[llvm-commits] [llvm] r74898 - /llvm/trunk/lib/CodeGen/PHIElimination.cpp

[Sanjiv Gupta]

Author: sgupta
Date: Tue Jul  7 03:04:51 2009
New Revision: 74898

URL: http://llvm.org/viewvc/llvm-project?rev=74898&view=rev
Log:
 if the terminator is a branch depending upon the side effects of a
 previous cmp; a copy can not be inserted here if the copy insn also has
 side effects. We don't have access to the attributes of copy insn here;
 so just play safe by finding a safe locations for branch terminators.

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=74898&r1=74897&r2=74898&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/PHIElimination.cpp (original)
+++ llvm/trunk/lib/CodeGen/PHIElimination.cpp Tue Jul  7 03:04:51 2009
@@ -169,9 +169,15 @@
     return MBB.begin();
 
   // If this basic block does not contain an invoke, then control flow always
-  // reaches the end of it, so place the copy there.  The logic below works in
-  // this case too, but is more expensive.
-  if (!isa<InvokeInst>(MBB.getBasicBlock()->getTerminator()))
+  // reaches the end of it, so place the copy there.
+  // If the terminator is a branch depending upon the side effects of a 
+  // previous cmp; a copy can not be inserted here if the copy insn also
+  // side effects. We don't have access to the attributes of copy insn here;
+  // so just play safe by finding a safe locations for branch terminators. 
+  //
+  // The logic below works in this case too, but is more expensive.
+  const TerminatorInst *TermInst = MBB.getBasicBlock()->getTerminator();
+  if (!(isa<InvokeInst>(TermInst) || isa<BranchInst>(TermInst)))
     return MBB.getFirstTerminator();
 
   // Discover any definition/uses in this basic block.