arch/blackfin/lib/memmove.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 .align 2
  10
  11 /*
  12  * C Library function MEMMOVE
  13  * R0 = To Address (leave unchanged to form result)
  14  * R1 = From Address
  15  * R2 = count
  16  * Data may overlap
  17  */
  18
  19 ENTRY(_memmove)
  20         I1 = P3;
  21         P0 = R0;                  /* P0 = To address */
  22         P3 = R1;                  /* P3 = From Address */
  23         P2 = R2;                  /* P2 = count */
  24         CC = P2 == 0;             /* Check zero count*/
  25         IF CC JUMP .Lfinished;    /* very unlikely */
  26
  27         CC = R1 < R0 (IU);        /* From < To */
  28         IF !CC JUMP .Lno_overlap;
  29         R3 = R1 + R2;
  30         CC = R0 <= R3 (IU);       /* (From+len) >= To */
  31         IF CC JUMP .Loverlap;
  32 .Lno_overlap:
  33         R3 = 11;
  34         CC = R2 <= R3;
  35         IF CC JUMP .Lbytes;
  36         R3 = R1 | R0;             /* OR addresses together */
  37         R3 <<= 30;                /* check bottom two bits */
  38         CC =  AZ;                 /* AZ set if zero.*/
  39         IF !CC JUMP .Lbytes;      /* Jump if addrs not aligned.*/
  40
  41         I0 = P3;
  42         P1 = P2 >> 2;             /* count = n/4 */
  43         P1 += -1;
  44         R3 =  3;
  45         R2 = R2 & R3;             /* remainder */
  46         P2 = R2;                  /* set remainder */
  47         R1 = [I0++];
  48
  49         LSETUP (.Lquad_loops, .Lquad_loope) LC0=P1;
  50 #if ANOMALY_05000202
  51 .Lquad_loops:
  52         [P0++] = R1;
  53 .Lquad_loope:
  54         R1 = [I0++];
  55 #else
  56 .Lquad_loops:
  57 .Lquad_loope:
  58          MNOP || [P0++] = R1 || R1 = [I0++];
  59 #endif
  60         [P0++] = R1;
  61
  62         CC = P2 == 0;             /* any remaining bytes? */
  63         P3 = I0;                  /* Amend P3 to updated ptr. */
  64         IF !CC JUMP .Lbytes;
  65         P3 = I1;
  66         RTS;
  67
  68 .Lbytes:     LSETUP (.Lbyte2_s, .Lbyte2_e) LC0=P2;
  69 .Lbyte2_s:   R1 = B[P3++](Z);
  70 .Lbyte2_e:   B[P0++] = R1;
  71
  72 .Lfinished:  P3 = I1;
  73         RTS;
  74
  75 .Loverlap:
  76         P2 += -1;
  77         P0 = P0 + P2;
  78         P3 = P3 + P2;
  79         R1 = B[P3--] (Z);
  80         CC = P2 == 0;
  81         IF CC JUMP .Lno_loop;
  82 #if ANOMALY_05000245
  83         NOP;
  84         NOP;
  85 #endif
  86         LSETUP (.Lol_s, .Lol_e) LC0 = P2;
  87 .Lol_s:    B[P0--] = R1;
  88 .Lol_e:    R1 = B[P3--] (Z);
  89 .Lno_loop: B[P0] = R1;
  90         P3 = I1;
  91         RTS;
  92
  93 ENDPROC(_memmove)