[llvm-commits] [llvm] r89608 - /llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Sun Nov 22 12:28:04 2009
New Revision: 89608

URL: http://llvm.org/viewvc/llvm-project?rev=89608&view=rev
Log:
Teach MachineBasicBlock::updateTerminator() to handle a failing TII->ReverseBranchCondition(Cond) call.

This fixes the MallocBench/cfrac test case regression.

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

Modified: llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp?rev=89608&r1=89607&r2=89608&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp Sun Nov 22 12:28:04 2009
@@ -279,8 +279,9 @@
       // successors is its layout successor, rewrite it to a fallthrough
       // conditional branch.
       if (isLayoutSuccessor(TBB)) {
+        if (TII->ReverseBranchCondition(Cond))
+          return;
         TII->RemoveBranch(*this);
-        TII->ReverseBranchCondition(Cond);
         TII->InsertBranch(*this, FBB, 0, Cond);
       } else if (isLayoutSuccessor(FBB)) {
         TII->RemoveBranch(*this);
@@ -292,8 +293,13 @@
       MachineBasicBlock *MBBB = *next(succ_begin());
       if (MBBA == TBB) std::swap(MBBB, MBBA);
       if (isLayoutSuccessor(TBB)) {
+        if (TII->ReverseBranchCondition(Cond)) {
+          // We can't reverse the condition, add an unconditional branch.
+          Cond.clear();
+          TII->InsertBranch(*this, MBBA, 0, Cond);
+          return;
+        }
         TII->RemoveBranch(*this);
-        TII->ReverseBranchCondition(Cond);
         TII->InsertBranch(*this, MBBA, 0, Cond);
       } else if (!isLayoutSuccessor(MBBA)) {
         TII->RemoveBranch(*this);