github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/x86_64/k10/hamdist.asm (about)

     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()