github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/arm/bdiv_dbm1c.asm (about)

     1  dnl  ARM mpn_bdiv_dbm1c.
     2  
     3  dnl  Copyright 2008, 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  C	     cycles/limb
    34  C StrongARM	 ?
    35  C XScale	 ?
    36  C Cortex-A7	 ?
    37  C Cortex-A8	 ?
    38  C Cortex-A9	 4.25
    39  C Cortex-A15	 2.5
    40  
    41  C TODO
    42  C  * Try using umlal or umaal.
    43  C  * Try using ldm/stm.
    44  
    45  define(`qp',	  `r0')
    46  define(`up',	  `r1')
    47  define(`n',	  `r2')
    48  define(`bd',	  `r3')
    49  define(`cy',	  `sp,#0')
    50  
    51  ASM_START()
    52  	TEXT
    53  	ALIGN(16)
    54  PROLOGUE(mpn_bdiv_dbm1c)
    55  	push	{r4, r5, r6, r7, r8}
    56  	ldr	r4, [up], #4
    57  	ldr	r5, [sp, #20]
    58  	ands	r12, n, #3
    59  	beq	L(fi0)
    60  	cmp	r12, #2
    61  	bcc	L(fi1)
    62  	beq	L(fi2)
    63  
    64  L(fi3):	umull	r8, r12, r4, bd
    65  	ldr	r4, [up], #4
    66  	b	L(lo3)
    67  
    68  L(fi0):	umull	r6, r7, r4, bd
    69  	ldr	r4, [up], #4
    70  	b	L(lo0)
    71  
    72  L(fi1):	subs	n, n, #1
    73  	umull	r8, r12, r4, bd
    74  	bls	L(wd1)
    75  	ldr	r4, [up], #4
    76  	b	L(lo1)
    77  
    78  L(fi2):	umull	r6, r7, r4, bd
    79  	ldr	r4, [up], #4
    80  	b	L(lo2)
    81  
    82  L(top):	ldr	r4, [up], #4
    83  	subs	r5, r5, r6
    84  	str	r5, [qp], #4
    85  	sbc	r5, r5, r7
    86  L(lo1):	umull	r6, r7, r4, bd
    87  	ldr	r4, [up], #4
    88  	subs	r5, r5, r8
    89  	str	r5, [qp], #4
    90  	sbc	r5, r5, r12
    91  L(lo0):	umull	r8, r12, r4, bd
    92  	ldr	r4, [up], #4
    93  	subs	r5, r5, r6
    94  	str	r5, [qp], #4
    95  	sbc	r5, r5, r7
    96  L(lo3):	umull	r6, r7, r4, bd
    97  	ldr	r4, [up], #4
    98  	subs	r5, r5, r8
    99  	str	r5, [qp], #4
   100  	sbc	r5, r5, r12
   101  L(lo2):	subs	n, n, #4
   102  	umull	r8, r12, r4, bd
   103  	bhi	L(top)
   104  
   105  L(wd2):	subs	r5, r5, r6
   106  	str	r5, [qp], #4
   107  	sbc	r5, r5, r7
   108  L(wd1):	subs	r5, r5, r8
   109  	str	r5, [qp]
   110  	sbc	r0, r5, r12
   111  	pop	{r4, r5, r6, r7, r8}
   112  	ret	lr
   113  EPILOGUE()