[PATCH] D20709: For RenderScript, set alignment and width of long to 64-bits

[Richard Smith via cfe-commits]

rsmith added a comment.

In http://reviews.llvm.org/D20709#446595, @srhines wrote:

> There is a coming patch that adds a single attribute (for "kernel"), that has error checking to ensure that it is only used by our RenderScript targets. I assume that the cleanest way to retain that diagnostic (and get the last of these divergent patches in) will be to still key off of a LangOpt. If you think it is preferable to check against a target instead, I can change the code to do that, but I figured this is more consistent with how other attributes work.


We discussed this again today, and our preferred way forward is:

1. We have new targets for 32-bit and 64-bit renderscript as described here. The new targets are exactly the same as the relevant ARM targets except that they force the size and alignment of long to 8. (We may want to consider also making these targets imply -emit-llvm, especially if our notional model for the target is that its "machine code" is LLVM IR with an ARM triple.)

2. We have a new LangOption and InputKind for renderscript, which can be specified via -x renderscript and is implied by a .rs file extension. This LangOption controls the existence of the "kernel" attribute, and some renderscript-specific implicit conversion rules.

... and we treat (1) and (2) as orthogonal concerns (much like the SPIR target and OpenCL language); you can compile plain C or C++ to the renderscript target if you want, or request the renderscript language rules while targeting x86, even though these are not likely to be particularly useful configurations in practice.


http://reviews.llvm.org/D20709