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80386 0x0F opcodes more or less fleshed out

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This commit is contained in:
Jeff Parsons 2015-03-29 20:37:46 -07:00 • committed by jeffpar
commit 177032223c
4 changed files with 452 additions and 15 deletions
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140
modules/pcjs/lib/x86func.js
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@ -204,6 +204,76 @@ X86.fnBOUND = function BOUND(dst, src)
return dst;
};
/**
* fnBSF(dst, src)
*
* Scan src starting at bit 0. If a set bit is found, the bit index is stored in dst and ZF is cleared;
* otherwise, ZF is set and dst is unchanged.
*
* 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
* @param {number} src
* @return {number}
*/
X86.fnBSF = function BSF(dst, src)
{
if (!src) {
this.setZF();
} else {
this.clearZF();
var i = 0, bit = 0x1;
while (bit & this.dataMask) {
if (src & bit) {
dst = i;
break;
}
bit <<= 1;
i++;
}
}
this.nStepCycles -= X86CPU.CYCLES_80386.nOpCyclesBitScan + i * 3;
return dst;
};
/**
* fnBSR(dst, src)
*
* Scan src starting from the highest bit. If a set bit is found, the bit index is stored in dst and ZF is
* cleared; otherwise, ZF is set and dst is unchanged.
*
* 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
* @param {number} src
* @return {number}
*/
X86.fnBSR = function BSR(dst, src)
{
if (!src) {
this.setZF();
} else {
this.clearZF();
var i = (this.dataSize == 2? 15 : 31), j = i, bit = 1 << i;
while (bit) {
if (src & bit) {
dst = i;
break;
}
bit >>>= 1;
i--;
}
}
this.nStepCycles -= X86CPU.CYCLES_80386.nOpCyclesBitScan + (j - i) * 3;
return dst;
};
/**
* fnBT(dst, src)
*
@ -1052,6 +1122,25 @@ X86.fnLES = function LES(dst, src)
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 + 2));
this.nStepCycles -= this.CYCLES.nOpCyclesLS;
return src;
};
/**
* fnLGDT(dst, src)
*
@ -1079,6 +1168,25 @@ X86.fnLGDT = function LGDT(dst, src)
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 + 2));
this.nStepCycles -= this.CYCLES.nOpCyclesLS;
return src;
};
/**
* fnLIDT(dst, src)
*
@ -1173,6 +1281,25 @@ X86.fnLSL = function LSL(dst, src)
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 + 2));
this.nStepCycles -= this.CYCLES.nOpCyclesLS;
return src;
};
/**
* fnLTR(dst, src)
*
@ -1208,6 +1335,19 @@ X86.fnMOV = function MOV(dst, src)
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)
*