From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 25 May 2012 19:05:02 +0000 (-0700)
Subject: Merge branch 'rs/xdiff-fast-hash-fix'
X-Git-Tag: v1.7.11-rc0~9
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/0bc8bea2b4d73b20ce418b88300f498396d0a924?ds=inline;hp=-c

Merge branch 'rs/xdiff-fast-hash-fix'

Fixes compilation issue on 32-bit in an earlier series.
---

0bc8bea2b4d73b20ce418b88300f498396d0a924
diff --combined xdiff/xutils.c
index ae6ce0d95c,179bc4fe04..9504eaecb8
--- a/xdiff/xutils.c
+++ b/xdiff/xutils.c
@@@ -122,6 -122,35 +122,6 @@@ void *xdl_cha_alloc(chastore_t *cha) 
  	return data;
  }
  
 -
 -void *xdl_cha_first(chastore_t *cha) {
 -	chanode_t *sncur;
 -
 -	if (!(cha->sncur = sncur = cha->head))
 -		return NULL;
 -
 -	cha->scurr = 0;
 -
 -	return (char *) sncur + sizeof(chanode_t) + cha->scurr;
 -}
 -
 -
 -void *xdl_cha_next(chastore_t *cha) {
 -	chanode_t *sncur;
 -
 -	if (!(sncur = cha->sncur))
 -		return NULL;
 -	cha->scurr += cha->isize;
 -	if (cha->scurr == sncur->icurr) {
 -		if (!(sncur = cha->sncur = sncur->next))
 -			return NULL;
 -		cha->scurr = 0;
 -	}
 -
 -	return (char *) sncur + sizeof(chanode_t) + cha->scurr;
 -}
 -
 -
  long xdl_guess_lines(mmfile_t *mf, long sample) {
  	long nl = 0, size, tsize = 0;
  	char const *data, *cur, *top;
@@@ -251,9 -280,11 +251,11 @@@ static unsigned long xdl_hash_record_wi
  
  #ifdef XDL_FAST_HASH
  
- #define ONEBYTES	0x0101010101010101ul
- #define NEWLINEBYTES	0x0a0a0a0a0a0a0a0aul
- #define HIGHBITS	0x8080808080808080ul
+ #define REPEAT_BYTE(x)  ((~0ul / 0xff) * (x))
+ 
+ #define ONEBYTES	REPEAT_BYTE(0x01)
+ #define NEWLINEBYTES	REPEAT_BYTE(0x0a)
+ #define HIGHBITS	REPEAT_BYTE(0x80)
  
  /* Return the high bit set in the first byte that is a zero */
  static inline unsigned long has_zero(unsigned long a)
@@@ -270,21 -301,19 +272,19 @@@ static inline long count_masked_bytes(u
  		 * that works for the bytemasks without having to
  		 * mask them first.
  		 */
- 		return mask * 0x0001020304050608 >> 56;
- 	} else {
  		/*
- 		 * Modified Carl Chatfield G+ version for 32-bit *
+ 		 * return mask * 0x0001020304050608 >> 56;
  		 *
- 		 * (a) gives us
- 		 *   -1 (0, ff), 0 (ffff) or 1 (ffffff)
- 		 * (b) gives us
- 		 *   0 for 0, 1 for (ff ffff ffffff)
- 		 * (a+b+1) gives us
- 		 *   correct 0-3 bytemask count result
+ 		 * Doing it like this avoids warnings on 32-bit machines.
  		 */
- 		long a = (mask - 256) >> 23;
- 		long b = mask & 1;
- 		return a + b + 1;
+ 		long a = (REPEAT_BYTE(0x01) / 0xff + 1);
+ 		return mask * a >> (sizeof(long) * 7);
+ 	} else {
+ 		/* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
+ 		/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
+ 		long a = (0x0ff0001 + mask) >> 23;
+ 		/* Fix the 1 for 00 case */
+ 		return a & mask;
  	}
  }
  
@@@ -401,6 -430,20 +401,6 @@@ int xdl_num_out(char *out, long val) 
  	return str - out;
  }
  
 -
 -long xdl_atol(char const *str, char const **next) {
 -	long val, base;
 -	char const *top;
 -
 -	for (top = str; XDL_ISDIGIT(*top); top++);
 -	if (next)
 -		*next = top;
 -	for (val = 0, base = 1, top--; top >= str; top--, base *= 10)
 -		val += base * (long)(*top - '0');
 -	return val;
 -}
 -
 -
  int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
  		      const char *func, long funclen, xdemitcb_t *ecb) {
  	int nb = 0;