Do not ifcvt if either true / false path is a backedge. Not profitable in almost all cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37440 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2007-06-05 20:38:42 +00:00
parent a301a16841
commit e004317c66

View File

@ -237,6 +237,9 @@ void IfConverter::StructuralAnalysis(MachineBasicBlock *BB) {
!TII->AnalyzeBranch(*BB, BBI.TrueBB, BBI.FalseBB, BBI.BrCond);
if (!BBI.IsAnalyzable || BBI.BrCond.size() == 0)
return;
// Do not ifcvt if either path is a back edge to the entry block.
if (BBI.TrueBB == BB || BBI.FalseBB == BB)
return;
StructuralAnalysis(BBI.TrueBB);
BBInfo &TrueBBI = BBAnalysis[BBI.TrueBB->getNumber()];