Make loop not recalc getNumOperands() each time around

llvm-svn: 84138

1 files changed, 2 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index 74cc18b9155..7af0bba1973 100644
--- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -778,9 +778,7 @@ void PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) {
     // directly.
     for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ++I) {
       MachineInstr *MI = I;
-      // Likewise, call getNumOperands() each iteration, as the MI may change
-      // inside the loop (with 'i' updated accordingly).
-      for (unsigned i = 0; i != MI->getNumOperands(); ++i)
+      for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i)
         if (MI->getOperand(i).isReg()) {
           MachineOperand &MO = MI->getOperand(i);
           unsigned Reg = MO.getReg();
@@ -853,6 +851,7 @@ void PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) {
               // just calculating the value we already have.
               BB->erase(I, LastUseMI);
               MI = I = LastUseMI;
+              e = MI->getNumOperands();
 
               CurrentScratchReg = PrevScratchReg;
               // Extend the live range of the register