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[PATCH] remove unnecessary memset in strcoll
- From: Leonhard Holz <leonhard dot holz at web dot de>
- To: libc-alpha at sourceware dot org
- Date: Thu, 18 Jun 2015 13:41:32 +0200
- Subject: [PATCH] remove unnecessary memset in strcoll
- Authentication-results: sourceware.org; auth=none
This patch avoids some initialization overhead in the hot path of strcoll by
replacing a memset with zero assignments. It improves the file listing benchmark
by 15% on x86. Tests are ok.
filelist#C -1.30%
filelist#en_US.UTF-8 -15.08%
lorem_ipsum#vi_VN.UTF-8 -15.04%
lorem_ipsum#ar_SA.UTF-8 -11.83%
lorem_ipsum#en_US.UTF-8 -9.66%
lorem_ipsum#zh_CN.UTF-8 -8.63%
lorem_ipsum#cs_CZ.UTF-8 -8.28%
lorem_ipsum#en_GB.UTF-8 -18.07%
lorem_ipsum#da_DK.UTF-8 -11.13%
lorem_ipsum#pl_PL.UTF-8 -15.31%
lorem_ipsum#fr_FR.UTF-8 -12.26%
lorem_ipsum#pt_PT.UTF-8 -10.64%
lorem_ipsum#el_GR.UTF-8 -8.19%
lorem_ipsum#ru_RU.UTF-8 -0.65%
lorem_ipsum#iw_IL.UTF-8 -14.92%
lorem_ipsum#es_ES.UTF-8 -11.47%
lorem_ipsum#hi_IN.UTF-8 -1.05%
lorem_ipsum#sv_SE.UTF-8 6.44%
lorem_ipsum#hu_HU.UTF-8 -9.85%
lorem_ipsum#tr_TR.UTF-8 -14.96%
lorem_ipsum#is_IS.UTF-8 -10.35%
lorem_ipsum#it_IT.UTF-8 -11.33%
lorem_ipsum#sr_RS.UTF-8 -9.88%
lorem_ipsum#ja_JP.UTF-8 -3.23%
* string/strcoll_l.c (STRCOLL): Remove unnecessary memset.
diff --git a/string/strcoll_l.c b/string/strcoll_l.c
index 0fa005f..b4e3e9e 100644
--- a/string/strcoll_l.c
+++ b/string/strcoll_l.c
@@ -316,8 +316,11 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2,
__locale_t l)
int result = 0, rule = 0;
coll_seq seq1, seq2;
- memset (&seq1, 0, sizeof (seq1));
- seq2 = seq1;
+ seq1.len = 0;
+ seq1.idxmax = 0;
+ seq1.rule = 0;
+ seq2.len = 0;
+ seq2.idxmax = 0;
for (int pass = 0; pass < nrules; ++pass)
{