arch/h8300/lib/memcpy.S

   1 ;;; memcpy.S
   2
   3 #include <asm/linkage.h>
   4
   5 #if defined(__H8300H__)
   6         .h8300h
   7 #endif
   8 #if defined(__H8300S__)
   9         .h8300s
  10 #endif
  11
  12         .text
  13 .global SYMBOL_NAME(memcpy)
  14
  15 ;;; void *memcpy(void *to, void *from, size_t n)
  16 SYMBOL_NAME_LABEL(memcpy)
  17         mov.l   er2,er2
  18         bne     1f
  19         rts
  20 1:
  21         ;; address check
  22         bld     #0,r0l
  23         bxor    #0,r1l
  24         bcs     4f
  25         mov.l   er4,@-sp
  26         mov.l   er0,@-sp
  27         btst    #0,r0l
  28         beq     1f
  29         ;; (aligned even) odd address
  30         mov.b   @er1,r3l
  31         mov.b   r3l,@er0
  32         adds    #1,er1
  33         adds    #1,er0
  34         dec.l   #1,er2
  35         beq     3f
  36 1:
  37         ;; n < sizeof(unsigned long) check
  38         sub.l   er4,er4
  39         adds    #4,er4          ; loop count check value
  40         cmp.l   er4,er2
  41         blo     2f
  42         ;; unsigned long copy
  43 1:
  44         mov.l   @er1,er3
  45         mov.l   er3,@er0
  46         adds    #4,er0
  47         adds    #4,er1
  48         subs    #4,er2
  49         cmp.l   er4,er2
  50         bcc     1b
  51         ;; rest
  52 2:
  53         mov.l   er2,er2
  54         beq     3f
  55 1:
  56         mov.b   @er1,r3l
  57         mov.b   r3l,@er0
  58         adds    #1,er1
  59         adds    #1,er0
  60         dec.l   #1,er2
  61         bne     1b
  62 3:
  63         mov.l   @sp+,er0
  64         mov.l   @sp+,er4
  65         rts
  66
  67         ;; odd <- even / even <- odd
  68 4:
  69         mov.l   er4,er3
  70         mov.l   er2,er4
  71         mov.l   er5,er2
  72         mov.l   er1,er5
  73         mov.l   er6,er1
  74         mov.l   er0,er6
  75 1:
  76         eepmov.w
  77         mov.w   r4,r4
  78         bne     1b
  79         dec.w   #1,e4
  80         bpl     1b
  81         mov.l   er1,er6
  82         mov.l   er2,er5
  83         mov.l   er3,er4
  84         rts