This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: RFC Decrease excessive string literal alignment on IA-32/AMD64
- From: Richard Henderson <rth at redhat dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Wed, 21 Jan 2004 10:05:06 -0800
- Subject: Re: RFC Decrease excessive string literal alignment on IA-32/AMD64
- References: <20040121093425.GV31589@devserv.devel.redhat.com>
On Wed, Jan 21, 2004 at 04:34:25AM -0500, Jakub Jelinek wrote:
> I don't see anything which could take advantage of alignments bigger than
> word size.
I can only assume someone was thinking it would make it easier
for an sse-based str/memcpy.
> What do you think about either removing those 3 lines altogether
> (allowing string literal suffix merging to be really effective even on
> longer strings), or s/256/BITS_PER_WORD/ (suffix merging would only
> work between strings with equal sizes modulo UNITS_PER_WORD and not between
> really short and long strings), or s/256/BITS_PER_WORD/ and add
> !optimize_size, so that -Os makes the alignment 1?
I think the choice between BITS_PER_WORD and BITS_PER_UNIT (not 1!)
depends on how much merging we can show for your average application.
r~