https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104610
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Depends on| |104704
--- Comment #12 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Hongtao.liu from comment #8)
> Created attachment 52495 [details]
> untested patch.
>
> With the patch, it exposes one potential issue related to dse(or
> ix86_gen_scratch_sse_rtx usage). in dse1, it try to replace load insn with
> equivalent value, but the inserted new insns(insn 45, insn 44, insn 46) will
> set xmm31, but dse is not aware of that, and xmm31 is alive and will be used
> by insn 10 which is exactly after new added insns, and it breaks data flow.
>
I opened PR 104704.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104704
[Bug 104704] [12 Regression] ix86_gen_scratch_sse_rtx doesn't work with
explicit XMM7/XMM15/XMM31 usage
