From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 9 Jun 2011 21:43:25 +0000 (+0000)
Subject: AnalyzeBranch modifies the bb, but we don't want to modify a bb with
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=a899b223109ca5dba7b44439e955148a03f23d4c;p=oota-llvm.git

AnalyzeBranch modifies the bb, but we don't want to modify a bb with
eh edges. Swap the order of the checks to avoid it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132806 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp
index 5fe3cb09ff3..93acd5826f1 100644
--- a/lib/CodeGen/TailDuplication.cpp
+++ b/lib/CodeGen/TailDuplication.cpp
@@ -541,13 +541,13 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF,
 
     MachineBasicBlock *PredTBB, *PredFBB;
     SmallVector<MachineOperand, 4> PredCond;
+    // EH edges are ignored by AnalyzeBranch.
+    if (PredBB->succ_size() != 1)
+      continue;
     if (TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true))
       continue;
     if (!PredCond.empty())
       continue;
-    // EH edges are ignored by AnalyzeBranch.
-    if (PredBB->succ_size() != 1)
-      continue;
     // Don't duplicate into a fall-through predecessor (at least for now).
     if (PredBB->isLayoutSuccessor(TailBB) && PredBB->canFallThrough())
       continue;
@@ -603,12 +603,11 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF,
   MachineBasicBlock *PrevBB = prior(MachineFunction::iterator(TailBB));
   MachineBasicBlock *PriorTBB = 0, *PriorFBB = 0;
   SmallVector<MachineOperand, 4> PriorCond;
-  bool PriorUnAnalyzable =
-    TII->AnalyzeBranch(*PrevBB, PriorTBB, PriorFBB, PriorCond, true);
   // This has to check PrevBB->succ_size() because EH edges are ignored by
   // AnalyzeBranch.
-  if (!PriorUnAnalyzable && PriorCond.empty() && !PriorTBB &&
-      TailBB->pred_size() == 1 && PrevBB->succ_size() == 1 &&
+  if (PrevBB->succ_size() == 1 && 
+      !TII->AnalyzeBranch(*PrevBB, PriorTBB, PriorFBB, PriorCond, true) &&
+      PriorCond.empty() && !PriorTBB && TailBB->pred_size() == 1 &&
       !TailBB->hasAddressTaken()) {
     DEBUG(dbgs() << "\nMerging into block: " << *PrevBB
           << "From MBB: " << *TailBB);