1*0a6a1f1dSLionel Sambuc/* $NetBSD: mulsi3.S,v 1.1 2014/09/03 19:34:25 matt Exp $ */ 2*0a6a1f1dSLionel Sambuc 3*0a6a1f1dSLionel Sambuc/*- 4*0a6a1f1dSLionel Sambuc * Copyright (c) 2014 The NetBSD Foundation, Inc. 5*0a6a1f1dSLionel Sambuc * All rights reserved. 6*0a6a1f1dSLionel Sambuc * 7*0a6a1f1dSLionel Sambuc * This code is derived from software contributed to The NetBSD Foundation 8*0a6a1f1dSLionel Sambuc * by Matt Thomas of 3am Software Foundry. 9*0a6a1f1dSLionel Sambuc * 10*0a6a1f1dSLionel Sambuc * Redistribution and use in source and binary forms, with or without 11*0a6a1f1dSLionel Sambuc * modification, are permitted provided that the following conditions 12*0a6a1f1dSLionel Sambuc * are met: 13*0a6a1f1dSLionel Sambuc * 1. Redistributions of source code must retain the above copyright 14*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer. 15*0a6a1f1dSLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright 16*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer in the 17*0a6a1f1dSLionel Sambuc * documentation and/or other materials provided with the distribution. 18*0a6a1f1dSLionel Sambuc * 19*0a6a1f1dSLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20*0a6a1f1dSLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21*0a6a1f1dSLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22*0a6a1f1dSLionel Sambuc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23*0a6a1f1dSLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24*0a6a1f1dSLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25*0a6a1f1dSLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26*0a6a1f1dSLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27*0a6a1f1dSLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28*0a6a1f1dSLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29*0a6a1f1dSLionel Sambuc * POSSIBILITY OF SUCH DAMAGE. 30*0a6a1f1dSLionel Sambuc */ 31*0a6a1f1dSLionel Sambuc 32*0a6a1f1dSLionel Sambuc#include <machine/asm.h> 33*0a6a1f1dSLionel Sambuc 34*0a6a1f1dSLionel Sambuc__RCSID("$NetBSD: mulsi3.S,v 1.1 2014/09/03 19:34:25 matt Exp $") 35*0a6a1f1dSLionel Sambuc 36*0a6a1f1dSLionel SambucENTRY(__mulsi3) 37*0a6a1f1dSLionel Sambuc l.movhi r11, 0 38*0a6a1f1dSLionel Sambuc 39*0a6a1f1dSLionel Sambuc l.sfeqi r3, 0 40*0a6a1f1dSLionel Sambuc l.bf .Lret 41*0a6a1f1dSLionel Sambuc l.nop 42*0a6a1f1dSLionel Sambuc 43*0a6a1f1dSLionel Sambuc l.sfeqi r4, 0 44*0a6a1f1dSLionel Sambuc l.bf .Lret 45*0a6a1f1dSLionel Sambuc l.nop 46*0a6a1f1dSLionel Sambuc 47*0a6a1f1dSLionel Sambuc l.sfleu r3, r4 # is r3 < r4 (unsigned) 48*0a6a1f1dSLionel Sambuc#if 0 49*0a6a1f1dSLionel Sambuc l.ori r6, r3, 0 # move r3 to r6 50*0a6a1f1dSLionel Sambuc l.bf .Lloop # yes, r6 already has smaller value, 51*0a6a1f1dSLionel Sambuc l.nop 52*0a6a1f1dSLionel Sambuc l.ori r6, r4, 0 # move r4 to r6 because it's smaller than r3 53*0a6a1f1dSLionel Sambuc#else 54*0a6a1f1dSLionel Sambuc l.cmov r6, r3, r4 # choose lesser of r3 or r4 55*0a6a1f1dSLionel Sambuc#endif 56*0a6a1f1dSLionel Sambuc 57*0a6a1f1dSLionel Sambuc.Lloop: 58*0a6a1f1dSLionel Sambuc l.andi r5, r6, 1 # get LSB 59*0a6a1f1dSLionel Sambuc l.sub r8, r0, r5 # 0 -> 0, 1 -> 0xffffffff 60*0a6a1f1dSLionel Sambuc l.and r8, r8, r4 # r8 = r6 & 1 ? r4 : 0 61*0a6a1f1dSLionel Sambuc l.add r11, r11, r8 # add to result 62*0a6a1f1dSLionel Sambuc l.srli r4, r4, 1 # discard LSB 63*0a6a1f1dSLionel Sambuc l.slli r6, r6, 1 # multiply by 2 64*0a6a1f1dSLionel Sambuc.Lentry: 65*0a6a1f1dSLionel Sambuc l.sfeqi r4, 0 # only 0 left? 66*0a6a1f1dSLionel Sambuc l.bf .Lret # yes, we're done 67*0a6a1f1dSLionel Sambuc l.nop 68*0a6a1f1dSLionel Sambuc l.sfeqi r6, 0 # only 0 left? 69*0a6a1f1dSLionel Sambuc l.bnf .Lloop # no, another round of long multiplication. 70*0a6a1f1dSLionel Sambuc l.nop 71*0a6a1f1dSLionel Sambuc 72*0a6a1f1dSLionel Sambuc.Lret: l.jr lr 73*0a6a1f1dSLionel Sambuc l.nop 74*0a6a1f1dSLionel SambucEND(__mulsi3) 75