Re: [PHP4BETA] cvs: php4 /ext/standard/ levenshtein.c

The problem with the 'dirty trick' is that sizeof(void *) isn't necessarily 
equal to sizeof(int).  On many platforms it isn't.

Zeev

At 22:07 23/05/2000 , Hartmut Holzgraefe wrote:
>hholzgra                Tue May 23 22:07:32 2000 EDT
>
>   Modified files:
>     /php4/ext/standard  levenshtein.c
>   Log:
>   a little less optimized, but no dirty tricks anymore
>
>
>Index: php4/ext/standard/levenshtein.c
>diff -u php4/ext/standard/levenshtein.c:1.4 
>php4/ext/standard/levenshtein.c:1.5
>--- php4/ext/standard/levenshtein.c:1.4 Tue May 23 21:27:02 2000
>+++ php4/ext/standard/levenshtein.c     Tue May 23 22:07:32 2000
>@@ -15,7 +15,7 @@
>     | Author: Bjørn Borud - Guardian Networks AS <[email protected]>       |
>     +----------------------------------------------------------------------+
>   */
>-/* $Id: levenshtein.c,v 1.4 2000/05/23 19:27:02 sas Exp $ */
>+/* $Id: levenshtein.c,v 1.5 2000/05/23 20:07:32 hholzgra Exp $ */
>
>  #include "php.h"
>  #include <stdlib.h>
>@@ -25,10 +25,11 @@
>
>  static int calc_levdist(const char *s1, const char *s2) /* faster, but 
> obfuscated */
>  {
>-       register char *p1,*p2;
>+       register char *p1,*p2;
>         register int i,j,n;
>         int l1=0,l2=0;
>         char r[512];
>+       const char *tmp;
>
>         /* skip equal start sequence, if any */
>         while(*s1==*s2) {
>@@ -54,22 +55,15 @@
>         /* reset pointers, adjust length */
>         s1-=l1++;
>         s2-=l2++;
>+
>
>         /* possible dist to great? */
>         if(abs(l1-l2)>=255) return -1;
>
>         /* swap if l2 longer than l1 */
>         if(l1<l2) {
>-               const char *s3;
>-               int l3;
>-
>-               s3 = s1;
>-               s1 = s2;
>-               s2 = s3;
>-
>-               l3 = l1;
>-               l1 = l2;
>-               l2 = l3;
>+               tmp=s1; s1=s2; s2=tmp;
>+               l1 ^= l2; l2 ^= l1; l1 ^= l2;
>         }
>
>
>
>
>
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--
Zeev Suraski   <[email protected]>  http://www.zend.com/