[PATCH] Add a dereferencable attribute

[Jan Voung]

================
Comment at: include/llvm/Bitcode/LLVMBitCodes.h:378
@@ -378,1 +377,3 @@
+    ATTR_KIND_JUMP_TABLE = 40,
+    ATTR_KIND_DEFERERENCEABLE = 41
   };
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DEFERERENCEABLE -> DEREFERENCEABLE ?

================
Comment at: include/llvm/IR/Attributes.h:91
@@ -90,2 +90,3 @@
     NonNull,               ///< Pointer is known to be not null
+    Dereferenceable,       ///< Pointer is known to be dereferenceable
     NoRedZone,             ///< Disable redzone
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JF Bastien wrote:
> You'll make some people sad (not PNaCl, but Renderscript and others) by adding the attribute here in the enum instead of at the end, since it changes bitcode slightly.
I think the enum in the bitc:: namespace is the one that affects serialized bitcode and not this enum?

http://reviews.llvm.org/D4449