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InstCombine: Clean up foldLogOpOfMaskedICmps

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No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222229 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Majnemer 2014-11-18 09:31:36 +00:00
parent 0d7de42c25
commit 2c906a4607
1 changed files with 14 additions and 16 deletions
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30
lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
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@ -665,8 +665,8 @@ static unsigned foldLogOpOfMaskedICmpsHelper(Value*& A,
/// foldLogOpOfMaskedICmps:
/// try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
/// into a single (icmp(A & X) ==/!= Y)
static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
llvm::InstCombiner::BuilderTy* Builder) {
static Value *foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
llvm::InstCombiner::BuilderTy *Builder) {
Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr;
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
unsigned mask = foldLogOpOfMaskedICmpsHelper(A, B, C, D, E, LHS, RHS,
@ -697,26 +697,26 @@ static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
if (mask & FoldMskICmp_Mask_AllZeroes) {
// (icmp eq (A & B), 0) & (icmp eq (A & D), 0)
// -> (icmp eq (A & (B|D)), 0)
Value* newOr = Builder->CreateOr(B, D);
Value* newAnd = Builder->CreateAnd(A, newOr);
Value *newOr = Builder->CreateOr(B, D);
Value *newAnd = Builder->CreateAnd(A, newOr);
// we can't use C as zero, because we might actually handle
// (icmp ne (A & B), B) & (icmp ne (A & D), D)
// with B and D, having a single bit set
Value* zero = Constant::getNullValue(A->getType());
Value *zero = Constant::getNullValue(A->getType());
return Builder->CreateICmp(NEWCC, newAnd, zero);
}
if (mask & FoldMskICmp_BMask_AllOnes) {
// (icmp eq (A & B), B) & (icmp eq (A & D), D)
// -> (icmp eq (A & (B|D)), (B|D))
Value* newOr = Builder->CreateOr(B, D);
Value* newAnd = Builder->CreateAnd(A, newOr);
Value *newOr = Builder->CreateOr(B, D);
Value *newAnd = Builder->CreateAnd(A, newOr);
return Builder->CreateICmp(NEWCC, newAnd, newOr);
}
if (mask & FoldMskICmp_AMask_AllOnes) {
// (icmp eq (A & B), A) & (icmp eq (A & D), A)
// -> (icmp eq (A & (B&D)), A)
Value* newAnd1 = Builder->CreateAnd(B, D);
Value* newAnd = Builder->CreateAnd(A, newAnd1);
Value *newAnd1 = Builder->CreateAnd(B, D);
Value *newAnd = Builder->CreateAnd(A, newAnd1);
return Builder->CreateICmp(NEWCC, newAnd, A);
}
@ -766,18 +766,16 @@ static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
// with B and D, having a single bit set
ConstantInt *CCst = dyn_cast<ConstantInt>(C);
if (!CCst) return nullptr;
if (LHSCC != NEWCC)
CCst = dyn_cast<ConstantInt>( ConstantExpr::getXor(BCst, CCst) );
ConstantInt *ECst = dyn_cast<ConstantInt>(E);
if (!ECst) return nullptr;
if (LHSCC != NEWCC)
CCst = cast<ConstantInt>(ConstantExpr::getXor(BCst, CCst));
if (RHSCC != NEWCC)
ECst = dyn_cast<ConstantInt>( ConstantExpr::getXor(DCst, ECst) );
ConstantInt* MCst = dyn_cast<ConstantInt>(
ConstantExpr::getAnd(ConstantExpr::getAnd(BCst, DCst),
ConstantExpr::getXor(CCst, ECst)) );
ECst = cast<ConstantInt>(ConstantExpr::getXor(DCst, ECst));
// if there is a conflict we should actually return a false for the
// whole construct
if (!MCst->isZero())
if (((BCst->getValue() & DCst->getValue()) &
(CCst->getValue() ^ ECst->getValue())) != 0)
return nullptr;
Value *newOr1 = Builder->CreateOr(B, D);
Value *newOr2 = ConstantExpr::getOr(CCst, ECst);