diff options
Diffstat (limited to 'lib/CodeGen')
-rw-r--r-- | lib/CodeGen/OptimizePHIs.cpp | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/lib/CodeGen/OptimizePHIs.cpp b/lib/CodeGen/OptimizePHIs.cpp index c05be130ec..85fa041800 100644 --- a/lib/CodeGen/OptimizePHIs.cpp +++ b/lib/CodeGen/OptimizePHIs.cpp @@ -165,7 +165,11 @@ bool OptimizePHIs::OptimizeBB(MachineBasicBlock &MBB) { InstrSet PHIsInCycle; if (IsSingleValuePHICycle(MI, SingleValReg, PHIsInCycle) && SingleValReg != 0) { - MRI->replaceRegWith(MI->getOperand(0).getReg(), SingleValReg); + unsigned OldReg = MI->getOperand(0).getReg(); + if (!MRI->constrainRegClass(SingleValReg, MRI->getRegClass(OldReg))) + continue; + + MRI->replaceRegWith(OldReg, SingleValReg); MI->eraseFromParent(); ++NumPHICycles; Changed = true; |