Remove EAFUNCS

blog/2015/01/17/README.md

@@ -17,7 +17,8 @@ Here's how you embed an "uncompiled" machine in a PCjs Markdown file:
 
 	[Embedded IBM PC](/devices/pc/machine/5170/ega/1152kb/rev3/ "PCjs:at-ega-1152k-rev3::uncompiled:debugger")
 
-And here's that example in action, in the Markdown ([README.md]()) file you are reading right now:
+And here's that example in action, in the Markdown ([README.md]()) file you are reading right now -- assuming
+you are reading it on a [PCjs](http://www.pcjs.org/blog/2015/01/17/) web server:
 
 [Embedded IBM PC](/devices/pc/machine/5170/ega/1152kb/rev3/ "PCjs:at-ega-1152k-rev3::uncompiled:debugger")
 

modules/pcjs/bin/x86gen.js

@@ -284,7 +284,15 @@ function genSIB(sib) {
     print("     * @param {number} mod");
     print("     */");
     print("    function " + sFunc + "(mod) {");
-    var sBase = (base == 5? "(mod? this.reg" + aBase[base] + " : this.getIPWord())" : "this.reg" + aBase[base]);
+    var sMod = "this.reg" + aBase[base];
+    if (aBase[base] == "ESP" || aBase[base] == "EBP") {
+        if (base != 5) {
+            print("        this.segData = this.segStack;");
+        } else {
+            sMod = "((this.segData = this.segStack), " + sMod + ")";
+        }
+    }
+    var sBase = (base == 5? "(mod? " + sMod + " : this.getIPWord())" : "this.reg" + aBase[base]);
     if (index != 4) sBase += " + " + (scale? ("(this.reg" + aIndex[index] + " << " + scale + ")") : ("this.reg" + aIndex[index]));
     print("        return " + sBase + ";");
     print("    }" + (sib < 255? "," : ""));
@@ -419,7 +427,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
     var sModRegSet = null;
     var sModRegSetBegin = "", sModRegSetEnd = "";
     var sModRegBTLo = null, sModRegBTHi = null;
-    var sModRegSeg = "this.segData";
+    var sModRegSeg = "Data";
 
     if (!a) {
         switch (mod) {
@@ -438,13 +446,13 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
             case 2:
                 sModAddr = "this.regEBP + this.regESI";
                 sModFunc = "BPSI";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseIndexExtra";   // 8086: 8
                 break;
             case 3:
                 sModAddr = "this.regEBP + this.regEDI";
                 sModFunc = "BPDI";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseIndex";        // 8086: 7
                 break;
             case 4:
@@ -487,13 +495,13 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
             case 2:
                 sModAddr = "this.regEBP + this.regESI + this.getIPDisp()";
                 sModFunc = "BPSID8";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseIndexDispExtra";   // 8086: 12
                 break;
             case 3:
                 sModAddr = "this.regEBP + this.regEDI + this.getIPDisp()";
                 sModFunc = "BPDID8";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseIndexDisp";        // 8086: 11
                 break;
             case 4:
@@ -509,7 +517,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
             case 6:
                 sModAddr = "this.regEBP + this.getIPDisp()";
                 sModFunc = "BPD8";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseDisp";             // 8086: 9
                 break;
             case 7:
@@ -537,13 +545,13 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
             case 2:
                 sModAddr = "this.regEBP + this.regESI + this.getIPWord()";
                 sModFunc = "BPSID16";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseIndexDispExtra";   // 8086: 12
                 break;
             case 3:
                 sModAddr = "this.regEBP + this.regEDI + this.getIPWord()";
                 sModFunc = "BPDID16";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseIndexDisp";        // 8086: 11
                 break;
             case 4:
@@ -559,7 +567,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
             case 6:
                 sModAddr = "this.regEBP + this.getIPWord()";
                 sModFunc = "BPD16";
-                sModRegSeg = "this.segStack";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseDisp";             // 8086: 9
                 break;
             case 7:
@@ -763,6 +771,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
             case 5:
                 sModAddr = "this.regEBP + this.getIPDisp()";
                 sModFunc = "EBPD8";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseDisp";
                 break;
             case 6:
@@ -810,6 +819,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
             case 5:
                 sModAddr = "this.regEBP + this.getIPWord()";
                 sModFunc = "EBPD32";
+                sModRegSeg = "Stack";
                 nCycles = "this.CYCLES.nEACyclesBaseDisp";
                 break;
             case 6:
@@ -969,17 +979,11 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
         print("    function " + sOpMod + "(afnGrp, fnSrc) {");
 
         if (sModAddr) {
-            if (!a && sModAddr.indexOf("regE") >= 0) {
-                if (sModAddr.indexOf(' ') > 0) {
-                    sModAddr = "(" + sModAddr + ")";
-                }
-                sModAddr += " & 0xffff";
-            }
             if (!d) {
                 if (reg == 7 && sRO) {
                     if (sModFunc) {
                         if (fInline) {
-                            print("        afnGrp[" + reg + "].call(this, this.getEA" + aSize[w] + "(" + sModRegSeg + ", " + sModAddr + "), fnSrc.call(this));");
+                            print("        afnGrp[" + reg + "].call(this, this.getEA" + aSize[w] + sModRegSeg + "(" + sModAddr + "), fnSrc.call(this));");
                         } else {
                             sModFunc = "read" + sModFunc + aSize[w];
                             print("        var addr = X86Mods." + sModFunc + ".call(this);");
@@ -994,7 +998,7 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
                 else {
                     if (sModFunc) {
                         if (fInline) {
-                            print("        var " + sTemp + " = afnGrp[" + reg + "].call(this, this.modEA" + aSize[w] + "(" + sModRegSeg + ", " + sModAddr + "), fnSrc.call(this));");
+                            print("        var " + sTemp + " = afnGrp[" + reg + "].call(this, this.modEA" + aSize[w] + sModRegSeg + "(" + sModAddr + "), fnSrc.call(this));");
                             print("        this.setEA" + aSize[w] + "(" + sTemp + ");");
                         } else {
                             sModFunc = "write" + sModFunc + aSize[w];
@@ -1065,16 +1069,10 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
         print("    function " + sOpMod + "(fn) {");
 
         if (sModAddr && sRegGet) {
-            if (!a && sModAddr.indexOf("regE") >= 0) {
-                if (sModAddr.indexOf(' ') > 0) {
-                    sModAddr = "(" + sModAddr + ")";
-                }
-                sModAddr += " & 0xffff";
-            }
             if (!d) {
                 if (sModFunc) {
                     if (fInline) {
-                        print("        var " + sTemp + " = fn.call(this, this.modEA" + aSize[w] + "(" + sModRegSeg + ", " + sModAddr + "), " + sRegGet + ");");
+                        print("        var " + sTemp + " = fn.call(this, this.modEA" + aSize[w] + sModRegSeg + "(" + sModAddr + "), " + sRegGet + ");");
                         if (sRegBTLo) {
                             if (!sRegBTHi) {
                                 print("        if (BACKTRACK) this.backTrack.btiEALo = " + sRegBTLo + ";");
@@ -1119,9 +1117,9 @@ function genMode(a, d, w, mrm, sGroup, sRO) {
                 if (sModFunc) {
                     if (fInline) {
                         if (!sTemp) {
-                            print("        " + sRegSet + sRegSetBegin + "fn.call(this, " + sRegGet + ", this.getEA" + aSize[w] + "(" + sModRegSeg + ", " + sModAddr + "))" + sRegSetEnd + ";");
+                            print("        " + sRegSet + sRegSetBegin + "fn.call(this, " + sRegGet + ", this.getEA" + aSize[w] + sModRegSeg + "(" + sModAddr + "))" + sRegSetEnd + ";");
                         } else {
-                            print("        var " + sTemp + " = fn.call(this, " + sRegGet + ", this.getEA" + aSize[w] + "(" + sModRegSeg + ", " + sModAddr + "));");
+                            print("        var " + sTemp + " = fn.call(this, " + sRegGet + ", this.getEA" + aSize[w] + sModRegSeg + "(" + sModAddr + "));");
                             print("        " + sRegSet + sRegSetBegin + sTemp + sRegSetEnd + ";");
                         }
                     } else {

modules/pcjs/lib/bus.js

@@ -262,9 +262,7 @@ Bus.prototype.initMemory = function()
 Bus.prototype.reset = function()
 {
     this.setA20(true);
-    if (BACKTRACK) {
+    if (BACKTRACK) this.ibtLastDelete = 0;
-        this.ibtLastDelete = 0;
-    }
 };
 
 /**
@@ -349,6 +347,30 @@ Bus.prototype.cleanMemory = function(addr, size)
     return fClean;
 };
 
+/**
+ * scanMemory(addr, size, stats)
+ *
+ * @this {Bus}
+ * @param {number} [addr]
+ * @param {number} [size]
+ * @param {Object} [stats]
+ * @return {number} bytes allocated
+ */
+Bus.prototype.scanMemory = function(addr, size, stats)
+{
+    var cbTotal = 0;
+    if (addr === undefined) addr = 0;
+    if (size === undefined) size = (this.addrLimit + 1) - addr;
+    var iBlock = addr >>> this.blockShift;
+    var iBlockMax = ((addr + size - 1) >>> this.blockShift);
+    while (iBlock <= iBlockMax) {
+        var block = this.aMemBlocks[iBlock];
+        cbTotal += block.size;
+        iBlock++;
+    }
+    return cbTotal;
+};
+
 /**
  * getA20()
  *
@@ -820,6 +842,37 @@ Bus.prototype.updateBackTrackCode = function(addr, bti)
     }
 };
 
+/**
+ * getBackTrackObject(bti)
+ *
+ * @this {Bus}
+ * @param {number} bti
+ * @return {Object|null}
+ */
+Bus.prototype.getBackTrackObject = function(bti)
+{
+    if (BACKTRACK) {
+        var slot = bti >>> Bus.BACKTRACK.SLOT_SHIFT;
+        if (slot) {
+            var bto = this.abtObjects[slot-1];
+            if (bto) return bto.obj;
+        }
+    }
+    return null;
+};
+
+/**
+ * getBackTrackObjectFromAddr(addr)
+ *
+ * @this {Bus}
+ * @param {number} addr
+ * @return {Object|null}
+ */
+Bus.prototype.getBackTrackObjectFromAddr = function(addr)
+{
+    return BACKTRACK? this.getBackTrackObject(this.readBackTrack(addr)) : null;
+};
+
 /**
  * getBackTrackInfo(bti)
  *
@@ -830,10 +883,9 @@ Bus.prototype.updateBackTrackCode = function(addr, bti)
 Bus.prototype.getBackTrackInfo = function(bti)
 {
     if (BACKTRACK) {
-        var slot = bti >>> Bus.BACKTRACK.SLOT_SHIFT;
+        var bto = this.getBackTrackObject(bti);
-        if (slot) {
+        if (bto) {
             var off = bti & Bus.BACKTRACK.OFF_MASK;
-            var bto = this.abtObjects[slot-1];
             var file = bto.obj.file;
             if (file) {
                 this.assert(!bto.off);
@@ -854,8 +906,7 @@ Bus.prototype.getBackTrackInfo = function(bti)
  */
 Bus.prototype.getBackTrackInfoFromAddr = function(addr)
 {
-    var bti = this.readBackTrack(addr);
+    return BACKTRACK? this.getBackTrackInfo(this.readBackTrack(addr)) : null;
-    return this.getBackTrackInfo(bti);
 };
 
 /**

modules/pcjs/lib/debugger.js

@@ -3671,7 +3671,7 @@ if (DEBUGGER) {
         if (aAddr[0] == null) return;
 
         var sDump = "";
-        if (sCmd == "di") {
+        if (BACKTRACK && sCmd == "di") {
             var addr = this.getAddr(aAddr);
             sDump += '%' + str.toHex(addr) + ": ";
             var sInfo = this.bus.getBackTrackInfoFromAddr(addr);
@@ -4746,7 +4746,7 @@ if (DEBUGGER) {
                         if (this.cmp) this.cmp.reset();
                         return true;
                     case "ver":
-                        this.println((APPNAME || "PCjs") + " version " + APPVERSION + " (" + (I386? "80386" : "80286") + (COMPILED? ",RELEASE" : (DEBUG? ",DEBUG" : ",NODEBUG")) + (PREFETCH? ",PREFETCH" : ",NOPREFETCH") + (EAFUNCS? ",EAFUNCS" : ",EATESTS") + (TYPEDARRAYS? ",TYPEDARRAYS" : (FATARRAYS? ",FATARRAYS" : ",DWORDARRAYS")) + (BACKTRACK? ",BACKTRACK" : "") + ")");
+                        this.println((APPNAME || "PCjs") + " version " + APPVERSION + " (" + (I386? "80386" : "80286") + (COMPILED? ",RELEASE" : (DEBUG? ",DEBUG" : ",NODEBUG")) + (PREFETCH? ",PREFETCH" : ",NOPREFETCH") + (TYPEDARRAYS? ",TYPEDARRAYS" : (FATARRAYS? ",FATARRAYS" : ",DWORDARRAYS")) + (BACKTRACK? ",BACKTRACK" : "") + ")");
                         return true;
                     default:
                         ch0 = sCmd.charAt(0);

modules/pcjs/lib/defines.js

@@ -69,19 +69,6 @@ var DEBUGGER = true;            // this @define is overridden by the Closure Com
  */
 var PREFETCH = false;
 
-/**
- * @define {boolean}
- *
- * EAFUNCS enables dynamic function switching whenever the CPU needs to disable one or both EA (Effective Address)
- * memory functions for a ModRM instruction that doesn't observe the normal "read/modify/write" behavior.  The goal
- * is to avoid useless memory reads (which are mostly harmless) and stale memory writes (which are mostly destructive).
- *
- * If EAFUNCS is false, then the CPU falls back to setting/testing internal OP_NOREAD and OP_NOWRITE opFlags as
- * needed.  At the moment, it seems that "EAFUNCS mode" is a bit slower than "EATESTS mode", so EAFUNCS is turned off;
- * however, your mileage may vary, depending on the browser and its vintage.
- */
-var EAFUNCS = false;
-
 /**
  * @define {boolean}
  *
@@ -137,7 +124,6 @@ if (typeof module !== 'undefined') {
     global.PCJSCLASS = PCJSCLASS;
     global.DEBUGGER = DEBUGGER;
     global.PREFETCH = PREFETCH;
-    global.EAFUNCS = EAFUNCS;
     global.FATARRAYS = FATARRAYS;
     global.TYPEDARRAYS = TYPEDARRAYS;
     global.BACKTRACK = BACKTRACK;

modules/pcjs/lib/panel.js

@@ -121,6 +121,25 @@ Panel.prototype.powerUp = function(data, fRepower)
 {
     if (!fRepower) {
         Panel.init();
+        if (this.canvas) {
+            if (this.fBackTrack) {
+                /*
+                 * We need to calculate some parameters based on the canvas pixel dimensions.  For now, we're
+                 * going to use 100% of the canvas height, and 75% of the canvas width (starting with the left edge),
+                 * for the live memory display.
+                 *
+                 * For a 640x350 canvas, that means 480x350 pixels for the live memory display, or 168,000 pixels.
+                 * For a 16Mb (24-bit) address space, with 16,777,216 locations, the worst case would mean each pixel
+                 * represents roughly 100 memory locations.  But in a machine with only 1152Kb of RAM, 32Kb of Video RAM,
+                 * and 128Kb of ROM, that's only 1,343,488 locations we need to worry about, because we can ignore all
+                 * the unallocated regions.
+                 *
+                 * So to start, we need a function that scans the entire address space, and reports how many bytes are
+                 * actually allocated.  At the same time, we should also count how many different objects exist.
+                 */
+                this.bus.scanMemory()
+            }
+        }
     }
     return true;
 };
@@ -137,6 +156,11 @@ Panel.prototype.powerDown = function(fSave)
     return true;
 };
 
+Panel.prototype.scanMemory = function()
+{
+
+};
+
 /**
  * updateAnimation()
  *

modules/pcjs/lib/x86cpu.js

@@ -169,11 +169,6 @@ function X86CPU(parmsCPU) {
     this.aMemBlocks = [];
     this.addrMemMask = this.blockShift = this.blockLimit = this.blockMask = 0;
 
-    /*
-     * Establish all the default get/set functions for accessing memory; see this function for details.
-     */
-    this.setMemoryEnabled();
-
     if (SAMPLER) {
         /*
          * For now, we're just going to sample LIP values (well, LIP + cycle count)
@@ -1270,43 +1265,6 @@ X86CPU.prototype.restore = function(data)
     return this.bus.restoreMemory(data[4]);
 };
 
-/**
- * setMemoryEnabled()
- *
- * Set the default EA memory access functions (enabled vs. disabled).  When EAFUNCS is true, assorted
- * CPU opcode functions override the default functions whenever a CPU operation needs to temporarily disable the
- * "get" of a source operand (or the "set" of a destination operand, as in the case of a CMP instruction).
- *
- * However, it is ALSO every CPU opcode function's responsibility to restore those default access functions
- * back to their normal (eg, enabled) values below, so that stepCPU() doesn't have to do this after every
- * instruction (although in DEBUG builds, stepCPU() will call verifyMemoryEnabled() to assert that's been done).
- *
- * @this {X86CPU}
- */
-X86CPU.prototype.setMemoryEnabled = function()
-{
-    this.getEAByte = this.getEAByteEnabled;
-    this.getEAWord = this.getEAWordEnabled;
-    this.modEAByte = this.modEAByteEnabled;
-    this.modEAWord = this.modEAWordEnabled;
-    this.setEAByte = this.setEAByteEnabled;
-    this.setEAWord = this.setEAWordEnabled;
-};
-
-/**
- * verifyMemoryEnabled()
- *
- * Used by stepCPU() in DEBUG builds to confirm that all CPU opcode functions have re-enabled memory access.
- *
- * @this {X86CPU}
- */
-X86CPU.prototype.verifyMemoryEnabled = function()
-{
-    this.assert(!(this.regEAX & 0xffff0000) && !(this.regEBX & 0xffff0000) && !(this.regECX & 0xffff0000) && !(this.regEDX & 0xffff0000));
-    this.assert(!(this.regESI & 0xffff0000) && !(this.regEDI & 0xffff0000) && !(this.regEBP & 0xffff0000) && !(this.regESP & 0xffff0000));
-    this.assert((this.getEAByte == this.getEAByteEnabled && this.getEAWord == this.getEAWordEnabled && this.modEAByte == this.modEAByteEnabled && this.modEAWord == this.modEAWordEnabled && this.setEAByte == this.setEAByteEnabled && this.setEAWord == this.setEAWordEnabled), "verifyMemoryEnabled() failed");
-};
-
 /**
  * getSeg(sName)
  *
@@ -1977,117 +1935,36 @@ X86CPU.prototype.setWord = function(addr, w)
 };
 
 /**
- * getEAByteDisabled(seg, off)
+ * getEAByte(seg, off)
- *
- * @this {X86CPU}
- * @param {X86Seg} seg register (eg, segDS)
- * @param {number} off is a segment-relative offset
- * @return {number}
- *
-X86CPU.prototype.getEAByteDisabled = function getEAByteDisabled(seg, off)
-{
-    this.segEA = seg;
-    this.offEA = off;
-    //
-    // The LEA opcode is at least one unavoidable reason we must still calculate regEA in
-    // getEAWordDisabled(), but as for getEAByteDisabled(), I can't think of any reason for this.
-    //
-    this.regEA = seg.base + off;
-    return 0;
-};
- */
-
-/**
- * getEAWordDisabled(seg, off)
- *
- * @this {X86CPU}
- * @param {X86Seg} seg register (eg, segDS)
- * @param {number} off is a segment-relative offset
- * @return {number}
- */
-X86CPU.prototype.getEAWordDisabled = function getEAWordDisabled(seg, off)
-{
-    this.segEA = seg;
-    this.offEA = off;
-    /*
-     * The LEA opcode is at least one unavoidable reason we must still calculate regEA here....
-     */
-    this.regEA = seg.base + off;
-    return 0;
-};
-
-/**
- * modEAByteDisabled(seg, off)
- *
- * @this {X86CPU}
- * @param {X86Seg} seg register (eg, segDS)
- * @param {number} off is a segment-relative offset
- * @return {number}
- */
-X86CPU.prototype.modEAByteDisabled = function modEADisabled(seg, off)
-{
-    this.segEA = seg;
-    this.offEA = off;
-    /*
-     * TODO: Should this not also set regEA? Optimization or oversight?
-     */
-    this.regEAWrite = seg.base + off;
-    return 0;
-};
-
-X86CPU.prototype.modEAWordDisabled = X86CPU.prototype.modEAByteDisabled;
-
-/**
- * setEAByteDisabled(w)
- *
- * @this {X86CPU}
- * @param {number} w is the word (16-bit) value to write (ignored)
- */
-X86CPU.prototype.setEAByteDisabled = function setEAByteDisabled(w)
-{
-};
-
-/**
- * setEAWordDisabled(w)
- *
- * @this {X86CPU}
- * @param {number} w is the word (16-bit) value to write (ignored)
- */
-X86CPU.prototype.setEAWordDisabled = function setEAWordDisabled(w)
-{
-};
-
-/**
- * getEAByteEnabled(seg, off)
  *
  * @this {X86CPU}
  * @param {X86Seg} seg register (eg, segDS)
  * @param {number} off is a segment-relative offset
  * @return {number} byte (8-bit) value at that address
  */
-X86CPU.prototype.getEAByteEnabled = function getEAByteEnabled(seg, off)
+X86CPU.prototype.getEAByte = function(seg, off)
 {
     this.segEA = seg;
     this.regEA = seg.checkRead(this.offEA = off, 0);
-    if (!EAFUNCS && (this.opFlags & X86.OPFLAG.NOREAD)) return 0;
+    if (this.opFlags & X86.OPFLAG.NOREAD) return 0;
     var b = this.getByte(this.regEA);
     if (BACKTRACK) this.backTrack.btiEALo = this.backTrack.btiMemLo;
     return b;
 };
 
 /**
- * getEAWordEnabled(seg, off)
+ * getEAWord(seg, off)
  *
  * @this {X86CPU}
  * @param {X86Seg} seg register (eg, segDS)
  * @param {number} off is a segment-relative offset
  * @return {number} word (16-bit) value at that address
  */
-X86CPU.prototype.getEAWordEnabled = function getEAWordEnabled(seg, off)
+X86CPU.prototype.getEAWord = function(seg, off)
 {
     this.segEA = seg;
     this.regEA = seg.checkRead(this.offEA = off, 1);
-    if (!EAFUNCS && (this.opFlags & X86.OPFLAG.NOREAD)) return 0;
+    if (this.opFlags & X86.OPFLAG.NOREAD) return 0;
     var w = this.getWord(this.regEA);
     if (BACKTRACK) {
         this.backTrack.btiEALo = this.backTrack.btiMemLo;
@@ -2097,36 +1974,36 @@ X86CPU.prototype.getEAWordEnabled = function getEAWordEnabled(seg, off)
 };
 
 /**
- * modEAByteEnabled(seg, off)
+ * modEAByte(seg, off)
  *
  * @this {X86CPU}
  * @param {X86Seg} seg register (eg, segDS)
  * @param {number} off is a segment-relative offset
  * @return {number} byte (8-bit) value at that address
  */
-X86CPU.prototype.modEAByteEnabled = function modEAByteEnabled(seg, off)
+X86CPU.prototype.modEAByte = function(seg, off)
 {
     this.segEA = seg;
     this.regEAWrite = this.regEA = seg.checkRead(this.offEA = off, 0);
-    if (!EAFUNCS && (this.opFlags & X86.OPFLAG.NOREAD)) return 0;
+    if (this.opFlags & X86.OPFLAG.NOREAD) return 0;
     var b = this.getByte(this.regEA);
     if (BACKTRACK) this.backTrack.btiEALo = this.backTrack.btiMemLo;
     return b;
 };
 
 /**
- * modEAWordEnabled(seg, off)
+ * modEAWord(seg, off)
  *
  * @this {X86CPU}
  * @param {X86Seg} seg register (eg, segDS)
  * @param {number} off is a segment-relative offset
  * @return {number} word (16-bit) value at that address
  */
-X86CPU.prototype.modEAWordEnabled = function modEAWordEnabled(seg, off)
+X86CPU.prototype.modEAWord = function(seg, off)
 {
     this.segEA = seg;
     this.regEAWrite = this.regEA = seg.checkRead(this.offEA = off, 1);
-    if (!EAFUNCS && (this.opFlags & X86.OPFLAG.NOREAD)) return 0;
+    if (this.opFlags & X86.OPFLAG.NOREAD) return 0;
     var w = this.getWord(this.regEA);
     if (BACKTRACK) {
         this.backTrack.btiEALo = this.backTrack.btiMemLo;
@@ -2136,27 +2013,123 @@ X86CPU.prototype.modEAWordEnabled = function modEAWordEnabled(seg, off)
 };
 
 /**
- * setEAByteEnabled(b)
+ * getEAByteData(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} byte (8-bit) value at that address
+ */
+X86CPU.prototype.getEAByteData = function(off)
+{
+    return this.getEAByte(this.segData, off & this.addrMask);
+};
+
+/**
+ * getEAByteStack(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} byte (8-bit) value at that address
+ */
+X86CPU.prototype.getEAByteStack = function(off)
+{
+    return this.getEAByte(this.segStack, off & this.addrMask);
+};
+
+/**
+ * getEAWordData(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} word (16-bit) value at that address
+ */
+X86CPU.prototype.getEAWordData = function(off)
+{
+    return this.getEAWord(this.segData, off & this.addrMask);
+};
+
+/**
+ * getEAWordStack(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} word (16-bit) value at that address
+ */
+X86CPU.prototype.getEAWordStack = function(off)
+{
+    return this.getEAWord(this.segStack, off & this.addrMask);
+};
+
+/**
+ * modEAByteData(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} byte (8-bit) value at that address
+ */
+X86CPU.prototype.modEAByteData = function(off)
+{
+    return this.modEAByte(this.segData, off & this.addrMask);
+};
+
+/**
+ * modEAByteStack(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} byte (8-bit) value at that address
+ */
+X86CPU.prototype.modEAByteStack = function(off)
+{
+    return this.modEAByte(this.segStack, off & this.addrMask);
+};
+
+/**
+ * modEAWordData(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} word (16-bit) value at that address
+ */
+X86CPU.prototype.modEAWordData = function(off)
+{
+    return this.modEAWord(this.segData, off & this.addrMask);
+};
+
+/**
+ * modEAWordStack(off)
+ *
+ * @this {X86CPU}
+ * @param {number} off is a segment-relative offset
+ * @return {number} word (16-bit) value at that address
+ */
+X86CPU.prototype.modEAWordStack = function(off)
+{
+    return this.modEAWord(this.segStack, off & this.addrMask);
+};
+
+/**
+ * setEAByte(b)
  *
  * @this {X86CPU}
  * @param {number} b is the byte (8-bit) value to write
  */
-X86CPU.prototype.setEAByteEnabled = function setEAByteEnabled(b)
+X86CPU.prototype.setEAByte = function(b)
 {
-    if (!EAFUNCS && (this.opFlags & X86.OPFLAG.NOWRITE)) return;
+    if (this.opFlags & X86.OPFLAG.NOWRITE) return;
     if (BACKTRACK) this.backTrack.btiMemLo = this.backTrack.btiEALo;
     this.setByte(this.segEA.checkWrite(this.offEA, 0), b);
 };
 
 /**
- * setEAWordEnabled(w)
+ * setEAWord(w)
  *
  * @this {X86CPU}
  * @param {number} w is the word (16-bit) value to write
  */
-X86CPU.prototype.setEAWordEnabled = function setEAWordEnabled(w)
+X86CPU.prototype.setEAWord = function(w)
 {
-    if (!EAFUNCS && (this.opFlags & X86.OPFLAG.NOWRITE)) return;
+    if (this.opFlags & X86.OPFLAG.NOWRITE) return;
     if (BACKTRACK) {
         this.backTrack.btiMemLo = this.backTrack.btiEALo;
         this.backTrack.btiMemHi = this.backTrack.btiEAHi;
@@ -2235,7 +2208,7 @@ X86CPU.prototype.setSOWord = function(seg, off, w)
  */
 X86CPU.prototype.getBytePrefetch = function(addr)
 {
-    if (!EAFUNCS && (this.opFlags & X86.OPFLAG.NOREAD)) return 0;
+    if (this.opFlags & X86.OPFLAG.NOREAD) return 0;
     var b;
     if (!this.cbPrefetchQueued) {
         if (MAXDEBUG) {
@@ -2816,18 +2789,6 @@ X86CPU.prototype.stepCPU = function(nMinCycles)
         }
 
         if (DEBUG) {
-            /*
-             * Some opcode helpers are required to temporarily redirect getEAByte/getEAWord or setEAByte/setEAWord
-             * to null functions, effectively disabling a memory read that's unnecessary (or a memory write that could
-             * be destructive).  However, they weren't originally required to restore those memory functions when they
-             * were done; we would simply reset all the memory functions here, after every single instruction.
-             *
-             * That's no longer the case.  Those opcode helpers (or their callers) are now required to restore the
-             * memory access functions to their defaults, so that we don't have to waste time resetting them here, on
-             * every instruction.  The DEBUG-only verifyMemoryEnabled() simply confirms that everyone's doing their job.
-             */
-            this.verifyMemoryEnabled();
-
             /*
              * Make sure that every instruction is assessing a cycle cost, and that the cost is a net positive.
              */

modules/pcjs/lib/x86grps.js

@@ -138,7 +138,7 @@ var X86Grps = {
         this.resultSize = X86.RESULT.SIZE_BYTE;
         this.resultValue = this.resultParitySign = dst - src;
         this.nStepCycles -= (this.regEAWrite < 0? (this.regEA < 0? this.CYCLES.nOpCyclesArithRR : this.CYCLES.nOpCyclesCompareRM) : this.CYCLES.nOpCyclesArithRM);
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -275,7 +275,7 @@ var X86Grps = {
         this.resultSize = X86.RESULT.SIZE_WORD;
         this.resultValue = this.resultParitySign = dst - src;
         this.nStepCycles -= (this.regEAWrite < 0? (this.regEA < 0? this.CYCLES.nOpCyclesArithRR : this.CYCLES.nOpCyclesCompareRM) : this.CYCLES.nOpCyclesArithRM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -655,7 +655,7 @@ var X86Grps = {
         this.resultValue = this.resultParitySign = this.resultAuxOverflow = dst & src;
         this.resultSize = X86.RESULT.SIZE_BYTE;
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesTestRI : this.CYCLES.nOpCyclesTestMI);
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -669,7 +669,7 @@ var X86Grps = {
         this.resultValue = this.resultParitySign = this.resultAuxOverflow = dst & src;
         this.resultSize = X86.RESULT.SIZE_WORD;
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesTestRI : this.CYCLES.nOpCyclesTestMI);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -745,7 +745,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('MULB', src, dst, null, this.getPS(), this.regMD16);
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesMulBR : this.CYCLES.nOpCyclesMulBM);
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -789,7 +789,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('IMULB', src, dst, null, this.getPS(), this.regMD16);
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesIMulBR : this.CYCLES.nOpCyclesIMulBM);
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -828,7 +828,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('DIVB', src, dst, null, this.getPS(), this.regMD16);
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesDivBR : this.CYCLES.nOpCyclesDivBM);
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -875,7 +875,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('IDIVB', src, dst, null, this.getPS(), this.regMD16);
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesIDivBR : this.CYCLES.nOpCyclesIDivBM);
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -906,7 +906,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('MULW', src, dst, null, this.getPS(), this.regMD16 | (this.regMD32 << 16));
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesMulWR : this.CYCLES.nOpCyclesMulWM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -951,7 +951,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('IMULW', src, dst, null, this.getPS(), this.regMD16 | (this.regMD32 << 16));
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesIMulWR : this.CYCLES.nOpCyclesIMulWM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -996,7 +996,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('DIVW', src, dst, null, this.getPS(), this.regMD16 | (this.regMD32 << 16));
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesDivWR : this.CYCLES.nOpCyclesDivWM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -1046,7 +1046,7 @@ var X86Grps = {
          */
         if (DEBUG && DEBUGGER) this.traceLog('IDIVW', src, dst, null, this.getPS(), this.regMD16 | (this.regMD32 << 16));
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesIDivWR : this.CYCLES.nOpCyclesIDivWM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -1115,7 +1115,7 @@ var X86Grps = {
         this.pushWord(this.regEIP);
         this.setIP(dst);
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesCallWR : this.CYCLES.nOpCyclesCallWM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -1130,7 +1130,7 @@ var X86Grps = {
         }
         X86Help.opHelpCALLF.call(this, dst, this.getWord(this.regEA + 2));
         this.nStepCycles -= this.CYCLES.nOpCyclesCallDM;
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -1142,7 +1142,7 @@ var X86Grps = {
     opGrpJMPw: function(dst, src) {
         this.setIP(dst);
         this.nStepCycles -= (this.regEA < 0? this.CYCLES.nOpCyclesJmpWR : this.CYCLES.nOpCyclesJmpWM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -1158,7 +1158,7 @@ var X86Grps = {
         this.setCSIP(dst, this.getWord(this.regEA + 2));
         if (this.cIntReturn) this.checkIntReturn(this.regLIP);
         this.nStepCycles -= this.CYCLES.nOpCyclesJmpDM;
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -1186,7 +1186,7 @@ var X86Grps = {
         /*
          * The PUSH is the only write that needs to occur; dst was the source operand and does not need to be rewritten.
          */
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**

modules/pcjs/lib/x86help.js

@@ -67,7 +67,7 @@ var X86Help = {
         this.resultValue = this.resultParitySign = this.resultAuxOverflow = dst & src;
         this.resultSize = X86.RESULT.SIZE_BYTE;
         this.nStepCycles -= (this.regEAWrite < 0? (this.regEA < 0? this.CYCLES.nOpCyclesTestRR : this.CYCLES.nOpCyclesTestRM) : this.CYCLES.nOpCyclesTestRM);
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -80,7 +80,7 @@ var X86Help = {
         this.resultValue = this.resultParitySign = this.resultAuxOverflow = dst & src;
         this.resultSize = X86.RESULT.SIZE_WORD;
         this.nStepCycles -= (this.regEAWrite < 0? (this.regEA < 0? this.CYCLES.nOpCyclesTestRR : this.CYCLES.nOpCyclesTestRM) : this.CYCLES.nOpCyclesTestRM);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -251,7 +251,7 @@ var X86Help = {
             this.setIP(this.opLIP - this.segCS.base);
             X86Help.opHelpINT.call(this, X86.EXCEPTION.BOUND_ERR, null, 0);
         }
-        if (EAFUNCS) this.setEAByte = this.setEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     },
     /**
@@ -660,16 +660,14 @@ var X86Help = {
          * executing, and since we currently don't do anything to interrupt that execution (eg, throw a
          * JavaScript exception), we should shut off all further reads/writes for the current instruction.
          *
-         * That's easy for any EA-based memory accesses (provided we're not using EAFUNCS): simply set both
+         * That's easy for any EA-based memory accesses: simply set both the NOREAD and NOWRITE flags.
-         * the NOREAD and NOWRITE flags.  However, there are also direct, non-EA-based memory accesses to
+         * However, there are also direct, non-EA-based memory accesses to consider.  A perfect example is
-         * consider.  A perfect example is opPUSHA(): if a GP fault occurs on any PUSH other than the last,
+         * opPUSHA(): if a GP fault occurs on any PUSH other than the last, a subsequent PUSH is likely to
-         * a subsequent PUSH is likely to cause another fault, which we will misinterpret as a double-fault.
+         * cause another fault, which we will misinterpret as a double-fault.
          *
          * TODO: Throw a special JavaScript exception that cpu.js must intercept and quietly ignore.
          */
-        if (!EAFUNCS) {
+        this.opFlags &= ~(X86.OPFLAG.NOREAD | X86.OPFLAG.NOWRITE);
-            this.opFlags &= ~(X86.OPFLAG.NOREAD | X86.OPFLAG.NOWRITE);
-        }
     },
     /**
      * opHelpFaultMessage()

modules/pcjs/lib/x86modsib.js

@@ -82,6 +82,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB04(mod) {
+        this.segData = this.segStack;
         return this.regESP + this.regEAX;
     },
     /**
@@ -91,7 +92,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB05(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + this.regEAX;
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + this.regEAX;
     },
     /**
      * opModSIB06(): scale=00 (1)  index=000 (EAX)  base=110 (ESI)
@@ -154,6 +155,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB0C(mod) {
+        this.segData = this.segStack;
         return this.regESP + this.regECX;
     },
     /**
@@ -163,7 +165,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB0D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + this.regECX;
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + this.regECX;
     },
     /**
      * opModSIB0E(): scale=00 (1)  index=001 (ECX)  base=110 (ESI)
@@ -226,6 +228,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB14(mod) {
+        this.segData = this.segStack;
         return this.regESP + this.regEDX;
     },
     /**
@@ -235,7 +238,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB15(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + this.regEDX;
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + this.regEDX;
     },
     /**
      * opModSIB16(): scale=00 (1)  index=010 (EDX)  base=110 (ESI)
@@ -298,6 +301,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB1C(mod) {
+        this.segData = this.segStack;
         return this.regESP + this.regEBX;
     },
     /**
@@ -307,7 +311,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB1D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + this.regEBX;
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + this.regEBX;
     },
     /**
      * opModSIB1E(): scale=00 (1)  index=011 (EBX)  base=110 (ESI)
@@ -370,6 +374,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB24(mod) {
+        this.segData = this.segStack;
         return this.regESP;
     },
     /**
@@ -379,7 +384,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB25(mod) {
-        return (mod? this.regEBP : this.getIPWord());
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord());
     },
     /**
      * opModSIB26(): scale=00 (1)  index=100 (none)  base=110 (ESI)
@@ -442,6 +447,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB2C(mod) {
+        this.segData = this.segStack;
         return this.regESP + this.regEBP;
     },
     /**
@@ -451,7 +457,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB2D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + this.regEBP;
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + this.regEBP;
     },
     /**
      * opModSIB2E(): scale=00 (1)  index=101 (EBP)  base=110 (ESI)
@@ -514,6 +520,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB34(mod) {
+        this.segData = this.segStack;
         return this.regESP + this.regESI;
     },
     /**
@@ -523,7 +530,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB35(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + this.regESI;
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + this.regESI;
     },
     /**
      * opModSIB36(): scale=00 (1)  index=110 (ESI)  base=110 (ESI)
@@ -586,6 +593,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB3C(mod) {
+        this.segData = this.segStack;
         return this.regESP + this.regEDI;
     },
     /**
@@ -595,7 +603,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB3D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + this.regEDI;
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + this.regEDI;
     },
     /**
      * opModSIB3E(): scale=00 (1)  index=111 (EDI)  base=110 (ESI)
@@ -658,6 +666,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB44(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEAX << 1);
     },
     /**
@@ -667,7 +676,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB45(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEAX << 1);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEAX << 1);
     },
     /**
      * opModSIB46(): scale=01 (2)  index=000 (EAX)  base=110 (ESI)
@@ -730,6 +739,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB4C(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regECX << 1);
     },
     /**
@@ -739,7 +749,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB4D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regECX << 1);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regECX << 1);
     },
     /**
      * opModSIB4E(): scale=01 (2)  index=001 (ECX)  base=110 (ESI)
@@ -802,6 +812,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB54(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEDX << 1);
     },
     /**
@@ -811,7 +822,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB55(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEDX << 1);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEDX << 1);
     },
     /**
      * opModSIB56(): scale=01 (2)  index=010 (EDX)  base=110 (ESI)
@@ -874,6 +885,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB5C(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEBX << 1);
     },
     /**
@@ -883,7 +895,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB5D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEBX << 1);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEBX << 1);
     },
     /**
      * opModSIB5E(): scale=01 (2)  index=011 (EBX)  base=110 (ESI)
@@ -946,6 +958,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB64(mod) {
+        this.segData = this.segStack;
         return this.regESP;
     },
     /**
@@ -955,7 +968,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB65(mod) {
-        return (mod? this.regEBP : this.getIPWord());
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord());
     },
     /**
      * opModSIB66(): scale=01 (2)  index=100 (none)  base=110 (ESI)
@@ -1018,6 +1031,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB6C(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEBP << 1);
     },
     /**
@@ -1027,7 +1041,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB6D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEBP << 1);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEBP << 1);
     },
     /**
      * opModSIB6E(): scale=01 (2)  index=101 (EBP)  base=110 (ESI)
@@ -1090,6 +1104,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB74(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regESI << 1);
     },
     /**
@@ -1099,7 +1114,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB75(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regESI << 1);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regESI << 1);
     },
     /**
      * opModSIB76(): scale=01 (2)  index=110 (ESI)  base=110 (ESI)
@@ -1162,6 +1177,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB7C(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEDI << 1);
     },
     /**
@@ -1171,7 +1187,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB7D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEDI << 1);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEDI << 1);
     },
     /**
      * opModSIB7E(): scale=01 (2)  index=111 (EDI)  base=110 (ESI)
@@ -1234,6 +1250,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB84(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEAX << 2);
     },
     /**
@@ -1243,7 +1260,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB85(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEAX << 2);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEAX << 2);
     },
     /**
      * opModSIB86(): scale=10 (4)  index=000 (EAX)  base=110 (ESI)
@@ -1306,6 +1323,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB8C(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regECX << 2);
     },
     /**
@@ -1315,7 +1333,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB8D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regECX << 2);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regECX << 2);
     },
     /**
      * opModSIB8E(): scale=10 (4)  index=001 (ECX)  base=110 (ESI)
@@ -1378,6 +1396,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB94(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEDX << 2);
     },
     /**
@@ -1387,7 +1406,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB95(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEDX << 2);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEDX << 2);
     },
     /**
      * opModSIB96(): scale=10 (4)  index=010 (EDX)  base=110 (ESI)
@@ -1450,6 +1469,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB9C(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEBX << 2);
     },
     /**
@@ -1459,7 +1479,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIB9D(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEBX << 2);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEBX << 2);
     },
     /**
      * opModSIB9E(): scale=10 (4)  index=011 (EBX)  base=110 (ESI)
@@ -1522,6 +1542,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBA4(mod) {
+        this.segData = this.segStack;
         return this.regESP;
     },
     /**
@@ -1531,7 +1552,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBA5(mod) {
-        return (mod? this.regEBP : this.getIPWord());
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord());
     },
     /**
      * opModSIBA6(): scale=10 (4)  index=100 (none)  base=110 (ESI)
@@ -1594,6 +1615,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBAC(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEBP << 2);
     },
     /**
@@ -1603,7 +1625,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBAD(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEBP << 2);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEBP << 2);
     },
     /**
      * opModSIBAE(): scale=10 (4)  index=101 (EBP)  base=110 (ESI)
@@ -1666,6 +1688,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBB4(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regESI << 2);
     },
     /**
@@ -1675,7 +1698,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBB5(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regESI << 2);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regESI << 2);
     },
     /**
      * opModSIBB6(): scale=10 (4)  index=110 (ESI)  base=110 (ESI)
@@ -1738,6 +1761,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBBC(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEDI << 2);
     },
     /**
@@ -1747,7 +1771,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBBD(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEDI << 2);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEDI << 2);
     },
     /**
      * opModSIBBE(): scale=10 (4)  index=111 (EDI)  base=110 (ESI)
@@ -1810,6 +1834,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBC4(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEAX << 3);
     },
     /**
@@ -1819,7 +1844,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBC5(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEAX << 3);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEAX << 3);
     },
     /**
      * opModSIBC6(): scale=11 (8)  index=000 (EAX)  base=110 (ESI)
@@ -1882,6 +1907,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBCC(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regECX << 3);
     },
     /**
@@ -1891,7 +1917,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBCD(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regECX << 3);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regECX << 3);
     },
     /**
      * opModSIBCE(): scale=11 (8)  index=001 (ECX)  base=110 (ESI)
@@ -1954,6 +1980,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBD4(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEDX << 3);
     },
     /**
@@ -1963,7 +1990,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBD5(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEDX << 3);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEDX << 3);
     },
     /**
      * opModSIBD6(): scale=11 (8)  index=010 (EDX)  base=110 (ESI)
@@ -2026,6 +2053,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBDC(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEBX << 3);
     },
     /**
@@ -2035,7 +2063,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBDD(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEBX << 3);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEBX << 3);
     },
     /**
      * opModSIBDE(): scale=11 (8)  index=011 (EBX)  base=110 (ESI)
@@ -2098,6 +2126,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBE4(mod) {
+        this.segData = this.segStack;
         return this.regESP;
     },
     /**
@@ -2107,7 +2136,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBE5(mod) {
-        return (mod? this.regEBP : this.getIPWord());
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord());
     },
     /**
      * opModSIBE6(): scale=11 (8)  index=100 (none)  base=110 (ESI)
@@ -2170,6 +2199,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBEC(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEBP << 3);
     },
     /**
@@ -2179,7 +2209,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBED(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEBP << 3);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEBP << 3);
     },
     /**
      * opModSIBEE(): scale=11 (8)  index=101 (EBP)  base=110 (ESI)
@@ -2242,6 +2272,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBF4(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regESI << 3);
     },
     /**
@@ -2251,7 +2282,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBF5(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regESI << 3);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regESI << 3);
     },
     /**
      * opModSIBF6(): scale=11 (8)  index=110 (ESI)  base=110 (ESI)
@@ -2314,6 +2345,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBFC(mod) {
+        this.segData = this.segStack;
         return this.regESP + (this.regEDI << 3);
     },
     /**
@@ -2323,7 +2355,7 @@ X86ModSIB.aOpModSIB = [
      * @param {number} mod
      */
     function opModSIBFD(mod) {
-        return (mod? this.regEBP : this.getIPWord()) + (this.regEDI << 3);
+        return (mod? ((this.segData = this.segStack), this.regEBP) : this.getIPWord()) + (this.regEDI << 3);
     },
     /**
      * opModSIBFE(): scale=11 (8)  index=111 (EDI)  base=110 (ESI)

modules/pcjs/lib/x86op0f.js

@@ -47,10 +47,9 @@ var X86Op0F = {
     opGrp6: function() {
         var bModRM = this.getIPByte();
         if ((bModRM & 0x38) < 0x10) {   // possible reg values: 0x00, 0x08, 0x10, 0x18, 0x20, 0x28, 0x30, 0x38
-            if (EAFUNCS) this.modEAWord = this.modEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+            this.opFlags |= X86.OPFLAG.NOREAD;
         }
         this.opMods.aOpModGrpWord[bModRM].call(this, this.aOpGrp6, X86Grps.opGrpNoSrc);
-        if (EAFUNCS) { this.modEAWord = this.modEAWordEnabled; this.setEAWord = this.setEAWordEnabled; }
     },
     /**
      * @this {X86CPU}
@@ -60,10 +59,9 @@ var X86Op0F = {
     opGrp7: function() {
         var bModRM = this.getIPByte();
         if (!(bModRM & 0x10)) {
-            if (EAFUNCS) this.modEAWord = this.modEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+            this.opFlags |= X86.OPFLAG.NOREAD;
         }
         this.opMods.aOpModGrpWord[bModRM].call(this, X86Op0F.aOpGrp7, X86Grps.opGrpNoSrc);
-        if (EAFUNCS) { this.modEAWord = this.modEAWordEnabled; this.setEAWord = this.setEAWordEnabled; }
     },
     /**
      * @this {X86CPU}
@@ -200,7 +198,7 @@ var X86Op0F = {
      * @return {number}
      */
     opLLDT: function(dst, src) {
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         this.segLDT.load(dst);
         this.nStepCycles -= (17 + (this.regEA < 0? 0 : 2));
         return dst;
@@ -212,7 +210,7 @@ var X86Op0F = {
      * @return {number}
      */
     opLTR: function(dst, src) {
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         if (this.segTSS.load(dst) != X86.ADDR_INVALID) {
             this.setWord(this.segTSS.addrDesc + X86.DESC.ACC.OFFSET, this.segTSS.acc |= X86.DESC.ACC.TYPE.LDT);
             this.segTSS.type = X86.DESC.ACC.TYPE.TSS_BUSY;
@@ -227,7 +225,7 @@ var X86Op0F = {
      * @return {number}
      */
     opVERR: function(dst, src) {
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        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.
@@ -263,7 +261,7 @@ var X86Op0F = {
      * @return {number}
      */
     opVERW: function(dst, src) {
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        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.
@@ -386,7 +384,7 @@ var X86Op0F = {
         } else {
             this.addrGDT = this.getWord(this.regEA + 2) | (this.getByte(this.regEA + 4) << 16);
             this.addrGDTLimit = this.addrGDT + dst;
-            if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+            this.opFlags |= X86.OPFLAG.NOWRITE;
             this.nStepCycles -= 11;
         }
         return dst;
@@ -409,7 +407,7 @@ var X86Op0F = {
         } else {
             this.addrIDT = this.getWord(this.regEA + 2) | (this.getByte(this.regEA + 4) << 16);
             this.addrIDTLimit = this.addrIDT + dst;
-            if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+            this.opFlags |= X86.OPFLAG.NOWRITE;
             this.nStepCycles -= 12;
         }
         return dst;
@@ -433,7 +431,7 @@ var X86Op0F = {
     opLMSW: function(dst, src) {
         X86Help.opHelpLMSW.call(this, dst);
         this.nStepCycles -= (this.regEA < 0? 3 : 6);
-        if (EAFUNCS) this.setEAWord = this.setEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOWRITE;
+        this.opFlags |= X86.OPFLAG.NOWRITE;
         return dst;
     }
 };

modules/pcjs/lib/x86opxx.js

@@ -685,7 +685,6 @@ var X86OpXX = {
      */
     opCMPmb: function() {
         this.opMods.aOpModMemByte[this.getIPByte()].call(this, X86Grps.opGrpCMPb);
-        if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
     },
     /**
      * op=0x39 (CMP word,reg)
@@ -694,7 +693,6 @@ var X86OpXX = {
      */
     opCMPmw: function() {
         this.opMods.aOpModMemWord[this.getIPByte()].call(this, X86Grps.opGrpCMPw);
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
     },
     /**
      * op=0x3A (CMP reg,byte)
@@ -703,7 +701,6 @@ var X86OpXX = {
      */
     opCMPrb: function() {
         this.opMods.aOpModRegByte[this.getIPByte()].call(this, X86Grps.opGrpCMPb);
-        if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
     },
     /**
      * op=0x3B (CMP reg,word)
@@ -712,7 +709,6 @@ var X86OpXX = {
      */
     opCMPrw: function() {
         this.opMods.aOpModRegWord[this.getIPByte()].call(this, X86Grps.opGrpCMPw);
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
     },
     /**
      * op=0x3C (CMP AL,imm8)
@@ -721,7 +717,6 @@ var X86OpXX = {
      */
     opCMPALb: function() {
         X86Grps.opGrpCMPb.call(this, this.regEAX & 0xff, this.getIPByte());
-        if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
         /*
          * In the absence of any EA calculations, opGrpCMPb() will deduct nOpCyclesArithRR, and for all CPUs through
          * the 80286, we need deduct only one more cycle.
@@ -735,7 +730,6 @@ var X86OpXX = {
      */
     opCMPAXw: function() {
         X86Grps.opGrpCMPw.call(this, this.regEAX & this.opMask, this.getIPWord());
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
         /*
          * In the absence of any EA calculations, opGrpCMPw() will deduct nOpCyclesArithRR, and for all CPUs through
          * the 80286, we need deduct only one more cycle.
@@ -1749,7 +1743,6 @@ var X86OpXX = {
      */
     opGrp1b: function() {
         this.opMods.aOpModGrpByte[this.getIPByte()].call(this, X86Grps.aOpGrp1b, this.getIPByte);
-        if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
         this.nStepCycles -= (this.regEAWrite < 0? 1 : this.CYCLES.nOpCyclesArithMID);
     },
     /**
@@ -1759,7 +1752,6 @@ var X86OpXX = {
      */
     opGrp1w: function() {
         this.opMods.aOpModGrpWord[this.getIPByte()].call(this, X86Grps.aOpGrp1w, this.getIPWord);
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
         this.nStepCycles -= (this.regEAWrite < 0? 1 : this.CYCLES.nOpCyclesArithMID);
     },
     /**
@@ -1769,7 +1761,6 @@ var X86OpXX = {
      */
     opGrp1sw: function() {
         this.opMods.aOpModGrpWord[this.getIPByte()].call(this, X86Grps.aOpGrp1w, this.getIPDisp);
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
         this.nStepCycles -= (this.regEAWrite < 0? 1 : this.CYCLES.nOpCyclesArithMID);
     },
     /**
@@ -1779,7 +1770,6 @@ var X86OpXX = {
      */
     opTESTrb: function() {
         this.opMods.aOpModMemByte[this.getIPByte()].call(this, X86Help.opHelpTESTb);
-        if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
     },
     /**
      * op=0x85 (TEST reg,word)
@@ -1788,7 +1778,6 @@ var X86OpXX = {
      */
     opTESTrw: function() {
         this.opMods.aOpModMemWord[this.getIPByte()].call(this, X86Help.opHelpTESTw);
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
     },
     /**
      * op=0x86 (XCHG reg,byte)
@@ -1839,9 +1828,8 @@ var X86OpXX = {
         /*
          * Like other MOV operations, the destination does not need to be read, just written.
          */
-        if (EAFUNCS) this.modEAByte = this.modEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+        this.opFlags |= X86.OPFLAG.NOREAD;
         this.opMods.aOpModMemByte[this.getIPByte()].call(this, X86Help.opHelpMOV);
-        if (EAFUNCS) this.modEAByte = this.modEAByteEnabled;
     },
     /**
      * op=0x89 (MOV word,reg)
@@ -1852,9 +1840,8 @@ var X86OpXX = {
         /*
          * Like other MOV operations, the destination does not need to be read, just written.
          */
-        if (EAFUNCS) this.modEAWord = this.modEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+        this.opFlags |= X86.OPFLAG.NOREAD;
         this.opMods.aOpModMemWord[this.getIPByte()].call(this, X86Help.opHelpMOV);
-        if (EAFUNCS) this.modEAWord = this.modEAWordEnabled;
     },
     /**
      * op=0x8A (MOV reg,byte)
@@ -1904,9 +1891,8 @@ var X86OpXX = {
         /*
          * Like other MOV operations, the destination does not need to be read, just written.
          */
-        if (EAFUNCS) this.modEAWord = this.modEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+        this.opFlags |= X86.OPFLAG.NOREAD;
         this.opMods.aOpModMemWord[bModRM].call(this, X86Help.opHelpMOVSegSrc);
-        if (EAFUNCS) this.modEAWord = this.modEAWordEnabled;
     },
     /**
      * op=0x8D (LEA reg,word)
@@ -1914,10 +1900,9 @@ var X86OpXX = {
      * @this {X86CPU}
      */
     opLEA: function() {
-        if (EAFUNCS) this.getEAWord = this.getEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+        this.opFlags |= X86.OPFLAG.NOREAD;
         this.segData = this.segStack = this.segNULL;    // we can't have the EA calculation, if any, "polluted" by segment arithmetic
         this.opMods.aOpModRegWord[this.getIPByte()].call(this, X86Help.opHelpLEA);
-        if (EAFUNCS) this.getEAWord = this.getEAWordEnabled;
     },
     /**
      * op=0x8E (MOV sr,word)
@@ -2015,9 +2000,8 @@ var X86OpXX = {
         /*
          * Like other MOV operations, the destination does not need to be read, just written.
          */
-        if (EAFUNCS) this.modEAWord = this.modEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+        this.opFlags |= X86.OPFLAG.NOREAD;
         this.opMods.aOpModGrpWord[this.getIPByte()].call(this, X86Grps.aOpGrpPOPw, this.popWord);
-        if (EAFUNCS) this.modEAWord = this.modEAWordEnabled;
     },
     /**
      * op=0x90 (NOP, aka XCHG AX,AX)
@@ -2419,7 +2403,6 @@ var X86OpXX = {
                 this.assert(this.regLIP == this.opLIP);
                 this.opFlags |= X86.OPFLAG.REPEAT;
             }
-            if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
         }
     },
     /**
@@ -2468,7 +2451,6 @@ var X86OpXX = {
                 this.assert(this.regLIP == this.opLIP);
                 this.opFlags |= X86.OPFLAG.REPEAT;
             }
-            if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
         }
     },
     /**
@@ -2688,7 +2670,6 @@ var X86OpXX = {
                 this.assert(this.regLIP == this.opLIP);
                 this.opFlags |= X86.OPFLAG.REPEAT;
             }
-            if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
         }
     },
     /**
@@ -2729,7 +2710,6 @@ var X86OpXX = {
                 this.assert(this.regLIP == this.opLIP);
                 this.opFlags |= X86.OPFLAG.REPEAT;
             }
-            if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
         }
     },
     /**
@@ -2972,9 +2952,8 @@ var X86OpXX = {
         /*
          * Like other MOV operations, the destination does not need to be read, just written.
          */
-        if (EAFUNCS) this.modEAByte = this.modEAByteDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+        this.opFlags |= X86.OPFLAG.NOREAD;
         this.opMods.aOpModGrpByte[this.getIPByte()].call(this, X86Grps.aOpGrpMOVImm, this.getIPByte);
-        if (EAFUNCS) this.modEAByte = this.modEAByteEnabled;
     },
     /**
      * op=0xC7 (MOV word,imm16)
@@ -2985,9 +2964,8 @@ var X86OpXX = {
         /*
          * Like other MOV operations, the destination does not need to be read, just written.
          */
-        if (EAFUNCS) this.modEAWord = this.modEAWordDisabled; else this.opFlags |= X86.OPFLAG.NOREAD;
+        this.opFlags |= X86.OPFLAG.NOREAD;
         this.opMods.aOpModGrpWord[this.getIPByte()].call(this, X86Grps.aOpGrpMOVImm, this.getIPWord);
-        if (EAFUNCS) this.modEAWord = this.modEAWordEnabled;
     },
     /**
      * op=0xC8 (ENTER imm16,imm8) (80186/80188 and up)
@@ -3520,7 +3498,6 @@ var X86OpXX = {
         this.regMD16 = -1;
         this.opMods.aOpModGrpByte[this.getIPByte()].call(this, X86Grps.aOpGrp3b, X86Grps.opGrpNoSrc);
         if (this.regMD16 >= 0) this.regEAX = this.regMD16;
-        if (EAFUNCS) this.setEAByte = this.setEAByteEnabled;
     },
     /**
      * op=0xF7 (GRP3 word)
@@ -3547,7 +3524,6 @@ var X86OpXX = {
             this.regEAX = this.regMD16;
             this.regEDX = this.regMD32;
         }
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
     },
     /**
      * op=0xF8 (CLC)
@@ -3619,7 +3595,6 @@ var X86OpXX = {
      */
     opGrp4w: function() {
         this.opMods.aOpModGrpWord[this.getIPByte()].call(this, X86Grps.aOpGrp4w, X86Grps.opGrpNoSrc);
-        if (EAFUNCS) this.setEAWord = this.setEAWordEnabled;
     }
 };