1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27#pragma ident "%Z%%M% %I% %E% SMI" 28 29 .file "%M%" 30 31/ Double long divide routine. 32 33#include "SYS.h" 34 35 .set lop,16 36 .set rop,24 37 .set ans,0 38 39 ENTRY(ldivide) 40 popl %eax 41 xchgl %eax,0(%esp) 42 pushl %eax 43 44 pushl %esi 45 pushl %edi 46 47 movl lop(%esp),%eax 48 movl lop+4(%esp),%edx 49 50/ the following code is only for compatibility with original ldivide code 51 orl %edx,%edx / force numerator positive 52 jns .ldiv1 53 notl %edx 54 negl %eax 55 sbbl $0xffffffff,%edx 56.ldiv1: 57 testl $0x80000000,rop+4(%esp) 58 jz .ldiv2 59 notl rop+4(%esp) / force denominator positive 60 negl rop(%esp) 61 sbbl $0xffffffff,rop+4(%esp) 62.ldiv2: 63/ end of compatibility code 64 65 xorl %esi,%esi / initialize remainder to 0 66 movl %esi,%edi 67 movl $64,%ecx / initialize counter for 64-bits 68.div_mod_loop: 69 shll $1,%edi 70 rcll $1,%esi / remainder * 2 71 shll $1,%eax 72 rcll $1,%edx / numerator * 2 (also quotient) 73 adcl $0,%edi / add in any carry from the shift 74 subl rop(%esp),%edi / subtract denominator from remainder 75 sbbl rop+4(%esp),%esi 76 incl %eax / turn on quotient bit for now 77 jnc .inc_remainder / inc didn't affect carry flag 78/ can't subtract the denominator from the remainder, add it back 79 addl rop(%esp),%edi 80 adcl rop+4(%esp),%esi 81 decl %eax / turn quotient bit off 82.inc_remainder: 83 loop .div_mod_loop 84 85/ at this point, %edx:%eax has the quotient and %edi:%esi has the remainder 86 popl %edi 87 popl %esi 88 movl %eax,%ecx 89 popl %eax 90 movl %ecx,ans(%eax) 91 movl %edx,ans+4(%eax) 92 ret 93 SET_SIZE(ldivide) 94