[PATCH] Support for address space casting in order to map these on the new 'addrspacecast' IR instruction

[David Tweed]

  Having looked at this I believe it's doing the right thing in the OpenCL cases, and I'd support it going in on those grounds. However, address spaces are also intended to be usable for security, and I don't have any really understanding of that area.


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Comment at: lib/CodeGen/CGExprScalar.cpp:1299
@@ -1299,2 +1299,2 @@
   case CK_AnyPointerToBlockPointerCast:
   case CK_BitCast: {
----------------
One of the things I'm not sure about is that the two case labels above here are CK_CPointerToObjCPointerCast and CK_BlockPointerToObjCPointerCast; ought those to be split off into a separate switch-case and just use the old code? If nothing else it would minimise the amount of code that has to be security audited wrt address space casting. (As mentioned above, while this looks OK from the point of view of an OpenCL type situation, I'm not really competent to think about  the security uses of addrspace cast.)


http://llvm-reviews.chandlerc.com/D2241