[PATCH] avoid initialization overhead in strcoll

[Leonhard Holz <leonhard dot holz at web dot de>]

This patch removes some initialization overhead in the hot path of strcoll. It
improves the file listing benchmark by 20% on x86.

filelist#C			- 2.51%
filelist#en_US.UTF-8		-20.41%
lorem_ipsum#vi_VN.UTF-8		-29.86%
lorem_ipsum#en_US.UTF-8		-17.47%
lorem_ipsum#ar_SA.UTF-8		-15.81%
lorem_ipsum#zh_CN.UTF-8		- 5.03%
lorem_ipsum#cs_CZ.UTF-8		-13.44%
lorem_ipsum#en_GB.UTF-8		-14.51%
lorem_ipsum#da_DK.UTF-8		-18.99%
lorem_ipsum#pl_PL.UTF-8		-17.07%
lorem_ipsum#fr_FR.UTF-8		-16.64%
lorem_ipsum#pt_PT.UTF-8		-16.51%
lorem_ipsum#el_GR.UTF-8		-11.78%
lorem_ipsum#ru_RU.UTF-8		-14.07%
lorem_ipsum#iw_IL.UTF-8		- 9.20%
lorem_ipsum#es_ES.UTF-8		-22.05%
lorem_ipsum#hi_IN.UTF-8		  2.50%
lorem_ipsum#sv_SE.UTF-8		-18.63%
lorem_ipsum#hu_HU.UTF-8		-13.16%
lorem_ipsum#tr_TR.UTF-8		-16.54%
lorem_ipsum#is_IS.UTF-8		-17.30%
lorem_ipsum#it_IT.UTF-8		-17.82%
lorem_ipsum#sr_RS.UTF-8		-22.83%
lorem_ipsum#ja_JP.UTF-8		  4.99%


	* string/strcoll_l.c (STRCOLL): Removed unneeded initialization overhead.


diff --git a/string/strcoll_l.c b/string/strcoll_l.c
index 0fa005f..14bfb8b 100644
--- a/string/strcoll_l.c
+++ b/string/strcoll_l.c
@@ -62,7 +62,6 @@ typedef struct
   int len;			/* Length of the current sequence.  */
   size_t val;			/* Position of the sequence relative to the
 				   previous non-ignored sequence.  */
-  size_t idxnow;		/* Current index in sequences.  */
   size_t idxmax;		/* Maximum index in sequences.  */
   size_t idxcnt;		/* Current count of indices.  */
   size_t backw;			/* Current Backward sequence index.  */
@@ -313,20 +312,22 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2,
__locale_t l)
   assert (((uintptr_t) extra) % __alignof__ (extra[0]) == 0);
   assert (((uintptr_t) indirect) % __alignof__ (indirect[0]) == 0);

-  int result = 0, rule = 0;
-
+  int result = 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)
     {
       seq1.idxcnt = 0;
+      seq2.idxcnt = 0;
       seq1.idx = 0;
       seq2.idx = 0;
       seq1.backw_stop = ~0ul;
       seq1.backw = ~0ul;
-      seq2.idxcnt = 0;
       seq2.backw_stop = ~0ul;
       seq2.backw = ~0ul;

@@ -338,8 +339,7 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2,
__locale_t l)
       /* We assume that if a rule has defined `position' in one section
 	 this is true for all of them.  Please note that the localedef programs
 	 makes sure that `position' is not used at the first level.  */
-
-      int position = rulesets[rule * nrules + pass] & sort_position;
+      int position = rulesets[seq1.rule * nrules + pass] & sort_position;

       while (1)
 	{
@@ -372,8 +372,6 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2,
__locale_t l)
 	  if (result != 0)
 	    return result;
 	}
-
-      rule = seq1.rule;
     }

   return result;