X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FOptimizePHIs.cpp;h=6da313e632af8a36240efc8d4565401947994b0a;hb=10ad98bbbb00d67d4272e8f29186a65e2a75215e;hp=cfdf46d05956e09fffabfb888ddaf0e591a87831;hpb=ce665bd2e2b581ab0858d1afe359192bac96b868;p=oota-llvm.git

diff --git a/lib/CodeGen/OptimizePHIs.cpp b/lib/CodeGen/OptimizePHIs.cpp
index cfdf46d0595..6da313e632a 100644
--- a/lib/CodeGen/OptimizePHIs.cpp
+++ b/lib/CodeGen/OptimizePHIs.cpp
@@ -33,7 +33,9 @@ namespace {
 
   public:
     static char ID; // Pass identification
-    OptimizePHIs() : MachineFunctionPass(ID) {}
+    OptimizePHIs() : MachineFunctionPass(ID) {
+      initializeOptimizePHIsPass(*PassRegistry::getPassRegistry());
+    }
 
     virtual bool runOnMachineFunction(MachineFunction &MF);
 
@@ -54,11 +56,10 @@ namespace {
 }
 
 char OptimizePHIs::ID = 0;
+char &llvm::OptimizePHIsID = OptimizePHIs::ID;
 INITIALIZE_PASS(OptimizePHIs, "opt-phis",
                 "Optimize machine instruction PHIs", false, false)
 
-FunctionPass *llvm::createOptimizePHIsPass() { return new OptimizePHIs(); }
-
 bool OptimizePHIs::runOnMachineFunction(MachineFunction &Fn) {
   MRI = &Fn.getRegInfo();
   TII = Fn.getTarget().getInstrInfo();
@@ -163,7 +164,11 @@ 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;