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Fix a really nasty bug from my changes on Monday to PHIElim. These changes

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broke obsequi and a lot of other things.  It all boiled down to MBB being
overloaded in an inner scope and me confusing it with the one in the outer
scope.  Ugh!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13517 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-05-12 21:47:57 +00:00
parent 6df9e2ca70
commit bee887211b
1 changed files with 19 additions and 11 deletions
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30
lib/CodeGen/PHIElimination.cpp
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@ -70,21 +70,29 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
const MRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
// VRegPHIUseCount - Keep track of the number of times each virtual register
// is used by PHI nodes in this block.
// is used by PHI nodes in successors of this block.
DenseMap<unsigned, VirtReg2IndexFunctor> VRegPHIUseCount;
VRegPHIUseCount.grow(MF.getSSARegMap()->getLastVirtReg());
unsigned BBIsSuccOfPreds = 0; // Number of times MBB is a succ of preds
for (MachineBasicBlock::pred_iterator PI = MBB.pred_begin(),
E = MBB.pred_end(); PI != E; ++PI)
for (MachineBasicBlock::succ_iterator SI = (*PI)->succ_begin(),
E = (*PI)->succ_end(); SI != E; ++SI) {
BBIsSuccOfPreds += *SI == &MBB;
for (MachineBasicBlock::iterator BBI = (*SI)->begin(); BBI !=(*SI)->end() &&
BBI->getOpcode() == TargetInstrInfo::PHI; ++BBI)
for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2)
VRegPHIUseCount[BBI->getOperand(i).getReg()]++;
}
// Get an iterator to the first instruction after the last PHI node (this may
// allso be the end of the basic block). While we are scanning the PHIs,
// also be the end of the basic block). While we are scanning the PHIs,
// populate the VRegPHIUseCount map.
MachineBasicBlock::iterator AfterPHIsIt = MBB.begin();
while (AfterPHIsIt != MBB.end() &&
AfterPHIsIt->getOpcode() == TargetInstrInfo::PHI) {
MachineInstr *PHI = AfterPHIsIt;
for (unsigned i = 1, e = PHI->getNumOperands(); i < e; i += 2)
VRegPHIUseCount[PHI->getOperand(i).getReg()]++;
AfterPHIsIt->getOpcode() == TargetInstrInfo::PHI)
++AfterPHIsIt; // Skip over all of the PHI nodes...
}
while (MBB.front().getOpcode() == TargetInstrInfo::PHI) {
// Unlink the PHI node from the basic block... but don't delete the PHI yet
@ -148,7 +156,7 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
// Adjust the VRegPHIUseCount map to account for the removal of this PHI
// node.
for (unsigned i = 1; i != MI->getNumOperands(); i += 2)
VRegPHIUseCount[MI->getOperand(i).getReg()]--;
VRegPHIUseCount[MI->getOperand(i).getReg()] -= BBIsSuccOfPreds;
// Now loop over all of the incoming arguments, changing them to copy into
// the IncomingReg register in the corresponding predecessor basic block.
@ -215,10 +223,10 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
bool ValueIsLive = false;
for (MachineBasicBlock::succ_iterator SI = opBlock.succ_begin(),
E = opBlock.succ_end(); SI != E && !ValueIsLive; ++SI) {
MachineBasicBlock *MBB = *SI;
MachineBasicBlock *SuccMBB = *SI;
// Is it alive in this successor?
unsigned SuccIdx = LV->getMachineBasicBlockIndex(MBB);
unsigned SuccIdx = LV->getMachineBasicBlockIndex(SuccMBB);
if (SuccIdx < InRegVI.AliveBlocks.size() &&
InRegVI.AliveBlocks[SuccIdx]) {
ValueIsLive = true;
@ -227,7 +235,7 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
// Is it killed in this successor?
for (unsigned i = 0, e = InRegVI.Kills.size(); i != e; ++i)
if (InRegVI.Kills[i].first == MBB) {
if (InRegVI.Kills[i].first == SuccMBB) {
ValueIsLive = true;
break;
}