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[/] [openrisc/] [trunk/] [gnu-old/] [newlib-1.17.0/] [newlib/] [libc/] [machine/] [xscale/] [strlen.c] - Blame information for rev 855

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Line No. Rev Author Line
1 148 jeremybenn 
#if defined __thumb__ || defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
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#include "../../string/strlen.c"
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#else
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#include <string.h>
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#include "xscale.h"
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size_t
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strlen (const char *str)
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{
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  _CONST char *start = str;
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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 == '\0')
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            goto out;
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        }
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      while ((long)str & 3);
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    }
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  /* Load two constants:
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     R4 = 0xfefefeff [ == ~(0x80808080 << 1) ]
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     R5 = 0x80808080  */
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  asm ("mov     r5, #0x80\n\
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        add     r5, r5, #0x8000\n\
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        add     r5, r5, r5, lsl #16\n\
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        mvn     r4, r5, lsl #1\n\
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"
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#if defined __ARM_ARCH_5__ || defined __ARM_ARCH_5T__ || defined __ARM_ARCH_5E__ || defined __ARM_ARCH_5TE__
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"       tst     %0, #0x7\n\
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        ldreqd  r6, [%0]\n\
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        beq     1f\n\
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        ldr     r2, [%0]\n\
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        add     r3, r2, r4\n\
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        bic     r3, r3, r2\n\
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        ands    r2, r3, r5\n\
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        bne     2f\n\
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        sub     %0, %0, #4\n\
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\n\
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0:\n\
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        ldrd    r6, [%0, #8]!\n\
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"
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        PRELOADSTR ("%0")
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"\n\
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1:\n\
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        add     r3, r6, r4\n\
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        add     r2, r7, r4\n\
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        bic     r3, r3, r6\n\
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        bic     r2, r2, r7\n\
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        and     r3, r3, r5\n\
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        and     r2, r2, r5\n\
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        orrs    r3, r2, r3\n\
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        beq     0b\n\
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"
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#else
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"       sub     %0, %0, #4\n\
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\n\
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0:\n\
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        ldr     r6, [%0, #4]!\n\
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"
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        PRELOADSTR ("%0")
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"\n\
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        add     r3, r6, r4\n\
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        bic     r3, r3, r6\n\
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        ands    r3, r3, r5\n\
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        beq     0b\n\
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"
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#endif /* __ARM_ARCH_5[T][E]__ */
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"\n\
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2:\n\
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        ldrb    r3, [%0]\n\
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        cmp     r3, #0x0\n\
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        beq     1f\n\
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\n\
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0:\n\
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        ldrb    r3, [%0, #1]!\n\
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"
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        PRELOADSTR ("%0")
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"\n\
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        cmp     r3, #0x0\n\
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        bne     0b\n\
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1:\n\
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"
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       : "=r" (str) : "0" (str) : "r2", "r3", "r4", "r5", "r6", "r7");
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  out:
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  return str - start;
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}
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#endif

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