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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.17.0/] [newlib/] [libc/] [machine/] [xscale/] [memchr.c] - Blame information for rev 208

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Line No. Rev Author Line
1 148 jeremybenn
#if defined __thumb__
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#include "../../string/memchr.c"
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#else
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#include <string.h>
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#include "xscale.h"
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void *
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memchr (const void *start, int c, size_t len)
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{
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  const char *str = start;
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  if (len == 0)
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    return 0;
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  asm (PRELOADSTR ("%0") : : "r" (start));
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  c &= 0xff;
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#ifndef __OPTIMIZE_SIZE__
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  /* Skip unaligned part.  */
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  if ((long)str & 3)
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    {
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      str--;
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      do
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        {
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          if (*++str == c)
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            return (void *)str;
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        }
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      while (((long)str & 3) != 0 && --len > 0);
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    }
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  if (len > 3)
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    {
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      unsigned int c2 = c + (c << 8);
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      c2 += c2 << 16;
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      /* Load two constants:
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         R7 = 0xfefefeff [ == ~(0x80808080 << 1) ]
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         R6 = 0x80808080  */
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      asm (
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       "mov     r6, #0x80\n\
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        add     r6, r6, #0x8000\n\
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        add     r6, r6, r6, lsl #16\n\
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        mvn     r7, r6, lsl #1\n\
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\n\
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0:\n\
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        cmp     %1, #0x7\n\
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        bls     1f\n\
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\n\
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        ldmia   %0!, { r3, r9 }\n\
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"       PRELOADSTR ("%0") "\n\
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        sub     %1, %1, #8\n\
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        eor     r3, r3, %2\n\
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        eor     r9, r9, %2\n\
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        add     r2, r3, r7\n\
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        add     r8, r9, r7\n\
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        bic     r2, r2, r3\n\
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        bic     r8, r8, r9\n\
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        and     r1, r2, r6\n\
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        and     r9, r8, r6\n\
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        orrs    r1, r1, r9\n\
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        beq     0b\n\
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\n\
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        add     %1, %1, #8\n\
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        sub     %0, %0, #8\n\
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1:\n\
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        cmp     %1, #0x3\n\
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        bls     2f\n\
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\n\
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        ldr     r3, [%0], #4\n\
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"       PRELOADSTR ("%0") "\n\
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        sub     %1, %1, #4\n\
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        eor     r3, r3, %2\n\
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        add     r2, r3, r7\n\
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        bic     r2, r2, r3\n\
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        ands    r1, r2, r6\n\
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        beq     1b\n\
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\n\
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        sub     %0, %0, #4\n\
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        add     %1, %1, #4\n\
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2:\n\
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"
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       : "=&r" (str), "=&r" (len)
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       : "r" (c2), "0" (str), "1" (len)
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       : "r1", "r2", "r3", "r6", "r7", "r8", "r9", "cc");
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    }
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#endif
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  while (len-- > 0)
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    {
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      if (*str == c)
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        return (void *)str;
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      str++;
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    }
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  return 0;
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}
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#endif

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