Have InlineFunction use SimplifyInstruction rather than

hasConstantValue.  I was leery of using SimplifyInstruction
while the IR was still in a half-baked state, which is the
reason for delaying the simplification until the IR is fully
cooked.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119494 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 9 deletions

diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index e09666a..f57fec7 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Attributes.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/DebugInfo.h"
+#include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
@@ -579,10 +580,10 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) {
   // any users of the original call/invoke instruction.
   const Type *RTy = CalledFunc->getReturnType();
 
+  PHINode *PHI = 0;
   if (Returns.size() > 1) {
     // The PHI node should go at the front of the new basic block to merge all
     // possible incoming values.
-    PHINode *PHI = 0;
     if (!TheCall->use_empty()) {
       PHI = PHINode::Create(RTy, TheCall->getName(),
                             AfterCallBB->begin());
@@ -600,14 +601,6 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) {
                "Ret value not consistent in function!");
         PHI->addIncoming(RI->getReturnValue(), RI->getParent());
       }
-    
-      // Now that we inserted the PHI, check to see if it has a single value
-      // (e.g. all the entries are the same or undef).  If so, remove the PHI so
-      // it doesn't block other optimizations.
-      if (Value *V = PHI->hasConstantValue()) {
-        PHI->replaceAllUsesWith(V);
-        PHI->eraseFromParent();
-      }
     }
 
 
@@ -664,5 +657,14 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) {
   // Now we can remove the CalleeEntry block, which is now empty.
   Caller->getBasicBlockList().erase(CalleeEntry);
 
+  // If we inserted a phi node, check to see if it has a single value (e.g. all
+  // the entries are the same or undef).  If so, remove the PHI so it doesn't
+  // block other optimizations.
+  if (PHI)
+    if (Value *V = SimplifyInstruction(PHI, IFI.TD)) {
+      PHI->replaceAllUsesWith(V);
+      PHI->eraseFromParent();
+    }
+
   return true;
 }