[_CD6_]<dragon>ifu>IFUPLA>IFUPLAFetchPreDecodeImpl.mesa!10

IFUPLAFetchPreDecodeImpl.mesa

Last edited by Curry, September 11, 1986 0:18:56 am PDT

McCreight, March 20, 1986 7:03:39 pm PST

DIRECTORY

Basics,

Commander,

DragOpsCross,

IFUPLAFetchPreDecode,

IO,

PLAOps;

IFUPLAFetchPreDecodeImpl: CEDAR PROGRAM

IMPORTS Basics, Commander, IO, PLAOps =

BEGIN OPEN IFUPLAFetchPreDecode, PO: PLAOps;

FetchPreDecodePLA: PLAOps.PLA;

FetchPreDecodeProc: PROC[args: FetchPreDecodeIn] RETURNS[result: FetchPreDecodeOut];

GenFetchPreDecodePLA: PUBLIC PROC = {

op0: PO.BoolExpr ← BE[m:[op: 4], d:[op: 4]];

op1: PO.BoolExpr ← BE[m:[op: 2], d:[op: 2]];

op2: PO.BoolExpr ← BE[m:[op: 1], d:[op: 1]];

oneByter: PO.BoolExpr ← PO.Or[

PO.And[ PO.Not[op0], PO.Not[op1], PO.Not[op2] ],

PO.And[ PO.Not[op0], op1 ]

];

twoByter: PO.BoolExpr ← PO.And[ op0, PO.Not[op1] ];

threeByter: PO.BoolExpr ← PO.And[ op0, op1 ];

fiveByter: PO.BoolExpr ← PO.And[ PO.Not[op0], PO.Not[op1], op2 ];

bytesAvail0: PO.BoolExpr ← BE[m:[fetchBytesM1: 16], d:[fetchBytesM1: 16 ]];

bytesAvail1: PO.BoolExpr ← BE[m:[fetchBytesM1: 31], d:[fetchBytesM1: 0 ]];

bytesAvail2: PO.BoolExpr ← BE[m:[fetchBytesM1: 31], d:[fetchBytesM1: 1 ]];

bytesAvail3: PO.BoolExpr ← BE[m:[fetchBytesM1: 31], d:[fetchBytesM1: 2 ]];

bytesAvail4: PO.BoolExpr ← BE[m:[fetchBytesM1: 31], d:[fetchBytesM1: 3 ]];

notReady: PO.BoolExpr ← PO.Or[

bytesAvail0,

PO.And[ bytesAvail1, PO.Or[ twoByter, threeByter, fiveByter ] ],

PO.And[ bytesAvail2, PO.Or[ threeByter, fiveByter ] ],

PO.And[ PO.Or[ bytesAvail3, bytesAvail4 ], fiveByter ]

];

Set[out:[notInstReady: TRUE], s: notReady];

Set[out:[instFault0:TRUE], s:PO.And[notReady, BE[m:[iPFaulting:TRUE], d:[iPFaulting:TRUE]]]];

Set[out:[opLength: 5, opLengthb: 5], s: fiveByter ];

Set[out:[opLength: 1, opLengthb: 1], s: oneByter ];

Set[out:[opLength: 2, opLengthb: 2], s: twoByter ];

Set[out:[opLength: 3, opLengthb: 3], s: threeByter ];

Now select the offset to be used in the jump target address adder.

Set[out:[jumpOffset: alpha],

s: BE[m:[op: 7], d:[op: 4]]];

CheckInstRange[0, dJB, 7, 4];

Set[out:[jumpOffset: beta],

s: BE[m:[op: 7], d:[op: 7]]];

FOR inst: DragOpsCross.Inst IN [dRJEB..dRJLEBJ] DO

CheckInstRange[1, inst, 7, 7];

ENDLOOP;

FOR inst: DragOpsCross.Inst IN [dJEBB..dJNEBBJ] DO

CheckInstRange[1, inst, 7, 7];

ENDLOOP;

Set[out:[jumpOffset: alphaBeta],

s: BE[m:[op: 7], d:[op: 6]]];

CheckInstRange[2, dJDB, 7, 6];

CheckInstRange[2, dLFC, 7, 6];

Set[out:[jumpOffset: xa],

s: BE[m:[op: 7], d:[op: 2]]];

CheckInstRange[3, dJSR, 7, 2];

};

reservations: ARRAY [0..25) OF RECORD [ mask, val: WORD ];

CheckInstRange: PROC [group: [0..25), inst: DragOpsCross.Inst, mask, val: WORD] = {

Matches: PROC [g: [0..25)] RETURNS [BOOL] = {

diffs: WORD = Basics.BITXOR[val, reservations[g].val];

RETURN [Basics.BITAND[reservations[g].mask, diffs] = 0] };

reservations[group] ← [mask: mask, val: val];

FOR g: [0..25) DECREASING IN [0..group) DO IF Matches[g] THEN ERROR ENDLOOP;

IF NOT Matches[group] THEN ERROR;

IF Basics.BITAND[mask, Basics.BITXOR[val, Basics.BITSHIFT[LOOPHOLE[inst], -5] ] ] # 0

THEN ERROR};

BE: PROC [m, d: FetchPreDecodeIn] RETURNS[PO.BoolExpr] = {

mRef: REF FetchPreDecodeIn ← NARROW[FetchPreDecodePLA.mask];

dRef: REF FetchPreDecodeIn ← NARROW[FetchPreDecodePLA.data];

mRef^ ← m; dRef^ ← d; RETURN[PO.GetBEForDataMask[FetchPreDecodePLA]]};

Set: PROC [s: PO.BoolExpr ← NIL, m, d: FetchPreDecodeIn ← [ ], out: FetchPreDecodeOut] = {

res: REF FetchPreDecodeOut ← NARROW[FetchPreDecodePLA.out];

IF s=NIL

THEN s ← BE[m,d]

ELSE s ← PO.And[s, BE[m,d] ];

res^ ← out; PO.SetOutForBE[FetchPreDecodePLA, s]};

GenFetchPreDecode: Commander.CommandProc = {

filename: IO.ROPE ← PO.DefaultCMDLine[cmd.commandLine, defaultFile];

FetchPreDecodePLA ← PO.NewPLA["IFUPLAFetchPreDecode.FetchPreDecodeIn", "IFUPLAFetchPreDecode.FetchPreDecodeOut"];

GenFetchPreDecodePLA[];

[ ] ← PO.ConvertTermListToCompleteSum[FetchPreDecodePLA.termList, FALSE, FALSE, cmd.out];

[ ] ← PO.FindAMinimalCover[FetchPreDecodePLA.termList, 120, cmd.out];

PO.WritePLAFile[filename, cmd.out, FetchPreDecodePLA] };

defaultFile: IO.ROPE = "IFUPLAFetchPreDecode.ttt";

doc: IO.ROPE = "Expects the name of a ttt file";

Commander.Register[key:"GenFetchPreDecode", proc: GenFetchPreDecode, doc: doc];

END.