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Optimized PC8080's innermost CPU execution loop

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This commit is contained in:
Jeff Parsons 2016-08-22 17:17:14 -07:00
commit 702b9d36c7
4 changed files with 381 additions and 385 deletions
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16
modules/pc8080/lib/cpuops.js
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@ -1287,11 +1287,6 @@ CPUDef8080.opMOVML = function()
*/
CPUDef8080.opHLT = function()
{
/*
* The CPU is never REALLY halted by a HLT instruction; instead, by setting X86.INTFLAG.HALT,
* we are signalling to stepCPU() that it's free to end the current burst AND that it should not
* execute any more instructions until checkINTR() indicates a hardware interrupt is requested.
*/
var addr = this.getPC() - 1;
/*
@ -1304,9 +1299,15 @@ CPUDef8080.opHLT = function()
}
}
this.intFlags |= CPUDef8080.INTFLAG.HALT;
this.nStepCycles -= 7;
/*
* The CPU is never REALLY halted by a HLT instruction; instead, we call requestHALT(), which
* signals to stepCPU() that it should end the current burst AND that it should not execute any
* more instructions until checkINTR() indicates a hardware interrupt has been requested.
*/
this.requestHALT();
/*
* If a Debugger is present and the HALT message category is enabled, then we REALLY halt the CPU,
* on the theory that whoever's using the Debugger would like to see HLTs.
@ -2823,8 +2824,9 @@ CPUDef8080.opJM = function()
*/
CPUDef8080.opEI = function()
{
this.setIF();var w = this.getHL();
this.setIF();
this.nStepCycles -= 4;
this.checkINTR();
};
/**