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Re: [PATCH] Introduce MODE_SIZE mode attribute
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: "Joseph S. Myers" <joseph at codesourcery dot com>, Uros Bizjak <ubizjak at gmail dot com>, Richard Henderson <rth at redhat dot com>, Kirill Yukhin <kirill dot yukhin at gmail dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 18 Apr 2014 08:00:55 -0700
- Subject: Re: [PATCH] Introduce MODE_SIZE mode attribute
- Authentication-results: sourceware.org; auth=none
- References: <20140103084802 dot GV892 at tucnak dot redhat dot com> <Pine dot LNX dot 4 dot 64 dot 1401031529090 dot 6742 at digraph dot polyomino dot org dot uk> <20140103233757 dot GR892 at tucnak dot redhat dot com> <20140106152055 dot GI892 at tucnak dot redhat dot com>
On Mon, Jan 6, 2014 at 7:20 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Sat, Jan 04, 2014 at 12:37:57AM +0100, Jakub Jelinek wrote:
>> That is certainly doable (as attached), but strangely if the patch (that I've
>> already committed) is reverted and this one applied, the .text savings are
>> much smaller.
>>
>> Here are .text and .rodata readelf -WS lines from x86_64 (first 4 pairs) and
>> i686 (last 4 pairs) builds, always vanilla trunk before r206312, that plus
>> r206312 patch, without r206312 but with attached patch, with both r206312
>> and attached patch. So, for .text size the best is both patches, but
>> for .rodata patches just r206312. I'll try to look at details why this is so
>> next week.
>
> The difference is I think caused by the way gencondition.c works.
> As the array with the conditions is a toplevel array, __builtin_constant_p
> is folded there already during the parsing, after folding the conditions.
>
For some reason, it triggered:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60887
--
H.J.