This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: [x86-64 psABI]: Extend x86-64 psABI to support AVX-512
- From: Rich Felker <dalias at aerifal dot cx>
- To: OndÅej BÃlka <neleai at seznam dot cz>
- Cc: Jakub Jelinek <jakub at redhat dot com>, Richard Biener <richard dot guenther at gmail dot com>, "H.J. Lu" <hjl dot tools at gmail dot com>, GNU C Library <libc-alpha at sourceware dot org>, GCC Development <gcc at gcc dot gnu dot org>, Binutils <binutils at sourceware dot org>, "Girkar, Milind" <milind dot girkar at intel dot com>, "Kreitzer, David L" <david dot l dot kreitzer at intel dot com>
- Date: Sat, 27 Jul 2013 12:24:32 -0400
- Subject: Re: [x86-64 psABI]: Extend x86-64 psABI to support AVX-512
- References: <CAMe9rOrvMxSLj3LcYBs71tVdw6C0vJFKD2HxvnoHc13UamftwA at mail dot gmail dot com> <ddab98c2-bb3b-4d02-b403-e7d5690cfe00 at email dot android dot com> <CAMe9rOpxErCVtE-PDZ3Yb9mL+4E+XQ-are9Df4YBbEioj+MmZA at mail dot gmail dot com> <b9c5d467-834a-4b57-b48c-ac4bb450c9e5 at email dot android dot com> <20130725030655 dot GL14138 at laptop dot redhat dot com> <20130725065538 dot GA18427 at domone dot kolej dot mff dot cuni dot cz> <20130725165053 dot GJ4284 at brightrain dot aerifal dot cx> <20130727154405 dot GA25725 at domone dot kolej dot mff dot cuni dot cz> <20130727161257 dot GY4284 at brightrain dot aerifal dot cx>
On Sat, Jul 27, 2013 at 12:12:57PM -0400, Rich Felker wrote:
> By the way, I do have another horrible idea for how you could do it.
> glibc's jmp_buf is actually a sigjmp_buf and contains 120 wasted bytes
> of sigset_t for nonexistant HURD signals. So you could store a few
> registers after the actually-used part of the sigset_t.
And another, possibly more acceptable way to do it:
#define setjmp(x) __new_setjmp(x, (__new_jmp_buf){0}, sizeof(__new_jmp_buf))
This would allocate the extra space on the caller's stack with a
lifetime equivalent to the validity lifetime of the jmp_buf, so it
should be valid, but I'm not sure if it covers all the needed cases
for interaction between old code and new code.
Rich