1/* IBM POWER addmul_1 -- Multiply a limb vector with a limb and add 2 * the result to a second limb vector. 3 * 4 * Copyright (C) 1992, 1994, 1999, 2002 Free Software Foundation, Inc. 5 * 6 * This file is part of Libgcrypt. 7 * 8 * Libgcrypt is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU Lesser General Public License as 10 * published by the Free Software Foundation; either version 2.1 of 11 * the License, or (at your option) any later version. 12 * 13 * Libgcrypt is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 21 */ 22 23#include "sysdep.h" 24#include "asm-syntax.h" 25 26 27 28/* 29# INPUT PARAMETERS 30# res_ptr r3 31# s1_ptr r4 32# size r5 33# s2_limb r6 34 35# The RS/6000 has no unsigned 32x32->64 bit multiplication instruction. To 36# obtain that operation, we have to use the 32x32->64 signed multiplication 37# instruction, and add the appropriate compensation to the high limb of the 38# result. We add the multiplicand if the multiplier has its most significant 39# bit set, and we add the multiplier if the multiplicand has its most 40# significant bit set. We need to preserve the carry flag between each 41# iteration, so we have to compute the compensation carefully (the natural, 42# srai+and doesn't work). Since the POWER architecture has a branch unit 43# we can branch in zero cycles, so that's how we perform the additions. 44 */ 45 46 .toc 47 .csect ._gcry_mpih_addmul_1[PR] 48 .align 2 49 .globl _gcry_mpih_addmul_1 50 .globl ._gcry_mpih_addmul_1 51 .csect _gcry_mpih_addmul_1[DS] 52_gcry_mpih_addmul_1: 53 .long ._gcry_mpih_addmul_1[PR], TOC[tc0], 0 54 .csect ._gcry_mpih_addmul_1[PR] 55._gcry_mpih_addmul_1: 56 57 cal 3,-4(3) 58 l 0,0(4) 59 cmpi 0,6,0 60 mtctr 5 61 mul 9,0,6 62 srai 7,0,31 63 and 7,7,6 64 mfmq 8 65 cax 9,9,7 66 l 7,4(3) 67 a 8,8,7 # add res_limb 68 blt Lneg 69Lpos: bdz Lend 70 71Lploop: lu 0,4(4) 72 stu 8,4(3) 73 cmpi 0,0,0 74 mul 10,0,6 75 mfmq 0 76 ae 8,0,9 # low limb + old_cy_limb + old cy 77 l 7,4(3) 78 aze 10,10 # propagate cy to new cy_limb 79 a 8,8,7 # add res_limb 80 bge Lp0 81 cax 10,10,6 # adjust high limb for negative limb from s1 82Lp0: bdz Lend0 83 lu 0,4(4) 84 stu 8,4(3) 85 cmpi 0,0,0 86 mul 9,0,6 87 mfmq 0 88 ae 8,0,10 89 l 7,4(3) 90 aze 9,9 91 a 8,8,7 92 bge Lp1 93 cax 9,9,6 # adjust high limb for negative limb from s1 94Lp1: bdn Lploop 95 96 b Lend 97 98Lneg: cax 9,9,0 99 bdz Lend 100Lnloop: lu 0,4(4) 101 stu 8,4(3) 102 cmpi 0,0,0 103 mul 10,0,6 104 mfmq 7 105 ae 8,7,9 106 l 7,4(3) 107 ae 10,10,0 # propagate cy to new cy_limb 108 a 8,8,7 # add res_limb 109 bge Ln0 110 cax 10,10,6 # adjust high limb for negative limb from s1 111Ln0: bdz Lend0 112 lu 0,4(4) 113 stu 8,4(3) 114 cmpi 0,0,0 115 mul 9,0,6 116 mfmq 7 117 ae 8,7,10 118 l 7,4(3) 119 ae 9,9,0 # propagate cy to new cy_limb 120 a 8,8,7 # add res_limb 121 bge Ln1 122 cax 9,9,6 # adjust high limb for negative limb from s1 123Ln1: bdn Lnloop 124 b Lend 125 126Lend0: cal 9,0(10) 127Lend: st 8,4(3) 128 aze 3,9 129 br 130 131