[llvm] r220324 - Preserve 'nonnull' when changing type of the load.

[Philip Reames]

Author: reames
Date: Tue Oct 21 16:00:03 2014
New Revision: 220324

URL: http://llvm.org/viewvc/llvm-project?rev=220324&view=rev
Log:
Preserve 'nonnull' when changing type of the load.

When changing the type of a load in Chandler's recent InstCombine changes, we can preserve the new 'nonnull' metadata.  

I considered adding an assert since 'nonnull' is only valid on pointer types, but casting a pointer to a non-pointer would involve more than a bitcast anyways.  If someone extends this transform to handle more than bitcasts, the verifier will report the malformed IR, so a separate assertion isn't needed.  Also, the fpmath flags would have the same problem.


Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp?rev=220324&r1=220323&r2=220324&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp Tue Oct 21 16:00:03 2014
@@ -331,6 +331,7 @@ static LoadInst *combineLoadToNewType(In
     case LLVMContext::MD_noalias:
     case LLVMContext::MD_nontemporal:
     case LLVMContext::MD_mem_parallel_loop_access:
+    case LLVMContext::MD_nonnull:
       // All of these directly apply.
       NewLoad->setMetadata(ID, N);
       break;