Fix a memcpy lowering bug. Even though the memcpy alignment is smaller than the desir...

[oota-llvm.git] / lib / CodeGen / BranchFolding.cpp

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 1807f98cb139f3844efe4581219ee05e5a1c78af..e67339ab3860066f1d86587615c327b36a7cb7ac 100644 (file)
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -38,13 +38,13 @@ STATISTIC(NumBranchOpts, "Number of branches optimized");
 STATISTIC(NumTailMerge , "Number of block tails merged");
 static cl::opt<cl::boolOrDefault> FlagEnableTailMerge("enable-tail-merge", 
                               cl::init(cl::BOU_UNSET), cl::Hidden);
-namespace {
-  // Throttle for huge numbers of predecessors (compile speed problems)
-  static cl::opt<unsigned>
-  TailMergeThreshold("tail-merge-threshold", 
-            cl::desc("Max number of predecessors to consider tail merging"),
-            cl::init(100), cl::Hidden);
+// Throttle for huge numbers of predecessors (compile speed problems)
+static cl::opt<unsigned>
+TailMergeThreshold("tail-merge-threshold", 
+          cl::desc("Max number of predecessors to consider tail merging"),
+          cl::init(100), cl::Hidden);
 
+namespace {
   struct VISIBILITY_HIDDEN BranchFolder : public MachineFunctionPass {
     static char ID;
     explicit BranchFolder(bool defaultEnableTailMerge) : 
@@ -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