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Remove extra CFG edges before doing these passes; it makes them happier. 

llvm-svn: 37089
This commit is contained in:
Dale Johannesen 2007-05-15 21:19:17 +00:00
parent 9b7e57315e
commit 420a85d0cf
1 changed files with 16 additions and 1 deletions
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17
llvm/lib/CodeGen/BranchFolding.cpp
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@ -73,6 +73,12 @@ namespace {
char BranchFolder::ID = 0;
}
static bool CorrectExtraCFGEdges(MachineBasicBlock &MBB,
MachineBasicBlock *DestA,
MachineBasicBlock *DestB,
bool isCond,
MachineFunction::iterator FallThru);
FunctionPass *llvm::createBranchFoldingPass() { return new BranchFolder(); }
/// RemoveDeadBlock - Remove the specified dead machine basic block from the
@ -106,12 +112,21 @@ bool BranchFolder::runOnMachineFunction(MachineFunction &MF) {
TII = MF.getTarget().getInstrInfo();
if (!TII) return false;
// Fix CFG. The later algorithms expect it to be right.
bool EverMadeChange = false;
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; I++) {
MachineBasicBlock *MBB = I, *TBB = 0, *FBB = 0;
std::vector<MachineOperand> Cond;
if (!TII->AnalyzeBranch(*MBB, TBB, FBB, Cond))
EverMadeChange |= CorrectExtraCFGEdges(*MBB, TBB, FBB,
!Cond.empty(), next(I));
}
RegInfo = MF.getTarget().getRegisterInfo();
RS = RegInfo->requiresRegisterScavenging(MF) ? new RegScavenger() : NULL;
MMI = getAnalysisToUpdate<MachineModuleInfo>();
bool EverMadeChange = false;
bool MadeChangeThisIteration = true;
while (MadeChangeThisIteration) {
MadeChangeThisIteration = false;