github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/x86_64/core2/rshift.asm (about)

     1  dnl  x86-64 mpn_rshift optimized for "Core 2".
     2  
     3  dnl  Copyright 2007, 2009, 2011, 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  
    34  C	     cycles/limb
    35  C AMD K8,K9	 4.25
    36  C AMD K10	 4.25
    37  C Intel P4	14.7
    38  C Intel core2	 1.27
    39  C Intel NHM	 1.375	(up to about n = 260, then 1.5)
    40  C Intel SBR	 1.77
    41  C Intel atom	 ?
    42  C VIA nano	 ?
    43  
    44  
    45  C INPUT PARAMETERS
    46  define(`rp',	`%rdi')
    47  define(`up',	`%rsi')
    48  define(`n',	`%rdx')
    49  define(`cnt',	`%rcx')
    50  
    51  ABI_SUPPORT(DOS64)
    52  ABI_SUPPORT(STD64)
    53  
    54  ASM_START()
    55  	TEXT
    56  	ALIGN(16)
    57  PROLOGUE(mpn_rshift)
    58  	FUNC_ENTRY(4)
    59  	mov	R32(%rdx), R32(%rax)
    60  	and	$3, R32(%rax)
    61  	jne	L(nb00)
    62  L(b00):	C n = 4, 8, 12, ...
    63  	mov	(up), %r10
    64  	mov	8(up), %r11
    65  	xor	R32(%rax), R32(%rax)
    66  	shrd	R8(cnt), %r10, %rax
    67  	mov	16(up), %r8
    68  	lea	8(up), up
    69  	lea	-24(rp), rp
    70  	sub	$4, n
    71  	jmp	L(00)
    72  
    73  L(nb00):C n = 1, 5, 9, ...
    74  	cmp	$2, R32(%rax)
    75  	jae	L(nb01)
    76  L(b01):	mov	(up), %r9
    77  	xor	R32(%rax), R32(%rax)
    78  	shrd	R8(cnt), %r9, %rax
    79  	sub	$2, n
    80  	jb	L(le1)
    81  	mov	8(up), %r10
    82  	mov	16(up), %r11
    83  	lea	16(up), up
    84  	lea	-16(rp), rp
    85  	jmp	L(01)
    86  L(le1):	shr	R8(cnt), %r9
    87  	mov	%r9, (rp)
    88  	FUNC_EXIT()
    89  	ret
    90  
    91  L(nb01):C n = 2, 6, 10, ...
    92  	jne	L(b11)
    93  L(b10):	mov	(up), %r8
    94  	mov	8(up), %r9
    95  	xor	R32(%rax), R32(%rax)
    96  	shrd	R8(cnt), %r8, %rax
    97  	sub	$3, n
    98  	jb	L(le2)
    99  	mov	16(up), %r10
   100  	lea	24(up), up
   101  	lea	-8(rp), rp
   102  	jmp	L(10)
   103  L(le2):	shrd	R8(cnt), %r9, %r8
   104  	mov	%r8, (rp)
   105  	shr	R8(cnt), %r9
   106  	mov	%r9, 8(rp)
   107  	FUNC_EXIT()
   108  	ret
   109  
   110  	ALIGN(16)
   111  L(b11):	C n = 3, 7, 11, ...
   112  	mov	(up), %r11
   113  	mov	8(up), %r8
   114  	xor	R32(%rax), R32(%rax)
   115  	shrd	R8(cnt), %r11, %rax
   116  	mov	16(up), %r9
   117  	lea	32(up), up
   118  	sub	$4, n
   119  	jb	L(end)
   120  
   121  	ALIGN(16)
   122  L(top):	shrd	R8(cnt), %r8, %r11
   123  	mov	-8(up), %r10
   124  	mov	%r11, (rp)
   125  L(10):	shrd	R8(cnt), %r9, %r8
   126  	mov	(up), %r11
   127  	mov	%r8, 8(rp)
   128  L(01):	shrd	R8(cnt), %r10, %r9
   129  	mov	8(up), %r8
   130  	mov	%r9, 16(rp)
   131  L(00):	shrd	R8(cnt), %r11, %r10
   132  	mov	16(up), %r9
   133  	mov	%r10, 24(rp)
   134  	add	$32, up
   135  	lea	32(rp), rp
   136  	sub	$4, n
   137  	jnc	L(top)
   138  
   139  L(end):	shrd	R8(cnt), %r8, %r11
   140  	mov	%r11, (rp)
   141  	shrd	R8(cnt), %r9, %r8
   142  	mov	%r8, 8(rp)
   143  	shr	R8(cnt), %r9
   144  	mov	%r9, 16(rp)
   145  	FUNC_EXIT()
   146  	ret
   147  EPILOGUE()