github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/x86/k7/mode1o.asm (about)

     1  dnl  AMD K7 mpn_modexact_1_odd -- exact division style remainder.
     2  
     3  dnl  Copyright 2000-2002, 2004, 2007 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 Athlon:     11.0
    36  C Hammer:      7.0
    37  
    38  
    39  C mp_limb_t mpn_modexact_1_odd (mp_srcptr src, mp_size_t size,
    40  C                               mp_limb_t divisor);
    41  C mp_limb_t mpn_modexact_1c_odd (mp_srcptr src, mp_size_t size,
    42  C                                mp_limb_t divisor, mp_limb_t carry);
    43  C
    44  C With the loop running at just 11 cycles it doesn't seem worth bothering to
    45  C check for high<divisor to save one step.
    46  C
    47  C Using a divl for size==1 measures slower than the modexact method, which
    48  C is not too surprising since for the latter it's only about 24 cycles to
    49  C calculate the modular inverse.
    50  
    51  defframe(PARAM_CARRY,  16)
    52  defframe(PARAM_DIVISOR,12)
    53  defframe(PARAM_SIZE,   8)
    54  defframe(PARAM_SRC,    4)
    55  
    56  defframe(SAVE_EBX,     -4)
    57  defframe(SAVE_ESI,     -8)
    58  defframe(SAVE_EDI,    -12)
    59  defframe(SAVE_EBP,    -16)
    60  
    61  deflit(STACK_SPACE, 16)
    62  
    63  	TEXT
    64  
    65  	ALIGN(16)
    66  PROLOGUE(mpn_modexact_1c_odd)
    67  deflit(`FRAME',0)
    68  
    69  	movl	PARAM_CARRY, %ecx
    70  	jmp	L(start_1c)
    71  
    72  EPILOGUE()
    73  
    74  
    75  	ALIGN(16)
    76  PROLOGUE(mpn_modexact_1_odd)
    77  deflit(`FRAME',0)
    78  
    79  	xorl	%ecx, %ecx
    80  L(start_1c):
    81  	movl	PARAM_DIVISOR, %eax
    82  	subl	$STACK_SPACE, %esp	FRAME_subl_esp(STACK_SPACE)
    83  
    84  	movl	%esi, SAVE_ESI
    85  	movl	PARAM_DIVISOR, %esi
    86  
    87  	movl	%edi, SAVE_EDI
    88  
    89  	shrl	%eax			C d/2
    90  
    91  	andl	$127, %eax
    92  
    93  ifdef(`PIC',`
    94  	LEA(	binvert_limb_table, %edi)
    95  	movzbl	(%eax,%edi), %edi		C inv 8 bits
    96  ',`
    97  	movzbl	binvert_limb_table(%eax), %edi	C inv 8 bits
    98  ')
    99  
   100  	xorl	%edx, %edx		C initial extra carry
   101  	leal	(%edi,%edi), %eax	C 2*inv
   102  
   103  	imull	%edi, %edi		C inv*inv
   104  
   105  	movl	%ebp, SAVE_EBP
   106  	movl	PARAM_SIZE, %ebp
   107  
   108  	movl	%ebx, SAVE_EBX
   109  	movl	PARAM_SRC, %ebx
   110  
   111  	imull	%esi, %edi		C inv*inv*d
   112  
   113  	subl	%edi, %eax		C inv = 2*inv - inv*inv*d
   114  	leal	(%eax,%eax), %edi	C 2*inv
   115  
   116  	imull	%eax, %eax		C inv*inv
   117  
   118  	imull	%esi, %eax		C inv*inv*d
   119  
   120  	leal	(%ebx,%ebp,4), %ebx	C src end
   121  	negl	%ebp			C -size
   122  
   123  	subl	%eax, %edi		C inv = 2*inv - inv*inv*d
   124  
   125  	ASSERT(e,`	C d*inv == 1 mod 2^GMP_LIMB_BITS
   126  	movl	%esi, %eax
   127  	imull	%edi, %eax
   128  	cmpl	$1, %eax')
   129  
   130  
   131  C The dependent chain here is
   132  C
   133  C                            cycles
   134  C	subl	%edx, %eax	1
   135  C	imull	%edi, %eax	4
   136  C	mull	%esi		6  (high limb)
   137  C			      ----
   138  C       total		       11
   139  C
   140  C Out of order execution hides the load latency for the source data, so no
   141  C special scheduling is required.
   142  
   143  L(top):
   144  	C eax	src limb
   145  	C ebx	src end ptr
   146  	C ecx	next carry bit, 0 or 1 (or initial carry param)
   147  	C edx	carry limb, high of last product
   148  	C esi	divisor
   149  	C edi	inverse
   150  	C ebp	counter, limbs, negative
   151  
   152  	movl	(%ebx,%ebp,4), %eax
   153  
   154  	subl	%ecx, %eax		C apply carry bit
   155  	movl	$0, %ecx
   156  
   157  	setc	%cl			C new carry bit
   158  
   159  	subl	%edx, %eax		C apply carry limb
   160  	adcl	$0, %ecx
   161  
   162  	imull	%edi, %eax
   163  
   164  	mull	%esi
   165  
   166  	incl	%ebp
   167  	jnz	L(top)
   168  
   169  
   170  	movl	SAVE_ESI, %esi
   171  	movl	SAVE_EDI, %edi
   172  	leal	(%ecx,%edx), %eax
   173  
   174  	movl	SAVE_EBX, %ebx
   175  	movl	SAVE_EBP, %ebp
   176  	addl	$STACK_SPACE, %esp
   177  
   178  	ret
   179  
   180  EPILOGUE()
   181  ASM_END()