[llvm-commits] [llvm] r89139 - /llvm/trunk/lib/CodeGen/PHIElimination.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Tue Nov 17 14:46:00 2009
New Revision: 89139

URL: http://llvm.org/viewvc/llvm-project?rev=89139&view=rev
Log:
Never call UpdateTerminator() when AnalyzeBranch would fail.

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

Modified: llvm/trunk/lib/CodeGen/PHIElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PHIElimination.cpp?rev=89139&r1=89138&r2=89139&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/PHIElimination.cpp Tue Nov 17 14:46:00 2009
@@ -445,9 +445,21 @@
 MachineBasicBlock *PHIElimination::SplitCriticalEdge(MachineBasicBlock *A,
                                                      MachineBasicBlock *B) {
   assert(A && B && "Missing MBB end point");
-  ++NumSplits;
 
   MachineFunction *MF = A->getParent();
+
+  // We may need to update A's terminator, but we can't do that if AnalyzeBranch
+  // fails.
+  if (A->isLayoutSuccessor(B)) {
+    const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
+    MachineBasicBlock *TBB = 0, *FBB = 0;
+    SmallVector<MachineOperand, 4> Cond;
+    if (!TII->AnalyzeBranch(*A, TBB, FBB, Cond))
+      return NULL;
+  }
+
+  ++NumSplits;
+
   MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock();
   MF->push_back(NMBB);
   DEBUG(errs() << "PHIElimination splitting critical edge:"