github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/alpha/submul_1.asm (about)

     1  dnl  Alpha mpn_submul_1 -- Multiply a limb vector with a limb and subtract
     2  dnl  the result from a second limb vector.
     3  
     4  dnl  Copyright 1992, 1994, 1995, 2000, 2002 Free Software Foundation, Inc.
     5  
     6  dnl  This file is part of the GNU MP Library.
     7  dnl
     8  dnl  The GNU MP Library is free software; you can redistribute it and/or modify
     9  dnl  it under the terms of either:
    10  dnl
    11  dnl    * the GNU Lesser General Public License as published by the Free
    12  dnl      Software Foundation; either version 3 of the License, or (at your
    13  dnl      option) any later version.
    14  dnl
    15  dnl  or
    16  dnl
    17  dnl    * the GNU General Public License as published by the Free Software
    18  dnl      Foundation; either version 2 of the License, or (at your option) any
    19  dnl      later version.
    20  dnl
    21  dnl  or both in parallel, as here.
    22  dnl
    23  dnl  The GNU MP Library is distributed in the hope that it will be useful, but
    24  dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    25  dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    26  dnl  for more details.
    27  dnl
    28  dnl  You should have received copies of the GNU General Public License and the
    29  dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
    30  dnl  see https://www.gnu.org/licenses/.
    31  
    32  include(`../config.m4')
    33  
    34  C      cycles/limb
    35  C EV4:     42
    36  C EV5:     18
    37  C EV6:      7
    38  
    39  C  INPUT PARAMETERS
    40  C  rp	r16
    41  C  up	r17
    42  C  n	r18
    43  C  limb	r19
    44  
    45  
    46  ASM_START()
    47  PROLOGUE(mpn_submul_1)
    48  	ldq	r2,0(r17)	C r2 = s1_limb
    49  	addq	r17,8,r17	C s1_ptr++
    50  	subq	r18,1,r18	C size--
    51  	mulq	r2,r19,r3	C r3 = prod_low
    52  	ldq	r5,0(r16)	C r5 = *res_ptr
    53  	umulh	r2,r19,r0	C r0 = prod_high
    54  	beq	r18,$Lend1	C jump if size was == 1
    55  	ldq	r2,0(r17)	C r2 = s1_limb
    56  	addq	r17,8,r17	C s1_ptr++
    57  	subq	r18,1,r18	C size--
    58  	subq	r5,r3,r3
    59  	cmpult	r5,r3,r4
    60  	stq	r3,0(r16)
    61  	addq	r16,8,r16	C res_ptr++
    62  	beq	r18,$Lend2	C jump if size was == 2
    63  
    64  	ALIGN(8)
    65  $Loop:	mulq	r2,r19,r3	C r3 = prod_low
    66  	ldq	r5,0(r16)	C r5 = *res_ptr
    67  	addq	r4,r0,r0	C cy_limb = cy_limb + 'cy'
    68  	subq	r18,1,r18	C size--
    69  	umulh	r2,r19,r4	C r4 = cy_limb
    70  	ldq	r2,0(r17)	C r2 = s1_limb
    71  	addq	r17,8,r17	C s1_ptr++
    72  	addq	r3,r0,r3	C r3 = cy_limb + prod_low
    73  	cmpult	r3,r0,r0	C r0 = carry from (cy_limb + prod_low)
    74  	subq	r5,r3,r3
    75  	cmpult	r5,r3,r5
    76  	stq	r3,0(r16)
    77  	addq	r16,8,r16	C res_ptr++
    78  	addq	r5,r0,r0	C combine carries
    79  	bne	r18,$Loop
    80  
    81  $Lend2:	mulq	r2,r19,r3	C r3 = prod_low
    82  	ldq	r5,0(r16)	C r5 = *res_ptr
    83  	addq	r4,r0,r0	C cy_limb = cy_limb + 'cy'
    84  	umulh	r2,r19,r4	C r4 = cy_limb
    85  	addq	r3,r0,r3	C r3 = cy_limb + prod_low
    86  	cmpult	r3,r0,r0	C r0 = carry from (cy_limb + prod_low)
    87  	subq	r5,r3,r3
    88  	cmpult	r5,r3,r5
    89  	stq	r3,0(r16)
    90  	addq	r5,r0,r0	C combine carries
    91  	addq	r4,r0,r0	C cy_limb = prod_high + cy
    92  	ret	r31,(r26),1
    93  $Lend1:	subq	r5,r3,r3
    94  	cmpult	r5,r3,r5
    95  	stq	r3,0(r16)
    96  	addq	r0,r5,r0
    97  	ret	r31,(r26),1
    98  EPILOGUE(mpn_submul_1)
    99  ASM_END()