github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/arm/v6/dive_1.asm (about)

     1  dnl  ARM v6 mpn_divexact_1
     2  
     3  dnl  Contributed to the GNU project by Torbjörn Granlund.
     4  
     5  dnl  Copyright 2012, 2013 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       cycles/limb
    36  C               norm    unorm    modexact_1c_odd
    37  C StrongARM	 -	 -
    38  C XScale	 -	 -
    39  C Cortex-A7	 ?	 ?
    40  C Cortex-A8	 ?	 ?
    41  C Cortex-A9	 9	10		 9
    42  C Cortex-A15	 7	 7		 7
    43  
    44  C Architecture requirements:
    45  C v5	-
    46  C v5t	clz
    47  C v5te	-
    48  C v6	umaal
    49  C v6t2	-
    50  C v7a	-
    51  
    52  define(`rp', `r0')
    53  define(`up', `r1')
    54  define(`n',  `r2')
    55  define(`d',  `r3')
    56  
    57  define(`cy',  `r7')
    58  define(`cnt', `r6')
    59  define(`tnc', `r10')
    60  
    61  ASM_START()
    62  PROLOGUE(mpn_divexact_1)
    63  	push	{r4,r5,r6,r7,r8,r9}
    64  
    65  	tst	d, #1
    66  
    67  	rsb	r4, d, #0
    68  	and	r4, r4, d
    69  	clz	r4, r4
    70  	rsb	cnt, r4, #31		C count_trailing_zeros
    71  	mov	d, d, lsr cnt
    72  
    73  C binvert limb
    74  	LEA(	r4, binvert_limb_table)
    75  	and	r12, d, #254
    76  	ldrb	r4, [r4, r12, lsr #1]
    77  	mul	r12, r4, r4
    78  	mul	r12, d, r12
    79  	rsb	r12, r12, r4, lsl #1
    80  	mul	r4, r12, r12
    81  	mul	r4, d, r4
    82  	rsb	r4, r4, r12, lsl #1	C r4 = inverse
    83  
    84  	ldr	r5, [up], #4		C up[0]
    85  	mov	cy, #0
    86  	rsb	r8, r4, #0		C r8 = -inverse
    87  	beq	L(unnorm)
    88  
    89  L(norm):
    90  	subs	n, n, #1
    91  	mul	r5, r5, r4
    92  	beq	L(end)
    93  
    94  	ALIGN(16)
    95  L(top):	ldr	r9, [up], #4
    96  	mov	r12, #0
    97  	str	r5, [rp], #4
    98  	umaal	r12, cy, r5, d
    99  	mul	r5, r9, r4
   100  	mla	r5, cy, r8, r5
   101  	subs	n, n, #1
   102  	bne	L(top)
   103  
   104  L(end):	str	r5, [rp]
   105  	pop	{r4,r5,r6,r7,r8,r9}
   106  	bx	r14
   107  
   108  L(unnorm):
   109  	push	{r10,r11}
   110  	rsb	tnc, cnt, #32
   111  	mov	r11, r5, lsr cnt
   112  	subs	n, n, #1
   113  	beq	L(edx)
   114  
   115  	ldr	r12, [up], #4
   116  	orr	r9, r11, r12, lsl tnc
   117  	mov	r11, r12, lsr cnt
   118  	mul	r5, r9, r4
   119  	subs	n, n, #1
   120  	beq	L(edu)
   121  
   122  	ALIGN(16)
   123  L(tpu):	ldr	r12, [up], #4
   124  	orr	r9, r11, r12, lsl tnc
   125  	mov	r11, r12, lsr cnt
   126  	mov	r12, #0
   127  	str	r5, [rp], #4
   128  	umaal	r12, cy, r5, d
   129  	mul	r5, r9, r4
   130  	mla	r5, cy, r8, r5
   131  	subs	n, n, #1
   132  	bne	L(tpu)
   133  
   134  L(edu):	str	r5, [rp], #4
   135  	mov	r12, #0
   136  	umaal	r12, cy, r5, d
   137  	mul	r5, r11, r4
   138  	mla	r5, cy, r8, r5
   139  	str	r5, [rp]
   140  	pop	{r10,r11}
   141  	pop	{r4,r5,r6,r7,r8,r9}
   142  	bx	r14
   143  
   144  L(edx):	mul	r5, r11, r4
   145  	str	r5, [rp]
   146  	pop	{r10,r11}
   147  	pop	{r4,r5,r6,r7,r8,r9}
   148  	bx	r14
   149  EPILOGUE()