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refactor a blob of code out to a new 'FoldOrOfFCmps' function and 

simplify it.

llvm-svn: 76866
This commit is contained in:
Chris Lattner 2009-07-23 05:46:22 +00:00
parent 077415e84b
commit 88ab854873
1 changed files with 70 additions and 67 deletions
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137
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -192,6 +192,7 @@ namespace {
Instruction *FoldAndOfFCmps(Instruction &I, FCmpInst *LHS, FCmpInst *RHS);
Instruction *visitAnd(BinaryOperator &I);
Instruction *FoldOrOfICmps(Instruction &I, ICmpInst *LHS, ICmpInst *RHS);
Instruction *FoldOrOfFCmps(Instruction &I, FCmpInst *LHS, FCmpInst *RHS);
Instruction *FoldOrWithConstants(BinaryOperator &I, Value *Op,
Value *A, Value *B, Value *C);
Instruction *visitOr (BinaryOperator &I);
@ -4639,6 +4640,72 @@ Instruction *InstCombiner::FoldOrOfICmps(Instruction &I,
return 0;
}
Instruction *InstCombiner::FoldOrOfFCmps(Instruction &I, FCmpInst *LHS,
FCmpInst *RHS) {
if (LHS->getPredicate() == FCmpInst::FCMP_UNO &&
RHS->getPredicate() == FCmpInst::FCMP_UNO &&
LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType()) {
if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
// If either of the constants are nans, then the whole thing returns
// true.
if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
return ReplaceInstUsesWith(I, Context->getTrue());
// Otherwise, no need to compare the two constants, compare the
// rest.
return new FCmpInst(*Context, FCmpInst::FCMP_UNO,
LHS->getOperand(0), RHS->getOperand(0));
}
// Handle vector zeros. This occurs because the canonical form of
// "fcmp uno x,x" is "fcmp uno x, 0".
if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
isa<ConstantAggregateZero>(RHS->getOperand(1)))
return new FCmpInst(*Context, FCmpInst::FCMP_UNO,
LHS->getOperand(0), RHS->getOperand(0));
return 0;
}
Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
// Swap RHS operands to match LHS.
Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
std::swap(Op1LHS, Op1RHS);
}
if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
// Simplify (fcmp cc0 x, y) | (fcmp cc1 x, y).
if (Op0CC == Op1CC)
return new FCmpInst(*Context, (FCmpInst::Predicate)Op0CC,
Op0LHS, Op0RHS);
if (Op0CC == FCmpInst::FCMP_TRUE || Op1CC == FCmpInst::FCMP_TRUE)
return ReplaceInstUsesWith(I, Context->getTrue());
if (Op0CC == FCmpInst::FCMP_FALSE)
return ReplaceInstUsesWith(I, RHS);
if (Op1CC == FCmpInst::FCMP_FALSE)
return ReplaceInstUsesWith(I, LHS);
bool Op0Ordered;
bool Op1Ordered;
unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
if (Op0Ordered == Op1Ordered) {
// If both are ordered or unordered, return a new fcmp with
// or'ed predicates.
Value *RV = getFCmpValue(Op0Ordered, Op0Pred|Op1Pred,
Op0LHS, Op0RHS, Context);
if (Instruction *I = dyn_cast<Instruction>(RV))
return I;
// Otherwise, it's a constant boolean value...
return ReplaceInstUsesWith(I, RV);
}
}
return 0;
}
/// FoldOrWithConstants - This helper function folds:
///
/// ((A | B) & C1) | (B & C2)
@ -4930,73 +4997,9 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
// (fcmp uno x, c) | (fcmp uno y, c) -> (fcmp uno x, y)
if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0))) {
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1))) {
if (LHS->getPredicate() == FCmpInst::FCMP_UNO &&
RHS->getPredicate() == FCmpInst::FCMP_UNO &&
LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType()) {
if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
// If either of the constants are nans, then the whole thing returns
// true.
if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
return ReplaceInstUsesWith(I, Context->getTrue());
// Otherwise, no need to compare the two constants, compare the
// rest.
return new FCmpInst(*Context, FCmpInst::FCMP_UNO,
LHS->getOperand(0), RHS->getOperand(0));
}
// Handle vector zeros. This occurs because the canonical form of
// "fcmp uno x,x" is "fcmp uno x, 0".
if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
isa<ConstantAggregateZero>(RHS->getOperand(1)))
return new FCmpInst(*Context, FCmpInst::FCMP_UNO,
LHS->getOperand(0), RHS->getOperand(0));
} else {
Value *Op0LHS, *Op0RHS, *Op1LHS, *Op1RHS;
FCmpInst::Predicate Op0CC, Op1CC;
if (match(Op0, m_FCmp(Op0CC, m_Value(Op0LHS),
m_Value(Op0RHS)), *Context) &&
match(Op1, m_FCmp(Op1CC, m_Value(Op1LHS),
m_Value(Op1RHS)), *Context)) {
if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
// Swap RHS operands to match LHS.
Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
std::swap(Op1LHS, Op1RHS);
}
if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
// Simplify (fcmp cc0 x, y) | (fcmp cc1 x, y).
if (Op0CC == Op1CC)
return new FCmpInst(*Context, (FCmpInst::Predicate)Op0CC,
Op0LHS, Op0RHS);
else if (Op0CC == FCmpInst::FCMP_TRUE ||
Op1CC == FCmpInst::FCMP_TRUE)
return ReplaceInstUsesWith(I, Context->getTrue());
else if (Op0CC == FCmpInst::FCMP_FALSE)
return ReplaceInstUsesWith(I, Op1);
else if (Op1CC == FCmpInst::FCMP_FALSE)
return ReplaceInstUsesWith(I, Op0);
bool Op0Ordered;
bool Op1Ordered;
unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
if (Op0Ordered == Op1Ordered) {
// If both are ordered or unordered, return a new fcmp with
// or'ed predicates.
Value *RV = getFCmpValue(Op0Ordered, Op0Pred|Op1Pred,
Op0LHS, Op0RHS, Context);
if (Instruction *I = dyn_cast<Instruction>(RV))
return I;
// Otherwise, it's a constant boolean value...
return ReplaceInstUsesWith(I, RV);
}
}
}
}
}
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
if (Instruction *Res = FoldOrOfFCmps(I, LHS, RHS))
return Res;
}
return Changed ? &I : 0;