commit 0f2af7f93b8fe43178eea5e42006021121401921
author Daniel Berlin <dberlin@dberlin.org> Mon May 08 17:37:33 2017 +0000
committer Daniel Berlin <dberlin@dberlin.org> Mon May 08 17:37:33 2017 +0000
tree 8c68d54ea86933d0c8dc190fea42b70fbe7a0469
parent 74ffa5c62fd248c3009c615808da8737a45301ab

ConstantFold: Handle gep nonnull, undef as well

llvm-svn: 302447

llvm/lib/IR/ConstantFold.cpp

diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp
index c185933..a20f3f8 100644
--- a/llvm/lib/IR/ConstantFold.cpp
+++ b/llvm/lib/IR/ConstantFold.cpp
@@ -2041,9 +2041,6 @@
                                           Optional<unsigned> InRangeIndex,
                                           ArrayRef<Value *> Idxs) {
   if (Idxs.empty()) return C;
-  Constant *Idx0 = cast<Constant>(Idxs[0]);
-  if ((Idxs.size() == 1 && Idx0->isNullValue()))
-    return C;
 
   if (isa<UndefValue>(C)) {
     Type *GEPTy = GetElementPtrInst::getGEPReturnType(
@@ -2051,6 +2048,10 @@
     return UndefValue::get(GEPTy);
   }
 
+  Constant *Idx0 = cast<Constant>(Idxs[0]);
+  if (Idxs.size() == 1 && (Idx0->isNullValue() || isa<UndefValue>(Idx0)))
+    return C;
+
   if (C->isNullValue()) {
     bool isNull = true;
     for (unsigned i = 0, e = Idxs.size(); i != e; ++i)