From: Dale Johannesen <dalej@apple.com>
Date: Fri, 23 May 2008 17:19:02 +0000 (+0000)
Subject: Rewrite a loop to avoid using iterators pointing to
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=679860e31bd7b8f043ba1ccdc5990cb9bafd9055;p=oota-llvm.git

Rewrite a loop to avoid using iterators pointing to
elements that have been erased.  Based on a patch
by Nicolas Capens.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51485 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index e935898f196..e67339ab386 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -529,18 +529,20 @@ unsigned BranchFolder::ComputeSameTails(unsigned CurHash,
 void BranchFolder::RemoveBlocksWithHash(unsigned CurHash, 
                                         MachineBasicBlock* SuccBB,
                                         MachineBasicBlock* PredBB) {
-  for (MPIterator CurMPIter = prior(MergePotentials.end()),
-                  B = MergePotentials.begin(); 
+  MPIterator CurMPIter, B;
+  for (CurMPIter = prior(MergePotentials.end()), B = MergePotentials.begin(); 
        CurMPIter->first==CurHash;
        --CurMPIter) {
     // Put the unconditional branch back, if we need one.
     MachineBasicBlock *CurMBB = CurMPIter->second;
     if (SuccBB && CurMBB != PredBB)
       FixTail(CurMBB, SuccBB, TII);
-    MergePotentials.erase(CurMPIter);
-    if (CurMPIter==B) 
+    if (CurMPIter==B)
       break;
   }
+  if (CurMPIter->first!=CurHash)
+    CurMPIter++;
+  MergePotentials.erase(CurMPIter, MergePotentials.end());
 }
 
 /// CreateCommonTailOnlyBlock - None of the blocks to be tail-merged consist