{
LispBox.mc
Last edit: by don 16-Feb-84 10:35:14 fixed for big mem
Created:  29-Nov-83 15:36:28 by don
}

SetTask[0];

{- - - - - - - - - - - - - - - - - - - - - - - - - -
  #      name        len-1    stk level effect   UFN table entry
366	BOXIPLUS     0        -1                 \BOXIPLUS
367	BOXIDIFFERENCE  0     -1                 \BOXIDIFFERENCE

Same as IPLUS2, IDIFFERENCE, except store result @tos {stack - 1} -- first arg is
number box (for which optionally check) -- and no overflow check.

- - - - - - - - - - - - - - - - - - - - - - - - - -}

@BOXIPLUS:	opcode[366'b],
	MAR _ [rhS, S + 0], L2 _ L2.boxiplus,	c1;
	uTOSH _ TOSH, GOTO[BoxComStart],	c2;

	TOS _ Rx + TOS, CarryBr,	c3, at[L2.boxiplus, 10, ArithDOp]; {boxplus}

	L3Disp, BRANCH[$, ArithBoxAddCar],	c1;
	TOSH _ TT + TOSH, DISP4[ArithBoxCom],	c2;
ArithBoxAddCar:
	TOSH _ TT + TOSH + 1, DISP4[ArithBoxCom],	c2;

@BOXIDIFFERENCE:	opcode[367'b],
	MAR _ [rhS, S + 0], L2 _ L2.boxidiff,	c1;
	uTOSH _ TOSH, GOTO[BoxComStart],	c2;
BoxComStart:
	Rx _ MD, uTOS _ TOS, L3 _ L3.FptArg1,	c3;

	Q _ TOSH and 0FF,	c1;
	Ybus _ Q xor smallpl, ZeroBr,	c2;
	Ybus _ Q xor smallneg, ZeroBr, BRANCH[$, ArithBoxPos],	c3;

	BRANCH[ArithBoxnotsmall, ArithBoxNeg],	c1;
ArithBoxPos:
	TOSH _ 0, CANCELBR[$],	c1;
	,	c2;
	GOTO[ArithA1done],	c3;

ArithBoxNeg:
	TOSH _ TOSH xor ~TOSH,	c2;
	GOTO[ArithA1done],	c3;

ArithBoxnotsmall:
	,	c2;
	GOTO[ArithBoxE],	c3;

	TOS _ Rx - TOS, CarryBr,	c3, at[L2.boxidiff, 10, ArithDOp]; {boxdiff}

	L3Disp, BRANCH[$, ArithBoxSubCar],	c1;
	TOSH _ TT - TOSH - 1, DISP4[ArithBoxCom],	c2;
ArithBoxSubCar:
	TOSH _ TT - TOSH, DISP4[ArithBoxCom],	c2;

	GOTO[ufnZ1],	c3, at[L3.FptArg1, 10, ArithBoxCom];
	TT _ uChain,	c3, at[L3.FptArg2, 10, ArithBoxCom];

	Map _ [rhTT, TT], L0 _ L0.RedoBox,	c1;
	Q _ rhTT,	c2;
	rhRx _ Rx _ MD, XwdDisp{XDirtyDisp},	c3;

	MAR _ [rhRx, TT + 0], DISP2[ArithBoxMap],	c1, at[L0.RedoBox, 10, WMapFixCaller];
	MDR _ TOSH,	c2, at[1, 4, ArithBoxMap];
	TOSH _ Q,	c3;

	MAR _ [rhRx, TT + 1],	c1;
	MDR _ TOS, CANCELBR[$, CB2], LOOPHOLE[wok],	c2;
	TOS _ TT,	c3;

	S _ S - 2, GOTO[IB.pc1],	c1;

	GOTO[WLMapFix],	c2, at[0, 4, ArithBoxMap];
	GOTO[WLMapFix],	c2, at[2, 4, ArithBoxMap];
	GOTO[WLMapFix],	c2, at[3, 4, ArithBoxMap];

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