[llvm-commits] [llvm] r73864 - /llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp

[Dan Gohman]

Author: djg
Date: Sun Jun 21 19:15:15 2009
New Revision: 73864

URL: http://llvm.org/viewvc/llvm-project?rev=73864&view=rev
Log:
Fix this code to correctly handle loops with multiple exits. Until
now, this hasn't mattered, because ScalarEvolution hasn't been able
to compute trip counts for loops with multiple exits. But it will
soon.

Modified:
    llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp?rev=73864&r1=73863&r2=73864&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp Sun Jun 21 19:15:15 2009
@@ -299,11 +299,11 @@
         // If this instruction is dead now, delete it.
         RecursivelyDeleteTriviallyDeadInstructions(Inst);
 
-        // See if this is a single-entry LCSSA PHI node.  If so, we can (and
-        // have to) remove
-        // the PHI entirely.  This is safe, because the NewVal won't be variant
+        // If we're inserting code into the exit block rather than the
+        // preheader, we can (and have to) remove the PHI entirely.
+        // This is safe, because the NewVal won't be variant
         // in the loop, so we don't need an LCSSA phi node anymore.
-        if (NumPreds == 1) {
+        if (ExitBlocks.size() == 1) {
           PN->replaceAllUsesWith(ExitVal);
           RecursivelyDeleteTriviallyDeadInstructions(PN);
           break;