This is the mail archive of the binutils@sourceware.org mailing list for the binutils project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

[patch] Use unaligned access on x86_64

From: Rafael EspÃndola <rafael dot espindola at gmail dot com>
To: Binutils <binutils at sourceware dot org>
Cc: Cary Coutant <ccoutant at gmail dot com>
Date: Fri, 24 Apr 2015 10:54:33 -0400
Subject: [patch] Use unaligned access on x86_64
Authentication-results: sourceware.org; auth=none

Hi,

x86_64 has exquisite support for unaligned loads. It is a shame not to use it.

The attached patch avoids aligning archive members on x86_64. The
results when linking clang are very interesting:

* massif reports that the malloc memory usage goes from 331,295,192
bytes to just 133,415,136 bytes.

* the linking time (30 runs average) goes from

1.310065610 seconds time elapsed ( +-  0.19% )

to

1.162564763 seconds time elapsed ( +-  0.14% )


Cheers,
Rafael


2015-04-24  Rafael Ãvila de EspÃndola <rafael.espindola@gmail.com>

* fileread.cc (find_or_make_view): Don't align on x86_64.

Attachment: t.patch
Description: Binary data

Follow-Ups:
- Re: [patch] Use unaligned access on x86_64
  - From: Rafael EspÃndola

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]