fixes for host gcc 4.6.1
[zpugcc/jano.git] / toolchain / gcc / newlib / libc / string / strchr.c
blob60b0fde8e6461e0eea6c21afb7b49366a239771e
1 /*
2 FUNCTION
3 <<strchr>>---search for character in string
5 INDEX
6 strchr
8 ANSI_SYNOPSIS
9 #include <string.h>
10 char * strchr(const char *<[string]>, int <[c]>);
12 TRAD_SYNOPSIS
13 #include <string.h>
14 char * strchr(<[string]>, <[c]>);
15 const char *<[string]>;
16 int <[c]>;
18 DESCRIPTION
19 This function finds the first occurence of <[c]> (converted to
20 a char) in the string pointed to by <[string]> (including the
21 terminating null character).
23 RETURNS
24 Returns a pointer to the located character, or a null pointer
25 if <[c]> does not occur in <[string]>.
27 PORTABILITY
28 <<strchr>> is ANSI C.
30 <<strchr>> requires no supporting OS subroutines.
32 QUICKREF
33 strchr ansi pure
36 #include <string.h>
37 #include <limits.h>
39 /* Nonzero if X is not aligned on a "long" boundary. */
40 #define UNALIGNED(X) ((long)X & (sizeof (long) - 1))
42 /* How many bytes are loaded each iteration of the word copy loop. */
43 #define LBLOCKSIZE (sizeof (long))
45 #if LONG_MAX == 2147483647L
46 #define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
47 #else
48 #if LONG_MAX == 9223372036854775807L
49 /* Nonzero if X (a long int) contains a NULL byte. */
50 #define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080)
51 #else
52 #error long int is not a 32bit or 64bit type.
53 #endif
54 #endif
56 /* DETECTCHAR returns nonzero if (long)X contains the byte used
57 to fill (long)MASK. */
58 #define DETECTCHAR(X,MASK) (DETECTNULL(X ^ MASK))
60 char *
61 _DEFUN (strchr, (s1, i),
62 _CONST char *s1 _AND
63 int i)
65 _CONST unsigned char *s = (_CONST unsigned char *)s1;
66 #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
67 unsigned char c = (unsigned int)i;
69 while (*s && *s != c)
71 s++;
74 if (*s != c)
76 s = NULL;
79 return (char *) s;
80 #else
81 unsigned char c = (unsigned char)i;
82 unsigned long mask,j;
83 unsigned long *aligned_addr;
85 if (!UNALIGNED (s))
87 mask = 0;
88 for (j = 0; j < LBLOCKSIZE; j++)
89 mask = (mask << 8) | c;
91 aligned_addr = (unsigned long*)s;
92 while (!DETECTNULL (*aligned_addr) && !DETECTCHAR (*aligned_addr, mask))
93 aligned_addr++;
95 /* The block of bytes currently pointed to by aligned_addr
96 contains either a null or the target char, or both. We
97 catch it using the bytewise search. */
99 s = (unsigned char*)aligned_addr;
102 while (*s && *s != c)
103 s++;
104 if (*s == c)
105 return (char *)s;
106 return NULL;
107 #endif /* not PREFER_SIZE_OVER_SPEED */