[IC] Turn non-null MD on pointer loads to range MD on integer loads.

Summary:
This change fixes the FIXME that you recently added when you committed
(a modified version of) my patch.  When `InstCombine` combines a load and
store of an pointer to those of an equivalently-sized integer, it currently
drops any `!nonnull` metadata that might be present.  This change replaces
`!nonnull` metadata with `!range !{ 1, -1 }` metadata instead.

Reviewers: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7621

llvm-svn: 230462

1 files changed, 7 insertions, 3 deletions

diff --git a/llvm/lib/IR/MDBuilder.cpp b/llvm/lib/IR/MDBuilder.cpp
index d6d03b48d0f..a9010114044 100644
--- a/llvm/lib/IR/MDBuilder.cpp
+++ b/llvm/lib/IR/MDBuilder.cpp
@@ -55,14 +55,18 @@ MDNode *MDBuilder::createBranchWeights(ArrayRef<uint32_t> Weights) {
 
 MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
   assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
+
+  Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
+  return createRange(ConstantInt::get(Ty, Lo), ConstantInt::get(Ty, Hi));
+}
+
+MDNode *MDBuilder::createRange(Constant *Lo, Constant *Hi) {
   // If the range is everything then it is useless.
   if (Hi == Lo)
     return nullptr;
 
   // Return the range [Lo, Hi).
-  Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
-  Metadata *Range[2] = {createConstant(ConstantInt::get(Ty, Lo)),
-                        createConstant(ConstantInt::get(Ty, Hi))};
+  Metadata *Range[2] = {createConstant(Lo), createConstant(Hi)};
   return MDNode::get(Context, Range);
 }