diff options
Diffstat (limited to 'src/kmk/inlined_memchr.h')
| -rw-r--r-- | src/kmk/inlined_memchr.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/kmk/inlined_memchr.h b/src/kmk/inlined_memchr.h new file mode 100644 index 0000000..9666635 --- /dev/null +++ b/src/kmk/inlined_memchr.h @@ -0,0 +1,162 @@ +#define _GNU_SOURCE 1 +#include <string.h> + +#ifdef _MSC_VER +_inline void * +#else +static __inline__ void * +#endif +my_inline_memchr(const void *pv, int ch, register size_t cb) +{ + register const unsigned int uch = (unsigned)ch; + register const unsigned char *pb = (const unsigned char *)pv; +#if 0 /* 8-byte loop unroll */ + while (cb >= 8) + { + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + if (pb[3] == uch) + return (unsigned char *)pb + 3; + if (pb[4] == uch) + return (unsigned char *)pb + 4; + if (pb[5] == uch) + return (unsigned char *)pb + 5; + if (pb[6] == uch) + return (unsigned char *)pb + 6; + if (pb[7] == uch) + return (unsigned char *)pb + 7; + cb -= 8; + pb += 8; + } + switch (cb & 7) + { + case 0: + break; + case 1: + if (*pb == uch) + return (unsigned char *)pb; + break; + case 2: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + break; + case 3: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + break; + case 4: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + if (pb[3] == uch) + return (unsigned char *)pb + 3; + break; + case 5: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + if (pb[3] == uch) + return (unsigned char *)pb + 3; + if (pb[4] == uch) + return (unsigned char *)pb + 4; + break; + case 6: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + if (pb[3] == uch) + return (unsigned char *)pb + 3; + if (pb[4] == uch) + return (unsigned char *)pb + 4; + if (pb[5] == uch) + return (unsigned char *)pb + 5; + break; + case 7: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + if (pb[3] == uch) + return (unsigned char *)pb + 3; + if (pb[4] == uch) + return (unsigned char *)pb + 4; + if (pb[5] == uch) + return (unsigned char *)pb + 5; + if (pb[6] == uch) + return (unsigned char *)pb + 6; + break; + } + +#elif 1 /* 4 byte loop unroll */ + while (cb >= 4) + { + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + if (pb[3] == uch) + return (unsigned char *)pb + 3; + cb -= 4; + pb += 4; + } + switch (cb & 3) + { + case 0: + break; + case 1: + if (*pb == uch) + return (unsigned char *)pb; + break; + case 2: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + break; + case 3: + if (*pb == uch) + return (unsigned char *)pb; + if (pb[1] == uch) + return (unsigned char *)pb + 1; + if (pb[2] == uch) + return (unsigned char *)pb + 2; + break; + } + +#else /* the basic loop */ + while (cb > 0) + { + if (*pb == uch) + return (void *)pb; + cb--; + pb++; + } +#endif + return 0; +} + +#define memchr my_inline_memchr + |