Don't insert a PHI node to merge "returns" from an inlined function if there
is only a single return from the function!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3878 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/InlineSimple.cpp b/lib/Transforms/IPO/InlineSimple.cpp
index d88a923..41f849a 100644
--- a/lib/Transforms/IPO/InlineSimple.cpp
+++ b/lib/Transforms/IPO/InlineSimple.cpp
@@ -190,7 +190,18 @@
RemapInstruction(II, ValueMap);
}
- if (PHI) RemapInstruction(PHI, ValueMap); // Fix the PHI node also...
+ if (PHI) {
+ RemapInstruction(PHI, ValueMap); // Fix the PHI node also...
+
+ // Check to see if the PHI node only has one argument. This is a common
+ // case resulting from there only being a single return instruction in the
+ // function call. Because this is so common, eliminate the PHI node.
+ //
+ if (PHI->getNumIncomingValues() == 1) {
+ PHI->replaceAllUsesWith(PHI->getIncomingValue(0));
+ PHI->getParent()->getInstList().erase(PHI);
+ }
+ }
// Change the branch that used to go to NewBB to branch to the first basic
// block of the inlined function.