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Re: New optimized string routines for Intel and alignment of stack.
- From: Florian Weimer <fweimer at redhat dot com>
- To: Joseph Myers <joseph at codesourcery dot com>, "Carlos O'Donell" <carlos at redhat dot com>, GNU C Library <libc-alpha at sourceware dot org>, "H.J. Lu" <hjl dot tools at gmail dot com>
- Date: Sat, 11 Jun 2016 11:30:23 +0200
- Subject: Re: New optimized string routines for Intel and alignment of stack.
- Authentication-results: sourceware.org; auth=none
- References: <57566200 dot 2040203 at redhat dot com> <dea8c68f-cc02-9427-4e54-acd795a930cf at redhat dot com> <alpine dot DEB dot 2 dot 20 dot 1606071730590 dot 10967 at digraph dot polyomino dot org dot uk> <20160611060155 dot GJ4053 at vapier dot lan>
On 06/11/2016 08:01 AM, Mike Frysinger wrote:
On 07 Jun 2016 17:35, Joseph Myers wrote:
On Tue, 7 Jun 2016, Florian Weimer wrote:
On 06/07/2016 07:56 AM, Carlos O'Donell wrote:
We have had several users that have built legacy applications
for 32-bit x86 with stack alignment that does not match the
Let's say the GNU project broke the i386 ABI, which is more accurate. The
stack pointer alignment requirement is a recent change.
I place the ABI change around 2006, when GCC stopped using
-mpreferred-stack-boundary=2 even with -Os, and so compatibility
requirements as applying to GLIBC_2.4 and older symbols.
indeed, the ship has sailed. i don't think trying to revert things after
10 years makes sense.
Yeah, I didn't realize the only thing that might work is âpreserve
alignment, but don't rely on itâ. Performance-wise, this is the worst
option. But maybe we should do this in glibc.