r600/llvm: Fix hang in R600LowerInstructions pass

1 files changed, 2 insertions, 7 deletions

diff --git a/src/gallium/drivers/radeon/R600LowerInstructions.cpp b/src/gallium/drivers/radeon/R600LowerInstructions.cpp
index 22792aa646e..eac4d80e639 100644
--- a/src/gallium/drivers/radeon/R600LowerInstructions.cpp
+++ b/src/gallium/drivers/radeon/R600LowerInstructions.cpp
@@ -93,8 +93,8 @@ bool R600LowerInstructionsPass::runOnMachineFunction(MachineFunction &MF)
   for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
                                                   BB != BB_E; ++BB) {
     MachineBasicBlock &MBB = *BB;
-    for (MachineBasicBlock::iterator I = MBB.begin(), Prev = NULL;
-         I != MBB.end(); Prev = I, I ? ++I : I = MBB.begin() ) {
+    for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I);
+         I != MBB.end(); I = Next, Next = llvm::next(I) ) {
 
       MachineInstr &MI = *I;
       switch(MI.getOpcode()) {
@@ -398,11 +398,6 @@ bool R600LowerInstructionsPass::runOnMachineFunction(MachineFunction &MF)
         continue;
       }
       MI.eraseFromParent();
-      if (Prev) {
-        I = Prev;
-      } else {
-        I = NULL;
-      }
     }
   }
   return false;