This is the mail archive of the
mailing list for the glibc project.
Re: [COMMITTED] tilegx: enable wordsize-64 support for ieee745 dbl-64.
- From: Chris Metcalf <cmetcalf at ezchip dot com>
- To: Andrew Pinski <pinskia at gmail dot com>
- Cc: "H.J. Lu" <hjl dot tools at gmail dot com>, Joseph Myers <joseph at codesourcery dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Fri, 26 Dec 2014 10:06:30 -0500
- Subject: Re: [COMMITTED] tilegx: enable wordsize-64 support for ieee745 dbl-64.
- Authentication-results: sourceware.org; auth=none
- Authentication-results: spf=none (sender IP is ) smtp dot mailfrom=cmetcalf at ezchip dot com;
- References: <201412231905 dot sBNJ5c3C004622 at farm-0002 dot internal dot tilera dot com> <alpine dot DEB dot 2 dot 10 dot 1412231958370 dot 31777 at digraph dot polyomino dot org dot uk> <5499D4FE dot 8070405 at ezchip dot com> <5499DA84 dot 3010205 at ezchip dot com> <CAMe9rOr2DU5qYDQriF9RvAJCJF_wZ3gzqqHGDZXf+-OZFuJX0g at mail dot gmail dot com> <5499E115 dot 9000502 at ezchip dot com> <CAMe9rOrFEVEpPik-qMR=SPM-Eqgetwg9C3oztjT4yTf74S+EWw at mail dot gmail dot com> <549AF3A3 dot 8070007 at ezchip dot com> <CA+=Sn1kumpH2iCOYykmJb8LjNA1jufoKj8hhqiA4XR=KtCJA-g at mail dot gmail dot com>
On 12/24/2014 6:45 PM, Andrew Pinski wrote:
On Wed, Dec 24, 2014 at 9:10 AM, Chris Metcalf <email@example.com> wrote:
On 12/23/2014 5:39 PM, H.J. Lu wrote:
You can provide a safe default and let x32 override it.
I think it's conventional now to require that platforms are explicit
about #defines, and use #if with -Wundef. It seems to make good sense
in this case, since it's really not clear what the right default for
any given platform is.
And since there are currently just two platforms that use wordsize-64
and are !_LP64 (x32 and tilegx32), it feels pretty reasonable to be
explicit for both. The AArch64 guys will need to set the right default
for their ILP32 mode; I'm not even sure what the right answer is for them.
AARCH64:ILP32 is fine with having the upper bits being undefined when
dealing with passing and return values.
So sounds like two in each "camp", x32 and AArch64:ILP32 not wanting a cast,
and tilegx32 and MIPS needing the explicit cast, so requiring a
preprocessor symbol to be defined for that code seems like the right thing.
Any objections to the proposed code to do the extension in llround.c?
Chris Metcalf, EZChip Semiconductor