LXR linux/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
  17memmove:
  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
 182