revert 132986 to see if the bots go green.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132988 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index b43884e..719cd26 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -799,22 +799,14 @@
// First find blocks with no successors.
MergePotentials.clear();
- for (MachineFunction::iterator I = MF.begin(), E = MF.end();
- I != E && MergePotentials.size() < TailMergeThreshold; ++I) {
- if (TriedMerging.count(I))
- continue;
+ for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
if (I->succ_empty())
MergePotentials.push_back(MergePotentialsElt(HashEndOfMBB(I), I));
}
- // If this is a large problem, avoid visiting the same basic blocks
- // multiple times.
- if (MergePotentials.size() == TailMergeThreshold)
- for (unsigned i = 0, e = MergePotentials.size(); i != e; ++i)
- TriedMerging.insert(MergePotentials[i].getBlock());
-
// See if we can do any tail merging on those.
- if (MergePotentials.size() >= 2)
+ if (MergePotentials.size() < TailMergeThreshold &&
+ MergePotentials.size() >= 2)
MadeChange |= TryTailMergeBlocks(NULL, NULL);
// Look at blocks (IBB) with multiple predecessors (PBB).
@@ -838,17 +830,15 @@
for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
I != E; ++I) {
- if (I->pred_size() >= 2) {
+ if (I->pred_size() >= 2 && I->pred_size() < TailMergeThreshold) {
SmallPtrSet<MachineBasicBlock *, 8> UniquePreds;
MachineBasicBlock *IBB = I;
MachineBasicBlock *PredBB = prior(I);
MergePotentials.clear();
for (MachineBasicBlock::pred_iterator P = I->pred_begin(),
E2 = I->pred_end();
- P != E2 && MergePotentials.size() < TailMergeThreshold; ++P) {
+ P != E2; ++P) {
MachineBasicBlock *PBB = *P;
- if (TriedMerging.count(PBB))
- continue;
// Skip blocks that loop to themselves, can't tail merge these.
if (PBB == IBB)
continue;
@@ -901,12 +891,6 @@
MergePotentials.push_back(MergePotentialsElt(HashEndOfMBB(PBB), *P));
}
}
- // If this is a large problem, avoid visiting the same basic blocks
- // multiple times.
- if (MergePotentials.size() == TailMergeThreshold)
- for (unsigned i = 0, e = MergePotentials.size(); i != e; ++i)
- TriedMerging.insert(MergePotentials[i].getBlock());
-
if (MergePotentials.size() >= 2)
MadeChange |= TryTailMergeBlocks(IBB, PredBB);
// Reinsert an unconditional branch if needed.