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32-bit multiplication

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This commit is contained in:
Jeff Parsons 2015-04-22 17:24:40 -07:00 • committed by jeffpar
commit d68f1bd985
6 changed files with 157 additions and 63 deletions
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36
modules/pcjs/lib/x86ops.js
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@ -2057,8 +2057,8 @@ X86.opMOVrw = function MOVrw()
* op=0x8C (MOV word,sreg)
*
* NOTE: Since the ModRM decoders deal only with general-purpose registers, we must move
* the appropriate segment register into a special variable (regMD16), which our helper function
* (fnMOVMD16) will use to replace the decoder's src operand.
* the appropriate segment register into a special variable (regXX), which our helper function
* (fnMOVxx) will use to replace the decoder's src operand.
*
* @this {X86CPU}
*/
@ -2068,27 +2068,27 @@ X86.opMOVwsr = function MOVwsr()
var reg = (bModRM & 0x38) >> 3;
switch (reg) {
case 0x0:
this.regMD16 = this.segES.sel;
this.regXX = this.segES.sel;
break;
case 0x1:
this.regMD16 = this.segCS.sel;
this.regXX = this.segCS.sel;
break;
case 0x2:
this.regMD16 = this.segSS.sel;
this.regXX = this.segSS.sel;
break;
case 0x3:
this.regMD16 = this.segDS.sel;
this.regXX = this.segDS.sel;
break;
case 0x4:
if (I386 && this.model >= X86.MODEL_80386) {
this.regMD16 = this.segFS.sel;
this.regXX = this.segFS.sel;
break;
}
X86.opInvalid.call(this);
break;
case 0x5:
if (I386 && this.model >= X86.MODEL_80386) {
this.regMD16 = this.segGS.sel;
this.regXX = this.segGS.sel;
break;
}
/* falls through */
@ -2100,7 +2100,7 @@ X86.opMOVwsr = function MOVwsr()
* Like other MOV operations, the destination does not need to be read, just written.
*/
this.opFlags |= X86.OPFLAG.NOREAD;
this.aOpModMemWord[bModRM].call(this, X86.fnMOVMD16);
this.aOpModMemWord[bModRM].call(this, X86.fnMOVxx);
};
/**
@ -2207,8 +2207,6 @@ X86.opMOVsrw = function MOVsrw()
this.setDS(this.regEDI);
this.regEDI = temp;
break;
default:
break; // there IS no other case, but JavaScript inspections don't know that
}
};
@ -3841,7 +3839,7 @@ X86.opCMC = function CMC()
* know what the target is (only the target's value), it cannot easily work around the problem.
*
* A simple, albeit kludgy, solution is for fnMULb to always save its result in a special
* "register" (eg, regMD16), which we will then put back into regEAX if it's been updated.
* "register" (eg, regMDLo), which we will then put back into regEAX if it's been updated.
* This also relieves us from having to decode any part of the ModRM byte, so maybe it's not
* such a bad work-around after all.
*
@ -3851,9 +3849,9 @@ X86.opCMC = function CMC()
*/
X86.opGRP3b = function GRP3b()
{
this.regMD16 = -1;
this.fMDSet = false;
this.aOpModGrpByte[this.getIPByte()].call(this, X86.aOpGrp3b, X86.fnSrcNone);
if (this.regMD16 >= 0) this.regEAX = this.regMD16;
if (this.fMDSet) this.regEAX = (this.regEAX & ~this.dataMask) | (this.regMDLo & this.dataMask);
};
/**
@ -3869,7 +3867,7 @@ X86.opGRP3b = function GRP3b()
* know what the target is (only the target's value), it cannot easily work around the problem.
*
* A simple, albeit kludgey, solution is for fnMULw to always save its result in a special
* "register" (eg, regMD16/regMD32), which we will then put back into regEAX/regEDX if it's been
* "register" (eg, regMDLo/regMDHi), which we will then put back into regEAX/regEDX if it's been
* updated. This also relieves us from having to decode any part of the ModRM byte, so maybe
* it's not such a bad work-around after all.
*
@ -3877,11 +3875,11 @@ X86.opGRP3b = function GRP3b()
*/
X86.opGRP3w = function GRP3w()
{
this.regMD16 = -1;
this.fMDSet = false;
this.aOpModGrpWord[this.getIPByte()].call(this, X86.aOpGrp3w, X86.fnSrcNone);
if (this.regMD16 >= 0) {
this.regEAX = this.regMD16;
this.regEDX = this.regMD32;
if (this.fMDSet) {
this.regEAX = (this.regEAX & ~this.dataMask) | (this.regMDLo & this.dataMask);
this.regEDX = (this.regEDX & ~this.dataMask) | (this.regMDHi & this.dataMask);
}
};