Date: Thu, 8 Oct 2015 12:33:55 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Garrett Cooper <yaneurabeya@gmail.com> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Subject: Re: Comparing behavior of test-fesetenv.c on AMD Opterons and Intel Xeons: running FNSTENV on Opteron -- should it zero out __x87.__other? Message-ID: <20151008093355.GS2257@kib.kiev.ua> In-Reply-To: <C2CE118D-8CB1-483B-9216-1ED89B9B830B@gmail.com> References: <CAGHfRMBwPfx2rNhHW2xviz59YsEDobjWfemY985PZc3=VM5C6w@mail.gmail.com> <20151008072444.GO2257@kib.kiev.ua> <F04AE220-DF83-44AC-8C23-A36F8D6EB9CA@gmail.com> <20151008080621.GP2257@kib.kiev.ua> <C2CE118D-8CB1-483B-9216-1ED89B9B830B@gmail.com>
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On Thu, Oct 08, 2015 at 02:14:12AM -0700, Garrett Cooper wrote: > > > On Oct 8, 2015, at 01:06, Konstantin Belousov <kostikbel@gmail.com> wrote: > > > >> On Thu, Oct 08, 2015 at 12:38:15AM -0700, Garrett Cooper wrote: > > ... > > >> Hi kib! > >> > >> Ok -- that's what my gut was telling me when I was reading the spec, but I needed a second opinion. Interesting how Intel leaves the __other field alone and AMD [opterons] don't ;/.. > > > > Your statement does not make any sense. Re-read what I tell above. > > The __other field is not written by code, the code does not change > > by the matter of being run on Intel or AMD processors. It just happens > > so that on one of your system the stack are seems to be zero, while on > > another, it does not. > > I thought __other corresponded to C0-C3 based on my read of the spec -- is that incorrect? What are C0-C3 you reference ? I can only think about condition code bits from the FPU status word which have that names, but the word is put into the __status field of fenv_t. And, what spec did you read ?
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