github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpn/s390_32/submul_1.asm (about)

     1  dnl  S/390 mpn_submul_1 -- Multiply a limb vector with a limb and subtract the
     2  dnl  result from a second limb vector.
     3  
     4  dnl  Copyright 2001 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  define(`rp',2)
    35  define(`up',3)
    36  define(`n',4)
    37  define(`vlimb',5)
    38  define(`cylimb',7)
    39  
    40  ASM_START()
    41  PROLOGUE(mpn_submul_1)
    42  	stm	6,7,24(15)
    43  	slr	cylimb,cylimb	# clear cylimb
    44  	ltr	vlimb,vlimb
    45  	jnl	.Loopp
    46  
    47  .Loopn:	l	1,0(up)		# load from u
    48  	lr	6,1		#
    49  	mr	0,vlimb		# multiply signed
    50  	alr	0,6		# add vlimb to phi
    51  	sra	6,31		# make mask
    52  	nr	6,vlimb		# 0 or vlimb
    53  	alr	0,6		# conditionally add vlimb to phi
    54  	alr	1,cylimb	# add carry limb to plo
    55  	brc	8+4,+8		# branch if not carry
    56  	ahi	0,1		# increment phi
    57  	l	6,0(rp)		# load r limb
    58  	slr	6,1		# add u limb to plo
    59  	brc	2+1,+8		# branch if not carry
    60  	ahi	0,1		# increment phi
    61  	lr	cylimb,0	# new cylimb
    62  	st	6,0(rp)		# store
    63  	la	up,4(,up)
    64  	la	rp,4(,rp)
    65  	brct	n,.Loopn
    66  
    67  	lr	2,cylimb
    68  	lm	6,7,24(15)
    69  	br	14
    70  
    71  .Loopp:	l	1,0(up)		# load from u
    72  	lr	6,1		#
    73  	mr	0,vlimb		# multiply signed
    74  	sra	6,31		# make mask
    75  	nr	6,vlimb		# 0 or vlimb
    76  	alr	0,6		# conditionally add vlimb to phi
    77  	alr	1,cylimb	# add carry limb to plo
    78  	brc	8+4,+8		# branch if not carry
    79  	ahi	0,1		# increment phi
    80  	l	6,0(rp)		# load r limb
    81  	slr	6,1		# add u limb to plo
    82  	brc	2+1,+8		# branch if not carry
    83  	ahi	0,1		# increment phi
    84  	lr	cylimb,0	# new cylimb
    85  	st	6,0(rp)		# store
    86  	la	up,4(,up)
    87  	la	rp,4(,rp)
    88  	brct	n,.Loopp
    89  
    90  	lr	2,cylimb
    91  	lm	6,7,24(15)
    92  	br	14
    93  EPILOGUE(mpn_submul_1)