Kristof Beyls 0f36e68f62 [GlobalISel] Support vector-of-pointers in LLT ... This fixes PR32471. As comment 10 on that bug report highlights (https://bugs.llvm.org//show_bug.cgi?id=32471#c10), there are quite a few different defendable design tradeoffs that could be made, including not representing pointers at all in LLT. I decided to go for representing vector-of-pointer as a concept in LLT, while keeping the size of the LLT type 64 bits (this is an increase from 48 bits before). My rationale for keeping pointers explicit is that on some targets probably it's very handy to have the distinction between pointer and non-pointer (e.g. 68K has a different register bank for pointers IIRC). If we keep a scalar pointer, it probably is easiest to also have a vector-of-pointers to keep LLT relatively conceptually clean and orthogonal, while we don't have a very strong reason to break that orthogonality. Once we gain more experience on the use of LLT, we can of course reconsider this direction. Rejecting vector-of-pointer types in the IRTranslator is also an option to avoid the crash reported in PR32471, but that is only a very short-term solution; also needs quite a bit of code tweaks in places, and is probably fragile. Therefore I didn't consider this the best option. llvm-svn: 300664		2017-04-19 07:23:57 +00:00
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llvm	[GlobalISel] Support vector-of-pointers in LLT	2017-04-19 07:23:57 +00:00
llvm-c	Introducing LLVMMetadataRef	2017-04-17 11:52:54 +00:00