arch/alpha/lib/memmove.S

   1 /*
   2  * arch/alpha/lib/memmove.S
   3  *
   4  * Barely optimized memmove routine for Alpha EV5.
   5  *
   6  * This is hand-massaged output from the original memcpy.c.  We defer to
   7  * memcpy whenever possible; the backwards copy loops are not unrolled.
   8  */
   9
  10         .set noat
  11         .set noreorder
  12         .text
  13
  14         .align 4
  15         .globl memmove
  16         .ent memmove
  17 memmove:
  18         ldgp $29, 0($27)
  19         unop
  20         nop
  21         .prologue 1
  22
  23         addq $16,$18,$4
  24         addq $17,$18,$5
  25         cmpule $4,$17,$1                /*  dest + n <= src  */
  26         cmpule $5,$16,$2                /*  dest >= src + n  */
  27
  28         bis $1,$2,$1
  29         mov $16,$0
  30         xor $16,$17,$2
  31         bne $1,memcpy                   !samegp
  32
  33         and $2,7,$2                     /* Test for src/dest co-alignment.  */
  34         and $16,7,$1
  35         cmpule $16,$17,$3
  36         bne $3,$memmove_up              /* dest < src */
  37
  38         and $4,7,$1
  39         bne $2,$misaligned_dn
  40         unop
  41         beq $1,$skip_aligned_byte_loop_head_dn
  42
  43 $aligned_byte_loop_head_dn:
  44         lda $4,-1($4)
  45         lda $5,-1($5)
  46         unop
  47         ble $18,$egress
  48
  49         ldq_u $3,0($5)
  50         ldq_u $2,0($4)
  51         lda $18,-1($18)
  52         extbl $3,$5,$1
  53
  54         insbl $1,$4,$1
  55         mskbl $2,$4,$2
  56         bis $1,$2,$1
  57         and $4,7,$6
  58
  59         stq_u $1,0($4)
  60         bne $6,$aligned_byte_loop_head_dn
  61
  62 $skip_aligned_byte_loop_head_dn:
  63         lda $18,-8($18)
  64         blt $18,$skip_aligned_word_loop_dn
  65
  66 $aligned_word_loop_dn:
  67         ldq $1,-8($5)
  68         nop
  69         lda $5,-8($5)
  70         lda $18,-8($18)
  71
  72         stq $1,-8($4)
  73         nop
  74         lda $4,-8($4)
  75         bge $18,$aligned_word_loop_dn
  76
  77 $skip_aligned_word_loop_dn:
  78         lda $18,8($18)
  79         bgt $18,$byte_loop_tail_dn
  80         unop
  81         ret $31,($26),1
  82
  83         .align 4
  84 $misaligned_dn:
  85         nop
  86         fnop
  87         unop
  88         beq $18,$egress
  89
  90 $byte_loop_tail_dn:
  91         ldq_u $3,-1($5)
  92         ldq_u $2,-1($4)
  93         lda $5,-1($5)
  94         lda $4,-1($4)
  95
  96         lda $18,-1($18)
  97         extbl $3,$5,$1
  98         insbl $1,$4,$1
  99         mskbl $2,$4,$2
 100
 101         bis $1,$2,$1
 102         stq_u $1,0($4)
 103         bgt $18,$byte_loop_tail_dn
 104         br $egress
 105
 106 $memmove_up:
 107         mov $16,$4
 108         mov $17,$5
 109         bne $2,$misaligned_up
 110         beq $1,$skip_aligned_byte_loop_head_up
 111
 112 $aligned_byte_loop_head_up:
 113         unop
 114         ble $18,$egress
 115         ldq_u $3,0($5)
 116         ldq_u $2,0($4)
 117
 118         lda $18,-1($18)
 119         extbl $3,$5,$1
 120         insbl $1,$4,$1
 121         mskbl $2,$4,$2
 122
 123         bis $1,$2,$1
 124         lda $5,1($5)
 125         stq_u $1,0($4)
 126         lda $4,1($4)
 127
 128         and $4,7,$6
 129         bne $6,$aligned_byte_loop_head_up
 130
 131 $skip_aligned_byte_loop_head_up:
 132         lda $18,-8($18)
 133         blt $18,$skip_aligned_word_loop_up
 134
 135 $aligned_word_loop_up:
 136         ldq $1,0($5)
 137         nop
 138         lda $5,8($5)
 139         lda $18,-8($18)
 140
 141         stq $1,0($4)
 142         nop
 143         lda $4,8($4)
 144         bge $18,$aligned_word_loop_up
 145
 146 $skip_aligned_word_loop_up:
 147         lda $18,8($18)
 148         bgt $18,$byte_loop_tail_up
 149         unop
 150         ret $31,($26),1
 151
 152         .align 4
 153 $misaligned_up:
 154         nop
 155         fnop
 156         unop
 157         beq $18,$egress
 158
 159 $byte_loop_tail_up:
 160         ldq_u $3,0($5)
 161         ldq_u $2,0($4)
 162         lda $18,-1($18)
 163         extbl $3,$5,$1
 164
 165         insbl $1,$4,$1
 166         mskbl $2,$4,$2
 167         bis $1,$2,$1
 168         stq_u $1,0($4)
 169
 170         lda $5,1($5)
 171         lda $4,1($4)
 172         nop
 173         bgt $18,$byte_loop_tail_up
 174
 175 $egress:
 176         ret $31,($26),1
 177         nop
 178         nop
 179         nop
 180
 181         .end memmove