source/libs/gmp/gmp-src/mpn/x86/k7/mmx/copyd.asm

   1 dnl  AMD K7 mpn_copyd -- copy limb vector, decrementing.
   2
   3 dnl  Copyright 1999, 2000, 2002 Free Software Foundation, Inc.
   4
   5 dnl  This file is part of the GNU MP Library.
   6 dnl
   7 dnl  The GNU MP Library is free software; you can redistribute it and/or modify
   8 dnl  it under the terms of either:
   9 dnl
  10 dnl    * the GNU Lesser General Public License as published by the Free
  11 dnl      Software Foundation; either version 3 of the License, or (at your
  12 dnl      option) any later version.
  13 dnl
  14 dnl  or
  15 dnl
  16 dnl    * the GNU General Public License as published by the Free Software
  17 dnl      Foundation; either version 2 of the License, or (at your option) any
  18 dnl      later version.
  19 dnl
  20 dnl  or both in parallel, as here.
  21 dnl
  22 dnl  The GNU MP Library is distributed in the hope that it will be useful, but
  23 dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  24 dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  25 dnl  for more details.
  26 dnl
  27 dnl  You should have received copies of the GNU General Public License and the
  28 dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
  29 dnl  see https://www.gnu.org/licenses/.
  30
  31 include(`../config.m4')
  32
  33
  34 C    alignment dst/src, A=0mod8 N=4mod8
  35 C       A/A   A/N   N/A   N/N
  36 C K7    0.75  1.0   1.0   0.75
  37
  38
  39 C void mpn_copyd (mp_ptr dst, mp_srcptr src, mp_size_t size);
  40 C
  41 C The various comments in mpn/x86/k7/copyi.asm apply here too.
  42
  43 defframe(PARAM_SIZE,12)
  44 defframe(PARAM_SRC, 8)
  45 defframe(PARAM_DST, 4)
  46 deflit(`FRAME',0)
  47
  48 dnl  parameter space reused
  49 define(SAVE_EBX,`PARAM_SIZE')
  50 define(SAVE_ESI,`PARAM_SRC')
  51
  52 dnl  minimum 5 since the unrolled code can't handle less than 5
  53 deflit(UNROLL_THRESHOLD, 5)
  54
  55         TEXT
  56         ALIGN(32)
  57 PROLOGUE(mpn_copyd)
  58
  59         movl    PARAM_SIZE, %ecx
  60         movl    %ebx, SAVE_EBX
  61
  62         movl    PARAM_SRC, %eax
  63         movl    PARAM_DST, %edx
  64
  65         cmpl    $UNROLL_THRESHOLD, %ecx
  66         jae     L(unroll)
  67
  68         orl     %ecx, %ecx
  69         jz      L(simple_done)
  70
  71 L(simple):
  72         C eax   src
  73         C ebx   scratch
  74         C ecx   counter
  75         C edx   dst
  76         C
  77         C this loop is 2 cycles/limb
  78
  79         movl    -4(%eax,%ecx,4), %ebx
  80         movl    %ebx, -4(%edx,%ecx,4)
  81         decl    %ecx
  82         jnz     L(simple)
  83
  84 L(simple_done):
  85         movl    SAVE_EBX, %ebx
  86         ret
  87
  88
  89 L(unroll):
  90         movl    %esi, SAVE_ESI
  91         leal    (%eax,%ecx,4), %ebx
  92         leal    (%edx,%ecx,4), %esi
  93
  94         andl    %esi, %ebx
  95         movl    SAVE_ESI, %esi
  96         subl    $4, %ecx                C size-4
  97
  98         testl   $4, %ebx   C testl to pad code closer to 16 bytes for L(top)
  99         jz      L(aligned)
 100
 101         C both src and dst unaligned, process one limb to align them
 102         movl    12(%eax,%ecx,4), %ebx
 103         movl    %ebx, 12(%edx,%ecx,4)
 104         decl    %ecx
 105 L(aligned):
 106
 107
 108         ALIGN(16)
 109 L(top):
 110         C eax   src
 111         C ebx
 112         C ecx   counter, limbs
 113         C edx   dst
 114
 115         movq    8(%eax,%ecx,4), %mm0
 116         movq    (%eax,%ecx,4), %mm1
 117         subl    $4, %ecx
 118         movq    %mm0, 16+8(%edx,%ecx,4)
 119         movq    %mm1, 16(%edx,%ecx,4)
 120         jns     L(top)
 121
 122
 123         C now %ecx is -4 to -1 representing respectively 0 to 3 limbs remaining
 124
 125         testb   $2, %cl
 126         jz      L(finish_not_two)
 127
 128         movq    8(%eax,%ecx,4), %mm0
 129         movq    %mm0, 8(%edx,%ecx,4)
 130 L(finish_not_two):
 131
 132         testb   $1, %cl
 133         jz      L(done)
 134
 135         movl    (%eax), %ebx
 136         movl    %ebx, (%edx)
 137
 138 L(done):
 139         movl    SAVE_EBX, %ebx
 140         emms
 141         ret
 142
 143
 144 EPILOGUE()