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
  21 ENTRY(_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
  47 ENDPROC(_memchr)