-- CgenUtil.mesa,
-- last modified by Sweet, May 24, 1980 11:35 AM
-- last modified by Satterthwaite, January 10, 1983 10:10 am
DIRECTORY
Alloc: TYPE USING [FreeChunk, GetChunk, Handle, Notifier, Words],
Code: TYPE USING [
bodyFileIndex, codeptr, fileindex, xtracting, xtractsei, ZEROlexeme],
CodeDefs: TYPE USING [
Base, Byte, CCIndex, CCItem, CCNull, ChunkIndex, CodeCCIndex, CodeChunkType,
codeType, JumpCCIndex, JumpCCNull, JumpType, LabelCCIndex, LabelCCNull,
Lexeme, NULLfileindex, OpWordCount, RelFileIndex],
ComData: TYPE USING [typeSTRING, zone],
FOpCodes: TYPE USING [qJ, qJREL, qLI],
LiteralOps: TYPE USING [Find, FindDescriptor, Value],
OpTableDefs: TYPE USING [InstLength],
P5: TYPE USING [NumberOfParams, P5Error, PushEffect],
P5U: TYPE USING [],
PackageSymbols: TYPE USING [ConstRecord, constType, WordIndex],
PrincOps: TYPE USING [FrameVec],
Runtime: TYPE USING [CallDebugger],
Stack: TYPE USING [Check],
SymbolOps: TYPE USING [
FirstCtxSe, NextSe, NormalType, RecordRoot, TypeRoot, UnderType, WordsForType],
Symbols: TYPE USING [
Base, BitAddress, CSEIndex, CTXIndex, ISEIndex, ISENull, RecordSEIndex,
SEIndex, SENull, seType, typeANY, typeTYPE, WordLength],
Table: TYPE USING [Base, Limit],
Tree: TYPE USING [Base, Index, Link, Null, NullIndex, treeType],
TreeOps: TYPE USING [PopTree, PushNode, PushTree, ScanList, SetInfo];
CgenUtil: PROGRAM
IMPORTS Alloc, MPtr: ComData, CPtr: Code, LiteralOps, OpTableDefs,
P5, Runtime, Stack, SymbolOps, TreeOps
EXPORTS P5U =
BEGIN
OPEN SymbolOps, CodeDefs;
-- imported definitions
BitAddress: TYPE = Symbols.BitAddress;
CSEIndex: TYPE = Symbols.CSEIndex;
ISEIndex: TYPE = Symbols.ISEIndex;
ISENull: ISEIndex = Symbols.ISENull;
RecordSEIndex: TYPE = Symbols.RecordSEIndex;
SEIndex: TYPE = Symbols.SEIndex;
SENull: SEIndex = Symbols.SENull;
WordLength: CARDINAL = Symbols.WordLength;
table: Alloc.Handle ← NIL;
tb: Tree.Base; -- tree base (local copy)
seb: Symbols.Base; -- semantic entry base (local copy)
cb: CodeDefs.Base; -- code base (local copy)
cstb: Table.Base; -- constant table base (local copy)
CgenUtilNotify: PUBLIC Alloc.Notifier =
BEGIN -- called by allocator whenever table area is repacked
seb ← base[Symbols.seType];
tb ← base[Tree.treeType];
cb ← base[codeType];
cstb ← base[PackageSymbols.constType];
END;
AllocCodeCCItem: PUBLIC PROC [n: [0..3]] RETURNS [c: CodeCCIndex] =
BEGIN
c ← GetChunk[CCItem.code.SIZE + n];
cb[c] ← CCItem[free: FALSE, flink: CCNull, blink: CCNull, ccvalue:
code[inst: 0, realinst: FALSE, isize: 0, fill: 0, parameters: ]];
LinkCCItem[c];
RETURN
END;
BitsForOperand: PUBLIC PROC [t: Tree.Link] RETURNS [CARDINAL] =
BEGIN
RETURN [WITH t SELECT FROM
literal => WordLength, -- not always TRUE, but good enough
ENDCASE => BitsForType[OperandType[t]]]
END;
BitsForType: PUBLIC PROC [sei: SEIndex] RETURNS [CARDINAL] =
BEGIN
csei: CSEIndex = UnderType[sei];
RETURN [WITH seb[csei] SELECT FROM
record => length,
ENDCASE => CARDINAL[WordsForType[csei]]*WordLength]
END;
CCellAlloc: PUBLIC PROC [t: CodeChunkType] =
BEGIN -- allocates a cell for other than code or label
c: CCIndex;
nwords: CARDINAL;
SELECT t FROM
code => P5.P5Error[262];
label => P5.P5Error[263];
jump => nwords ← CCItem.jump.SIZE;
other => nwords ← CCItem.other.SIZE; -- NB: not relSource OR absSource
ENDCASE;
c ← GetChunk[nwords];
SELECT t FROM
jump => cb[c] ← CCItem[free: FALSE, flink: , blink: , ccvalue: jump[,,,,,,,]];
other => cb[c] ← CCItem[free: FALSE, flink: , blink: , ccvalue: other[obody: ]];
ENDCASE;
LinkCCItem[c];
END;
CgenUtilInit: PUBLIC PROC [ownTable: Alloc.Handle] =
BEGIN
table ← ownTable;
CPtr.ZEROlexeme ← Lexeme[literal[word[LiteralOps.Find[0].lti]]];
CPtr.fileindex ← 0;
END;
ComputeFrameSize: PUBLIC PROC [fs: CARDINAL] RETURNS [CARDINAL] =
BEGIN -- finds alloc-vector index for frame of size fs
OPEN PrincOps;
FOR fx: CARDINAL IN [0..FrameVec.LENGTH) DO
IF fs <= FrameVec[fx] THEN RETURN [fx] ENDLOOP;
ERROR
END;
CreateLabel: PUBLIC PROC RETURNS [c: LabelCCIndex] =
BEGIN -- allocates and inserts a label at codeptr
c ← LabelAlloc[];
InsertLabel[c];
END;
DeleteCell: PUBLIC PROC [c: CCIndex] =
BEGIN -- deletes cell from code stream
nwords: CARDINAL;
IF cb[c].blink # CCNull THEN cb[cb[c].blink].flink ← cb[c].flink;
IF cb[c].flink # CCNull THEN cb[cb[c].flink].blink ← cb[c].blink;
nwords ← WITH cc: cb[c] SELECT FROM
code => ParamCount[LOOPHOLE[c]] + CCItem.code.SIZE,
label => CCItem.label.SIZE,
jump => CCItem.jump.SIZE,
other => WITH cc SELECT FROM
absSource => CCItem.other.absSource.SIZE,
relSource => CCItem.other.relSource.SIZE,
ENDCASE => CCItem.other.SIZE, -- NB: see CCellAllocate
ENDCASE => ERROR;
FreeChunk[c, nwords];
END;
EnumerateCaseArms: PUBLIC PROC [node: Tree.Index, action: PROC [t: Tree.Link]] =
BEGIN
ProcessItem: PROC [t: Tree.Link] =
BEGIN
inode: Tree.Index;
WITH t SELECT FROM
subtree => inode ← index;
ENDCASE;
SELECT tb[inode].name FROM
item, casetest => action[tb[inode].son[2]];
caseswitch => TreeOps.ScanList[tb[inode].son[3], ProcessItem];
ENDCASE;
END;
TreeOps.ScanList[tb[node].son[2], ProcessItem];
IF tb[node].son[3] # Tree.Null THEN action[tb[node].son[3]];
END;
FreeChunk: PUBLIC PROC [i: CodeDefs.ChunkIndex, size: CARDINAL] =
BEGIN
FOR p: LONG POINTER TO MonitorRecord ← monList, p.next WHILE p # NIL DO
IF p.cell = i AND p.action = free THEN Runtime.CallDebugger["From FreeChunk"L];
ENDLOOP;
table.FreeChunk[LOOPHOLE[i], size, codeType];
END;
FullWordBits: PUBLIC PROC [bits: CARDINAL] RETURNS [CARDINAL] =
BEGIN
RETURN [((bits+WordLength-1)/WordLength) * WordLength]
END;
GetChunk: PUBLIC PROC [size: CARDINAL] RETURNS [c: CodeDefs.ChunkIndex] =
BEGIN
c ← LOOPHOLE[table.GetChunk[size, codeType]];
FOR p: LONG POINTER TO MonitorRecord ← monList, p.next WHILE p # NIL DO
IF p.cell = c AND p.action = allocate THEN Runtime.CallDebugger["From GetChunk"L];
ENDLOOP;
RETURN [c]
END;
InsertLabel: PUBLIC PROC [c: LabelCCIndex] = LinkCCItem;
LabelAlloc: PUBLIC PROC RETURNS [c: LabelCCIndex] =
BEGIN -- gets a chunk for a label but does not insert it in stream
c ← GetChunk[CCItem.label.SIZE];
cb[c] ← CCItem[free: FALSE, flink: , blink: , ccvalue:
label[labelseen: FALSE, labelinfo: generating[filltoword: , jumplist: JumpCCNull]]];
RETURN
END;
LinkCCItem: PROC[c: CCIndex] =
BEGIN -- inserts a CCItem in list @ codeptr
IF CPtr.codeptr # CCNull THEN
BEGIN
cb[c].flink ← cb[CPtr.codeptr].flink;
IF cb[CPtr.codeptr].flink # CCNull THEN cb[cb[CPtr.codeptr].flink].blink ← c;
cb[CPtr.codeptr].flink ← c;
END
ELSE cb[c].flink ← CCNull;
cb[c].blink ← CPtr.codeptr;
CPtr.codeptr ← c;
END;
LongTreeAddress: PUBLIC PROC [t: Tree.Link] RETURNS [long: BOOL ← FALSE] =
BEGIN
node: Tree.Index;
WITH t SELECT FROM
subtree =>
BEGIN node ← index;
IF node # Tree.NullIndex THEN
SELECT tb[node].name FROM
loophole, cast, openx, pad, chop =>
long ← LongTreeAddress[tb[node].son[1]];
dot, uparrow, dindex, seqindex, dollar, index, new, reloc =>
long ← tb[node].attr2;
assignx => WITH tb[node].son[2] SELECT FROM
subtree => IF tb[index].name = mwconst THEN
long ← LongTreeAddress[tb[node].son[1]]
ELSE long ← LongTreeAddress[tb[node].son[2]];
ENDCASE => long ← LongTreeAddress[tb[node].son[2]];
ifx => long ← LongTreeAddress[tb[node].son[2]] OR
LongTreeAddress[tb[node].son[3]];
casex =>
BEGIN
LongArm: PROC [t: Tree.Link] = {long ← long OR LongTreeAddress[t]};
EnumerateCaseArms[node, LongArm];
END;
ENDCASE => NULL;
END;
ENDCASE => NULL;
RETURN
END;
MakeLongTreeLiteral: PUBLIC PROC [d: DESCRIPTOR FOR ARRAY OF WORD, type: CSEIndex]
RETURNS [Tree.Link] =
BEGIN
TreeOps.PushTree[[literal[LiteralOps.FindDescriptor[d]]]];
TreeOps.PushNode[mwconst, 1]; TreeOps.SetInfo[type];
RETURN [TreeOps.PopTree[]]
END;
MakeTreeLiteral: PUBLIC PROC [val: WORD] RETURNS [Tree.Link] =
BEGIN
RETURN [[literal[LiteralOps.Find[val]]]]
END;
MarkedType: PUBLIC PROC [type: SEIndex] RETURNS [CSEIndex] =
BEGIN
subType: CSEIndex = NormalType[UnderType[type]];
RETURN [WITH t: seb[subType] SELECT FROM
ref => UnderType[TypeRoot[t.refType]],
transfer => subType,
ENDCASE => Symbols.typeANY]
END;
MonitorAction: TYPE = {allocate, free};
MonitorRecord: TYPE = RECORD [
next: LONG POINTER TO MonitorRecord, cell: CCIndex, action: MonitorAction];
monList: LONG POINTER TO MonitorRecord ← NIL;
Monitor: PROC [cell: CCIndex, action: MonitorAction] =
BEGIN
p: LONG POINTER TO MonitorRecord = (MPtr.zone).NEW[MonitorRecord];
p↑ ← [monList, cell, action];
monList ← p;
END;
NextVar: PUBLIC PROC [sei: ISEIndex] RETURNS [ISEIndex] =
BEGIN -- starting at sei returns first variable on ctx-list
RETURN [SELECT TRUE FROM
(sei = ISENull) => ISENull,
(seb[sei].idType # Symbols.typeTYPE) => sei,
ENDCASE => NextVar[NextSe[sei]]]
END;
OperandType: PUBLIC PROC [t: Tree.Link] RETURNS [sei: CSEIndex] =
BEGIN -- compute type of tree
RETURN [WITH e:t SELECT FROM
symbol => UnderType[seb[e.index].idType],
literal => IF e.index.litTag = string THEN MPtr.typeSTRING ELSE ERROR,
subtree =>
IF e = Tree.Null THEN
IF CPtr.xtracting THEN UnderType[seb[CPtr.xtractsei].idType] ELSE ERROR
ELSE tb[e.index].info,
ENDCASE => ERROR]
END;
Out0: PUBLIC PROC [i: Byte] =
BEGIN -- outputs an parameter-less instruction
c: CodeCCIndex;
pushEffect: CARDINAL = P5.PushEffect[i];
Stack.Check[i];
IF P5.NumberOfParams[i] # 0 THEN P5.P5Error[257];
c ← AllocCodeCCItem[0];
cb[c].inst ← i;
END;
Out1: PUBLIC PROC [i: Byte, p1: WORD] =
BEGIN -- outputs an one-parameter instruction
c: CodeCCIndex;
pushEffect: CARDINAL = P5.PushEffect[i];
Stack.Check[i];
IF P5.NumberOfParams[i] # 1 THEN P5.P5Error[258];
c ← AllocCodeCCItem[1];
cb[c].inst ← i;
cb[c].parameters[1] ← p1;
END;
Out2: PUBLIC PROC [i: Byte, p1, p2: WORD] =
BEGIN -- outputs an two-parameter instruction
c: CodeCCIndex;
pushEffect: CARDINAL = P5.PushEffect[i];
Stack.Check[i];
IF P5.NumberOfParams[i] # 2 THEN P5.P5Error[259];
c ← AllocCodeCCItem[2];
cb[c].inst ← i;
cb[c].parameters[1] ← p1;
cb[c].parameters[2] ← p2;
END;
Out3: PUBLIC PROC [i: Byte, p1, p2, p3: WORD] =
BEGIN -- outputs an three-parameter instruction
c: CodeCCIndex;
pushEffect: CARDINAL = P5.PushEffect[i];
Stack.Check[i];
IF P5.NumberOfParams[i] # 3 THEN P5.P5Error[260];
c ← AllocCodeCCItem[3];
cb[c].inst ← i;
cb[c].parameters[1] ← p1;
cb[c].parameters[2] ← p2;
cb[c].parameters[3] ← p3;
END;
OutJump: PUBLIC PROC [jt: JumpType, l: LabelCCIndex] =
BEGIN -- outputs a jump-type code ceel into the code stream
Stack.Check[SELECT jt FROM
Jump, JumpA, JumpC, JumpCA, JumpRet => FOpCodes.qJ,
ENDCASE => FOpCodes.qJREL];
CCellAlloc[jump];
WITH cb[CPtr.codeptr] SELECT FROM
jump =>
BEGIN
fixedup ← FALSE;
completed ← FALSE;
jtype ← jt;
destlabel ← l;
IF l # LabelCCNull THEN
BEGIN
thread ← cb[l].jumplist;
cb[l].jumplist ← LOOPHOLE[CPtr.codeptr, JumpCCIndex];
END
ELSE thread ← JumpCCNull;
END;
ENDCASE
END;
OutSource: PUBLIC PROC [index: CARDINAL] =
BEGIN
c: CCIndex;
relIndex: CARDINAL;
IF index # NULLfileindex AND index >= CPtr.bodyFileIndex
AND (relIndex ← index-CPtr.bodyFileIndex) IN RelFileIndex THEN
BEGIN
c ← GetChunk[CCItem.other.relSource.SIZE];
cb[c] ← [free: FALSE, flink: , blink: ,
ccvalue: other[relSource[relIndex: relIndex]]];
END
ELSE
BEGIN
c ← GetChunk[CCItem.other.absSource.SIZE];
cb[c] ← [free: FALSE, flink: , blink: ,
ccvalue: other[absSource[index: index]]];
END;
LinkCCItem[c];
END;
ParamCount: PUBLIC PROC [c: CodeCCIndex] RETURNS [CARDINAL] =
BEGIN
RETURN [SELECT TRUE FROM
(cb[c].isize # 0) => cb[c].isize-1,
cb[c].realinst => OpTableDefs.InstLength[cb[c].inst]-1,
ENDCASE => P5.NumberOfParams[cb[c].inst]]
END;
PrevVar: PUBLIC PROC [ssei, sei : ISEIndex] RETURNS [ISEIndex] =
BEGIN -- returns vars in reverse order as those returned by NextVar
psei: ISEIndex ← NextVar[ssei];
rsei: ISEIndex;
IF psei = sei THEN RETURN [psei];
UNTIL psei = sei DO rsei ← psei; psei ← NextVar[NextSe[psei]] ENDLOOP;
RETURN [rsei];
END;
PushLitVal: PUBLIC PROC [v: UNSPECIFIED] =
BEGIN -- forces a constant onto the stack
Out1[FOpCodes.qLI, v];
END;
RecordConstant: PUBLIC PROC [offset: PackageSymbols.WordIndex, length: CARDINAL] =
BEGIN OPEN PackageSymbols;
csti: Table.Base RELATIVE POINTER [0..Table.Limit) TO ConstRecord =
table.Words[constType, ConstRecord.SIZE];
cstb[csti] ← [offset: offset, length: length];
END;
ReferentType: PUBLIC PROC [type: SEIndex] RETURNS [SEIndex] =
BEGIN
subType: CSEIndex = NormalType[UnderType[type]];
RETURN [WITH t: seb[subType] SELECT FROM
ref => t.refType,
ENDCASE => Symbols.typeANY]
END;
TreeLiteral: PUBLIC PROC [t: Tree.Link] RETURNS [BOOL] =
BEGIN
RETURN [WITH t SELECT FROM
literal => index.litTag = word,
subtree =>
SELECT tb[index].name FROM
cast => TreeLiteral[tb[index].son[1]],
mwconst => TRUE,
ENDCASE => FALSE,
ENDCASE => FALSE]
END;
TreeLiteralValue: PUBLIC PROC [t: Tree.Link] RETURNS [WORD] =
BEGIN
RETURN [WITH e:t SELECT FROM
literal =>
WITH e.index SELECT FROM
word => LiteralOps.Value[lti],
ENDCASE => ERROR,
subtree =>
SELECT tb[e.index].name FROM
cast, mwconst => TreeLiteralValue[tb[e.index].son[1]],
ENDCASE => ERROR,
ENDCASE => ERROR]
END;
TypeForTree: PUBLIC PROC [t: Tree.Link] RETURNS [SEIndex] =
BEGIN
RETURN [WITH t SELECT FROM
subtree => tb[index].info,
symbol => index,
ENDCASE => ERROR]
END;
UnMonitor: PROC [cell: CCIndex, action: MonitorAction] =
BEGIN
p, q: LONG POINTER TO MonitorRecord;
IF monList = NIL THEN RETURN;
IF monList.cell = cell AND monList.action = action THEN
{p ← monList.next; (MPtr.zone).FREE[@monList]; monList ← p};
FOR p ← monList, p.next UNTIL p.next = NIL DO
IF p.next.cell = cell AND p.next.action = action THEN
BEGIN
q ← p.next.next; (MPtr.zone).FREE[@p.next]; p.next ← q;
RETURN
END;
ENDLOOP;
END;
VariantTag: PUBLIC PROC [type: SEIndex, ctx: Symbols.CTXIndex] RETURNS [WORD] =
BEGIN
next: SEIndex;
FOR sei: SEIndex ← type, next UNTIL sei = SENull DO
WITH se: seb[sei] SELECT FROM
id =>
BEGIN
IF se.idCtx = ctx THEN RETURN [se.idValue];
next ← se.idInfo;
END;
ENDCASE => EXIT;
ENDLOOP;
ERROR
END;
WordAligned: PUBLIC PROC [tsei: RecordSEIndex] RETURNS [BOOL] =
BEGIN -- sees if a word-aligned record (never TRUE for a variant record)
-- always true for an argument record
sei: ISEIndex;
wa: INTEGER ← 0;
a: BitAddress;
tsei ← RecordRoot[tsei];
IF seb[tsei].hints.variant THEN RETURN [FALSE];
IF seb[tsei].argument THEN RETURN [TRUE];
sei ← NextVar[FirstCtxSe[seb[tsei].fieldCtx]];
UNTIL sei = ISENull DO
a ← seb[sei].idValue;
IF a.bd # 0 THEN RETURN [FALSE];
IF a.wd < wa THEN RETURN [FALSE];
wa ← a.wd;
sei ← NextVar[NextSe[sei]];
ENDLOOP;
RETURN [TRUE]
END;
WordsForOperand: PUBLIC PROC [t: Tree.Link] RETURNS [OpWordCount] =
BEGIN -- compute number of words for storing value of tree
RETURN [WITH t SELECT FROM
literal => 1, -- multiwords will be subtrees
symbol => WordsForSei[seb[index].idType],
ENDCASE => OpWordCount[WordsForType[OperandType[t]]]]
END;
WordsForSei: PUBLIC PROC [sei: SEIndex] RETURNS [OpWordCount] =
BEGIN
RETURN [IF sei # SENull THEN OpWordCount[WordsForType[UnderType[sei]]] ELSE 0]
END;
WordsForString: PUBLIC PROC [nChars: CARDINAL] RETURNS [CARDINAL] =
BEGIN -- computed for the object machine
RETURN [(nChars+1)/2 + 2]
END;
END.