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DEC's "TRAP TEST" finally passes (and I learned a lot about PDP-11 opcode idiosyncrasies in the process)

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Jeff 2016-11-12 12:54:13 -08:00 • committed by Jeff Parsons
commit 2c1191ce6e
14 changed files with 616 additions and 518 deletions
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18
modules/pdp11/lib/cpuops.js
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@ -693,7 +693,9 @@ PDP11.opBISB = function(opCode)
*/
PDP11.opBIT = function(opCode)
{
this.updateNZVFlags(this.readSrcWord(opCode) & this.readDstWord(opCode));
var src = this.readSrcWord(opCode);
var dst = this.readDstWord(opCode);
this.updateNZVFlags((src < 0? this.regsGen[-src-1] : src) & dst);
this.nStepCycles -= (this.dstMode? (3 + 1) + (this.srcReg && this.dstReg >= 6? 1 : 0) : (this.srcMode? (3 + 1) : (2 + 1)) + (this.dstReg == 7? 2 : 0));
};
@ -705,7 +707,9 @@ PDP11.opBIT = function(opCode)
*/
PDP11.opBITB = function(opCode)
{
this.updateNZVFlags((this.readSrcByte(opCode) & this.readDstByte(opCode)) << 8);
var src = this.readSrcByte(opCode);
var dst = this.readDstByte(opCode);
this.updateNZVFlags(((src < 0? (this.regsGen[-src-1] & 0xff) : src) & dst) << 8);
this.nStepCycles -= (this.dstMode? (3 + 1) + (this.srcReg && this.dstReg >= 6? 1 : 0) : (this.srcMode? (3 + 1) : (2 + 1)) + (this.dstReg == 7? 2 : 0));
};
@ -964,7 +968,7 @@ PDP11.opCMP = function(opCode)
{
var src = this.readSrcWord(opCode);
var dst = this.readDstWord(opCode);
var result = src - dst;
var result = (src = (src < 0? this.regsGen[-src-1] : src)) - dst;
/*
* NOTE: CMP calculates (src - dst) rather than (dst - src), so src and dst updateSubFlags() parms must be reversed.
*/
@ -980,9 +984,9 @@ PDP11.opCMP = function(opCode)
*/
PDP11.opCMPB = function(opCode)
{
var src = this.readSrcByte(opCode) << 8;
var dst = this.readDstByte(opCode) << 8;
var result = src - dst;
var src = this.readSrcByte(opCode);
var dst = this.readDstByte(opCode);
var result = (src = (src < 0? (this.regsGen[-src-1] & 0xff): src) << 8) - (dst <<= 8);
/*
* NOTE: CMP calculates (src - dst) rather than (dst - src), so src and dst updateSubFlags() parms must be reversed.
*/
@ -1667,7 +1671,7 @@ PDP11.opSPL = function(opCode)
}
if (!(this.regPSW & PDP11.PSW.CMODE)) {
this.regPSW = (this.regPSW & ~(PDP11.PSW.UNUSED | PDP11.PSW.PRI)) | ((opCode & 0x7) << PDP11.PSW.SHIFT.PRI);
this.opFlags |= PDP11.OPFLAG.INTQ_SPL;
this.opFlags |= PDP11.OPFLAG.INTQ_CHK;
}
this.nStepCycles -= (4 + 1);
};