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

     1  dnl  AMD64 mpn_lshift -- mpn left shift, optimised for Atom.
     2  
     3  dnl  Contributed to the GNU project by Torbjorn Granlund.
     4  
     5  dnl  Copyright 2011, 2012 Free Software Foundation, Inc.
     6  
     7  dnl  This file is part of the GNU MP Library.
     8  dnl
     9  dnl  The GNU MP Library is free software; you can redistribute it and/or modify
    10  dnl  it under the terms of either:
    11  dnl
    12  dnl    * the GNU Lesser General Public License as published by the Free
    13  dnl      Software Foundation; either version 3 of the License, or (at your
    14  dnl      option) any later version.
    15  dnl
    16  dnl  or
    17  dnl
    18  dnl    * the GNU General Public License as published by the Free Software
    19  dnl      Foundation; either version 2 of the License, or (at your option) any
    20  dnl      later version.
    21  dnl
    22  dnl  or both in parallel, as here.
    23  dnl
    24  dnl  The GNU MP Library is distributed in the hope that it will be useful, but
    25  dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    26  dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    27  dnl  for more details.
    28  dnl
    29  dnl  You should have received copies of the GNU General Public License and the
    30  dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
    31  dnl  see https://www.gnu.org/licenses/.
    32  
    33  include(`../config.m4')
    34  
    35  C	     cycles/limb
    36  C AMD K8,K9	 ?
    37  C AMD K10	 ?
    38  C Intel P4	 ?
    39  C Intel core2	 ?
    40  C Intel NHM	 ?
    41  C Intel SBR	 ?
    42  C Intel atom	 4.5
    43  C VIA nano	 ?
    44  
    45  C TODO
    46  C  * Consider using 4-way unrolling.  We reach 4 c/l, but the code is 2.5 times
    47  C    larger.
    48  
    49  C INPUT PARAMETERS
    50  define(`rp',	`%rdi')
    51  define(`up',	`%rsi')
    52  define(`n',	`%rdx')
    53  define(`cnt',	`%rcx')
    54  
    55  ABI_SUPPORT(DOS64)
    56  ABI_SUPPORT(STD64)
    57  
    58  ASM_START()
    59  	TEXT
    60  	ALIGN(16)
    61  PROLOGUE(mpn_lshift)
    62  	FUNC_ENTRY(4)
    63  	lea	-8(up,n,8), up
    64  	lea	-8(rp,n,8), rp
    65  	shr	R32(n)
    66  	mov	(up), %rax
    67  	jnc	L(evn)
    68  
    69  	mov	%rax, %r11
    70  	shl	R8(%rcx), %r11
    71  	neg	R8(%rcx)
    72  	shr	R8(%rcx), %rax
    73  	test	n, n
    74  	jnz	L(gt1)
    75  	mov	%r11, (rp)
    76  	FUNC_EXIT()
    77  	ret
    78  
    79  L(gt1):	mov	-8(up), %r8
    80  	mov	%r8, %r10
    81  	shr	R8(%rcx), %r8
    82  	jmp	L(lo1)
    83  
    84  L(evn):	mov	%rax, %r10
    85  	neg	R8(%rcx)
    86  	shr	R8(%rcx), %rax
    87  	mov	-8(up), %r9
    88  	mov	%r9, %r11
    89  	shr	R8(%rcx), %r9
    90  	neg	R8(%rcx)
    91  	dec	n
    92  	lea	8(rp), rp
    93  	lea	-8(up), up
    94  	jz	L(end)
    95  
    96  	ALIGN(8)
    97  L(top):	shl	R8(%rcx), %r10
    98  	or	%r10, %r9
    99  	shl	R8(%rcx), %r11
   100  	neg	R8(%rcx)
   101  	mov	-8(up), %r8
   102  	mov	%r8, %r10
   103  	mov	%r9, -8(rp)
   104  	shr	R8(%rcx), %r8
   105  	lea	-16(rp), rp
   106  L(lo1):	mov	-16(up), %r9
   107  	or	%r11, %r8
   108  	mov	%r9, %r11
   109  	shr	R8(%rcx), %r9
   110  	lea	-16(up), up
   111  	neg	R8(%rcx)
   112  	mov	%r8, (rp)
   113  	dec	n
   114  	jg	L(top)
   115  
   116  L(end):	shl	R8(%rcx), %r10
   117  	or	%r10, %r9
   118  	shl	R8(%rcx), %r11
   119  	mov	%r9, -8(rp)
   120  	mov	%r11, -16(rp)
   121  	FUNC_EXIT()
   122  	ret
   123  EPILOGUE()