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Diffstat (limited to 'sysdeps/rs6000/submul_1.s')
| -rw-r--r-- | sysdeps/rs6000/submul_1.s | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/sysdeps/rs6000/submul_1.s b/sysdeps/rs6000/submul_1.s new file mode 100644 index 0000000000..41095ab001 --- /dev/null +++ b/sysdeps/rs6000/submul_1.s @@ -0,0 +1,128 @@ +# IBM POWER __mpn_submul_1 -- Multiply a limb vector with a limb and subtract +# the result from a second limb vector. + +# Copyright (C) 1992, 1994 Free Software Foundation, Inc. + +# This file is part of the GNU MP Library. + +# The GNU MP Library is free software; you can redistribute it and/or modify +# it under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or (at your +# option) any later version. + +# The GNU MP Library is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public +# License for more details. + +# You should have received a copy of the GNU Lesser General Public License +# along with the GNU MP Library; see the file COPYING.LIB. If not, write to +# the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, +# MA 02111-1307, USA. + + +# INPUT PARAMETERS +# res_ptr r3 +# s1_ptr r4 +# size r5 +# s2_limb r6 + +# The RS/6000 has no unsigned 32x32->64 bit multiplication instruction. To +# obtain that operation, we have to use the 32x32->64 signed multiplication +# instruction, and add the appropriate compensation to the high limb of the +# result. We add the multiplicand if the multiplier has its most significant +# bit set, and we add the multiplier if the multiplicand has its most +# significant bit set. We need to preserve the carry flag between each +# iteration, so we have to compute the compensation carefully (the natural, +# srai+and doesn't work). Since the POWER architecture has a branch unit +# we can branch in zero cycles, so that's how we perform the additions. + + .toc + .csect .__mpn_submul_1[PR] + .align 2 + .globl __mpn_submul_1 + .globl .__mpn_submul_1 + .csect __mpn_submul_1[DS] +__mpn_submul_1: + .long .__mpn_submul_1[PR], TOC[tc0], 0 + .csect .__mpn_submul_1[PR] +.__mpn_submul_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 11 + cax 9,9,7 + l 7,4(3) + sf 8,11,7 # add res_limb + a 11,8,11 # invert cy (r11 is junk) + 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 11,0,9 # low limb + old_cy_limb + old cy + l 7,4(3) + aze 10,10 # propagate cy to new cy_limb + sf 8,11,7 # add res_limb + a 11,8,11 # invert cy (r11 is junk) + bge Lp0 + cax 10,10,6 # 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 11,0,10 + l 7,4(3) + aze 9,9 + sf 8,11,7 + a 11,8,11 # invert cy (r11 is junk) + bge Lp1 + cax 9,9,6 # 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 11,7,9 + l 7,4(3) + ae 10,10,0 # propagate cy to new cy_limb + sf 8,11,7 # add res_limb + a 11,8,11 # invert cy (r11 is junk) + bge Ln0 + cax 10,10,6 # 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 11,7,10 + l 7,4(3) + ae 9,9,0 # propagate cy to new cy_limb + sf 8,11,7 # add res_limb + a 11,8,11 # invert cy (r11 is junk) + bge Ln1 + cax 9,9,6 # 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 |