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[PATCH] ARM: Fix performance issue in strcpy

From: "Wilco Dijkstra" <wdijkstr at arm dot com>
To: <libc-alpha at sourceware dot org>
Date: Thu, 7 Aug 2014 14:40:20 +0100
Subject: [PATCH] ARM: Fix performance issue in strcpy
Authentication-results: sourceware.org; auth=none

Hi,

This patch fixes a performance bug in strcp. The code dealing with unaligned copies uses mvns to
detect whether a register is 0. This is incorrect - the zero flag is only set if the value is -1. As
a result the code always does a byte-by-byte copy for the full string rather than doing the
word-based copy for the misaligned cases. Fixing this more than doubles performance.

OK for commit?

ChangeLog:
2014-08-07  Wilco Dijkstra <wdijkstr@arm.com>

	* sysdeps/arm/armv6/strcpy.S (strcpy):
	Fix performance issue in misaligned cases.

Attachment: Fix-performance-issue-in-strcpy.txt
Description: Text document

Follow-Ups:
- Re: [PATCH] ARM: Fix performance issue in strcpy
  - From: Joseph S. Myers

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