[llvm-commits] [llvm] r132806 - /llvm/trunk/lib/CodeGen/TailDuplication.cpp

[Rafael Espindola]

Author: rafael
Date: Thu Jun  9 16:43:25 2011
New Revision: 132806

URL: http://llvm.org/viewvc/llvm-project?rev=132806&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/CodeGen/TailDuplication.cpp

Modified: llvm/trunk/lib/CodeGen/TailDuplication.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/TailDuplication.cpp?rev=132806&r1=132805&r2=132806&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/TailDuplication.cpp (original)
+++ llvm/trunk/lib/CodeGen/TailDuplication.cpp Thu Jun  9 16:43:25 2011
@@ -541,13 +541,13 @@
 
     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 @@
   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);