[PATCH] Don't create illegal memset with address space >= 256 in memcpyopt.

Manuel Jacob me at manueljacob.de
Mon Jan 26 17:17:05 PST 2015

On 2015-01-26 23:15, Matt Arsenault wrote:
> On 01/26/2015 02:00 PM, Manuel Jacob wrote:
>> I don't think this is target dependent.  See this 
>> assert<http://reviews.llvm.org/diffusion/L/browse/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp;227138$4800>. 
>>  It fails for any target if the address space is >= 256.  As I said on 
>> IRC, you probably tested with assertions disabled.
> That's one of the places I was talking about. That assertion is a bug.
> It's an x86-ism that somehow infested itself there. The address space
> limit is much higher than that (the DataLayout enforces a limit of
> 24-bits)

Thank you, I think I now understand the source of my confusion.  This 
assert and other places you're probably referring to made me think that 
address spaces < 256 are in general reserved as "user-defined address 
spaces" that have no special meaning for the backend.

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