mpir/mpn/power/addmul_1.asm

118 lines
3.0 KiB
NASM

dnl IBM POWER mpn_addmul_1 -- Multiply a limb vector with a limb and add the
dnl result to a second limb vector.
dnl Copyright 1992, 1994, 1999, 2000, 2001 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of the GNU Lesser General Public License as published
dnl by the Free Software Foundation; either version 2.1 of the License, or (at
dnl your option) any later version.
dnl The GNU MP Library is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
dnl License for more details.
dnl You should have received a copy of the GNU Lesser General Public License
dnl along with the GNU MP Library; see the file COPYING.LIB. If not, write
dnl to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
dnl Boston, MA 02110-1301, USA.
dnl INPUT PARAMETERS
dnl res_ptr r3
dnl s1_ptr r4
dnl size r5
dnl s2_limb r6
dnl The POWER architecture has no unsigned 32x32->64 bit multiplication
dnl instruction. To obtain that operation, we have to use the 32x32->64
dnl signed multiplication instruction, and add the appropriate compensation to
dnl the high limb of the result. We add the multiplicand if the multiplier
dnl has its most significant bit set, and we add the multiplier if the
dnl multiplicand has its most significant bit set. We need to preserve the
dnl carry flag between each iteration, so we have to compute the compensation
dnl carefully (the natural, srai+and doesn't work). Since all POWER can
dnl branch in zero cycles, we use conditional branches to for the additions.
include(`../config.m4')
ASM_START()
PROLOGUE(mpn_addmul_1)
cal 3,-4(3)
l 0,0(4)
cmpi 0,6,0
mtctr 5
mul 9,0,6
srai 7,0,31
and 7,7,6
mfmq 8
cax 9,9,7
l 7,4(3)
a 8,8,7 C add res_limb
blt Lneg
Lpos: bdz Lend
Lploop: lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 10,0,6
mfmq 0
ae 8,0,9 C low limb + old_cy_limb + old cy
l 7,4(3)
aze 10,10 C propagate cy to new cy_limb
a 8,8,7 C add res_limb
bge Lp0
cax 10,10,6 C adjust high limb for negative limb from s1
Lp0: bdz Lend0
lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 9,0,6
mfmq 0
ae 8,0,10
l 7,4(3)
aze 9,9
a 8,8,7
bge Lp1
cax 9,9,6 C adjust high limb for negative limb from s1
Lp1: bdn Lploop
b Lend
Lneg: cax 9,9,0
bdz Lend
Lnloop: lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 10,0,6
mfmq 7
ae 8,7,9
l 7,4(3)
ae 10,10,0 C propagate cy to new cy_limb
a 8,8,7 C add res_limb
bge Ln0
cax 10,10,6 C adjust high limb for negative limb from s1
Ln0: bdz Lend0
lu 0,4(4)
stu 8,4(3)
cmpi 0,0,0
mul 9,0,6
mfmq 7
ae 8,7,10
l 7,4(3)
ae 9,9,0 C propagate cy to new cy_limb
a 8,8,7 C add res_limb
bge Ln1
cax 9,9,6 C adjust high limb for negative limb from s1
Ln1: bdn Lnloop
b Lend
Lend0: cal 9,0(10)
Lend: st 8,4(3)
aze 3,9
br
EPILOGUE(mpn_addmul_1)