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Simplified 80386 word/dword dispatching

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Jeff Parsons 2015-04-07 16:51:31 -07:00 • committed by jeffpar
commit b71fd5002b
6 changed files with 153 additions and 396 deletions
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20
modules/pcjs/lib/x86cpu.js
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@ -860,8 +860,8 @@ X86CPU.prototype.initProcessor = function()
this.aOps[X86.OPCODE.GS] = X86.opInvalid; // 0x65
this.aOps[X86.OPCODE.OS] = X86.opInvalid; // 0x66
this.aOps[X86.OPCODE.AS] = X86.opInvalid; // 0x67
this.aOps[X86.OPCODE.PUSH16] = X86.opPUSH16; // 0x68
this.aOps[X86.OPCODE.IMUL16] = X86.opIMUL16; // 0x69
this.aOps[X86.OPCODE.PUSHN] = X86.opPUSHn; // 0x68
this.aOps[X86.OPCODE.IMULN] = X86.opIMULn; // 0x69
this.aOps[X86.OPCODE.PUSH8] = X86.opPUSH8; // 0x6A
this.aOps[X86.OPCODE.IMUL8] = X86.opIMUL8; // 0x6B
this.aOps[X86.OPCODE.INSB] = X86.opINSb; // 0x6C
@ -900,16 +900,6 @@ X86CPU.prototype.initProcessor = function()
for (bOpcode in X86.aOps0F386) {
this.aOps0F[+bOpcode] = X86.aOps0F386[bOpcode];
}
/*
* Extend the opcode table by creating a mirror of the first 256 opcodes, but with dword-based
* opcode handlers (as defined in aOpsD) instead word-based opcode handlers. Whenever dataSize
* is changed from 2 bytes to 4, we trigger the appropriate set of opcode handlers by changing
* bOpcodeBias from 0 to 256.
*/
this.aOps = this.aOps.concat(this.aOps);
for (bOpcode in X86.aOpsD) {
this.aOps[+bOpcode + 256] = X86.aOpsD[bOpcode];
}
}
}
}
@ -1208,11 +1198,11 @@ X86CPU.prototype.setAddrSize = function()
X86CPU.prototype.setDataSize = function()
{
if (this.dataSize == 2) {
this.bOpcodeBias = 0;
this.dataType = X86.RESULT.WORD;
this.getWord = this.getShort;
this.setWord = this.setShort;
} else {
this.bOpcodeBias = 256;
this.dataType = X86.RESULT.DWORD;
this.getWord = this.getLong;
this.setWord = this.setLong;
}
@ -3651,7 +3641,7 @@ X86CPU.prototype.stepCPU = function(nMinCycles)
this.nSnapCycles = this.nStepCycles;
}
this.aOps[this.getIPByte() + (I386? this.bOpcodeBias : 0)].call(this);
this.aOps[this.getIPByte()].call(this);
if (PREFETCH) {
var nSpareCycles = (this.nSnapCycles - this.nStepCycles) - this.nBusCycles;