# IBM POWER __gmpn_mul_1 -- Multiply a limb vector with a limb and store # the result in a second limb vector. # Copyright (C) 1992, 1994, 1999, 2000 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 POWER architecture 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 .globl __gmpn_mul_1 .globl .__gmpn_mul_1 .csect __gmpn_mul_1[DS] __gmpn_mul_1: .long .__gmpn_mul_1, TOC[tc0], 0 .csect .text[PR] .align 2 .__gmpn_mul_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 ai 0,0,0 # reset carry cax 9,9,7 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 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 8,0,10 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 cax 10,10,0 # adjust high limb for negative s2_limb mfmq 0 ae 8,0,9 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 cax 9,9,0 # adjust high limb for negative s2_limb mfmq 0 ae 8,0,10 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