4162 lines
126 KiB
JavaScript
4162 lines
126 KiB
JavaScript
/**
|
||
* @fileoverview Implements PCjs 8086 opcode helpers.
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* @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
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* @version 1.0
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* Created 2012-Sep-05
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*
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* Copyright © 2012-2015 Jeff Parsons <Jeff@pcjs.org>
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*
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* This file is part of PCjs, which is part of the JavaScript Machines Project (aka JSMachines)
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* at <http://jsmachines.net/> and <http://pcjs.org/>.
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||
*
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* PCjs is free software: you can redistribute it and/or modify it under the terms of the
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* GNU General Public License as published by the Free Software Foundation, either version 3
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* of the License, or (at your option) any later version.
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*
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* PCjs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
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* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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||
* GNU General Public License for more details.
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||
*
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||
* You should have received a copy of the GNU General Public License along with PCjs. If not,
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* see <http://www.gnu.org/licenses/gpl.html>.
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||
*
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* You are required to include the above copyright notice in every source code file of every
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* copy or modified version of this work, and to display that copyright notice on every screen
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* that loads or runs any version of this software (see Computer.sCopyright).
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||
*
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* Some PCjs files also attempt to load external resource files, such as character-image files,
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||
* ROM files, and disk image files. Those external resource files are not considered part of the
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* PCjs program for purposes of the GNU General Public License, and the author does not claim
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* any copyright as to their contents.
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*/
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"use strict";
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if (typeof module !== 'undefined') {
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var str = require("../../shared/lib/strlib");
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var Messages = require("./messages");
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var X86 = require("./x86");
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}
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/**
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* fnADCb(dst, src)
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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*/
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X86.fnADCb = function ADCb(dst, src)
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{
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var b = (dst + src + this.getCarry())|0;
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this.setArithResult(dst, src, b, X86.RESULT.BYTE | X86.RESULT.ALL);
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this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
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return b & 0xff;
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};
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||
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/**
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* fnADCw(dst, src)
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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*/
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X86.fnADCw = function ADCw(dst, src)
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{
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var w = (dst + src + this.getCarry())|0;
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this.setArithResult(dst, src, w, this.typeData | X86.RESULT.ALL);
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this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
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return w & this.maskData;
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};
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/**
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* fnADDb(dst, src)
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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*/
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X86.fnADDb = function ADDb(dst, src)
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{
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var b = (dst + src)|0;
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this.setArithResult(dst, src, b, X86.RESULT.BYTE | X86.RESULT.ALL);
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this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
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return b & 0xff;
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};
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||
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/**
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* fnADDw(dst, src)
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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*/
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X86.fnADDw = function ADDw(dst, src)
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{
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var w = (dst + src)|0;
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this.setArithResult(dst, src, w, this.typeData | X86.RESULT.ALL);
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this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
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return w & this.maskData;
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};
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/**
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* fnANDb(dst, src)
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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*/
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X86.fnANDb = function ANDb(dst, src)
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{
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var b = dst & src;
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this.setLogicResult(b, X86.RESULT.BYTE);
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this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
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return b;
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};
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/**
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* fnANDw(dst, src)
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*
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* @this {X86CPU}
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||
* @param {number} dst
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* @param {number} src
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||
* @return {number}
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||
*/
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X86.fnANDw = function ANDw(dst, src)
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{
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this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
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return this.setLogicResult(dst & src, this.typeData);
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};
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/**
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* fnARPL(dst, src)
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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*/
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X86.fnARPL = function ARPL(dst, src)
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{
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this.nStepCycles -= (10 + (this.regEA === X86.ADDR_INVALID? 0 : 1));
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if ((dst & X86.SEL.RPL) < (src & X86.SEL.RPL)) {
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dst = (dst & ~X86.SEL.RPL) | (src & X86.SEL.RPL);
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this.setZF();
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return dst;
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}
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this.clearZF();
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return dst;
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};
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/**
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* fnBOUND(dst, src)
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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*/
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X86.fnBOUND = function BOUND(dst, src)
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{
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if (this.regEA === X86.ADDR_INVALID) {
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/*
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* Generate UD_FAULT (INT 0x06: Invalid Opcode) if src is not a memory operand.
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*/
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X86.opInvalid.call(this);
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return dst;
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}
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/*
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* Note that BOUND performs signed comparisons, so we must transform all arguments into signed values.
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*/
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var wIndex = dst;
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var wLower = this.getWord(this.regEA);
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var wUpper = this.getWord(this.regEA + this.sizeData);
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if (this.sizeData == 2) {
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wIndex = (dst << 16) >> 16;
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wLower = (wLower << 16) >> 16;
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wUpper = (wUpper << 16) >> 16;
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}
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this.nStepCycles -= this.cycleCounts.nOpCyclesBound;
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if (wIndex < wLower || wIndex > wUpper) {
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/*
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* The INT 0x05 handler must be called with CS:IP pointing to the BOUND instruction, which
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* fnFault() takes care of. TODO: Determine whether this should be treated like a fault, or like
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* a software interrupt, with an explicit call to fnINT() and nFault = -1, like opINT3(), opINTn()
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* and opINTO().
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*
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* TODO: Determine the cycle cost when a BOUND exception is triggered, over and above nCyclesBound,
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* and then call X86.fnFault(X86.EXCEPTION.BOUND_ERR, null, false, nCycles).
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*/
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X86.fnFault.call(this, X86.EXCEPTION.BOUND_ERR);
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}
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this.opFlags |= X86.OPFLAG.NOWRITE;
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return dst;
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};
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/**
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* fnBSF(dst, src)
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*
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* Scan src starting at bit 0. If a set bit is found, the bit index is stored in dst and ZF is cleared;
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* otherwise, ZF is set and dst is unchanged.
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*
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* NOTES: Early versions of the 80386 manuals misstated how ZF was set/cleared. Also, Intel insists that
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* dst is undefined whenever ZF is set, but in fact, the 80386 leaves dst unchanged when that happens;
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* unfortunately, some early 80486s would always modify dst, so it is unsafe to rely on dst when ZF is set.
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*
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* @this {X86CPU}
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* @param {number} dst
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* @param {number} src
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* @return {number}
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||
*/
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X86.fnBSF = function BSF(dst, src)
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{
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var n = 0;
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if (!src) {
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this.setZF();
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} else {
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this.clearZF();
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var bit = 0x1;
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while (bit & this.maskData) {
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if (src & bit) {
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dst = n;
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break;
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}
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bit <<= 1;
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n++; // TODO: Determine if n should be incremented before the bailout for an accurate cycle count
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}
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}
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this.nStepCycles -= 11 + n * 3;
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return dst;
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};
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/**
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* fnBSR(dst, src)
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*
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* Scan src starting from the highest bit. If a set bit is found, the bit index is stored in dst and ZF is
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* cleared; otherwise, ZF is set and dst is unchanged.
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*
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* NOTES: Early versions of the 80386 manuals misstated how ZF was set/cleared. Also, Intel insists that
|
||
* dst is undefined whenever ZF is set, but in fact, the 80386 leaves dst unchanged when that happens;
|
||
* unfortunately, some early 80486s would always modify dst, so it is unsafe to rely on dst when ZF is set.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
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||
* @param {number} src
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* @return {number}
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*/
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X86.fnBSR = function BSR(dst, src)
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{
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var n = 0;
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if (!src) {
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this.setZF();
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} else {
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this.clearZF();
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var i = (this.sizeData == 2? 15 : 31), bit = 1 << i;
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while (bit) {
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if (src & bit) {
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dst = i;
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break;
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||
}
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||
bit >>>= 1;
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||
n++; i--; // TODO: Determine if n should be incremented before the bailout for an accurate cycle count
|
||
}
|
||
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||
}
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this.nStepCycles -= 11 + n * 3;
|
||
return dst;
|
||
};
|
||
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/**
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* fnBT(dst, src)
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*
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* In this form of BT, src is an immediate operand (OR dst is register operand); immediate operands
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* are supposed to be masked with either 0xf or 0x1f for 16-bit or 32-bit operands, respectively.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBT = function BT(dst, src)
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{
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var bit = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
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if (dst & bit) this.setCF(); else this.clearCF();
|
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this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 3 : 6);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnBTC(dst, src)
|
||
*
|
||
* In this form of BTC, src is an immediate operand (OR dst is register operand); immediate operands
|
||
* are supposed to be masked with either 0xf or 0x1f for 16-bit or 32-bit operands, respectively.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBTC = function BTC(dst, src)
|
||
{
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||
var bit = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
|
||
if (dst & bit) this.setCF(); else this.clearCF();
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 6 : 8);
|
||
return dst ^ bit;
|
||
};
|
||
|
||
/**
|
||
* fnBTR(dst, src)
|
||
*
|
||
* In this form of BTR, src is an immediate operand (OR dst is register operand); immediate operands
|
||
* are supposed to be masked with either 0xf or 0x1f for 16-bit or 32-bit operands, respectively.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBTR = function BTR(dst, src)
|
||
{
|
||
var bit = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
|
||
if (dst & bit) this.setCF(); else this.clearCF();
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 6 : 8);
|
||
return dst & ~bit;
|
||
};
|
||
|
||
/**
|
||
* fnBTS(dst, src)
|
||
*
|
||
* In this form of BTS, src is an immediate operand (OR dst is register operand); immediate operands
|
||
* are supposed to be masked with either 0xf or 0x1f for 16-bit or 32-bit operands, respectively.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBTS = function BTS(dst, src)
|
||
{
|
||
var bit = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
|
||
if (dst & bit) this.setCF(); else this.clearCF();
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 6 : 8);
|
||
return dst | bit;
|
||
};
|
||
|
||
/**
|
||
* fnBTMem(dst, src)
|
||
*
|
||
* In this form of BT, src is a register operand, which is NOT truncated if dst is a memory operand;
|
||
* however, if dst is also a register operand, then we defer to the simpler function, fnBT().
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBTMem = function BTMem(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
return X86.fnBT.call(this, dst, src);
|
||
}
|
||
|
||
/*
|
||
* TODO: Consider a worker function that performs the following block of code for: BT, BTC, BTR, and BTS.
|
||
* It's somewhat inconvenient, because it needs to provide two results: an updated src AND an updated dst.
|
||
*
|
||
* src is usually positive BUT can also be negative (as the IA32 spec says: "The offset operand then selects
|
||
* a bit position within the range −231 to 231 − 1 for a register offset and 0 to 31 for an immediate offset.")
|
||
*/
|
||
var max = this.sizeData << 3;
|
||
if (src >= max || src < -max) {
|
||
/*
|
||
* We just divided src by 8, but now we need to divide src by 16 or 32, according to the OPERAND size,
|
||
* which means shifting it right by either 4 or 5 bits. That gives us a short or long INDEX, which we then
|
||
* multiply by the OPERAND size to obtain to the corresponding short or long OFFSET that we must add to
|
||
* the original EA offset.
|
||
*/
|
||
var i = src >> (this.sizeData == 2? 4 : 5);
|
||
dst = this.getEAWord(this.segEA, this.offEA + i * this.sizeData);
|
||
}
|
||
/*
|
||
* Now we convert src from a bit index to a bit mask.
|
||
*/
|
||
src = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
|
||
if (dst & src) this.setCF(); else this.clearCF();
|
||
/*
|
||
* End of common code block
|
||
*/
|
||
|
||
this.nStepCycles -= 6;
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnBTCMem(dst, src)
|
||
*
|
||
* In this form of BTC, src is a register operand, which is NOT truncated if dst is a memory operand;
|
||
* however, if dst is also a register operand, then we defer to the simpler function, fnBTC().
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBTCMem = function BTCMem(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
return X86.fnBTC.call(this, dst, src);
|
||
}
|
||
|
||
/*
|
||
* src is usually positive BUT can also be negative (as the IA32 spec says: "The offset operand then selects
|
||
* a bit position within the range −231 to 231 − 1 for a register offset and 0 to 31 for an immediate offset.")
|
||
*/
|
||
var max = this.sizeData << 3;
|
||
if (src >= max || src < -max) {
|
||
/*
|
||
* We just divided src by 8, but now we need to divide src by 16 or 32, according to the OPERAND size,
|
||
* which means shifting it right by either 4 or 5 bits. That gives us a short or long INDEX, which we then
|
||
* multiply by the OPERAND size to obtain to the corresponding short or long OFFSET that we must add to
|
||
* the original EA offset.
|
||
*/
|
||
var i = src >> (this.sizeData == 2? 4 : 5);
|
||
dst = this.getEAWord(this.segEA, this.offEA + i * this.sizeData);
|
||
}
|
||
/*
|
||
* Now we convert src from a bit index to a bit mask.
|
||
*/
|
||
src = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
|
||
if (dst & src) this.setCF(); else this.clearCF();
|
||
|
||
this.nStepCycles -= 8;
|
||
return dst ^ src;
|
||
};
|
||
|
||
/**
|
||
* fnBTRMem(dst, src)
|
||
*
|
||
* In this form of BTR, src is a register operand, which is NOT truncated if dst is a memory operand;
|
||
* however, if dst is also a register operand, then we defer to the simpler function, fnBTR().
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBTRMem = function BTRMem(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
return X86.fnBTR.call(this, dst, src);
|
||
}
|
||
|
||
/*
|
||
* src is usually positive BUT can also be negative (as the IA32 spec says: "The offset operand then selects
|
||
* a bit position within the range −231 to 231 − 1 for a register offset and 0 to 31 for an immediate offset.")
|
||
*/
|
||
var max = this.sizeData << 3;
|
||
if (src >= max || src < -max) {
|
||
/*
|
||
* We just divided src by 8, but now we need to divide src by 16 or 32, according to the OPERAND size,
|
||
* which means shifting it right by either 4 or 5 bits. That gives us a short or long INDEX, which we then
|
||
* multiply by the OPERAND size to obtain to the corresponding short or long OFFSET that we must add to
|
||
* the original EA offset.
|
||
*/
|
||
var i = src >> (this.sizeData == 2? 4 : 5);
|
||
dst = this.getEAWord(this.segEA, this.offEA + i * this.sizeData);
|
||
}
|
||
/*
|
||
* Now we convert src from a bit index to a bit mask.
|
||
*/
|
||
src = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
|
||
if (dst & src) this.setCF(); else this.clearCF();
|
||
|
||
this.nStepCycles -= 8;
|
||
return dst & ~src;
|
||
};
|
||
|
||
/**
|
||
* fnBTSMem(dst, src)
|
||
*
|
||
* In this form of BTS, src is a register operand, which is NOT truncated if dst is a memory operand;
|
||
* however, if dst is also a register operand, then we defer to the simpler function, fnBTS().
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnBTSMem = function BTSMem(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
return X86.fnBTS.call(this, dst, src);
|
||
}
|
||
|
||
/*
|
||
* src is usually positive BUT can also be negative (as the IA32 spec says: "The offset operand then selects
|
||
* a bit position within the range −231 to 231 − 1 for a register offset and 0 to 31 for an immediate offset.")
|
||
*/
|
||
var max = this.sizeData << 3;
|
||
if (src >= max || src < -max) {
|
||
/*
|
||
* We just divided src by 8, but now we need to divide src by 16 or 32, according to the OPERAND size,
|
||
* which means shifting it right by either 4 or 5 bits. That gives us a short or long INDEX, which we then
|
||
* multiply by the OPERAND size to obtain to the corresponding short or long OFFSET that we must add to
|
||
* the original EA offset.
|
||
*/
|
||
var i = src >> (this.sizeData == 2? 4 : 5);
|
||
dst = this.getEAWord(this.segEA, this.offEA + i * this.sizeData);
|
||
}
|
||
/*
|
||
* Now we convert src from a bit index to a bit mask.
|
||
*/
|
||
src = 1 << (src & (this.sizeData == 2? 0xf : 0x1f));
|
||
if (dst & src) this.setCF(); else this.clearCF();
|
||
|
||
this.nStepCycles -= 8;
|
||
return dst | src;
|
||
};
|
||
|
||
/**
|
||
* fnCALLw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnCALLw = function CALLw(dst, src)
|
||
{
|
||
this.pushWord(this.getIP());
|
||
this.setIP(dst);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesCallWR : this.cycleCounts.nOpCyclesCallWM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnCALLF(off, sel)
|
||
*
|
||
* For protected-mode, this function must attempt to load the new code segment first, because if the new segment
|
||
* requires a change in privilege level, the return address must be pushed on the NEW stack, not the current stack.
|
||
*
|
||
* Also, we rely on a new function, pushData(), instead of pushWord(), to accommodate the outgoing segment size,
|
||
* which may differ from the incoming segment. For example, when a 32-bit code segment performs a 16:32 call to a
|
||
* 16-bit code segment, we must push 32-bit segment and offset values.
|
||
*
|
||
* TODO: Since setCSIP() already informs the segCS load() function when it's making a call, the load() function
|
||
* could automatically push the old CS and IP values *before* segCS is updated (which would be a better time to do
|
||
* this); unfortunately, load() is also used by loadIDT(), and loadIDT() has different requirements (eg, pushing
|
||
* flags first), so it's not a trivial change.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} off
|
||
* @param {number} sel
|
||
*/
|
||
X86.fnCALLF = function CALLF(off, sel)
|
||
{
|
||
/*
|
||
* Originally, we would snapshot regLSP into opLSP because setCSIP() could trigger a segment fault,
|
||
* but additionally, the stack segment could trigger either a segment fault or a page fault; indeed,
|
||
* any operation that performs multiple stack modifications must take this precaution and snapshot regLSP.
|
||
*/
|
||
this.opLSP = this.regLSP;
|
||
|
||
var oldCS = this.getCS();
|
||
var oldIP = this.getIP();
|
||
var oldSize = (I386? this.sizeData : 2);
|
||
if (this.setCSIP(off, sel, true) != null) {
|
||
this.pushData(oldCS, oldSize);
|
||
this.pushData(oldIP, oldSize);
|
||
}
|
||
|
||
this.opLSP = X86.ADDR_INVALID;
|
||
};
|
||
|
||
/**
|
||
* fnCALLFdw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnCALLFdw = function CALLFdw(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
return X86.fnGRPUndefined.call(this, dst, src);
|
||
}
|
||
/*
|
||
* Originally, we would snapshot regLSP into opLSP because fnCALLF() could trigger a segment fault,
|
||
* but additionally, the stack segment could trigger either a segment fault or a page fault; indeed,
|
||
* any operation that performs multiple stack modifications must take this precaution and snapshot regLSP.
|
||
*/
|
||
this.opLSP = this.regLSP;
|
||
|
||
X86.fnCALLF.call(this, dst, this.getShort(this.regEA + this.sizeData));
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesCallDM;
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
|
||
this.opLSP = X86.ADDR_INVALID;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnCMPb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number} dst unchanged
|
||
*/
|
||
X86.fnCMPb = function CMPb(dst, src)
|
||
{
|
||
var b = (dst - src)|0;
|
||
this.setArithResult(dst, src, b, X86.RESULT.BYTE | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesCompareRM) : this.cycleCounts.nOpCyclesArithRM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnCMPw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number} dst unchanged
|
||
*/
|
||
X86.fnCMPw = function CMPw(dst, src)
|
||
{
|
||
var w = (dst - src)|0;
|
||
this.setArithResult(dst, src, w, this.typeData | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesCompareRM) : this.cycleCounts.nOpCyclesArithRM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnDECb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnDECb = function DECb(dst, src)
|
||
{
|
||
var b = (dst - 1)|0;
|
||
this.setArithResult(dst, 1, b, X86.RESULT.BYTE | X86.RESULT.NOTCF, true);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIncR : this.cycleCounts.nOpCyclesIncM);
|
||
return b & 0xff;
|
||
};
|
||
|
||
/**
|
||
* fnDECr(w)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} w
|
||
* @return {number}
|
||
*/
|
||
X86.fnDECr = function DECr(w)
|
||
{
|
||
var result = (w - 1)|0;
|
||
this.setArithResult(w, 1, result, this.typeData | X86.RESULT.NOTCF, true);
|
||
this.nStepCycles -= 2; // the register form of DEC takes 2 cycles on all CPUs
|
||
return (w & ~this.maskData) | (result & this.maskData);
|
||
};
|
||
|
||
/**
|
||
* fnDECw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnDECw = function DECw(dst, src)
|
||
{
|
||
var w = (dst - 1)|0;
|
||
this.setArithResult(dst, 1, w, this.typeData | X86.RESULT.NOTCF, true);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIncR : this.cycleCounts.nOpCyclesIncM);
|
||
return w & this.maskData;
|
||
};
|
||
|
||
/**
|
||
* fnSet64(lo, hi)
|
||
*
|
||
* @param {number} lo
|
||
* @param {number} hi
|
||
*/
|
||
X86.fnSet64 = function Set64(lo, hi)
|
||
{
|
||
return [lo >>> 0, hi >>> 0];
|
||
};
|
||
|
||
/**
|
||
* fnAdd64(dst, src)
|
||
*
|
||
* Adds src to dst.
|
||
*
|
||
* @param {Array} dst is a 64-bit value
|
||
* @param {Array} src is a 64-bit value
|
||
*/
|
||
X86.fnAdd64 = function Add64(dst, src)
|
||
{
|
||
dst[0] += src[0];
|
||
dst[1] += src[1];
|
||
if (dst[0] > 0xffffffff) {
|
||
dst[0] >>>= 0; // truncate dst[0] to 32 bits AND keep it unsigned
|
||
dst[1]++;
|
||
}
|
||
};
|
||
|
||
/**
|
||
* fnCmp64(dst, src)
|
||
*
|
||
* Compares dst to src, by computing dst - src.
|
||
*
|
||
* @param {Array} dst is a 64-bit value
|
||
* @param {Array} src is a 64-bit value
|
||
* @return {number} > 0 if dst > src, == 0 if dst == src, < 0 if dst < src
|
||
*/
|
||
X86.fnCmp64 = function Cmp64(dst, src)
|
||
{
|
||
var result = dst[1] - src[1];
|
||
if (!result) result = dst[0] - src[0];
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnSub64(dst, src)
|
||
*
|
||
* Subtracts src from dst.
|
||
*
|
||
* @param {Array} dst is a 64-bit value
|
||
* @param {Array} src is a 64-bit value
|
||
*/
|
||
X86.fnSub64 = function Sub64(dst, src)
|
||
{
|
||
dst[0] -= src[0];
|
||
dst[1] -= src[1];
|
||
if (dst[0] < 0) {
|
||
dst[0] >>>= 0; // truncate dst[0] to 32 bits AND keep it unsigned
|
||
dst[1]--;
|
||
}
|
||
};
|
||
|
||
/**
|
||
* fnShr64(dst)
|
||
*
|
||
* Shifts dst right one bit.
|
||
*
|
||
* @param {Array} dst is a 64-bit value
|
||
*/
|
||
X86.fnShr64 = function Shr64(dst)
|
||
{
|
||
dst[0] >>>= 1;
|
||
if (dst[1] & 0x1) {
|
||
dst[0] = (dst[0] | 0x80000000) >>> 0;
|
||
}
|
||
dst[1] >>>= 1;
|
||
};
|
||
|
||
/**
|
||
* fnDIV32(dstLo, dstHi, src)
|
||
*
|
||
* This sets regMDLo to dstHi:dstLo / src, and regMDHi to dstHi:dstLo % src; all inputs are treated as unsigned.
|
||
*
|
||
* If fMDset is not set, however, then there was a divide exception (ie, the divisor was either zero or too small).
|
||
*
|
||
* Refer to: http://lxr.linux.no/linux+v2.6.22/lib/div64.c
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dstLo (low 32-bit portion of dividend)
|
||
* @param {number} dstHi (high 32-bit portion of dividend)
|
||
* @param {number} src (32-bit divisor)
|
||
*/
|
||
X86.fnDIV32 = function DIV32(dstLo, dstHi, src)
|
||
{
|
||
this.fMDSet = false;
|
||
|
||
src >>>= 0;
|
||
if (!src || src <= (dstHi >>> 0)) return;
|
||
|
||
var result = 0, bit = 1;
|
||
|
||
var div = X86.fnSet64(src, 0);
|
||
var rem = X86.fnSet64(dstLo, dstHi);
|
||
|
||
while (X86.fnCmp64(rem, div) > 0) {
|
||
X86.fnAdd64(div, div);
|
||
bit += bit;
|
||
}
|
||
do {
|
||
if (X86.fnCmp64(rem, div) >= 0) {
|
||
X86.fnSub64(rem, div);
|
||
result += bit;
|
||
}
|
||
X86.fnShr64(div);
|
||
bit >>>= 1;
|
||
} while (bit);
|
||
|
||
this.assert(result <= 0xffffffff && !rem[1]);
|
||
|
||
this.regMDLo = result; // result is the quotient, which callers expect in the low MD register
|
||
this.regMDHi = rem[0]; // rem[0] is the remainder, which callers expect in the high MD register
|
||
this.fMDSet = true;
|
||
};
|
||
|
||
/**
|
||
* fnIDIV32(dstLo, dstHi, src)
|
||
*
|
||
* This sets regMDLo to dstHi:dstLo / src, and regMDHi to dstHi:dstLo % src; all inputs are treated as signed.
|
||
*
|
||
* If fMDset is not set, however, then there was a divide exception (ie, the divisor was either zero or too small).
|
||
*
|
||
* Refer to: http://lxr.linux.no/linux+v2.6.22/lib/div64.c
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dstLo (low 32-bit portion of dividend)
|
||
* @param {number} dstHi (high 32-bit portion of dividend)
|
||
* @param {number} src (32-bit divisor)
|
||
*/
|
||
X86.fnIDIV32 = function IDIV32(dstLo, dstHi, src)
|
||
{
|
||
var fNegLo = false, fNegHi = false;
|
||
if (src < 0) {
|
||
src = -src|0;
|
||
fNegLo = !fNegLo;
|
||
}
|
||
if (dstHi < 0) {
|
||
dstLo = -dstLo|0;
|
||
dstHi = (~dstHi + (dstLo? 0 : 1))|0;
|
||
fNegHi = true;
|
||
fNegLo = !fNegLo;
|
||
}
|
||
X86.fnDIV32.call(this, dstLo, dstHi, src);
|
||
if (this.regMDLo > 0x7fffffff) this.fMDSet = false;
|
||
if (fNegLo) this.regMDLo = -this.regMDLo;
|
||
if (fNegHi) this.regMDHi = -this.regMDHi;
|
||
};
|
||
|
||
/**
|
||
* fnDIVb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (the divisor)
|
||
* @param {number} src (null; AX is the implied src)
|
||
* @return {number} (we return dst unchanged, since it's actually AX that's modified)
|
||
*/
|
||
X86.fnDIVb = function DIVb(dst, src)
|
||
{
|
||
/*
|
||
* Detect zero divisor
|
||
*/
|
||
if (!dst) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
|
||
/*
|
||
* Detect too-small divisor (quotient overflow)
|
||
*/
|
||
var result = ((src = this.regEAX & 0xffff) / dst);
|
||
if (result > 0xff) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
|
||
this.fMDSet = true;
|
||
this.regMDLo = (result & 0xff) | (((src % dst) & 0xff) << 8);
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) this.traceLog('DIVb', src, dst, null, this.getPS(), this.regMDLo);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesDivBR : this.cycleCounts.nOpCyclesDivBM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnDIVw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (the divisor)
|
||
* @param {number} src (null; DX:AX or EDX:EAX is the implied src)
|
||
* @return {number} (we return dst unchanged, since it's actually DX:AX that's modified)
|
||
*/
|
||
X86.fnDIVw = function DIVw(dst, src)
|
||
{
|
||
if (this.sizeData == 2) {
|
||
/*
|
||
* Detect zero divisor
|
||
*/
|
||
if (!dst) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
/*
|
||
* Detect too-small divisor (quotient overflow)
|
||
*
|
||
* WARNING: We CANNOT simply do "src = (this.regEDX << 16) | this.regEAX", because if bit 15 of DX
|
||
* is set, JavaScript will create a negative 32-bit number. So we instead use non-bit-wise operators
|
||
* to force JavaScript to create a floating-point value that won't suffer from 32-bit-math side-effects.
|
||
*/
|
||
src = (this.regEDX & 0xffff) * 0x10000 + (this.regEAX & 0xffff);
|
||
var result = (src / dst)|0;
|
||
if (result >= 0x10000) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
this.fMDSet = true;
|
||
this.regMDLo = (result & 0xffff);
|
||
this.regMDHi = (src % dst) & 0xffff;
|
||
}
|
||
else {
|
||
X86.fnDIV32.call(this, this.regEAX, this.regEDX, dst);
|
||
if (!this.fMDSet) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
this.regMDLo |= 0;
|
||
this.regMDHi |= 0;
|
||
}
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) {
|
||
if (this.sizeData == 2) {
|
||
this.traceLog('DIVw', src, dst, null, this.getPS(), this.regMDLo | (this.regMDHi << 16));
|
||
} else {
|
||
this.traceLog('DIVd', src, dst, null, this.getPS(), this.regMDLo, this.regMDHi);
|
||
}
|
||
}
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesDivWR : this.cycleCounts.nOpCyclesDivWM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnESC(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number} dst unchanged
|
||
*/
|
||
X86.fnESC = function ESC(dst, src)
|
||
{
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnIDIVb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (the divisor)
|
||
* @param {number} src (null; AX is the implied src)
|
||
* @return {number} (we return dst unchanged, since it's actually AX that's modified)
|
||
*/
|
||
X86.fnIDIVb = function IDIVb(dst, src)
|
||
{
|
||
/*
|
||
* Detect zero divisor
|
||
*/
|
||
if (!dst) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
|
||
/*
|
||
* Detect too-small divisor (quotient overflow)
|
||
*/
|
||
var div = ((dst << 24) >> 24);
|
||
var result = ((src = (this.regEAX << 16) >> 16) / div)|0;
|
||
|
||
/*
|
||
* Note the following difference, from "AP-186: Introduction to the 80186 Microprocessor, March 1983":
|
||
*
|
||
* "The 8086 will cause a divide error whenever the absolute value of the quotient is greater then 7FFFH
|
||
* (for word operations) or if the absolute value of the quotient is greater than 7FH (for byte operations).
|
||
* The 80186 has expanded the range of negative numbers allowed as a quotient by 1 to include 8000H and 80H.
|
||
* These numbers represent the most negative numbers representable using 2's complement arithmetic (equaling
|
||
* -32768 and -128 in decimal, respectively)."
|
||
*/
|
||
if (result != ((result << 24) >> 24) || this.model == X86.MODEL_8086 && result == -128) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
|
||
this.fMDSet = true;
|
||
this.regMDLo = (result & 0xff) | (((src % div) & 0xff) << 8);
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) this.traceLog('IDIVb', src, dst, null, this.getPS(), this.regMDLo);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIDivBR : this.cycleCounts.nOpCyclesIDivBM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnIDIVw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (the divisor)
|
||
* @param {number} src (null; DX:AX or EDX:EAX is the implied src)
|
||
* @return {number} (we return dst unchanged, since it's actually DX:AX that's modified)
|
||
*/
|
||
X86.fnIDIVw = function IDIVw(dst, src)
|
||
{
|
||
if (this.sizeData == 2) {
|
||
/*
|
||
* Detect zero divisor
|
||
*/
|
||
if (!dst) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
|
||
/*
|
||
* Detect too-small divisor (quotient overflow)
|
||
*/
|
||
var div = ((dst << 16) >> 16);
|
||
var result = ((src = (this.regEDX << 16) | (this.regEAX & 0xffff)) / div)|0;
|
||
|
||
/*
|
||
* Note the following difference, from "AP-186: Introduction to the 80186 Microprocessor, March 1983":
|
||
*
|
||
* "The 8086 will cause a divide error whenever the absolute value of the quotient is greater then 7FFFH
|
||
* (for word operations) or if the absolute value of the quotient is greater than 7FH (for byte operations).
|
||
* The 80186 has expanded the range of negative numbers allowed as a quotient by 1 to include 8000H and 80H.
|
||
* These numbers represent the most negative numbers representable using 2's complement arithmetic (equaling
|
||
* -32768 and -128 in decimal, respectively)."
|
||
*/
|
||
if (result != ((result << 16) >> 16) || this.model == X86.MODEL_8086 && result == -32768) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
|
||
this.fMDSet = true;
|
||
this.regMDLo = (result & 0xffff);
|
||
this.regMDHi = (src % div) & 0xffff;
|
||
}
|
||
else {
|
||
X86.fnIDIV32.call(this, this.regEAX, this.regEDX, dst);
|
||
if (!this.fMDSet) {
|
||
X86.fnDIVOverflow.call(this);
|
||
return dst;
|
||
}
|
||
this.regMDLo |= 0;
|
||
this.regMDHi |= 0;
|
||
}
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) {
|
||
if (this.sizeData == 2) {
|
||
this.traceLog('IDIVw', src, dst, null, this.getPS(), this.regMDLo | (this.regMDHi << 16));
|
||
} else {
|
||
this.traceLog('IDIVd', src, dst, null, this.getPS(), this.regMDLo, this.regMDHi);
|
||
}
|
||
}
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIDivWR : this.cycleCounts.nOpCyclesIDivWM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnIMUL8(dst, src)
|
||
*
|
||
* 80286_and_80287_Programmers_Reference_Manual_1987.pdf, p.B-44 (p.254) notes that:
|
||
*
|
||
* "The low 16 bits of the product of a 16-bit signed multiply are the same as those of an
|
||
* unsigned multiply. The three operand IMUL instruction can be used for unsigned operands as well."
|
||
*
|
||
* However, we still sign-extend the operands before multiplying, making it easier to range-check the result.
|
||
*
|
||
* (80186/80188 and up)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnIMUL8 = function IMUL8(dst, src)
|
||
{
|
||
dst = this.getIPDisp();
|
||
var result = (((src << 16) >> 16) * dst)|0;
|
||
|
||
if (result > 32767 || result < -32768) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
|
||
result &= 0xffff;
|
||
if (DEBUG && DEBUGGER) this.traceLog('IMUL8', dst, src, null, this.getPS(), result);
|
||
|
||
/*
|
||
* NOTE: These are the cycle counts for the 80286; the 80186/80188 have slightly different values (ranges):
|
||
* 22-25 and 29-32 instead of 21 and 24, respectively. However, accurate cycle counts for the 80186/80188 is
|
||
* not super-critical. TODO: Fix this someday.
|
||
*/
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 21 : 24);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnIMULb(dst, src)
|
||
*
|
||
* This 16-bit multiplication must indicate when the upper 8 bits are simply a sign-extension of the
|
||
* lower 8 bits (carry clear) and when the upper 8 bits contain significant bits (carry set). The latter
|
||
* will occur whenever a positive result is > 127 (0x007f) and whenever a negative result is < -128
|
||
* (0xff80).
|
||
*
|
||
* Example 1: 16 * 4 = 64 (0x0040): carry is clear
|
||
* Example 2: 16 * 8 = 128 (0x0080): carry is set (the sign bit no longer fits in the lower 8 bits)
|
||
* Example 3: 16 * -8 (0xf8) = -128 (0xff80): carry is clear (the sign bit *still* fits in the lower 8 bits)
|
||
* Example 4: 16 * -16 (0xf0) = -256 (0xff00): carry is set (the sign bit no longer fits in the lower 8 bits)
|
||
*
|
||
* An earlier version of this function assumed it simply needed to check bit 7 of the result to determine carry,
|
||
* which was completely broken.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null; AL is the implied src)
|
||
* @return {number} (we return dst unchanged, since it's actually AX that's modified)
|
||
*/
|
||
X86.fnIMULb = function IMULb(dst, src)
|
||
{
|
||
var result = ((((src = this.regEAX) << 24) >> 24) * ((dst << 24) >> 24))|0;
|
||
|
||
this.fMDSet = true;
|
||
this.regMDLo = result & 0xffff;
|
||
|
||
if (result > 127 || result < -128) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) this.traceLog('IMULb', src, dst, null, this.getPS(), this.regMDLo);
|
||
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIMulBR : this.cycleCounts.nOpCyclesIMulBM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnIMULn(dst, src)
|
||
*
|
||
* 80286_and_80287_Programmers_Reference_Manual_1987.pdf, p.B-44 (p.254) notes that:
|
||
*
|
||
* "The low 16 bits of the product of a 16-bit signed multiply are the same as those of an
|
||
* unsigned multiply. The three operand IMUL instruction can be used for unsigned operands as well."
|
||
*
|
||
* However, we still sign-extend the operands before multiplying, making it easier to range-check the result.
|
||
*
|
||
* (80186/80188 and up)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (not used)
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnIMULn = function IMULn(dst, src)
|
||
{
|
||
var fOverflow, result;
|
||
dst = this.getIPWord();
|
||
if (this.sizeData == 2) {
|
||
result = (((src << 16) >> 16) * ((dst << 16) >> 16))|0;
|
||
fOverflow = (result > 32767 || result < -32768);
|
||
} else {
|
||
result = (src * dst);
|
||
fOverflow = (result > 2147483647 || result < -2147483648);
|
||
this.assert(fOverflow == (result != (result|0)));
|
||
}
|
||
|
||
if (fOverflow) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
|
||
result &= this.maskData;
|
||
if (DEBUG && DEBUGGER) this.traceLog('IMULn', dst, src, null, this.getPS(), result);
|
||
|
||
/*
|
||
* NOTE: These are the cycle counts for the 80286; the 80186/80188 have slightly different values (ranges):
|
||
* 22-25 and 29-32 instead of 21 and 24, respectively. However, accurate cycle counts for the 80186/80188 is
|
||
* not super-critical. TODO: Fix this someday.
|
||
*/
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 21 : 24);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnIMUL32(dst, src)
|
||
*
|
||
* This sets regMDHi:regMDLo to the 64-bit result of dst * src, both of which are treated as signed.
|
||
*
|
||
* TODO: Some potential optimizations include:
|
||
*
|
||
* 1) Early outs if either parameter is zero, since the result will obviously be zero
|
||
* 2) Using "normal" JavaScript multiplication if both parameters are >= -32768 && <= 32767
|
||
*
|
||
* Refer to: http://stackoverflow.com/questions/13597364/32-bit-signed-multiplication-with-a-64-bit-result-in-javascript
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (any 32-bit number, treated as signed)
|
||
* @param {number} src (any 32-bit number, treated as signed)
|
||
*/
|
||
X86.fnIMUL32 = function IMUL32(dst, src)
|
||
{
|
||
var fNeg = false;
|
||
if (src < 0) {
|
||
src = -src|0;
|
||
fNeg = !fNeg;
|
||
}
|
||
if (dst < 0) {
|
||
dst = -dst|0;
|
||
fNeg = !fNeg;
|
||
}
|
||
X86.fnMUL32.call(this, dst, src);
|
||
if (fNeg) {
|
||
this.regMDLo = (~this.regMDLo + 1)|0;
|
||
this.regMDHi = (~this.regMDHi + (this.regMDLo? 0 : 1))|0;
|
||
}
|
||
};
|
||
|
||
/**
|
||
* fnIMULw(dst, src)
|
||
*
|
||
* regMDHi:regMDLo = dst * regEAX
|
||
*
|
||
* This 32-bit multiplication must indicate when the upper 16 bits are simply a sign-extension of the
|
||
* lower 16 bits (carry clear) and when the upper 16 bits contain significant bits (carry set). The latter
|
||
* will occur whenever a positive result is > 32767 (0x00007fff) and whenever a negative result is < -32768
|
||
* (0xffff8000).
|
||
*
|
||
* Example 1: 256 * 64 = 16384 (0x00004000): carry is clear
|
||
* Example 2: 256 * 128 = 32768 (0x00008000): carry is set (the sign bit no longer fits in the lower 16 bits)
|
||
* Example 3: 256 * -128 (0xff80) = -32768 (0xffff8000): carry is clear (the sign bit *still* fits in the lower 16 bits)
|
||
* Example 4: 256 * -256 (0xff00) = -65536 (0xffff0000): carry is set (the sign bit no longer fits in the lower 16 bits)
|
||
*
|
||
* An earlier version of this function assumed it simply needed to check bit 15 of the result to determine carry,
|
||
* which was completely broken.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null; AX or EAX is the implied src)
|
||
* @return {number} (we return dst unchanged, since it's actually DX:AX that's modified)
|
||
*/
|
||
X86.fnIMULw = function IMULw(dst, src)
|
||
{
|
||
var fOverflow;
|
||
if (this.sizeData == 2) {
|
||
src = this.regEAX & 0xffff;
|
||
var result = (((src << 16) >> 16) * ((dst << 16) >> 16))|0;
|
||
this.fMDSet = true;
|
||
this.regMDLo = result & 0xffff;
|
||
this.regMDHi = (result >> 16) & 0xffff;
|
||
fOverflow = (result > 32767 || result < -32768);
|
||
} else {
|
||
X86.fnIMUL32.call(this, dst, this.regEAX);
|
||
fOverflow = (this.regMDHi != (this.regMDLo >> 31));
|
||
}
|
||
|
||
if (fOverflow) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) {
|
||
if (this.sizeData == 2) {
|
||
this.traceLog('IMULw', src, dst, null, this.getPS(), this.regMDLo | (this.regMDHi << 16));
|
||
} else {
|
||
this.traceLog('IMULd', src, dst, null, this.getPS(), this.regMDLo, this.regMDHi);
|
||
}
|
||
}
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIMulWR : this.cycleCounts.nOpCyclesIMulWM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnIMULrw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnIMULrw = function IMULrw(dst, src)
|
||
{
|
||
var result = (((dst << 16) >> 16) * ((src << 16) >> 16))|0;
|
||
if (result > 32767 || result < -32768) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
result &= 0xffff;
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 9 : 12);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnIMULrd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnIMULrd = function IMULrd(dst, src)
|
||
{
|
||
var result = dst * src;
|
||
if (result > 2147483647 || result < -2147483648) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
result |= 0;
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 9 : 12);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnINCb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnINCb = function INCb(dst, src)
|
||
{
|
||
var b = (dst + 1)|0;
|
||
this.setArithResult(dst, 1, b, X86.RESULT.BYTE | X86.RESULT.NOTCF);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIncR : this.cycleCounts.nOpCyclesIncM);
|
||
return b & 0xff;
|
||
};
|
||
|
||
/**
|
||
* fnINCr(w)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} w
|
||
* @return {number}
|
||
*/
|
||
X86.fnINCr = function INCr(w)
|
||
{
|
||
var result = (w + 1)|0;
|
||
this.setArithResult(w, 1, result, this.typeData | X86.RESULT.NOTCF);
|
||
this.nStepCycles -= 2; // the register form of INC takes 2 cycles on all CPUs
|
||
return (w & ~this.maskData) | (result & this.maskData);
|
||
};
|
||
|
||
/**
|
||
* fnINCw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnINCw = function INCw(dst, src)
|
||
{
|
||
var w = (dst + 1)|0;
|
||
this.setArithResult(dst, 1, w, this.typeData | X86.RESULT.NOTCF);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesIncR : this.cycleCounts.nOpCyclesIncM);
|
||
return w & this.maskData;
|
||
};
|
||
|
||
/**
|
||
* fnINT(nIDT, nError, nCycles)
|
||
*
|
||
* NOTE: We no longer use setCSIP(), because it always loads the new CS using segCS.load(), which only knows
|
||
* how to load GDT and LDT descriptors, whereas interrupts must use setCS.loadIDT(), which deals exclusively
|
||
* with IDT descriptors.
|
||
*
|
||
* This means we must take care to replicate critical features of setCSIP(); ie, updating regLIP and regLIPLimit,
|
||
* resetting default operand and address sizes, and flushing the prefetch queue AFTER calling loadIDT().
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} nIDT
|
||
* @param {number|null|undefined} nError
|
||
* @param {number} nCycles (in addition to the default of nOpCyclesInt)
|
||
*/
|
||
X86.fnINT = function INT(nIDT, nError, nCycles)
|
||
{
|
||
/*
|
||
* TODO: We assess the cycle cost up front, because otherwise, if loadIDT() fails, no cost may be assessed.
|
||
*/
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesInt + nCycles;
|
||
var oldPS = this.getPS();
|
||
var oldCS = this.getCS();
|
||
var oldIP = this.getIP();
|
||
var addr = this.segCS.loadIDT(nIDT);
|
||
if (addr !== X86.ADDR_INVALID) {
|
||
/*
|
||
* TODO: Harmonize this with the code in fnCALLF(), which relies on the OPERAND size in
|
||
* effect at the time of the call, NOT the size of the new segCS.
|
||
*/
|
||
var size = this.segCS.sizeFrame;
|
||
this.pushData(oldPS, size);
|
||
this.pushData(oldCS, size);
|
||
this.pushData(oldIP, size);
|
||
if (nError != null) this.pushData(nError, size);
|
||
this.nFault = -1;
|
||
/*
|
||
* TODO: Should this code be factored into a setLIP() function? The other primary client would be setCSIP().
|
||
*/
|
||
if (I386) this.resetSizes();
|
||
this.regLIP = addr;
|
||
this.regLIPLimit = (this.segCS.base + this.segCS.limit)|0;
|
||
this.nCPL = this.segCS.cpl; // cache the current CPL where it's more convenient
|
||
if (PREFETCH) this.flushPrefetch(this.regLIP);
|
||
}
|
||
};
|
||
|
||
/**
|
||
* fnIRET()
|
||
*
|
||
* @this {X86CPU}
|
||
*/
|
||
X86.fnIRET = function IRET()
|
||
{
|
||
/*
|
||
* Originally, we would snapshot regLSP into opLSP because newCS could trigger a segment fault,
|
||
* but additionally, the stack segment could trigger either a segment fault or a page fault; indeed,
|
||
* any operation that performs multiple stack modifications must take this precaution and snapshot regLSP.
|
||
*/
|
||
this.opLSP = this.regLSP;
|
||
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesIRet;
|
||
|
||
if ((this.regCR0 & X86.CR0.MSW.PE) && (this.regPS & X86.PS.NT)) {
|
||
var addrNew = this.segTSS.base;
|
||
/*
|
||
* Fortunately, X86.TSS286.PREV_TSS and X86.TSS386.PREV_TSS refer to the same TSS offset.
|
||
* TODO: Update switchTS() to assess a cycle cost; currently, all we assess is what's shown above.
|
||
*/
|
||
var sel = this.getShort(addrNew + X86.TSS286.PREV_TSS);
|
||
this.segCS.switchTSS(sel, false);
|
||
}
|
||
else {
|
||
var cpl = this.nCPL;
|
||
var newIP = this.popWord();
|
||
var newCS = this.popWord();
|
||
var newPS = this.popWord();
|
||
|
||
if (I386) {
|
||
if (this.regPS & X86.PS.VM) {
|
||
/*
|
||
* On the 80386, in V86-mode, RF is the only defined EFLAGS bit above bit 15 that may be changed by IRETD.
|
||
* This is less restrictive than POPFD, which cannot change ANY bits above bit 15; see opPOPF() for details.
|
||
*/
|
||
newPS = (newPS & (0xffff | X86.PS.RF)) | (this.regPS & ~(0xffff | X86.PS.RF));
|
||
}
|
||
else {
|
||
if (newPS & X86.PS.VM) {
|
||
this.assert(!!(this.regCR0 & X86.CR0.MSW.PE));
|
||
/*
|
||
* We have to assume that a full V86-mode interrupt frame was on the protected-mode stack; namely:
|
||
*
|
||
* GS
|
||
* FS
|
||
* DS
|
||
* ES
|
||
* SS
|
||
* ESP
|
||
* EFLAGS
|
||
* CS
|
||
* EIP
|
||
*
|
||
* We've already popped EIP, CS, and EFLAGS into newIP, newCS and newPS, respectively, so we must now
|
||
* pop the rest, while we're still in protected-mode, before the switch to V86-mode alters the current
|
||
* operand size (among other things).
|
||
*/
|
||
var newSP = this.popWord();
|
||
var newSS = this.popWord();
|
||
var newES = this.popWord();
|
||
var newDS = this.popWord();
|
||
var newFS = this.popWord();
|
||
var newGS = this.popWord();
|
||
this.setProtMode(true, true); // flip the switch to V86-mode now
|
||
this.setSS(newSS);
|
||
this.setSP(newSP);
|
||
this.setES(newES);
|
||
this.setDS(newDS);
|
||
this.setFS(newFS);
|
||
this.setGS(newGS);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (this.setCSIP(newIP, newCS, false) != null) {
|
||
this.setPS(newPS, cpl);
|
||
if (this.cIntReturn) this.checkIntReturn(this.regLIP);
|
||
}
|
||
}
|
||
|
||
this.opLSP = X86.ADDR_INVALID;
|
||
};
|
||
|
||
/**
|
||
* fnJMPw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnJMPw = function JMPw(dst, src)
|
||
{
|
||
this.setIP(dst);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesJmpWR : this.cycleCounts.nOpCyclesJmpWM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnJMPFdw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnJMPFdw = function JMPFdw(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
return X86.fnGRPUndefined.call(this, dst, src);
|
||
}
|
||
this.setCSIP(dst, this.getShort(this.regEA + this.sizeData));
|
||
if (MAXDEBUG && this.cIntReturn) this.checkIntReturn(this.regLIP);
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesJmpDM;
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnLAR(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnLAR = function LAR(dst, src)
|
||
{
|
||
this.nStepCycles -= (14 + (this.regEA === X86.ADDR_INVALID? 0 : 2));
|
||
/*
|
||
* Currently, segVER.load() will return an error only if the selector is beyond the bounds of the
|
||
* descriptor table or the descriptor is not for a segment.
|
||
*
|
||
* TODO: This instruction's 80286 documentation does not discuss conforming code segments; determine
|
||
* if we need a special check for them.
|
||
*/
|
||
this.clearZF();
|
||
if (this.segVER.load(src) !== X86.ADDR_INVALID) {
|
||
if (this.segVER.dpl >= this.nCPL && this.segVER.dpl >= (src & X86.SEL.RPL)) {
|
||
this.setZF();
|
||
dst = this.segVER.acc & ~X86.DESC.ACC.BASE1623;
|
||
if (this.sizeData > 2) {
|
||
dst |= ((this.segVER.ext & ~X86.DESC.EXT.BASE2431) << 16);
|
||
}
|
||
}
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnLCR0(l)
|
||
*
|
||
* This is called by an 80386 control instruction (ie, MOV CR0,reg).
|
||
*
|
||
* TODO: Determine which CR0 bits, if any, cannot be modified by MOV CR0,reg.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} l
|
||
*/
|
||
X86.fnLCR0 = function LCR0(l)
|
||
{
|
||
this.regCR0 = l;
|
||
this.setProtMode();
|
||
if (this.regCR0 & X86.CR0.PG) {
|
||
this.enablePageBlocks();
|
||
} else {
|
||
this.disablePageBlocks();
|
||
}
|
||
};
|
||
|
||
/**
|
||
* fnLCR3(l)
|
||
*
|
||
* This is called by an 80386 control instruction (ie, MOV CR3,reg) or an 80386 task switch.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} l
|
||
*/
|
||
X86.fnLCR3 = function LCR3(l)
|
||
{
|
||
this.regCR3 = l;
|
||
/*
|
||
* Normal use of regCR3 involves adding a 0-4K (12-bit) offset to obtain a page directory entry,
|
||
* so let's ensure that the low 12 bits of regCR3 are always zero.
|
||
*/
|
||
this.assert(!(this.regCR3 & X86.LADDR.OFFSET));
|
||
if (this.regCR0 & X86.CR0.PG) this.enablePageBlocks();
|
||
};
|
||
|
||
/**
|
||
* fnLDS(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnLDS = function LDS(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
X86.opUndefined.call(this);
|
||
return dst;
|
||
}
|
||
this.setDS(this.getShort(this.regEA + this.sizeData));
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesLS;
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnLEA(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnLEA = function LEA(dst, src)
|
||
{
|
||
/*
|
||
* TODO: Until I bite the bullet and choose a truly invalid value for X86.ADDR_INVALID (eg, null),
|
||
* this code must be disabled, because otherwise an instruction like "LEA ECX,[EAX-1]" will fail when
|
||
* EAX is zero. And we can't have that.
|
||
*
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
//
|
||
// TODO: After reading http://www.os2museum.com/wp/undocumented-8086-opcodes/, it seems that this
|
||
// form of LEA (eg, "LEA AX,DX") simply returns the last calculated EA. Since we always reset regEA
|
||
// at the start of a new instruction, we would need to preserve the previous EA if we want to mimic
|
||
// that (undocumented) behavior.
|
||
//
|
||
// And for completeness, we would have to extend EA tracking beyond the usual ModRM instructions
|
||
// (eg, XLAT, instructions that modify the stack pointer, and string instructions). Anything else?
|
||
//
|
||
X86.opUndefined.call(this);
|
||
return dst;
|
||
}
|
||
*/
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesLEA;
|
||
return this.regEA;
|
||
};
|
||
|
||
/**
|
||
* fnLES(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnLES = function LES(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
X86.opUndefined.call(this);
|
||
return dst;
|
||
}
|
||
this.setES(this.getShort(this.regEA + this.sizeData));
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesLS;
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnLFS(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnLFS = function LFS(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
X86.opUndefined.call(this);
|
||
return dst;
|
||
}
|
||
this.setFS(this.getShort(this.regEA + this.sizeData));
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesLS;
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnLGDT(dst, src)
|
||
*
|
||
* op=0x0F,0x01,reg=0x2 (GRP7:LGDT)
|
||
*
|
||
* The 80286 LGDT instruction assumes a 40-bit operand: a 16-bit limit followed by a 24-bit base address;
|
||
* the ModRM decoder has already supplied the first word of the operand (in dst), which corresponds to
|
||
* the limit, so we must fetch the remaining bits ourselves.
|
||
*
|
||
* The 80386 LGDT instruction assumes a 48-bit operand: a 16-bit limit followed by a 32-bit base address,
|
||
* but it ignores the last 8 bits of the base address if the OPERAND size is 16 bits; we interpret that to
|
||
* mean that the 24-bit base address should be zero-extended to 32 bits.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnLGDT = function LGDT(dst, src)
|
||
{
|
||
/*
|
||
* TODO: Consider swapping out this function whenever setProtMode() changes the mode to V86-mode.
|
||
*/
|
||
if (this.regEA === X86.ADDR_INVALID || I386 && (this.regPS & X86.PS.VM)) {
|
||
X86.opInvalid.call(this);
|
||
} else {
|
||
/*
|
||
* Hopefully it won't hurt to always fetch a 32-bit base address (even on an 80286), which we then
|
||
* mask apppropriately.
|
||
*/
|
||
this.addrGDT = this.getLong(this.regEA + 2) & (this.maskData | (this.maskData << 8));
|
||
/*
|
||
* An idiosyncrasy of our ModRM decoders is that, if the OPERAND size is 32 bits, then it will have
|
||
* fetched a 32-bit dst operand; we mask off those extra bits now.
|
||
*/
|
||
dst &= 0xffff;
|
||
this.addrGDTLimit = this.addrGDT + dst;
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
this.nStepCycles -= 11;
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnLGS(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnLGS = function LGS(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
X86.opUndefined.call(this);
|
||
return dst;
|
||
}
|
||
this.setGS(this.getShort(this.regEA + this.sizeData));
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesLS;
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnLIDT(dst, src)
|
||
*
|
||
* op=0x0F,0x01,reg=0x3 (GRP7:LIDT)
|
||
*
|
||
* The 80286 LIDT instruction assumes a 40-bit operand: a 16-bit limit followed by a 24-bit base address;
|
||
* the ModRM decoder has already supplied the first word of the operand (in dst), which corresponds to
|
||
* the limit, so we must fetch the remaining bits ourselves.
|
||
*
|
||
* The 80386 LIDT instruction assumes a 48-bit operand: a 16-bit limit followed by a 32-bit base address,
|
||
* but it ignores the last 8 bits of the base address if the OPERAND size is 16 bits; we interpret that to
|
||
* mean that the 24-bit base address should be zero-extended to 32 bits.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnLIDT = function LIDT(dst, src)
|
||
{
|
||
/*
|
||
* TODO: Consider swapping out this function whenever setProtMode() changes the mode to V86-mode.
|
||
*/
|
||
if (this.regEA === X86.ADDR_INVALID || I386 && (this.regPS & X86.PS.VM)) {
|
||
X86.opInvalid.call(this);
|
||
} else {
|
||
/*
|
||
* Hopefully it won't hurt to always fetch a 32-bit base address (even on an 80286), which we then
|
||
* mask apppropriately.
|
||
*/
|
||
this.addrIDT = this.getLong(this.regEA + 2) & (this.maskData | (this.maskData << 8));
|
||
/*
|
||
* An idiosyncrasy of our ModRM decoders is that, if the OPERAND size is 32 bits, then it will have
|
||
* fetched a 32-bit dst operand; we mask off those extra bits now.
|
||
*/
|
||
dst &= 0xffff;
|
||
this.addrIDTLimit = this.addrIDT + dst;
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
this.nStepCycles -= 12;
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnLLDT(dst, src)
|
||
*
|
||
* op=0x0F,0x00,reg=0x2 (GRP6:LLDT)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnLLDT = function LLDT(dst, src)
|
||
{
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
this.segLDT.load(dst);
|
||
this.nStepCycles -= (17 + (this.regEA === X86.ADDR_INVALID? 0 : 2));
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnLMSW(dst, src)
|
||
*
|
||
* op=0x0F,0x01,reg=0x6 (GRP7:LMSW)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnLMSW = function LMSW(dst, src)
|
||
{
|
||
/*
|
||
* TODO: Consider swapping out this function whenever setProtMode() changes the mode to V86-mode.
|
||
*/
|
||
if (I386 && (this.regPS & X86.PS.VM)) {
|
||
X86.opInvalid.call(this);
|
||
} else {
|
||
this.setMSW(dst);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 3 : 6);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnLSL(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (the selector)
|
||
* @return {number}
|
||
*/
|
||
X86.fnLSL = function LSL(dst, src)
|
||
{
|
||
/*
|
||
* TODO: Is this an invalid operation if regEAWrite is set? dst is required to be a register.
|
||
*/
|
||
this.nStepCycles -= (14 + (this.regEA === X86.ADDR_INVALID? 0 : 2));
|
||
/*
|
||
* Currently, segVER.load() will return an error only if the selector is beyond the bounds of the
|
||
* descriptor table or the descriptor is not for a segment.
|
||
*
|
||
* TODO: LSL is explicitly documented as ALSO requiring a non-null selector, so we check X86.SEL.MASK;
|
||
* are there any other instructions that were, um, less explicit but also require a non-null selector?
|
||
*/
|
||
if ((src & X86.SEL.MASK) && this.segVER.load(src) !== X86.ADDR_INVALID) {
|
||
var fConforming = ((this.segVER.acc & X86.DESC.ACC.TYPE.CODE_CONFORMING) == X86.DESC.ACC.TYPE.CODE_CONFORMING);
|
||
if ((fConforming || this.segVER.dpl >= this.nCPL) && this.segVER.dpl >= (src & X86.SEL.RPL)) {
|
||
this.setZF();
|
||
return this.segVER.limit;
|
||
}
|
||
}
|
||
this.clearZF();
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnLSS(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnLSS = function LSS(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
X86.opUndefined.call(this);
|
||
return dst;
|
||
}
|
||
this.setSS(this.getShort(this.regEA + this.sizeData));
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesLS;
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnLTR(dst, src)
|
||
*
|
||
* op=0x0F,0x00,reg=0x3 (GRP6:LTR)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnLTR = function LTR(dst, src)
|
||
{
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
if (this.segTSS.load(dst) !== X86.ADDR_INVALID) {
|
||
this.setShort(this.segTSS.addrDesc + X86.DESC.ACC.OFFSET, this.segTSS.acc |= X86.DESC.ACC.TSS_BUSY);
|
||
this.segTSS.type |= X86.DESC.ACC.TSS_BUSY;
|
||
}
|
||
this.nStepCycles -= (17 + (this.regEA === X86.ADDR_INVALID? 0 : 2));
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnMOV(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (current value, ignored)
|
||
* @param {number} src (new value)
|
||
* @return {number} dst (updated value, from src)
|
||
*/
|
||
X86.fnMOV = function MOV(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesMovRR : this.cycleCounts.nOpCyclesMovRM) : this.cycleCounts.nOpCyclesMovMR);
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnMOVX(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (current value, ignored)
|
||
* @param {number} src (new value)
|
||
* @return {number} dst (updated value, from src)
|
||
*/
|
||
X86.fnMOVX = function MOVX(dst, src)
|
||
{
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnMOVn(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (current value, ignored)
|
||
* @param {number} src (new value)
|
||
* @return {number} dst (updated value, from src)
|
||
*/
|
||
X86.fnMOVn = function MOVn(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesMovRI : this.cycleCounts.nOpCyclesMovMI);
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnMOVxx(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (current value, ignored)
|
||
* @param {number} src (new value)
|
||
* @return {number} dst (src is overridden, replaced with regXX, as specified by opMOVwsr() or opMOVrc())
|
||
*/
|
||
X86.fnMOVxx = function MOVxx(dst, src)
|
||
{
|
||
if (this.regEAWrite !== X86.ADDR_INVALID) {
|
||
/*
|
||
* When a 32-bit OPERAND size is in effect, opMOVwsr() will write 32 bits (zero-extended) if the destination
|
||
* is a register, but only 16 bits if the destination is memory. The only other caller, opMOVrc(), is not
|
||
* affected, because it writes only to register destinations.
|
||
*/
|
||
this.setDataSize(2);
|
||
}
|
||
return X86.fnMOV.call(this, dst, this.regXX);
|
||
};
|
||
|
||
/**
|
||
* fnMULb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number} (we return dst unchanged, since it's actually AX that's modified)
|
||
*/
|
||
X86.fnMULb = function MULb(dst, src)
|
||
{
|
||
this.fMDSet = true;
|
||
this.regMDLo = ((src = this.regEAX & 0xff) * dst) & 0xffff;
|
||
|
||
if (this.regMDLo & 0xff00) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) this.traceLog('MULb', src, dst, null, this.getPS(), this.regMDLo);
|
||
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesMulBR : this.cycleCounts.nOpCyclesMulBM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnMUL32(dst, src)
|
||
*
|
||
* This sets regMDHi:regMDLo to the 64-bit result of dst * src, both of which are treated as unsigned.
|
||
*
|
||
* TODO: Some potential optimizations include:
|
||
*
|
||
* 1) Early outs if either parameter is zero, since the result will obviously be zero
|
||
* 2) Using "normal" JavaScript multiplication if both parameters are < 32767
|
||
*
|
||
* Refer to: http://stackoverflow.com/questions/13597364/32-bit-signed-multiplication-with-a-64-bit-result-in-javascript
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (any 32-bit number, treated as unsigned)
|
||
* @param {number} src (any 32-bit number, treated as unsigned)
|
||
*/
|
||
X86.fnMUL32 = function MUL32(dst, src)
|
||
{
|
||
var srcLo = src & 0xffff;
|
||
var srcHi = src >>> 16;
|
||
var dstLo = dst & 0xffff;
|
||
var dstHi = dst >>> 16;
|
||
|
||
var mul00 = srcLo * dstLo;
|
||
var mul16 = ((mul00 >>> 16) + (srcHi * dstLo));
|
||
var mul32 = mul16 >>> 16;
|
||
mul16 = ((mul16 & 0xffff) + (srcLo * dstHi));
|
||
mul32 += ((mul16 >>> 16) + (srcHi * dstHi));
|
||
|
||
this.fMDSet = true;
|
||
this.regMDLo = (mul16 << 16) | (mul00 & 0xffff);
|
||
this.regMDHi = mul32|0;
|
||
};
|
||
|
||
/**
|
||
* fnMULw(dst, src)
|
||
*
|
||
* regMDHi:regMDLo = dst * regEAX
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null; AX or EAX is the implied src)
|
||
* @return {number} (we return dst unchanged, since it's actually DX:AX that's modified)
|
||
*/
|
||
X86.fnMULw = function MULw(dst, src)
|
||
{
|
||
if (this.sizeData == 2) {
|
||
src = this.regEAX & 0xffff;
|
||
var result = (src * dst)|0;
|
||
this.fMDSet = true;
|
||
this.regMDLo = result & 0xffff;
|
||
this.regMDHi = (result >> 16) & 0xffff;
|
||
} else {
|
||
X86.fnMUL32.call(this, dst, this.regEAX);
|
||
}
|
||
|
||
if (this.regMDHi) {
|
||
this.setCF(); this.setOF();
|
||
} else {
|
||
this.clearCF(); this.clearOF();
|
||
}
|
||
|
||
/*
|
||
* Multiply/divide instructions specify only a single operand, which the decoders pass to us
|
||
* via the dst parameter, so we set src to the other implied operand (either AX or DX:AX).
|
||
* However, src is technically an output, and dst is merely an input (which is why we must return
|
||
* dst unchanged). So, to make traceLog() more consistent, we reverse the order of dst and src.
|
||
*/
|
||
if (DEBUG && DEBUGGER) {
|
||
if (this.sizeData == 2) {
|
||
this.traceLog('MULw', src, dst, null, this.getPS(), this.regMDLo | (this.regMDHi << 16));
|
||
} else {
|
||
this.traceLog('MULd', src, dst, null, this.getPS(), this.regMDLo, this.regMDHi);
|
||
}
|
||
}
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesMulWR : this.cycleCounts.nOpCyclesMulWM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnNEGb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnNEGb = function NEGb(dst, src)
|
||
{
|
||
var b = (-dst)|0;
|
||
this.setArithResult(0, dst, b, X86.RESULT.BYTE | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesNegR : this.cycleCounts.nOpCyclesNegM);
|
||
return b & 0xff;
|
||
};
|
||
|
||
/**
|
||
* fnNEGw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnNEGw = function NEGw(dst, src)
|
||
{
|
||
var w = (-dst)|0;
|
||
this.setArithResult(0, dst, w, this.typeData | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesNegR : this.cycleCounts.nOpCyclesNegM);
|
||
return w & this.maskData;
|
||
};
|
||
|
||
/**
|
||
* fnNOTb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnNOTb = function NOTb(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesNegR : this.cycleCounts.nOpCyclesNegM);
|
||
return dst ^ 0xff;
|
||
};
|
||
|
||
/**
|
||
* fnNOTw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnNOTw = function NOTw(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesNegR : this.cycleCounts.nOpCyclesNegM);
|
||
return dst ^ this.maskData;
|
||
};
|
||
|
||
/**
|
||
* fnORb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnORb = function ORb(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return this.setLogicResult(dst | src, X86.RESULT.BYTE);
|
||
};
|
||
|
||
/**
|
||
* fnORw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnORw = function ORw(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return this.setLogicResult(dst | src, this.typeData);
|
||
};
|
||
|
||
/**
|
||
* fnPOPw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (current value, ignored)
|
||
* @param {number} src (new value)
|
||
* @return {number} dst (updated value, from src)
|
||
*/
|
||
X86.fnPOPw = function POPw(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesPopReg : this.cycleCounts.nOpCyclesPopMem);
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnPUSHw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnPUSHw = function PUSHw(dst, src)
|
||
{
|
||
var w = dst;
|
||
if (this.opFlags & X86.OPFLAG.PUSHSP) {
|
||
/*
|
||
* This is the one case where must actually modify dst, so that the ModRM function will
|
||
* not put a stale value back into the SP register.
|
||
*/
|
||
dst = (dst - 2) & 0xffff;
|
||
/*
|
||
* And on the 8086/8088, the value we just calculated also happens to be the value that must
|
||
* be pushed.
|
||
*/
|
||
if (this.model < X86.MODEL_80286) w = dst;
|
||
}
|
||
this.pushWord(w);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesPushReg : this.cycleCounts.nOpCyclesPushMem);
|
||
/*
|
||
* The PUSH is the only write that needs to occur; dst was the source operand and does not need to be rewritten.
|
||
*/
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnRCLb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRCLb = function RCLb(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = this.getCarry();
|
||
count %= 9;
|
||
if (!count) {
|
||
carry <<= 7;
|
||
} else {
|
||
result = ((dst << count) | (carry << (count - 1)) | (dst >> (9 - count))) & 0xff;
|
||
carry = dst << (count - 1);
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.BYTE);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RCLb', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRCLw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRCLw = function RCLw(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = this.getCarry();
|
||
count %= 17;
|
||
if (!count) {
|
||
carry <<= 15;
|
||
} else {
|
||
result = ((dst << count) | (carry << (count - 1)) | (dst >> (17 - count))) & 0xffff;
|
||
carry = dst << (count - 1);
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.WORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RCLw', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRCLd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRCLd = function RCLd(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask; // this 32-bit-only function could mask with 0x1f directly
|
||
if (count) {
|
||
var carry = this.getCarry();
|
||
/*
|
||
* JavaScript Alert: much like a post-8086 Intel CPU, JavaScript shift counts are mod 32,
|
||
* so "dst >>> 32" is equivalent to "dst >>> 0", which doesn't shift any bits at all. To
|
||
* compensate, we shift one bit less than the maximum, and then shift one bit farther.
|
||
*/
|
||
result = (dst << count) | (carry << (count - 1)) | ((dst >>> (32 - count)) >>> 1);
|
||
carry = dst << (count - 1);
|
||
this.setRotateResult(result, carry, X86.RESULT.DWORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RCLd', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRCRb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRCRb = function RCRb(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = this.getCarry();
|
||
count %= 9;
|
||
if (!count) {
|
||
carry <<= 7;
|
||
} else {
|
||
result = ((dst >> count) | (carry << (8 - count)) | (dst << (9 - count))) & 0xff;
|
||
carry = dst << (8 - count);
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.BYTE);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RCRb', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRCRw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRCRw = function RCRw(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = this.getCarry();
|
||
count %= 17;
|
||
if (!count) {
|
||
carry <<= 15;
|
||
} else {
|
||
result = ((dst >> count) | (carry << (16 - count)) | (dst << (17 - count))) & 0xffff;
|
||
carry = dst << (16 - count);
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.WORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RCRw', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRCRd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRCRd = function RCRd(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask; // this 32-bit-only function could mask with 0x1f directly
|
||
if (count) {
|
||
var carry = this.getCarry();
|
||
/*
|
||
* JavaScript Alert: much like a post-8086 Intel CPU, JavaScript shift counts are mod 32,
|
||
* so "dst << 32" is equivalent to "dst << 0", which doesn't shift any bits at all. To
|
||
* compensate, we shift one bit less than the maximum, and then shift one bit farther.
|
||
*/
|
||
result = (dst >>> count) | (carry << (32 - count)) | ((dst << (32 - count)) << 1);
|
||
carry = dst << (32 - count);
|
||
this.setRotateResult(result, carry, X86.RESULT.DWORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RCRd', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRETF(n)
|
||
*
|
||
* For protected-mode, this function must pop any arguments off the current stack AND whatever stack
|
||
* we may have switched to; setCSIP() returns true if a stack switch occurred, false if not, and null
|
||
* if an error occurred.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} n
|
||
*/
|
||
X86.fnRETF = function RETF(n)
|
||
{
|
||
/*
|
||
* Originally, we would snapshot regLSP into opLSP because newCS could trigger a segment fault,
|
||
* but additionally, the stack segment could trigger either a segment fault or a page fault; indeed,
|
||
* any operation that performs multiple stack modifications must take this precaution and snapshot regLSP.
|
||
*/
|
||
this.opLSP = this.regLSP;
|
||
|
||
var newIP = this.popWord();
|
||
var newCS = this.popWord();
|
||
|
||
if (n) this.setSP(this.getSP() + n); // TODO: optimize
|
||
|
||
if (this.setCSIP(newIP, newCS, false)) { // returns true if a stack switch occurred
|
||
/*
|
||
* Fool me once, shame on... whatever. If setCSIP() indicates a stack switch occurred,
|
||
* make sure we're in protected mode, because automatic stack switches can't occur in real mode.
|
||
*/
|
||
this.assert(!!(this.regCR0 & X86.CR0.MSW.PE));
|
||
|
||
if (n) this.setSP(this.getSP() + n); // TODO: optimize
|
||
|
||
/*
|
||
* As per Intel documentation: "If any of [the DS or ES] registers refer to segments whose DPL is
|
||
* less than the new CPL (excluding conforming code segments), the segment register is loaded with
|
||
* the null selector."
|
||
*
|
||
* TODO: I'm not clear on whether a conforming code segment must also be marked readable, so I'm playing
|
||
* it safe and using CODE_CONFORMING instead of CODE_CONFORMING_READABLE. Also, for the record, I've not
|
||
* seen this situation occur yet (eg, in OS/2 1.0).
|
||
*/
|
||
this.zeroSeg(this.segDS);
|
||
this.zeroSeg(this.segES);
|
||
if (I386 && this.model >= X86.MODEL_80386) {
|
||
this.zeroSeg(this.segFS);
|
||
this.zeroSeg(this.segGS);
|
||
}
|
||
}
|
||
if (n == 2 && this.cIntReturn) this.checkIntReturn(this.regLIP);
|
||
|
||
this.opLSP = X86.ADDR_INVALID;
|
||
};
|
||
|
||
/**
|
||
* fnROLb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnROLb = function ROLb(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry;
|
||
count &= 0x7;
|
||
if (!count) {
|
||
carry = dst << 7;
|
||
} else {
|
||
carry = dst << (count - 1);
|
||
result = ((dst << count) | (dst >> (8 - count))) & 0xff;
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.BYTE);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('ROLb', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnROLw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnROLw = function ROLw(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry;
|
||
count &= 0xf;
|
||
if (!count) {
|
||
carry = dst << 15;
|
||
} else {
|
||
carry = dst << (count - 1);
|
||
result = ((dst << count) | (dst >> (16 - count))) & 0xffff;
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.WORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('ROLw', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnROLd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnROLd = function ROLd(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = dst << (count - 1);
|
||
result = (dst << count) | (dst >>> (32 - count));
|
||
this.setRotateResult(result, carry, X86.RESULT.DWORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('ROLd', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRORb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRORb = function RORb(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry;
|
||
count &= 0x7;
|
||
if (!count) {
|
||
carry = dst;
|
||
} else {
|
||
carry = dst << (8 - count);
|
||
result = ((dst >>> count) | carry) & 0xff;
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.BYTE);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RORb', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRORw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRORw = function RORw(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry;
|
||
count &= 0xf;
|
||
if (!count) {
|
||
carry = dst;
|
||
} else {
|
||
carry = dst << (16 - count);
|
||
result = ((dst >>> count) | carry) & 0xffff;
|
||
}
|
||
this.setRotateResult(result, carry, X86.RESULT.WORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RORw', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnRORd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL)
|
||
* @return {number}
|
||
*/
|
||
X86.fnRORd = function RORd(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = dst << (32 - count);
|
||
result = (dst >>> count) | carry;
|
||
this.setRotateResult(result, carry, X86.RESULT.DWORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('RORd', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnSARb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSARb = function SARb(dst, src)
|
||
{
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
if (count > 9) count = 9;
|
||
var carry = ((dst << 24) >> 24) >> (count - 1);
|
||
dst = (carry >> 1) & 0xff;
|
||
this.setLogicResult(dst, X86.RESULT.BYTE, carry & 0x1);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSARw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSARw = function SARw(dst, src)
|
||
{
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
if (count > 17) count = 17;
|
||
var carry = ((dst << 16) >> 16) >> (count - 1);
|
||
dst = (carry >> 1) & 0xffff;
|
||
this.setLogicResult(dst, X86.RESULT.WORD, carry & 0x1);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSARd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSARd = function SARd(dst, src)
|
||
{
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = dst >> (count - 1);
|
||
dst = (carry >> 1);
|
||
this.setLogicResult(dst, X86.RESULT.DWORD, carry & 0x1);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSBBb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSBBb = function SBBb(dst, src)
|
||
{
|
||
var b = (dst - src - this.getCarry())|0;
|
||
this.setArithResult(dst, src, b, X86.RESULT.BYTE | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return b & 0xff;
|
||
};
|
||
|
||
/**
|
||
* fnSBBw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSBBw = function SBBw(dst, src)
|
||
{
|
||
var w = (dst - src - this.getCarry())|0;
|
||
this.setArithResult(dst, src, w, this.typeData | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return w & this.maskData;
|
||
};
|
||
|
||
/**
|
||
* fnSETcc()
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {function(number,number)} fnSet
|
||
*/
|
||
X86.fnSETcc = function SETcc(fnSet)
|
||
{
|
||
this.opFlags |= X86.OPFLAG.NOREAD;
|
||
this.aOpModMemByte[this.getIPByte()].call(this, fnSet);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 4 : 5);
|
||
};
|
||
|
||
/**
|
||
* fnSETO(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETO = function SETO(dst, src)
|
||
{
|
||
return (this.getOF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNO(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNO = function SETNO(dst, src)
|
||
{
|
||
return (this.getOF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSETC(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETC = function SETC(dst, src)
|
||
{
|
||
return (this.getCF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNC(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNC = function SETNC(dst, src)
|
||
{
|
||
return (this.getCF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSETZ(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETZ = function SETZ(dst, src)
|
||
{
|
||
return (this.getZF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNZ(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNZ = function SETNZ(dst, src)
|
||
{
|
||
return (this.getZF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSETBE(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETBE = function SETBE(dst, src)
|
||
{
|
||
return (this.getCF() || this.getZF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNBE(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNBE = function SETNBE(dst, src)
|
||
{
|
||
return (this.getCF() || this.getZF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSETS(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETS = function SETS(dst, src)
|
||
{
|
||
return (this.getSF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNS(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNS = function SETNS(dst, src)
|
||
{
|
||
return (this.getSF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSETP(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETP = function SETP(dst, src)
|
||
{
|
||
return (this.getPF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNP(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNP = function SETNP(dst, src)
|
||
{
|
||
return (this.getPF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSETL(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETL = function SETL(dst, src)
|
||
{
|
||
return (!this.getSF() != !this.getOF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNL(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNL = function SETNL(dst, src)
|
||
{
|
||
return (!this.getSF() != !this.getOF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSETLE(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETLE = function SETLE(dst, src)
|
||
{
|
||
return (this.getZF() || !this.getSF() != !this.getOF()? 1 : 0);
|
||
};
|
||
|
||
/**
|
||
* fnSETNLE(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst (ignored)
|
||
* @param {number} src (ignored)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSETNLE = function SETNLE(dst, src)
|
||
{
|
||
return (this.getZF() || !this.getSF() != !this.getOF()? 0 : 1);
|
||
};
|
||
|
||
/**
|
||
* fnSGDT(dst, src)
|
||
*
|
||
* op=0x0F,0x01,reg=0x0 (GRP7:SGDT)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSGDT = function SGDT(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
X86.opInvalid.call(this);
|
||
} else {
|
||
/*
|
||
* We don't need to setShort() the first word of the operand, because the ModRM group decoder that
|
||
* calls us does that automatically with the value we return (dst).
|
||
*/
|
||
dst = this.addrGDTLimit - this.addrGDT;
|
||
this.assert(!(dst & ~0xffff));
|
||
/*
|
||
* We previously left the 6th byte of the target operand "undefined". But it turns out we have to set
|
||
* it to *something*, because there's processor detection in PC-DOS 7.0 (at least in the SETUP portion)
|
||
* that looks like this:
|
||
*
|
||
* 145E:4B84 9C PUSHF
|
||
* 145E:4B85 55 PUSH BP
|
||
* 145E:4B86 8BEC MOV BP,SP
|
||
* 145E:4B88 B80000 MOV AX,0000
|
||
* 145E:4B8B 50 PUSH AX
|
||
* 145E:4B8C 9D POPF
|
||
* 145E:4B8D 9C PUSHF
|
||
* 145E:4B8E 58 POP AX
|
||
* 145E:4B8F 2500F0 AND AX,F000
|
||
* 145E:4B92 3D00F0 CMP AX,F000
|
||
* 145E:4B95 7511 JNZ 4BA8
|
||
* 145E:4BA8 C8060000 ENTER 0006,00
|
||
* 145E:4BAC 0F0146FA SGDT [BP-06]
|
||
* 145E:4BB0 807EFFFF CMP [BP-01],FF
|
||
* 145E:4BB4 C9 LEAVE
|
||
* 145E:4BB5 BA8603 MOV DX,0386
|
||
* 145E:4BB8 7503 JNZ 4BBD
|
||
* 145E:4BBA BA8602 MOV DX,0286
|
||
* 145E:4BBD 89163004 MOV [0430],DX
|
||
* 145E:4BC1 5D POP BP
|
||
* 145E:4BC2 9D POPF
|
||
* 145E:4BC3 CB RETF
|
||
*
|
||
* This code is expecting SGDT on an 80286 to set the 6th "undefined" byte to 0xFF.
|
||
*
|
||
* The 80386 adds an additional wrinkle: the 6th byte must be 0x00 if the OPERAND size is 2, whereas
|
||
* it must passed through if the OPERAND size is 4.
|
||
*
|
||
* In addition, when the OPERAND size is 4, the ModRM group decoder will call setLong(dst) rather than
|
||
* setShort(dst); we could fix that by forcing the dataSize to 2, but it seems simpler to set the high
|
||
* bits (16-31) of dst to match the low bits (0-15) of addr, so that the caller will harmlessly rewrite
|
||
* what we already wrote with the setLong() below.
|
||
*/
|
||
var addr = this.addrGDT;
|
||
if (this.model == X86.MODEL_80286) {
|
||
addr |= (0xff000000|0);
|
||
}
|
||
else if (this.model >= X86.MODEL_80386) {
|
||
if (this.sizeData == 2) {
|
||
addr &= 0x00ffffff;
|
||
} else {
|
||
dst |= (addr << 16);
|
||
}
|
||
}
|
||
this.setLong(this.regEA + 2, addr);
|
||
this.nStepCycles -= 11;
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHLb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLb = function SHLb(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = 0;
|
||
if (count > 8) {
|
||
result = 0;
|
||
} else {
|
||
carry = dst << (count - 1);
|
||
result = (carry << 1) & 0xff;
|
||
}
|
||
this.setLogicResult(result, X86.RESULT.BYTE, carry & X86.RESULT.BYTE, (result ^ carry) & X86.RESULT.BYTE);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('SHLb', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnSHLw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLw = function SHLw(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = 0;
|
||
if (count > 16) {
|
||
result = 0;
|
||
} else {
|
||
carry = dst << (count - 1);
|
||
result = (carry << 1) & 0xffff;
|
||
}
|
||
this.setLogicResult(result, X86.RESULT.WORD, carry & X86.RESULT.WORD, (result ^ carry) & X86.RESULT.WORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('SHLw', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnSHLd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLd = function SHLd(dst, src)
|
||
{
|
||
var result = dst;
|
||
var flagsIn = (DEBUG? this.getPS() : 0);
|
||
var count = src & this.nShiftCountMask; // this 32-bit-only function could mask with 0x1f directly
|
||
if (count) {
|
||
var carry = dst << (count - 1);
|
||
result = (carry << 1);
|
||
this.setLogicResult(result, X86.RESULT.DWORD, carry & X86.RESULT.DWORD, (result ^ carry) & X86.RESULT.DWORD);
|
||
}
|
||
if (DEBUG && DEBUGGER) this.traceLog('SHLd', dst, src, flagsIn, this.getPS(), result);
|
||
return result;
|
||
};
|
||
|
||
/**
|
||
* fnSHLDw(dst, src, count)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @param {number} count (0-31)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLDw = function SHLDw(dst, src, count)
|
||
{
|
||
if (count) {
|
||
if (count > 16) {
|
||
dst = src;
|
||
count -= 16;
|
||
}
|
||
var carry = dst << (count - 1);
|
||
dst = ((carry << 1) | (src >>> (16 - count))) & 0xffff;
|
||
this.setLogicResult(dst, X86.RESULT.WORD, carry & X86.RESULT.WORD);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHLDd(dst, src, count)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @param {number} count
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLDd = function SHLDd(dst, src, count)
|
||
{
|
||
if (count) {
|
||
var carry = dst << (count - 1);
|
||
dst = (carry << 1) | (src >>> (32 - count));
|
||
this.setLogicResult(dst, X86.RESULT.DWORD, carry & X86.RESULT.DWORD);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHLDwi(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLDwi = function SHLDwi(dst, src)
|
||
{
|
||
return X86.fnSHLDw.call(this, dst, src, this.getIPByte());
|
||
};
|
||
|
||
/**
|
||
* fnSHLDdi(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLDdi = function SHLDdi(dst, src)
|
||
{
|
||
return X86.fnSHLDd.call(this, dst, src, this.getIPByte());
|
||
};
|
||
|
||
/**
|
||
* fnSHLDwCL(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLDwCL = function SHLDwCL(dst, src)
|
||
{
|
||
return X86.fnSHLDw.call(this, dst, src, this.regECX & 0x1f);
|
||
};
|
||
|
||
/**
|
||
* fnSHLDdCL(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHLDdCL = function SHLDdCL(dst, src)
|
||
{
|
||
return X86.fnSHLDd.call(this, dst, src, this.regECX & 0x1f);
|
||
};
|
||
|
||
/**
|
||
* fnSHRb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRb = function SHRb(dst, src)
|
||
{
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = (count > 8? 0 : (dst >>> (count - 1)));
|
||
dst = (carry >>> 1) & 0xff;
|
||
this.setLogicResult(dst, X86.RESULT.BYTE, carry & 0x1, dst & X86.RESULT.BYTE);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHRw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRw = function SHRw(dst, src)
|
||
{
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = (count > 16? 0 : (dst >>> (count - 1)));
|
||
dst = (carry >>> 1) & 0xffff;
|
||
this.setLogicResult(dst, X86.RESULT.WORD, carry & 0x1, dst & X86.RESULT.WORD);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHRd(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (1 or CL, or an immediate byte for 80186/80188 and up)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRd = function SHRd(dst, src)
|
||
{
|
||
var count = src & this.nShiftCountMask;
|
||
if (count) {
|
||
var carry = (dst >>> (count - 1));
|
||
dst = (carry >>> 1);
|
||
this.setLogicResult(dst, X86.RESULT.DWORD, carry & 0x1, dst & X86.RESULT.DWORD);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHRDw(dst, src, count)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @param {number} count (0-31)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRDw = function SHRDw(dst, src, count)
|
||
{
|
||
if (count) {
|
||
if (count > 16) {
|
||
dst = src;
|
||
count -= 16;
|
||
}
|
||
var carry = dst >>> (count - 1);
|
||
dst = ((carry >>> 1) | (src << (16 - count))) & 0xffff;
|
||
this.setLogicResult(dst, X86.RESULT.WORD, carry & 0x1);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHRDd(dst, src, count)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @param {number} count
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRDd = function SHRDd(dst, src, count)
|
||
{
|
||
if (count) {
|
||
var carry = dst >>> (count - 1);
|
||
dst = (carry >>> 1) | (src << (32 - count));
|
||
this.setLogicResult(dst, X86.RESULT.DWORD, carry & 0x1);
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSHRDwi(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRDwi = function SHRDwi(dst, src)
|
||
{
|
||
return X86.fnSHRDw.call(this, dst, src, this.getIPByte());
|
||
};
|
||
|
||
/**
|
||
* fnSHRDdi(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRDdi = function SHRDdi(dst, src)
|
||
{
|
||
return X86.fnSHRDd.call(this, dst, src, this.getIPByte());
|
||
};
|
||
|
||
/**
|
||
* fnSHRDwCL(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRDwCL = function SHRDwCL(dst, src)
|
||
{
|
||
return X86.fnSHRDw.call(this, dst, src, this.regECX & 0x1f);
|
||
};
|
||
|
||
/**
|
||
* fnSHRDdCL(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSHRDdCL = function SHRDdCL(dst, src)
|
||
{
|
||
return X86.fnSHRDd.call(this, dst, src, this.regECX & 0x1f);
|
||
};
|
||
|
||
/**
|
||
* fnSIDT(dst, src)
|
||
*
|
||
* op=0x0F,0x01,reg=0x1 (GRP7:SIDT)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSIDT = function SIDT(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
X86.opInvalid.call(this);
|
||
} else {
|
||
/*
|
||
* We don't need to setShort() the first word of the operand, because the ModRM group decoder that calls
|
||
* us does that automatically with the value we return (dst).
|
||
*/
|
||
dst = this.addrIDTLimit - this.addrIDT;
|
||
this.assert(!(dst & ~0xffff));
|
||
/*
|
||
* As with SGDT, the 6th byte is technically "undefined" on an 80286, but we now set it to 0xFF, for the
|
||
* same reasons discussed in SGDT (above).
|
||
*/
|
||
var addr = this.addrIDT;
|
||
if (this.model == X86.MODEL_80286) {
|
||
addr |= (0xff000000|0);
|
||
}
|
||
else if (this.model >= X86.MODEL_80386) {
|
||
if (this.sizeData == 2) {
|
||
addr &= 0x00ffffff;
|
||
} else {
|
||
dst |= (addr << 16);
|
||
}
|
||
}
|
||
this.setLong(this.regEA + 2, addr);
|
||
this.nStepCycles -= 12;
|
||
}
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnSLDT(dst, src)
|
||
*
|
||
* op=0x0F,0x00,reg=0x0 (GRP6:SLDT)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSLDT = function SLDT(dst, src)
|
||
{
|
||
this.nStepCycles -= (2 + (this.regEA === X86.ADDR_INVALID? 0 : 1));
|
||
return this.segLDT.sel;
|
||
};
|
||
|
||
/**
|
||
* fnSMSW(dst, src)
|
||
*
|
||
* TODO: I've seen a claim that SMSW can be used with an operand size override to obtain the entire CR0.
|
||
* I don't dispute that, and since I don't mask the return value, that should be possible here; however, it
|
||
* should still be confirmed on real hardware at some point. Note that this differs from LMSW, which is
|
||
* REQUIRED to mask the source operand.
|
||
*
|
||
* op=0x0F,0x01,reg=0x4 (GRP7:SMSW)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSMSW = function SMSW(dst, src)
|
||
{
|
||
this.nStepCycles -= (2 + (this.regEA === X86.ADDR_INVALID? 0 : 1));
|
||
return this.regCR0;
|
||
};
|
||
|
||
/**
|
||
* fnSTR(dst, src)
|
||
*
|
||
* op=0x0F,0x00,reg=0x1 (GRP6:STR)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnSTR = function STR(dst, src)
|
||
{
|
||
this.nStepCycles -= (2 + (this.regEA === X86.ADDR_INVALID? 0 : 1));
|
||
return this.segTSS.sel;
|
||
};
|
||
|
||
/**
|
||
* fnSUBb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSUBb = function SUBb(dst, src)
|
||
{
|
||
var b = (dst - src)|0;
|
||
this.setArithResult(dst, src, b, X86.RESULT.BYTE | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return b & 0xff;
|
||
};
|
||
|
||
/**
|
||
* fnSUBw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnSUBw = function SUBw(dst, src)
|
||
{
|
||
var w = (dst - src)|0;
|
||
this.setArithResult(dst, src, w, this.typeData | X86.RESULT.ALL, true);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return w & this.maskData;
|
||
};
|
||
|
||
/**
|
||
* fnTESTib(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null; we have to supply the source ourselves)
|
||
* @return {number}
|
||
*/
|
||
X86.fnTESTib = function TESTib(dst, src)
|
||
{
|
||
src = this.getIPByte();
|
||
this.setLogicResult(dst & src, X86.RESULT.BYTE);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesTestRI : this.cycleCounts.nOpCyclesTestMI);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnTESTiw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null; we have to supply the source ourselves)
|
||
* @return {number}
|
||
*/
|
||
X86.fnTESTiw = function TESTiw(dst, src)
|
||
{
|
||
src = this.getIPWord();
|
||
this.setLogicResult(dst & src, this.typeData);
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesTestRI : this.cycleCounts.nOpCyclesTestMI);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnTESTb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnTESTb = function TESTb(dst, src)
|
||
{
|
||
this.setLogicResult(dst & src, X86.RESULT.BYTE);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesTestRR : this.cycleCounts.nOpCyclesTestRM) : this.cycleCounts.nOpCyclesTestRM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnTESTw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnTESTw = function TESTw(dst, src)
|
||
{
|
||
this.setLogicResult(dst & src, this.typeData);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesTestRR : this.cycleCounts.nOpCyclesTestRM) : this.cycleCounts.nOpCyclesTestRM);
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnVERR(dst, src)
|
||
*
|
||
* op=0x0F,0x00,reg=0x4 (GRP6:VERR)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnVERR = function VERR(dst, src)
|
||
{
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
/*
|
||
* Currently, segVER.load() will return an error only if the selector is beyond the bounds of the
|
||
* descriptor table or the descriptor is not for a segment.
|
||
*/
|
||
this.nStepCycles -= (14 + (this.regEA === X86.ADDR_INVALID? 0 : 2));
|
||
if (this.segVER.load(dst) !== X86.ADDR_INVALID) {
|
||
/*
|
||
* Verify that this is a readable segment; that is, of these four combinations (code+readable,
|
||
* code+nonreadable, data+writable, date+nonwritable), make sure we're not the second combination.
|
||
*/
|
||
if ((this.segVER.acc & (X86.DESC.ACC.TYPE.READABLE | X86.DESC.ACC.TYPE.CODE)) != X86.DESC.ACC.TYPE.CODE) {
|
||
/*
|
||
* For VERR, if the code segment is readable and conforming, the descriptor privilege level
|
||
* (DPL) can be any value.
|
||
*
|
||
* Otherwise, DPL must be greater than or equal to (have less or the same privilege as) both the
|
||
* current privilege level and the selector's RPL.
|
||
*/
|
||
if (this.segVER.dpl >= this.nCPL && this.segVER.dpl >= (dst & X86.SEL.RPL) ||
|
||
(this.segVER.acc & X86.DESC.ACC.TYPE.CODE_CONFORMING) == X86.DESC.ACC.TYPE.CODE_CONFORMING) {
|
||
this.setZF();
|
||
return dst;
|
||
}
|
||
}
|
||
}
|
||
this.clearZF();
|
||
if (DEBUG && (this.sizeData > 2 || this.sizeAddr > 2)) this.stopCPU();
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnVERW(dst, src)
|
||
*
|
||
* op=0x0F,0x00,reg=0x5 (GRP6:VERW)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src (null)
|
||
* @return {number}
|
||
*/
|
||
X86.fnVERW = function VERW(dst, src)
|
||
{
|
||
this.opFlags |= X86.OPFLAG.NOWRITE;
|
||
/*
|
||
* Currently, segVER.load() will return an error only if the selector is beyond the bounds of the
|
||
* descriptor table or the descriptor is not for a segment.
|
||
*/
|
||
this.nStepCycles -= (14 + (this.regEA === X86.ADDR_INVALID? 0 : 2));
|
||
if (this.segVER.load(dst) !== X86.ADDR_INVALID) {
|
||
/*
|
||
* Verify that this is a writable data segment
|
||
*/
|
||
if ((this.segVER.acc & (X86.DESC.ACC.TYPE.WRITABLE | X86.DESC.ACC.TYPE.CODE)) == X86.DESC.ACC.TYPE.WRITABLE) {
|
||
/*
|
||
* DPL must be greater than or equal to (have less or the same privilege as) both the current
|
||
* privilege level and the selector's RPL.
|
||
*/
|
||
if (this.segVER.dpl >= this.nCPL && this.segVER.dpl >= (dst & X86.SEL.RPL)) {
|
||
this.setZF();
|
||
return dst;
|
||
}
|
||
}
|
||
}
|
||
this.clearZF();
|
||
if (DEBUG && (this.sizeData > 2 || this.sizeAddr > 2)) this.stopCPU();
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnXCHGrb(dst, src)
|
||
*
|
||
* If an instruction like "XCHG AL,AH" was a traditional "op dst,src" instruction, dst would contain AL,
|
||
* src would contain AH, and we would return src, which the caller would then store in AL, and we'd be done.
|
||
*
|
||
* However, that's only half of what XCHG does, so THIS function must perform the other half; in the previous
|
||
* example, that means storing the original AL (dst) into AH (src).
|
||
*
|
||
* BACKTRACK support is incomplete without also passing bti values as parameters, because the caller will
|
||
* store btiAH in btiAL, but the original btiAL will be lost. Similarly, if src is a memory operand, the
|
||
* caller will store btiEALo in btiAL, but again, the original btiAL will be lost.
|
||
*
|
||
* BACKTRACK support for memory operands could be fixed by decoding the dst register in order to determine the
|
||
* corresponding bti and then temporarily storing it in btiEALo around the setEAByte() call below. Register-only
|
||
* XCHGs would require a more extensive hack. For now, I'm going to live with one-way BACKTRACK support here.
|
||
*
|
||
* TODO: Implement full BACKTRACK support for XCHG instructions.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnXCHGrb = function XCHGRb(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
/*
|
||
* Decode which register was src
|
||
*/
|
||
this.assert(!(dst & ~0xff)); // confirm that dst contains only 8 bits
|
||
switch (this.bModRM & 0x7) {
|
||
case 0x0: // AL
|
||
this.regEAX = (this.regEAX & ~0xff) | dst;
|
||
break;
|
||
case 0x1: // CL
|
||
this.regECX = (this.regECX & ~0xff) | dst;
|
||
break;
|
||
case 0x2: // DL
|
||
this.regEDX = (this.regEDX & ~0xff) | dst;
|
||
break;
|
||
case 0x3: // BL
|
||
this.regEBX = (this.regEBX & ~0xff) | dst;
|
||
break;
|
||
case 0x4: // AH
|
||
this.regEAX = (this.regEAX & ~0xff00) | (dst << 8);
|
||
break;
|
||
case 0x5: // CH
|
||
this.regECX = (this.regECX & ~0xff00) | (dst << 8);
|
||
break;
|
||
case 0x6: // DH
|
||
this.regEDX = (this.regEDX & ~0xff00) | (dst << 8);
|
||
break;
|
||
case 0x7: // BH
|
||
this.regEBX = (this.regEBX & ~0xff00) | (dst << 8);
|
||
break;
|
||
default:
|
||
break; // there IS no other case, but JavaScript inspections don't know that
|
||
}
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesXchgRR;
|
||
} else {
|
||
/*
|
||
* This is a case where the ModRM decoder that's calling us didn't know it should have called modEAByte()
|
||
* instead of getEAByte(), so we compensate by updating regEAWrite. However, setEAByte() has since been
|
||
* changed to revalidate the write using segEA:offEA, so updating regEAWrite here isn't strictly necessary.
|
||
*/
|
||
this.regEAWrite = this.regEA;
|
||
this.setEAByte(dst);
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesXchgRM;
|
||
}
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnXCHGrw(dst, src)
|
||
*
|
||
* If an instruction like "XCHG AX,DX" was a traditional "op dst,src" instruction, dst would contain AX,
|
||
* src would contain DX, and we would return src, which the caller would then store in AX, and we'd be done.
|
||
*
|
||
* However, that's only half of what XCHG does, so THIS function must perform the other half; in the previous
|
||
* example, that means storing the original AX (dst) into DX (src).
|
||
*
|
||
* TODO: Implement full BACKTRACK support for XCHG instructions (see fnXCHGrb comments).
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnXCHGrw = function XCHGRw(dst, src)
|
||
{
|
||
if (this.regEA === X86.ADDR_INVALID) {
|
||
/*
|
||
* Decode which register was src
|
||
*/
|
||
this.assert(!(dst & ~this.maskData)); // confirm that dst contains only 16 or 32 bits
|
||
switch (this.bModRM & 0x7) {
|
||
case 0x0: // [E]AX
|
||
this.regEAX = (this.regEAX & ~this.maskData) | dst;
|
||
break;
|
||
case 0x1: // [E]CX
|
||
this.regECX = (this.regECX & ~this.maskData) | dst;
|
||
break;
|
||
case 0x2: // [E]DX
|
||
this.regEDX = (this.regEDX & ~this.maskData) | dst;
|
||
break;
|
||
case 0x3: // [E]BX
|
||
this.regEBX = (this.regEBX & ~this.maskData) | dst;
|
||
break;
|
||
case 0x4: // [E]SP
|
||
this.setSP((this.getSP() & ~this.maskData) | dst);
|
||
break;
|
||
case 0x5: // [E]BP
|
||
this.regEBP = (this.regEBX & ~this.maskData) | dst;
|
||
break;
|
||
case 0x6: // [E]SI
|
||
this.regESI = (this.regESI & ~this.maskData) | dst;
|
||
break;
|
||
case 0x7: // [E]DI
|
||
this.regEDI = (this.regEDI & ~this.maskData) | dst;
|
||
break;
|
||
default:
|
||
break; // there IS no other case, but JavaScript inspections don't know that
|
||
}
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesXchgRR;
|
||
} else {
|
||
/*
|
||
* This is a case where the ModRM decoder that's calling us didn't know it should have called modEAWord()
|
||
* instead of getEAWord(), so we compensate by updating regEAWrite. However, setEAWord() has since been
|
||
* changed to revalidate the write using segEA:offEA, so updating regEAWrite here isn't strictly necessary.
|
||
*/
|
||
this.regEAWrite = this.regEA;
|
||
this.setEAWord(dst);
|
||
this.nStepCycles -= this.cycleCounts.nOpCyclesXchgRM;
|
||
}
|
||
return src;
|
||
};
|
||
|
||
/**
|
||
* fnXORb(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnXORb = function XORb(dst, src)
|
||
{
|
||
var b = dst ^ src;
|
||
this.setLogicResult(b, X86.RESULT.BYTE);
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return b;
|
||
};
|
||
|
||
/**
|
||
* fnXORw(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnXORw = function XORw(dst, src)
|
||
{
|
||
this.nStepCycles -= (this.regEAWrite === X86.ADDR_INVALID? (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesArithRR : this.cycleCounts.nOpCyclesArithRM) : this.cycleCounts.nOpCyclesArithMR);
|
||
return this.setLogicResult(dst ^ src, this.typeData);
|
||
};
|
||
|
||
/**
|
||
* fnGRPFault(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnGRPFault = function GRPFault(dst, src)
|
||
{
|
||
X86.fnFault.call(this, X86.EXCEPTION.GP_FAULT, 0);
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnGRPInvalid(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnGRPInvalid = function GRPInvalid(dst, src)
|
||
{
|
||
X86.opInvalid.call(this);
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnGRPUndefined(dst, src)
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} dst
|
||
* @param {number} src
|
||
* @return {number}
|
||
*/
|
||
X86.fnGRPUndefined = function GRPUndefined(dst, src)
|
||
{
|
||
X86.opUndefined.call(this);
|
||
return dst;
|
||
};
|
||
|
||
/**
|
||
* fnDIVOverflow()
|
||
*
|
||
* @this {X86CPU}
|
||
*/
|
||
X86.fnDIVOverflow = function DIVOverflow()
|
||
{
|
||
/*
|
||
* TODO: Determine the proper cycle cost.
|
||
*/
|
||
X86.fnFault.call(this, X86.EXCEPTION.DIV_ERR, null, false, 2);
|
||
};
|
||
|
||
/**
|
||
* fnSRCCount1()
|
||
*
|
||
* @this {X86CPU}
|
||
* @return {number}
|
||
*/
|
||
X86.fnSRCCount1 = function SRCCount1()
|
||
{
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? 2 : this.cycleCounts.nOpCyclesShift1M);
|
||
return 1;
|
||
};
|
||
|
||
/**
|
||
* fnSRCCountCL()
|
||
*
|
||
* @this {X86CPU}
|
||
* @return {number}
|
||
*/
|
||
X86.fnSRCCountCL = function SRCCountCL()
|
||
{
|
||
var count = this.regECX & 0xff;
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesShiftCR : this.cycleCounts.nOpCyclesShiftCM) + (count << this.cycleCounts.nOpCyclesShiftCS);
|
||
return count;
|
||
};
|
||
|
||
/**
|
||
* fnSRCCountN()
|
||
*
|
||
* @this {X86CPU}
|
||
* @return {number}
|
||
*/
|
||
X86.fnSRCCountN = function SRCCountN()
|
||
{
|
||
var count = this.getIPByte();
|
||
this.nStepCycles -= (this.regEA === X86.ADDR_INVALID? this.cycleCounts.nOpCyclesShiftCR : this.cycleCounts.nOpCyclesShiftCM) + (count << this.cycleCounts.nOpCyclesShiftCS);
|
||
return count;
|
||
};
|
||
|
||
/**
|
||
* fnSRCNone()
|
||
*
|
||
* @this {X86CPU}
|
||
* @return {number|null}
|
||
*/
|
||
X86.fnSRCNone = function SRCNone()
|
||
{
|
||
return null;
|
||
};
|
||
|
||
/**
|
||
* fnSRCxx()
|
||
*
|
||
* This is used by opPOPmw(), because the actual pop must occur BEFORE the effective address (EA)
|
||
* calculation. So opPOPmw() does the pop, saves the popped value in regXX, and this passes src function
|
||
* to the EA worker.
|
||
*
|
||
* @this {X86CPU}
|
||
* @return {number} regXX
|
||
*/
|
||
X86.fnSRCxx = function SRCxx()
|
||
{
|
||
return this.regXX;
|
||
};
|
||
|
||
/**
|
||
* fnFault(nFault, nError, fHalt, nCycles)
|
||
*
|
||
* Helper to dispatch faults.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} nFault
|
||
* @param {number|null} [nError] (if omitted, no error code will be pushed)
|
||
* @param {boolean} [fHalt] (true to halt the CPU, false to not, undefined if "it depends")
|
||
* @param {number} [nCycles] cycle count to pass through to fnINT(), if any
|
||
*/
|
||
X86.fnFault = function(nFault, nError, fHalt, nCycles)
|
||
{
|
||
var fDispatch = null;
|
||
|
||
if (!this.aFlags.fComplete) {
|
||
/*
|
||
* Prior to each new burst of instructions, stepCPU() sets fComplete to true, and the only (normal) way
|
||
* for fComplete to become false is through stopCPU(), which isn't ordinarily called, except by the Debugger.
|
||
*/
|
||
this.resetSizes();
|
||
this.setIP(this.opLIP - this.segCS.base);
|
||
}
|
||
else if (this.model >= X86.MODEL_80186) {
|
||
if (this.nFault < 0) {
|
||
/*
|
||
* Single-fault (error code is passed through, and the responsible instruction is restartable;
|
||
* the call to resetSizes() is critical, otherwise setIP() may update IP with the wrong size if
|
||
* the current instruction contains an OPERAND size override).
|
||
*/
|
||
this.resetSizes();
|
||
this.setIP(this.opLIP - this.segCS.base);
|
||
if (this.opLSP != X86.ADDR_INVALID) {
|
||
this.setSP((this.regESP & ~this.segSS.maskAddr) | (this.opLSP - this.segSS.base));
|
||
this.opLSP = X86.ADDR_INVALID;
|
||
}
|
||
fDispatch = true;
|
||
}
|
||
else if (this.nFault != X86.EXCEPTION.DF_FAULT) {
|
||
/*
|
||
* Double-fault (error code is always zero, and the responsible instruction is not restartable)
|
||
*/
|
||
nError = 0; nFault = X86.EXCEPTION.DF_FAULT;
|
||
fDispatch = true;
|
||
}
|
||
else {
|
||
/*
|
||
* Triple-fault (usually referred to in Intel literature as a "shutdown", but at least on the 80286,
|
||
* it's actually a "reset")
|
||
*/
|
||
nFault = -1; nError = 0;
|
||
this.resetRegs();
|
||
fHalt = false;
|
||
}
|
||
}
|
||
|
||
if (X86.fnFaultMessage.call(this, nFault, nError, fHalt)) {
|
||
fDispatch = false;
|
||
}
|
||
|
||
if (fDispatch) {
|
||
|
||
this.nFault = nFault;
|
||
X86.fnINT.call(this, nFault, nError, nCycles || 0);
|
||
|
||
/*
|
||
* REP'eated instructions that rewind regLIP to opLIP used to screw up this dispatch,
|
||
* so now we slip the new regLIP into opLIP, effectively turning their action into a no-op.
|
||
*/
|
||
this.opLIP = this.regLIP;
|
||
|
||
/*
|
||
* X86.OPFLAG.FAULT flag is used by selected opcodes to provide an early exit, restore register(s),
|
||
* or whatever is needed to help ensure instruction restartability; there is currently no general
|
||
* mechanism for snapping and restoring all registers for any instruction that might fault.
|
||
*
|
||
* X86.EXCEPTION.DEBUG exceptions set their own special flag, X86.OPFLAG.DEBUG, to prevent redundant
|
||
* DEBUG exceptions, so we don't need to set OPFLAG.FAULT in that case, because a DEBUG exception
|
||
* doesn't actually prevent an instruction from executing (and therefore doesn't need to be restarted).
|
||
*/
|
||
if (nFault == X86.EXCEPTION.DEBUG) {
|
||
this.opFlags |= X86.OPFLAG.DEBUG;
|
||
} else {
|
||
this.assert(nFault >= 0);
|
||
this.opFlags |= X86.OPFLAG.FAULT;
|
||
}
|
||
|
||
/*
|
||
* Since this fault is likely being issued in the context of an instruction that hasn't finished
|
||
* executing, if we don't do anything to interrupt that execution (eg, throw a JavaScript exception),
|
||
* then we would need to shut off all further reads/writes for the current instruction.
|
||
*
|
||
* That's easy for any EA-based memory accesses: simply set both the NOREAD and NOWRITE flags.
|
||
* However, there are also direct, non-EA-based memory accesses to consider. A perfect example is
|
||
* opPUSHA(): if a GP fault occurs on any PUSH other than the last, a subsequent PUSH is likely to
|
||
* cause another fault, which we will misinterpret as a double-fault -- unless the handler for
|
||
* such an opcode checks this.opFlags for X86.OPFLAG.FAULT after each step of the operation.
|
||
*
|
||
* this.opFlags |= (X86.OPFLAG.NOREAD | X86.OPFLAG.NOWRITE);
|
||
*
|
||
* Fortunately, we now throw an exception that terminates the current instruction, so the above hack
|
||
* should no longer be necessary.
|
||
*/
|
||
throw nFault;
|
||
}
|
||
};
|
||
|
||
/**
|
||
* fnPageFault(addr, fPresent, fWrite)
|
||
*
|
||
* Helper to dispatch page faults.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} addr
|
||
* @param {boolean} fPresent
|
||
* @param {boolean} fWrite
|
||
*/
|
||
X86.fnPageFault = function(addr, fPresent, fWrite)
|
||
{
|
||
this.regCR2 = addr;
|
||
var nError = 0;
|
||
if (fPresent) nError |= X86.PTE.PRESENT;
|
||
if (fWrite) nError |= X86.PTE.READWRITE;
|
||
if (this.nCPL == 3) nError |= X86.PTE.USER;
|
||
X86.fnFault.call(this, X86.EXCEPTION.PG_FAULT, nError);
|
||
};
|
||
|
||
/**
|
||
* fnFaultMessage(nFault, nError, fHalt)
|
||
*
|
||
* Aside from giving the Debugger an opportunity to report every fault, this also gives us the ability to
|
||
* halt exception processing in tracks: return true to prevent the fault handler from being dispatched.
|
||
*
|
||
* At the moment, the only Debugger control you have over fault interception is setting MESSAGE.FAULT, which
|
||
* will display faults as they occur, and MESSAGE.HALT, which will halt after any Debugger message, including
|
||
* MESSAGE.FAULT. If you want execution to continue after halting, clear MESSAGE.FAULT and/or MESSAGE.HALT,
|
||
* or single-step over the offending instruction, which will allow the fault to be dispatched.
|
||
*
|
||
* @this {X86CPU}
|
||
* @param {number} nFault
|
||
* @param {number|null} [nError] (if omitted, no error code will be reported)
|
||
* @param {boolean} [fHalt] (true to halt the CPU, false to not, undefined if "it depends")
|
||
* @return {boolean|undefined} true to block the fault (often desirable when fHalt is true), otherwise dispatch it
|
||
*/
|
||
X86.fnFaultMessage = function(nFault, nError, fHalt)
|
||
{
|
||
var bitsMessage = Messages.FAULT;
|
||
|
||
var bOpcode = this.probeAddr(this.regLIP);
|
||
|
||
/*
|
||
* OS/2 1.0 uses an INT3 (0xCC) opcode in conjunction with an invalid IDT to trigger a triple-fault
|
||
* reset and return to real-mode, and these resets happen quite frequently during boot; for example,
|
||
* OS/2 startup messages are displayed using a series of INT 0x10 BIOS calls for each character, and
|
||
* each series of BIOS calls requires a round-trip mode switch.
|
||
*
|
||
* Since we really only want to halt on "bad" faults, not "good" (ie, intentional) faults, we take
|
||
* advantage of the fact that all 3 faults comprising the triple-fault point to an INT3 (0xCC) opcode,
|
||
* and so whenever we see that opcode, we ignore the caller's fHalt flag, and suppress FAULT messages
|
||
* unless CPU messages are also enabled.
|
||
*
|
||
* When a triple fault shows up, nFault is -1; it displays as 0xff only because we use toHexByte().
|
||
*/
|
||
if (bOpcode == X86.OPCODE.INT3 && !this.addrIDTLimit) {
|
||
fHalt = false;
|
||
}
|
||
|
||
/*
|
||
* There are a number of V86-mode exceptions we don't need to know about. For starters, Windows 3.00
|
||
* (and other versions of enhanced-mode Windows) use an ARPL to switch out of V86-mode, so we can ignore
|
||
* those UD_FAULTs.
|
||
*
|
||
* Ditto for software interrupts, which will generate a GP_FAULT when the interrupt number (eg, 0x6D)
|
||
* exceeds the protected-mode IDT's limit (eg, a limit of 0x2FF corresponds to a maximum interrupt number
|
||
* of 0x5F). Windows doesn't really care if its IDT is too small, because it has to simulate all software
|
||
* interrupts in V86-mode regardless (they generate a GP_FAULT if IOPL < 3, and even when IOPL == 3, only
|
||
* the protected-mode IDT handler gets to run).
|
||
*/
|
||
if ((this.regPS & X86.PS.VM)) {
|
||
if (nFault == X86.EXCEPTION.UD_FAULT && bOpcode == X86.OPCODE.ARPL ||
|
||
nFault == X86.EXCEPTION.GP_FAULT && bOpcode == X86.OPCODE.INTN) {
|
||
fHalt = false;
|
||
}
|
||
}
|
||
if (nFault == X86.EXCEPTION.PG_FAULT && bOpcode == X86.OPCODE.IRET) {
|
||
fHalt = true;
|
||
}
|
||
|
||
/*
|
||
* If fHalt has been explicitly set to false, we also take that as a cue to disable fault messages
|
||
* (which you can override by turning on CPU messages).
|
||
*/
|
||
if (fHalt === false) {
|
||
bitsMessage |= Messages.CPU;
|
||
}
|
||
|
||
/*
|
||
* Similarly, the PC AT ROM BIOS deliberately generates a couple of GP faults as part of the POST
|
||
* (Power-On Self Test); we don't want to ignore those, but we don't want to halt on them either. We
|
||
* detect those faults by virtue of the LIP being in the range 0x0F0000 to 0x0FFFFF.
|
||
*
|
||
* TODO: Be aware that this test can trigger false positives, such as when a V86-mode ARPL is hit; eg:
|
||
*
|
||
* &FD82:22F7 6338 ARPL [BX+SI],DI
|
||
*/
|
||
if (this.regLIP >= 0x0F0000 && this.regLIP <= 0x0FFFFF) {
|
||
fHalt = false;
|
||
}
|
||
|
||
/*
|
||
* However, the foregoing notwithstanding, if MESSAGE.HALT is enabled along with all the other required
|
||
* MESSAGE bits, then we want to halt regardless.
|
||
*/
|
||
if (this.messageEnabled(bitsMessage | Messages.HALT)) {
|
||
fHalt = true;
|
||
}
|
||
|
||
if (this.messageEnabled(bitsMessage) || fHalt) {
|
||
|
||
var fRunning = this.aFlags.fRunning;
|
||
var sMessage = "Fault " + str.toHexByte(nFault) + (nError != null? " (" + str.toHexWord(nError) + ")" : "") + " on opcode " + str.toHexByte(bOpcode);
|
||
if (fHalt && fRunning) sMessage += " (blocked by PCjs Debugger)";
|
||
|
||
if (this.printMessage(sMessage, fHalt || bitsMessage, true)) {
|
||
if (fHalt) {
|
||
/*
|
||
* By setting fHalt to fRunning (which is true while running but false while single-stepping),
|
||
* this allows a fault to be dispatched when you single-step over a faulting instruction; you can
|
||
* then continue single-stepping into the fault handler, or start running again.
|
||
*
|
||
* Note that we had to capture fRunning before calling printMessage(), because if MESSAGE.HALT
|
||
* is set, printMessage() will have already halted the CPU.
|
||
*/
|
||
fHalt = fRunning;
|
||
this.dbg.stopCPU();
|
||
}
|
||
} else {
|
||
/*
|
||
* If printMessage() returned false, then there's no Debugger, which means that messageEnabled() must have
|
||
* returned false as well, which means that fHalt must be true. Which means we should shut the machine down.
|
||
*/
|
||
this.assert(fHalt);
|
||
this.notice(sMessage);
|
||
this.stopCPU();
|
||
}
|
||
}
|
||
return fHalt;
|
||
};
|