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Re: [PATCH 25/27] S390: Optimize wmemset.

From: Stefan Liebler <stli at linux dot vnet dot ibm dot com>
To: libc-alpha at sourceware dot org
Date: Mon, 29 Jun 2015 11:23:52 +0200
Subject: Re: [PATCH 25/27] S390: Optimize wmemset.
Authentication-results: sourceware.org; auth=none
References: <1435319512-22245-1-git-send-email-stli at linux dot vnet dot ibm dot com> <1435319512-22245-26-git-send-email-stli at linux dot vnet dot ibm dot com> <20150626135358 dot GE20165 at domone>

On 06/26/2015 03:53 PM, OndÅej BÃlka wrote:

On Fri, Jun 26, 2015 at 01:51:50PM +0200, Stefan Liebler wrote:

This patch provides optimized version of wmemset with the z13 vector
instructions.

Why do you optimize wmemset but not memset?

The current memset implementation uses mvc instruction.
It is optimized for setting one byte, which is still the preferred way
for memset. But setting four bytes with mvc is not optimized in this
way and thus only wmemset is optimized with vector instructions.

Follow-Ups:
- Re: [PATCH 25/27] S390: Optimize wmemset.
  - From: OndÅej BÃlka

References:
- [PATCH 00/27] S390: Optimize string, wcsmbs and memory functions.
  - From: Stefan Liebler
- [PATCH 25/27] S390: Optimize wmemset.
  - From: Stefan Liebler
- Re: [PATCH 25/27] S390: Optimize wmemset.
  - From: OndÅej BÃlka

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