Hej Henrik, On Thu, 19 Apr 2018, Henrik Gramner via cfe-commits wrote:
The force_align_arg_pointer attribute was using a hardcoded 16-byte alignment value which in combination with -mstack-alignment=32 (or larger) would produce a misaligned stack which could result in crashes when accessing stack buffers using aligned AVX load/store instructions. The attached patch fixes the issue by using the "stackrealign" function attribute instead of using a hardcoded 16-byte alignment. Tested on 64-bit Linux and it works as far as I can see, unable to test on anything else though.
You need to update the corresponding tests as well, run "ninja check-clang" to see that this change alters the output from test/CodeGen/function-attributes.c, breaking that test. You at least need to update it with how this patch changes the behaviour of the existing tests, but ideally also add a new test case (either in this file or as a completely new file) for the specific usecase that you had in mind (32 byte alignment).
For better visibility, I'd also recommend uploading the patch at https://reviews.llvm.org (even though the official guidelines say this is optional). I don't know off-hand who would be best to add as reviewer for it though (I'm not authoritative in this area)...
// Martin _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
