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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73864 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 429de9353696bb1374498712b0fe00aa427cc5eb..326fb38909b5d1d9948342c2b494530163e9af8b 100644 (file)
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -299,11 +299,11 @@ void IndVarSimplify::RewriteLoopExitValues(Loop *L,
         // 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;