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rename stuff improve comment grammar. 

llvm-svn: 100273
This commit is contained in:
Chris Lattner 2010-04-03 06:11:07 +00:00
parent d77bde5f94
commit 0b941347f9
1 changed files with 21 additions and 22 deletions
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43
llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
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@ -625,8 +625,8 @@ void IndVarSimplify::SinkUnusedInvariants(Loop *L) {
/// Return true if it is OK to use SIToFPInst for an induction variable
/// with given initial and exit values.
static bool useSIToFPInst(ConstantFP *InitV, ConstantFP *ExitV,
uint64_t intIV, uint64_t intEV) {
static bool CanUseSIToFP(ConstantFP *InitV, ConstantFP *ExitV,
uint64_t intIV, uint64_t intEV) {
if (InitV->getValueAPF().isNegative() || ExitV->getValueAPF().isNegative())
return true;
@ -698,24 +698,25 @@ void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PH) {
// Find exit condition, which is an fcmp. If it doesn't exist, or if it isn't
// only used by a branch, we can't transform it.
FCmpInst *EC = dyn_cast<FCmpInst>(U1);
if (!EC)
EC = dyn_cast<FCmpInst>(U2);
if (EC == 0 || !EC->hasOneUse() || !isa<BranchInst>(EC->use_back()))
FCmpInst *Compare = dyn_cast<FCmpInst>(U1);
if (!Compare)
Compare = dyn_cast<FCmpInst>(U2);
if (Compare == 0 || !Compare->hasOneUse() ||
!isa<BranchInst>(Compare->use_back()))
return;
BranchInst *TheBr = cast<BranchInst>(EC->use_back());
BranchInst *TheBr = cast<BranchInst>(Compare->use_back());
// If it isn't a comparison with an integer-as-fp (the exit value), we can't
// transform it.
ConstantFP *ExitValueVal = dyn_cast<ConstantFP>(EC->getOperand(1));
ConstantFP *ExitValueVal = dyn_cast<ConstantFP>(Compare->getOperand(1));
uint64_t ExitValue;
if (ExitValueVal == 0 || !convertToInt(ExitValueVal->getValueAPF(),ExitValue))
return;
// Find new predicate for integer comparison.
CmpInst::Predicate NewPred = CmpInst::BAD_ICMP_PREDICATE;
switch (EC->getPredicate()) {
switch (Compare->getPredicate()) {
default: return; // Unknown comparison.
case CmpInst::FCMP_OEQ:
case CmpInst::FCMP_UEQ: NewPred = CmpInst::ICMP_EQ; break;
@ -731,7 +732,7 @@ void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PH) {
const IntegerType *Int32Ty = Type::getInt32Ty(PH->getContext());
// Insert new integer induction variable.
// Insert new i32 integer induction variable.
PHINode *NewPHI = PHINode::Create(Int32Ty, PH->getName()+".int", PH);
NewPHI->addIncoming(ConstantInt::get(Int32Ty, InitValue),
PH->getIncomingBlock(IncomingEdge));
@ -741,23 +742,21 @@ void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PH) {
Incr->getName()+".int", Incr);
NewPHI->addIncoming(NewAdd, PH->getIncomingBlock(BackEdge));
// The back edge is edge 1 of newPHI, whatever it may have been in the
// original PHI.
ConstantInt *NewEV = ConstantInt::get(Int32Ty, ExitValue);
ICmpInst *NewCompare = new ICmpInst(TheBr, NewPred, NewAdd, NewEV,
EC->getName());
ICmpInst *NewCompare = new ICmpInst(TheBr, NewPred, NewAdd,
ConstantInt::get(Int32Ty, ExitValue),
Compare->getName());
// In the following deletions, PH may become dead and may be deleted.
// Use a WeakVH to observe whether this happens.
WeakVH WeakPH = PH;
// Delete old, floating point, exit comparison instruction.
NewCompare->takeName(EC);
EC->replaceAllUsesWith(NewCompare);
RecursivelyDeleteTriviallyDeadInstructions(EC);
// Delete the old floating point exit comparison. The branch starts using the
// new comparison.
NewCompare->takeName(Compare);
Compare->replaceAllUsesWith(NewCompare);
RecursivelyDeleteTriviallyDeadInstructions(Compare);
// Delete old, floating point, increment instruction.
// Delete the old floating point increment.
Incr->replaceAllUsesWith(UndefValue::get(Incr->getType()));
RecursivelyDeleteTriviallyDeadInstructions(Incr);
@ -765,7 +764,7 @@ void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PH) {
// Give SIToFPInst preference over UIToFPInst because it is faster on
// platforms that are widely used.
if (WeakPH && !PH->use_empty()) {
if (useSIToFPInst(InitValueVal, ExitValueVal, InitValue, ExitValue)) {
if (CanUseSIToFP(InitValueVal, ExitValueVal, InitValue, ExitValue)) {
SIToFPInst *Conv = new SIToFPInst(NewPHI, PH->getType(), "indvar.conv",
PH->getParent()->getFirstNonPHI());
PH->replaceAllUsesWith(Conv);