Reverts wrong modification to MachineBlockPlacement & BranchFolding; uses a new strat...

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

diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 604feeddd355bf30603c0a297dc896816234783b..a56fec468cc94cd282e56543663cecaf565e41ad 100644 (file)
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -744,18 +744,6 @@ bool BranchFolder::CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
   return true;
 }
 
-static bool hasIdenticalMMOs(const MachineInstr *MI1, const MachineInstr *MI2) {
-  auto I1 = MI1->memoperands_begin(), E1 = MI1->memoperands_end();
-  auto I2 = MI2->memoperands_begin(), E2 = MI2->memoperands_end();
-  if ((E1 - I1) != (E2 - I2))
-    return false;
-  for (; I1 != E1; ++I1, ++I2) {
-    if (**I1 != **I2)
-      return false;
-  }
-  return true;
-}
-
 static void
 removeMMOsFromMemoryOperations(MachineBasicBlock::iterator MBBIStartPos,
                                MachineBasicBlock &MBBCommon) {
@@ -792,8 +780,7 @@ removeMMOsFromMemoryOperations(MachineBasicBlock::iterator MBBIStartPos,
     assert(MBBICommon->isIdenticalTo(&*MBBI) && "Expected matching MIIs!");
 
     if (MBBICommon->mayLoad() || MBBICommon->mayStore())
-      if (!hasIdenticalMMOs(&*MBBI, &*MBBICommon))
-        MBBICommon->dropMemRefs();
+      MBBICommon->setMemRefs(MBBICommon->mergeMemRefsWith(*MBBI));
 
     ++MBBI;
     ++MBBICommon;
@@ -1129,6 +1116,12 @@ bool BranchFolder::OptimizeBranches(MachineFunction &MF) {
   for (MachineFunction::iterator I = std::next(MF.begin()), E = MF.end();
        I != E; ) {
     MachineBasicBlock *MBB = &*I++;
+    // XXX-disabled: Don't optimize blocks that contain intentionally added fake
+    // conditional branch.
+    if (!MBB->getCanEliminateMachineBB()) {
+      continue;
+    }
+
     MadeChange |= OptimizeBlock(MBB);
 
     // If it is dead, remove it.