{
File name dbRbbSubs.mc
Last edited by Jim Frandeen: January 12, 1982  4:18 PM: Reverse labels at SLRBack+1 and DLRBack+1.
Last edited by Jim Frandeen: January 11, 1982  1:35 PM: Fix at 3,4,mapSFixes.
Sandman: January 8, 1982  11:03 AM: init rhVS(VD) from uReg in Src(Dst)VAMod.
Last edited by Jim Frandeen: August 20, 1981  2:18 PM: Change for new Assembler.
Last edited by Jim Frandeen: March 16, 1981  3:52 PM: Change MoverhVtoStkandRestore to fix bug for crossing 64K boundaries.
Last edited by Jim Frandeen: March 15, 1981  11:05 PM: Add entry points to RestoreRandRHRegs and rearrange for new Block.mc that includes Checksum.
Last edited by Don Charnley: February 26, 1981  2:39 PM: Make MoverhVToStkandRestore smaller for new stack size.
Last edited by Jim Frandeen: February 24, 1981  8:46 PM: Add entry points to RestoreRandRHRegs and rearrange for new Block.mc.
Created by: Don Charnley January, 1980
Description: BitBlt op-code
}

{
	dT  SUBROUTINE
	first cycle = c* , one cycle long
This subroutine is used to aid in loading a link register.
	REGISTERS
rL	value to place in link register
Lx	link register to be loaded
	CALLING SEQUENCE
To load a link register
	[] ← rL, YDisp	,c2;
	[] ← retnum, Lx ← 0, XDisp, DISP4[dT]	,c3;

{rtn here}	Noop	,c2, at[retnum,10,dTrets];

	RETURNS THRU
dTRets
}

dT:
{0}	RET[dTRets]	,c*, at[0,10,dT];
{1}	RET[dTRets]	,c*, at[1,10,dT];
{2}	RET[dTRets]	,c*, at[2,10,dT];
{3}	RET[dTRets]	,c*, at[3,10,dT];
{4}	RET[dTRets]	,c*, at[4,10,dT];
{5}	RET[dTRets]	,c*, at[5,10,dT];
{6}	RET[dTRets]	,c*, at[6,10,dT];
{7}	RET[dTRets]	,c*, at[7,10,dT];
{8}	RET[dTRets]	,c*, at[8,10,dT];
{9}	RET[dTRets]	,c*, at[9,10,dT];
{0A}	RET[dTRets]	,c*, at[0A,10,dT];
{0B}	RET[dTRets]	,c*, at[0B,10,dT];
{0C}	RET[dTRets]	,c*, at[0C,10,dT];
{0D}	RET[dTRets]	,c*, at[0D,10,dT];
{0E}	RET[dTRets]	,c*, at[0E,10,dT];
{0F}	RET[dTRets]	,c*, at[0F,10,dT];

{
	MoverhVToStkandRestore  SUBROUTINE
	length = 3 clicks
This subroutine is used to move the rhV registers into the stack.
	USES
L0	caller
	MOVES
Rbb1	to UDstBit
Q	to USrcBit
	EXITS TO RestoreRandRHRegs  SUBROUTINE
}

MoverhVToStkandRestore:
	rhPV ← nRhS, GOTO[RestoreRandRHRegspl1],	,c*{c1}, at[3,8,MoverhVToStkandRestore];

{
	RestoreRandRHRegs  SUBROUTINE
	length = 2 1/3 clicks
This subroutine is used to restore the R registers and rh registers which were saved at the entry into BitBlt.
	USES
L0	caller
	RESTORES
L	from ULsave
G	from UGsave
PC	from UPCsave
rhMDS	from UrhMDSsave
rhPC	from UrhPCsave
rhG	from UrhGsave
rhL	from UrhLsave
	RETURNS THRU
RestoreCallers
RestoreBlockRegs entries are used by Block.mc in order to end up on the right cycle. 
Block.mc saves all registers but does not use them all.
}

RestoreRandRHRegs:
	rhPV ← nRhS	,c*{c1}, at[2,8, LSEPReturn];
RestoreRandRHRegspl1:
	rhPC ← UrhPCsave	,c*{c2};
		,c*{c3};

	rhS ← nRhS	,c*{c1};
	PC ← UPCsave	,c*{c2};
	S ← UGsave, L0Disp	,c*{c3};

	PV ← ULsave, RET[RestoreCallers]	,c*{c1};

{
	DstVAMod  SUBROUTINE
	first cycle = c3 , last cycle = c2
	Timing: 4 clicks, + 1 if neg, + 1 if rh fix
This subroutine is used to modify the destination virtual address.
	CALLING ARGUMENTS
rhWho	caller
TempBpl	increment for the destination address
UDstVALo	virtual destination page and word
UDstBit	virtual destination bit
rhDstVA	virtual destination rh
	always UPDATES
UDstVALo	virtual destination page and word
UDstBit	virtual destination bit
rhDstVA	virtual destination rh
	USES
Q	virtual page and word
TempB	bit
rhRet	to call VAModSub
	CALLS
VAModSub
	RETURNS THRU
DstVAModRtn
}

DstVAMod:	Noop	,c*{c1};
	Noop	,c*{c2};
	rhVD ← UrhVD	,c*{c3};

	Q ← UDstVALo	,c*{c1};
	TempB ← UDstBit	,c*{c2};
	rhRet ← VAaRet, CALL[VAMod]	,c*{c3};

	{VAMod subroutine here {2 or 3 clicks}	,c*{c1}-c*{c3};}

	{return here if rh needs fix}
	VD ← UrhVD	,c*{c1}, at[Or[VAaRet,1],8,VAModRet];
	VD ← VD + TempBpl	,c*{c2};
	UrhVD ← VD	,c*{c3};

	Noop	,c*{c1};
fixrhVD:	[] ← rhRet, XDisp	,c*{c2};
	rhVD ← VD LRot0, DISP3{RET}[VAModRet]	,c*{c3};

	{return here if no rh fix or after rh fix}
	UDstVALo ← Q	,c*{c1}, at[VAaRet,8,VAModRet];

DstVAExit:	[] ← rhWho, XDisp	,c*{c2};
	UDstBit ← TempB, DISP2{RET}[DstVAModRet]	,c*{c3};


{
	SrcVAMod  SUBROUTINE
	first cycle = c3 , last cycle = c2
	Timing: 4 clicks, + 1 if neg, + 1 if rh fix
This subroutine is used to modify the source virtual address.
	CALLING ARGUMENTS
rhWho	caller
TempBpl	increment for the source address
USrcVALo	virtual source page and word
USrcBit	virtual source bit
rhSrcVA	virtual source rh
	always UPDATES
USrcVALo	virtual source page and word
USrcBit	virtual source bit
rhSrcVA	virtual source rh
	USES
Q	virtual page and word
TempB	bit
rhRet	to call VAModSub and SrcRemap
	CALLS
VAModSub
	RETURNS THRU
SrcVAModRtn
}

SrcVAMod:	Noop	,c*{c1};
	Noop	,c*{c2};
	rhVS ← UrhVS	,c*{c3};

	Q ← USrcVALo	,c*{c1};
	TempB ← USrcBit	,c*{c2};
	rhRet ← VAbRet, CALL[VAMod]	,c*{c3};

	{VAMod subroutine here {2 or 3 clicks}	,c*{c1}-c*{c3};}

	{return here if rh needs fix}
	VS ← UrhVS	,c*{c1}, at[Or[VAbRet,1],8,VAModRet];
	VS ← VS + TempBpl	,c*{c2};
	UrhVS ← VS	,c*{c3};

	Noop	,c*{c1};
fixrhVS:	[] ← rhRet, XDisp	,c*{c2};
	rhVS ← VS LRot0, DISP3{RET}[VAModRet]	,c*{c3};

	{return here if no rh fix or after fix}
	USrcVALo ← Q	,c*{c1}, at[VAbRet,8,VAModRet];

SrcVAExit:	[] ← rhWho, XDisp	,c*{c2};
	USrcBit ← TempB, DISP2{RET}[SrcVAModRet]	,c*{c3};

{
	VAMod  SUBROUTINE
	first cycle = c3 , last cycle = c2
	Timing: 2 clicks, + 1 if neg
This subroutine is used to modify a virtual address.
	CALLING ARGUMENTS
rhRet	caller
Q	virtual page and word
TempBpl	increment for the address
TempB	bit
	always UPDATES
Q	virtual page and word
TempB	bit
	RETURNS
TempBpl	modifier for rh
}

VAMod:	TempB ← TempB + TempBpl, NibCarryBr, GOTO[VAmod1]	,c*{c1};

VAmod1:	TempBpl ← TempBpl and ~0F, NegBr, BRANCH[oldWord, nextWord]	,c*{c2};
oldWord:	TempBpl ← TempBpl LRot12, BRANCH[oldWPos, oldWNeg]	,c*{c3};
nextWord:	TempBpl ← TempBpl LRot12, BRANCH[nextWPos, nextWNeg]	,c*{c3};
oldWPos:	Q ← Q + TempBpl, CarryBr, GOTO[bPP]	,c*{c1};

bPP:	[] ← rhRet, XDisp, BRANCH[oldPSeg, newPSeg]	,c*{c2};

nextWPos:	Q ← Q + TempBpl + 1, CarryBr, GOTO[bPP]	,c*{c1};

oldWNeg:	TempBpl ← TempBpl LRot4	,c*{c1};

	TempBpl ← TempBpl or 0F	,c*{c2};
	TempBpl ← TempBpl LRot12	,c*{c3};
	Q ← Q + TempBpl, CarryBr	,c*{c1};

bPN:	[] ← rhRet, XDisp, BRANCH[newNSeg, oldNSeg]	,c*{c2};

nextWNeg:	TempBpl ← TempBpl LRot4	,c*{c1};

	TempBpl ← TempBpl or 0F	,c*{c2};
	TempBpl ← TempBpl LRot12	,c*{c3};
	Q ← Q + TempBpl + 1, CarryBr, GOTO[bPN]	,c*{c1};

oldPSeg:	TempBpl ← 0, DISP3{RET}[VAModRet]	,c*{c3};

newPSeg:	TempBpl ← 1, DISP3{RET}[VAModRet,1] {signal rh update}	,c*{c3};

oldNSeg:	TempBpl ← 0, DISP3{RET}[VAModRet]	,c*{c3};

newNSeg:	TempBpl ← {-1}TempBpl xor ~TempBpl, DISP3{RET}[VAModRet,1] {signal rh update}	,c*{c3};

{
	SrcLRemap  SUBROUTINE
	first cycle = c1 , last cycle = c3
This subroutine is used to remap the source virtual address.
	CALLING ARGUMENTS
rhRet	caller
USrcVALo	virtual source page
rhVS	virtual source rh
	always UPDATES
SrcA	real source page and word
rhSrcA	real source rh
	USES
UQSave	saved value of Q
UVSsave	saved contents of VS
uT	saved contents or rhVS
	RETURNS THRU
SrcRemapReturn
}

SrcLRemap:	UQSave ← Q	,c1;
	UXsave ← VS	,c2;
	VS ← USrcVALoSav, dirDisp	,c3;

	Q ← 0FF + 1, dirDISP[SrcInc]	,c1;
SLRFor:	VS ← VS + Q, CarryBr	,c2, at[dir.forward,dirM,SrcInc];
	Q ← rhVS + 1, LOOPHOLE[byteTiming], BRANCH[nofixSRhP,fixSRhP]	,c3;

fixSRhP:	rhVS ← Q LRot0	,c1;
fixRSh:	Noop	,c2;
	Noop	,c3;

nofixSRhP:	Map ← USrcVALoSav ← [rhVS, VS], GOTO[mpS1]	,c1;

SLRBack:	VS ← VS - Q, CarryBr	,c2, at[dir.backwards,dirM,SrcInc];
	Q ← rhVS - 1, LOOPHOLE[byteTiming], BRANCH[fixSRhN,nofixSRhN]	,c3;

fixSRhN:	rhVS ← Q LRot0, GOTO[fixRSh]	,c1;
nofixSRhN:	Map ← USrcVALoSav ← [rhVS, VS], GOTO[mpS1]	,c1;


mpS1:	Q ← SrcA and 0FF	,c2;
	SrcA ← MD, rhSrcA ← MD, ReadXRefBr	,c3;

	Noop, ReadBRANCH[fixSMap, nofixSMap]	,c1;
nofixSMap:	SrcA ← SrcA and ~0FF	,c2;
	SrcA ← SrcA or Q	,c3;

mfsR:	Q ← UQSave	,c1;
	[] ← rhRet, XDisp	,c2;
	VS ← UXsave, RET[SrcRemapReturn]	,c3;

fixSMap:	Noop	,c2;
	[] ← SrcA LRot0, XwdDisp	,c3;

	Map ← [rhVS, VS], DISP2[mapSFixes]	,c1;
mapSFixes:
	MDR ← SrcA or 80, GOTO[mfS1]	,c2, at[PgClean,4,mapSFixes];
	MDR ← SrcA or 80, GOTO[mfS1]	,c2, at[PgDirty,4,mapSFixes];
	MDR ← SrcA or 80, GOTO[mfS1]	,c2, at[PgProt,4,mapSFixes];
	GOTO[mfS1]	,c2, at[PgVacant,4,mapSFixes];
mfS1:	SrcA ← SrcA and ~0FF	,c3;

	SrcA ← SrcA or Q	,c1;
	Noop	,c2;
	GOTO[mfsR]	,c3;



{
	DstLRemap  SUBROUTINE
	first cycle = c1 , last cycle = c3
This subroutine is used to remap the source virtual address.
	CALLING ARGUMENTS
rhRet	caller
UDstVALo	virtual source page
rhVD	virtual source rh
	always UPDATES
DstA	real source page and word
rhDstA	real source rh
	USES
UQSave	saved value of Q
UVDsave	saved contents of VD
uT	saved contents or rhVD
	RETURNS THRU
DstRemapReturn
}

DstLRemap:	UQSave ← Q	,c1;
	UXsave ← VD	,c2;
	VD ← UDstVALoSav, dirDisp	,c3;

	Q ← 0FF + 1, dirDISP[DstInc]	,c1;
DLRFor:	VD ← VD + Q, CarryBr	,c2, at[dir.forward,dirM,DstInc];
	Q ← rhVD + 1, LOOPHOLE[byteTiming], BRANCH[nofixDRhP,fixDRhP]	,c3;

fixDRhP:	rhVD ← Q LRot0	,c1;
fixRDh:	Noop	,c2;
	Noop	,c3;

nofixDRhP:	Map ← UDstVALoSav ← [rhVD, VD], GOTO[mpD1]	,c1;

DLRBack:	VD ← VD - Q, CarryBr	,c2, at[dir.backwards,dirM,DstInc];
	Q ← rhVD - 1, LOOPHOLE[byteTiming], BRANCH[fixDRhN,nofixDRhN]	,c3;

fixDRhN:	rhVD ← Q LRot0, GOTO[fixRDh]	,c1;
nofixDRhN:	Map ← UDstVALoSav ← [rhVD, VD], GOTO[mpD1]	,c1;


mpD1:	Q ← DstA and 0FF	,c2;
	DstA ← MD, rhDstA ← MD, ReadXRefBr	,c3;

testDMap:
	Noop, ReadBRANCH[fixDMap, nofixDMap]	,c1;
nofixDMap:	DstA ← DstA and ~0FF	,c2;
	DstA ← DstA or Q	,c3;

mfdR:	Q ← UQSave	,c1;
	[] ← rhRet, XDisp	,c2;
	VD ← UXsave, RET[DstRemapReturn]	,c3;

fixDMap:	Noop	,c2;
	{[] ← DstA LRot0, XwdDisp}	,c3;

	Map ← [rhVD, VD], {DISP2[mapDFixes, 2]}	,c1;
mapDFixes:
	MDR ← DstA or 0C0, GOTO[mfD1]	,c2, ;
	{page fault cant happen.  Checked before entering loop}
mfD1:	Xbus ← 3, XDisp, GOTO[testDMap]	,c3;


{
	DstMap  SUBROUTINE
	first cycle = c3 , last cycle = c3
	Timing: 2 1/3 clicks, + 1 if fix map flags
This subroutine is used to map the destination virtual address.
	CALLING ARGUMENTS
rhRet	caller
UDstVALo	virtual destination
rhVD	virtual destination rh
	always UPDATES
DstA	real destination page and word
rhDstA	real destination rh
UDstVALoSav	virtual destination
	uses as a temp
Q	real destination page and word
	RETURNS THRU
DstMapRet
}

DstMap:	VD ← UDstVALoSav	,c3;

DstMapSpec:	Map ← [rhVD, VD]	,c1;
	UDstVALoSav ← VD	,c2;
	DstA ← MD, rhDstA ← MD, XwdDisp{XDirtyDisp}	,c3;

DMapRef:	MAR ← Q ← [rhDstA, VD + 0], DISP2[upDMap]	,c1;
	Xbus ← rhRet, XDisp	,c2, at[PgDirty, 4, upDMap];
	DstA ← Q, DISP2{RET}[DstMapRet]	,c3;

	Noop	,c2, at[PgClean, 4, upDMap];
	{[] ← DstA LRot0,{ XwdDisp}}	,c3;

	Map ← [rhVD, VD], {DISP2[upDMapHere]}	,c1;
	MDR ← DstA or 0C0,	c2;
	Xbus ← PgDirty, XDisp, GOTO[DMapRef]	,c3;

	{Q ← qWriteProtect, }GOTO[DFault]	,c2, at[PgProt,4,upDMap];
	{Q ← qPageFault, }GOTO[DFault]	,c2, at[PgVacant,4,upDMap];


{
	SrcMap  SUBROUTINE
	first cycle = c3 , last cycle = c3
	Timing: 2 1/3 clicks, + 1 if fix map flags
This subroutine is used to map the source virtual address.
	CALLING ARGUMENTS
rhRet	caller
USrcVALo	virtual source
rhVS	virtual source rh
	always UPDATES
SrcA	real source page and word
rhSrcA	real source rh
USrcVALoSav	virtual destination
	uses as a temp
Q	real destination page and word
	RETURNS THRU
SrcMapRet
}

SrcMap:	VS ← USrcVALoSav	,c3;

SrcMapSpec:	Map ← [rhVS, VS]	,c1;
	USrcVALoSav ← VS	,c2;
	SrcA ← MD, rhSrcA ← MD, ReadXRefBr	,c3;

SMapRef:	MAR ← Q ← [rhSrcA, VS + 0], ReadBRANCH[upSMap, SMapOK]	,c1;
SMapOK:	Xbus ← rhRet, XDisp	,c2;
	SrcA ← Q, DISP3{RET}[SrcMapRet]	,c3;

upSMap:	Noop	,c2;
	Xbus ← SrcA LRot0, XwdDisp	,c3;

	Map ← [rhVS, VS], DISP2[upSMapHere]	,c1;
upSMapHere:	MDR ← SrcA or 80, GOTO[mapS]	,c2, at[PgClean,4,upSMapHere];
	MDR ← SrcA or 80, GOTO[mapS]	,c2, at[PgDirty,4,upSMapHere];
	MDR ← SrcA or 80, GOTO[mapS]	,c2, at[PgProt,4,upSMapHere];
	GOTO[SFault]	,c2, at[PgVacant,4,upSMapHere];

mapS:	Xbus ← 3, XDisp, GOTO[SMapRef]	,c3;

{
	SavebbRegs  SUBROUTINE
	length = 2 2/3 clicks
This subroutine is used to move the rh registers in U.
Note that the caller MUST save L before calling.
	MOVES
TOS	STK
G	to UGsave
rhG	UrhGsave
PC	to UPCsave
rhPC	UrhPCsave
L	UrhLsave
rhL	UrhLsave
rhMDS	UrhMDSsave
	EXITS TO SavebbRegsRet
}

SavebbRegs:	
	PC ← PC - 1	,c*{c2}, at[0,10,SavebbRegs];
	UPCsave ← PC	,c*{c3};

	UGsave ← S	,c*{c1};
	PC ← rhPC, L2Disp,	,c*{c2};
	UrhPCsave ← PC, RET[SavebbRegsRet],	,c*{c3};

	{END}