LXR linux/arch/blackfin/lib/memchr.S

   1/*
   2 * Copyright 2005-2009 Analog Devices Inc.
   3 *
   4 * Licensed under the Clear BSD license or the GPL-2 (or later)
   5 */
   6
   7#include <linux/linkage.h>
   8
   9/* void *memchr(const void *s, int c, size_t n);
  10 * R0 = address (s)
  11 * R1 = sought byte (c)
  12 * R2 = count (n)
  13 *
  14 * Returns pointer to located character.
  15 */
  16
  17.text
  18
  19.align 2
  20
  21ENTRY(_memchr)
  22        P0 = R0;                /* P0 = address */
  23        P2 = R2;                /* P2 = count */
  24        R1 = R1.B(Z);
  25        CC = R2 == 0;
  26        IF CC JUMP .Lfailed;
  27
  28.Lbytes:
  29        LSETUP (.Lbyte_loop_s, .Lbyte_loop_e) LC0=P2;
  30
  31.Lbyte_loop_s:
  32        R3 = B[P0++](Z);
  33        CC = R3 == R1;
  34        IF CC JUMP .Lfound;
  35.Lbyte_loop_e:
  36        NOP;
  37
  38.Lfailed:
  39        R0=0;
  40        RTS;
  41
  42.Lfound:
  43        R0 = P0;
  44        R0 += -1;
  45        RTS;
  46
  47ENDPROC(_memchr)
  48