SI: Fix crash in unused register search in LowerFlowControl pass

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/R600/@165115 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/Target/AMDGPU/SILowerFlowControl.cpp b/lib/Target/AMDGPU/SILowerFlowControl.cpp
index 7ddb1df2c59..62b059f74af 100644
--- a/lib/Target/AMDGPU/SILowerFlowControl.cpp
+++ b/lib/Target/AMDGPU/SILowerFlowControl.cpp
@@ -93,12 +93,12 @@ FunctionPass *llvm::createSILowerFlowControlPass(TargetMachine &tm) {
 bool SILowerFlowControlPass::runOnMachineFunction(MachineFunction &MF) {
 
   // Find all the unused registers that can be used for the predicate stack.
-  for (TargetRegisterClass::iterator S = AMDGPU::SReg_64RegClass.begin(),
-                                     I = AMDGPU::SReg_64RegClass.end();
-                                     I != S; --I) {
+  for (TargetRegisterClass::iterator I = AMDGPU::SReg_64RegClass.begin(),
+                                     S = AMDGPU::SReg_64RegClass.end();
+                                     I != S; ++I) {
     unsigned Reg = *I;
     if (!MF.getRegInfo().isPhysRegOrOverlapUsed(Reg)) {
-      UnusedRegisters.push_back(Reg);
+      UnusedRegisters.insert(UnusedRegisters.begin(), Reg);
     }
   }