source/libs/gmp/gmp-src/mpn/x86_64/k10/hamdist.asm

   1 dnl  AMD64 mpn_hamdist -- hamming distance.
   2
   3 dnl  Copyright 2008, 2010-2012 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 C                   cycles/limb
  34 C AMD K8,K9              n/a
  35 C AMD K10                2
  36 C Intel P4               n/a
  37 C Intel core2            n/a
  38 C Intel corei            2.05
  39 C Intel atom             n/a
  40 C VIA nano               n/a
  41
  42 C This is very straightforward 2-way unrolled code.
  43
  44 C TODO
  45 C  * Write something less basic.  It should not be hard to reach 1.5 c/l with
  46 C    4-way unrolling.
  47
  48 define(`ap',            `%rdi')
  49 define(`bp',            `%rsi')
  50 define(`n',             `%rdx')
  51
  52 ABI_SUPPORT(DOS64)
  53 ABI_SUPPORT(STD64)
  54
  55 ASM_START()
  56         TEXT
  57         ALIGN(32)
  58 PROLOGUE(mpn_hamdist)
  59         FUNC_ENTRY(3)
  60         mov     (ap), %r8
  61         xor     (bp), %r8
  62
  63         lea     (ap,n,8), ap                    C point at A operand end
  64         lea     (bp,n,8), bp                    C point at B operand end
  65         neg     n
  66
  67         bt      $0, R32(n)
  68         jnc     L(2)
  69
  70 L(1):   .byte   0xf3,0x49,0x0f,0xb8,0xc0        C popcnt %r8, %rax
  71         xor     R32(%r10), R32(%r10)
  72         add     $1, n
  73         js      L(top)
  74         FUNC_EXIT()
  75         ret
  76
  77         ALIGN(16)
  78 L(2):   mov     8(ap,n,8), %r9
  79         .byte   0xf3,0x49,0x0f,0xb8,0xc0        C popcnt %r8, %rax
  80         xor     8(bp,n,8), %r9
  81         .byte   0xf3,0x4d,0x0f,0xb8,0xd1        C popcnt %r9, %r10
  82         add     $2, n
  83         js      L(top)
  84         lea     (%r10, %rax), %rax
  85         FUNC_EXIT()
  86         ret
  87
  88         ALIGN(16)
  89 L(top): mov     (ap,n,8), %r8
  90         lea     (%r10, %rax), %rax
  91         mov     8(ap,n,8), %r9
  92         xor     (bp,n,8), %r8
  93         xor     8(bp,n,8), %r9
  94         .byte   0xf3,0x49,0x0f,0xb8,0xc8        C popcnt %r8, %rcx
  95         lea     (%rcx, %rax), %rax
  96         .byte   0xf3,0x4d,0x0f,0xb8,0xd1        C popcnt %r9, %r10
  97         add     $2, n
  98         js      L(top)
  99
 100         lea     (%r10, %rax), %rax
 101         FUNC_EXIT()
 102         ret
 103 EPILOGUE()