de7684b
commit 80a3abf34f
2 changed files with 18 additions and 29 deletions
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34
lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
View File

@ -1599,31 +1599,25 @@ Value *InstCombiner::foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
// TODO support vector splats
if (LHS->getPredicate() == ICmpInst::ICMP_EQ && LHSC && LHSC->isZero() &&
RHS->getPredicate() == ICmpInst::ICMP_EQ && RHSC && RHSC->isZero()) {
BinaryOperator *LAnd = dyn_cast<BinaryOperator>(LHS->getOperand(0));
BinaryOperator *RAnd = dyn_cast<BinaryOperator>(RHS->getOperand(0));
if (LAnd && RAnd && LAnd->hasOneUse() && RHS->hasOneUse() &&
LAnd->getOpcode() == Instruction::And &&
RAnd->getOpcode() == Instruction::And) {
Value *A, *B, *C, *D;
if (match(LHS->getOperand(0), m_And(m_Value(A), m_Value(B))) &&
match(RHS->getOperand(0), m_And(m_Value(C), m_Value(D)))) {
if (A == D || B == D)
std::swap(C, D);
if (B == C)
std::swap(A, B);
Value *Mask = nullptr;
Value *Masked = nullptr;
if (LAnd->getOperand(0) == RAnd->getOperand(0) &&
isKnownToBeAPowerOfTwo(LAnd->getOperand(1), false, 0, CxtI) &&
isKnownToBeAPowerOfTwo(RAnd->getOperand(1), false, 0, CxtI)) {
Mask = Builder->CreateOr(LAnd->getOperand(1), RAnd->getOperand(1));
Masked = Builder->CreateAnd(LAnd->getOperand(0), Mask);
} else if (LAnd->getOperand(1) == RAnd->getOperand(1) &&
isKnownToBeAPowerOfTwo(LAnd->getOperand(0), false, 0, CxtI) &&
isKnownToBeAPowerOfTwo(RAnd->getOperand(0), false, 0, CxtI)) {
Mask = Builder->CreateOr(LAnd->getOperand(0), RAnd->getOperand(0));
Masked = Builder->CreateAnd(LAnd->getOperand(1), Mask);
}
if (Masked)
if (A == C &&
isKnownToBeAPowerOfTwo(B, false, 0, CxtI) &&
isKnownToBeAPowerOfTwo(D, false, 0, CxtI)) {
Value *Mask = Builder->CreateOr(B, D);
Value *Masked = Builder->CreateAnd(A, Mask);
return Builder->CreateICmp(ICmpInst::ICMP_NE, Masked, Mask);
}
}
}

13
test/Transforms/InstCombine/onehot_merge.ll
View File

@ -34,21 +34,16 @@ bb:
}
; Same as above but with operands commuted one of the ands, but not the other.
; TODO handle this form correctly
define i1 @foo1_and_commuted(i32 %k, i32 %c1, i32 %c2) {
; CHECK-LABEL: @foo1_and_commuted(
; CHECK-NEXT: bb:
; CHECK-NEXT: [[K2:%.*]] = mul i32 [[K:%.*]], [[K]]
; CHECK-NEXT: [[TMP:%.*]] = shl i32 1, [[C1:%.*]]
; CHECK-NEXT: [[TMP4:%.*]] = lshr i32 -2147483648, [[C2:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[K2]], [[TMP]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 0
; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], [[K2]]
; CHECK-NEXT: [[TMP6:%.*]] = icmp eq i32 [[TMP5]], 0
; CHECK-NEXT: [[OR:%.*]] = or i1 [[TMP2]], [[TMP6]]
; CHECK-NEXT: ret i1 [[OR]]
; CHECK-NEXT: [[TMP0:%.*]] = or i32 [[TMP]], [[TMP4]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[K2]], [[TMP0]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[TMP1]], [[TMP0]]
; CHECK-NEXT: ret i1 [[TMP2]]
;
bb:
%k2 = mul i32 %k, %k ; to trick the complexity sorting
%tmp = shl i32 1, %c1
%tmp4 = lshr i32 -2147483648, %c2