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yap-6.3/C/index.c

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This commit was generated by cvs2svn to compensate for changes in r4, which included commits to RCS files with non-trunk default branches. git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@5 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
2001-04-09 20:54:03 +01:00
/*************************************************************************
* *
* Yap Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: index.c *
* Last rev: 5/2/88 *
* mods: *
* comments: Indexing a Prolog predicate *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif
/*
* This file compiles and removes the indexation code for the prolog compiler
*
* Some remarks: *try_me always point to inside the code;
* try always points to outside
*
*/
#include "Yap.h"
#include "compile.h"
#include "clause.h"
#include "index.h"
#ifdef YAPOR
#include "or.macros.h"
#endif /* YAPOR */
#ifdef DEBUG
#include "yapio.h"
#endif
#ifndef NULL
#define NULL (void *)0
#endif
int IPredArity;
STATIC_PROTO(int clause_has_cut, (yamop *));
STATIC_PROTO(int followed_by_cut, (yamop *));
STATIC_PROTO(void emit_tr, (compiler_vm_op, yamop *, int, int));
STATIC_PROTO(void emit_try, (compiler_vm_op, int, yamop *, int, int));
STATIC_PROTO(yamop * Body, (yamop *));
STATIC_PROTO(yamop * SecB, (yamop *));
STATIC_PROTO(yamop * SecLB, (yamop *));
STATIC_PROTO(yamop * ThiB, (yamop *));
STATIC_PROTO(yamop * ThiLB, (yamop *));
STATIC_PROTO(void emit_cp_inst, (compiler_vm_op, yamop *, int, int));
STATIC_PROTO(CELL emit_space, (compiler_vm_op, int, int));
STATIC_PROTO(CELL emit_go, (int, Term));
STATIC_PROTO(void emit_if_not, (Term, CELL, CELL));
STATIC_PROTO(void fill_go, (CELL *, CELL));
STATIC_PROTO(void fill_switch_slots, (CELL *, CELL, CELL, CELL, CELL, int));
STATIC_PROTO(void ClrSpace, (CELL *, int));
STATIC_PROTO(int NGroupsIn, (PredEntry *));
STATIC_PROTO(void CountGroups, (GroupDef *, int));
STATIC_PROTO(yamop *FindFirst, (int, int));
STATIC_PROTO(int SizeTable, (int));
STATIC_PROTO(void BuildHash, (CELL *, int, int, int));
STATIC_PROTO(void BuildIfTable, (CELL *, int));
STATIC_PROTO(void TreatEntry, (EntryDef *, int, int, GroupDef *));
STATIC_PROTO(CELL DealFixed, (ClauseDef *, int, compiler_vm_op, int, GroupDef *));
STATIC_PROTO(CELL DealFixedWithBips, (ClauseDef *, int, int, GroupDef *));
STATIC_PROTO(CELL DealCons, (int));
STATIC_PROTO(CELL DealAppl, (int));
STATIC_PROTO(CELL StartList, (int));
STATIC_PROTO(CELL DealLAt, (ClauseDef *, int, int));
STATIC_PROTO(CELL DealLAppl, (ClauseDef *, int, int));
STATIC_PROTO(CELL DealLList, (ClauseDef *, int, int, int));
STATIC_PROTO(int NoHeadVar, (ClauseDef *, int));
STATIC_PROTO(CELL DealList, (int));
STATIC_PROTO(CELL GetFailToGo, (int));
STATIC_PROTO(int IsExtendedSingle, (int));
STATIC_PROTO(int gr_has_cuts, (GroupDef *));
STATIC_PROTO(void EmitGrSwitch, (int));
STATIC_PROTO(int IndexNonVarGr, (int));
STATIC_PROTO(void IndexVarGr, (int));
STATIC_PROTO(int SimpleCase, (void));
STATIC_PROTO(int ComplexCase, (void));
STATIC_PROTO(int SpecialCases, (void));
static int NClauses, NGroups;
static ClauseDef *ArOfCl;
static GroupDef *Groups;
static EntryDef *Entries;
static CELL labelno;
static int ExtendedSingle, AtomsOnlyNil;
static yamop *FailAddress;
static CELL *StorePoint;
static yamop * FirstCl;
static int RemovedCl; /* There were some clauses removed */
static yamop * indexed_code_for_cut = NIL;
static CELL log_update;
static inline int
clause_has_cut(yamop * C)
{
#ifdef YAPOR
return(YAMOP_CUT(C));
#else
return(FALSE);
#endif /* YAPOR */
}
/*
Detect whether the next instruction is a cut.
Only useful for try and friends.
*/
static int followed_by_cut(yamop * code)
{
register yamop *p = code;
while (TRUE)
{
if (p->opc == opcode(_get_x_var))
p = NEXTOP(p,xx);
if (p->opc == opcode(_get_y_var))
p = NEXTOP(p,yx);
else if (p->opc == opcode(_allocate))
p = NEXTOP(p,e);
else if (p->opc == opcode(_unify_x_var))
p = NEXTOP(p,ox);
else if (p->opc == opcode(_unify_y_var))
p = NEXTOP(p,oy);
else if (p->opc == opcode(_unify_l_x_var))
p = NEXTOP(p,ox);
else if (p->opc == opcode(_unify_l_y_var))
p = NEXTOP(p,oy);
else if (p->opc == opcode(_unify_void))
p = NEXTOP(p,o);
else if (p->opc == opcode(_unify_n_voids))
p = NEXTOP(p,os);
else if (p->opc == opcode(_unify_l_void))
p = NEXTOP(p,o);
else if (p->opc == opcode(_unify_l_n_voids))
p = NEXTOP(p,os);
else if (p->opc == opcode(_cut))
return(TRUE);
else if (p->opc == opcode(_cut_t))
return(TRUE);
else if (p->opc == opcode(_cut_e))
return(TRUE);
else return(FALSE);
}
/* make lcc happy */
return(FALSE);
}
/* emits an opcode followed by an adress */
inline static void
emit_tr(compiler_vm_op op, yamop * Address, int NClauses, int HasCut)
{
emit(op, Unsigned(Address), (NClauses << 1) + HasCut);
}
/* emits an opcode followed by an adress */
static void
emit_try(compiler_vm_op op, int op_offset, yamop * Address, int NClauses, int HasCut)
{
if (op == try_op) {
/* if a try, then try to use cuts if possible */
indexed_code_for_cut = NIL;
if (followed_by_cut(Address)) {
indexed_code_for_cut = Address;
return;
}
}
emit((compiler_vm_op)((int)op + op_offset), Unsigned(Address), (NClauses << 1) + HasCut);
}
/*
* compute address of first instruction of clause: try addr,n
*/
inline static yamop *
Body(yamop * Arg)
{
return (NEXTOP(Arg,ld));
}
/*
* compute address of instruction after get_atom or get_struct try
* addr,n get_atom atom,reg
*/
inline static yamop *
SecB(yamop * Arg)
{
yamop *pc = NEXTOP(Arg,ld);
if (pc->opc == opcode(_get_struct))
return (NEXTOP(pc,xf));
else
return (NEXTOP(pc,xc));
}
/*
* compute address of instruction after get_list try addr,n
* et_list reg
*/
inline static yamop *
SecLB(yamop * Arg)
{
return (NEXTOP(NEXTOP(Arg,ld),x));
}
/*
* compute address of instruction after get_list and unify try
* addr,n get_list reg
* nify_atom atom
*/
inline static yamop *
ThiB(yamop * Arg)
{
yamop *pc = NEXTOP(NEXTOP(Arg,ld),x);
if (pc->opc == opcode(_unify_struct))
return (NEXTOP(pc,of));
else
return (NEXTOP(pc,oc));
}
/*
* compute address of instruction after get_list unify_list try
* addr,n get_list reg unify_list
*/
inline static yamop *
ThiLB(yamop * Arg)
{
return ( NEXTOP(NEXTOP(NEXTOP(Arg,ld),x),o));
}
/* emits a try, retry or trust, optimizing for a particular case */
static void
emit_cp_inst(compiler_vm_op op, yamop * Address, int Flag, int NClausesAfter)
{
int HasCut = clause_has_cut(Address);
indexed_code_for_cut = NIL;
if (op != try_op && profiling)
emit(retry_profiled_op, Unsigned(CurrentPred), Zero);
if (NGroups == 1)
Flag = Flag | LoneGroup;
else if (Flag & LastGroup) {
if (op == try_op) {
Flag &= (FirstIndex | LastFoundList | HeadIndex | IsAtom);
switch (Flag) {
case 0:
emit_tr(trylf_op, Body(Address), NClausesAfter, HasCut);
return;
case FirstIndex | LastFoundList:
emit_tr(trylf_op, SecLB(Address), NClausesAfter, HasCut);
return;
case FirstIndex | IsAtom:
emit_tr(retry_op, SecB(Address), NClausesAfter, HasCut);
return;
case FirstIndex:
emit_tr(trylf_op, SecB(Address), NClausesAfter, HasCut);
return;
case HeadIndex | LastFoundList:
emit_tr(trylh_op, ThiLB(Address), NClausesAfter, HasCut);
return;
case HeadIndex | IsAtom:
emit_tr(trylf_op, ThiB(Address), NClausesAfter, HasCut);
return;
case HeadIndex:
emit_tr(trylh_op, ThiB(Address), NClausesAfter, HasCut);
return;
}
} else
Flag ^= LastGroup;
Flag |= LoneGroup;
}
if (ExtendedSingle) {
if (op == trust_op) {
emit_cp_inst(retry_op, Address, Flag, NClausesAfter);
emit_tr(trust_op, FailAddress, NClausesAfter-1, HasCut);
return;
}
Flag |= LoneGroup;
}
switch (Flag) {
case 0:
emit_try(op, tryin_op - try_op, Body(Address), NClausesAfter, HasCut);
return;
case LoneGroup:
emit_try(op, try_op - try_op, Body(Address), NClausesAfter, HasCut);
return;
case FirstIndex:
emit_try(op, tryfin_op - try_op, SecB(Address), NClausesAfter, HasCut);
return;
case FirstIndex | IsAtom:
emit_try(op, tryin_op - try_op, SecB(Address), NClausesAfter, HasCut);
return;
case FirstIndex | LastFoundList:
emit_try(op, tryfin_op - try_op, SecLB(Address), NClausesAfter, HasCut);
return;
case FirstIndex | LoneGroup:
emit_try(op, tryf_op - try_op, SecB(Address), NClausesAfter, HasCut);
return;
case FirstIndex | LoneGroup | IsAtom:
emit_try(op, try_op - try_op, SecB(Address), NClausesAfter, HasCut);
return;
case FirstIndex | LoneGroup | LastFoundList:
emit_try(op, tryf_op - try_op, SecLB(Address), NClausesAfter, HasCut);
return;
case HeadIndex:
emit_try(op, tryhin_op - try_op, ThiB(Address), NClausesAfter, HasCut);
return;
case HeadIndex | LastFoundList:
emit_try(op, tryhin_op - try_op, ThiLB(Address), NClausesAfter, HasCut);
return;
case HeadIndex | IsAtom:
emit_try(op, trytin_op - try_op, ThiB(Address), NClausesAfter, HasCut);
return;
case HeadIndex | LoneGroup:
emit_try(op, tryh_op - try_op, ThiB(Address), NClausesAfter, HasCut);
return;
case HeadIndex | LoneGroup | LastFoundList:
emit_try(op, tryh_op - try_op, ThiLB(Address), NClausesAfter, HasCut);
return;
case HeadIndex | LoneGroup | IsAtom:
emit_try(op, tryt_op - try_op, ThiB(Address), NClausesAfter, HasCut);
return;
default:
return;
}
}
/* emits a large switch instruction */
static CELL
emit_space(compiler_vm_op op, int space, int nof)
{
labelno += 2;
emit(label_op, labelno, Zero);
StorePoint = emit_extra_size(op, Unsigned(nof), space);
return (labelno);
}
/* emits a go instruction */
static CELL
emit_go(int Gender, Term Name)
{
labelno += 2;
emit(label_op, labelno, Zero);
if (Gender == ApplCl)
StorePoint = emit_extra_size(go_f_op, Zero, 3 * CellSize);
else
StorePoint = emit_extra_size(go_c_op, Zero, 3 * CellSize);
*StorePoint++ = Unsigned(Name);
StorePoint[1] = (CELL)FailAddress;
return (labelno);
}
/* emits an if_not_then instruction */
static void
emit_if_not(Term T1, CELL Ad1, CELL Ad2)
{
StorePoint = emit_extra_size(if_not_op, Zero, 3 * CellSize);
*StorePoint++ = Unsigned(T1);
*StorePoint++ = Unsigned(Ad1);
StorePoint[0] = Unsigned(Ad2);
}
/* places the code where to go in a go instruction */
static void
fill_go(CELL *LCons, CELL Code)
{
LCons[0] = Code;
}
/* fills a space after a first instruction with four addresses */
static void
fill_switch_slots(CELL *WhereTo, CELL FAddr, CELL SecAddr, CELL ThirdAddr, CELL ThourthAddr, int NOf)
{
*WhereTo++ = FAddr;
*WhereTo++ = SecAddr;
*WhereTo++ = ThirdAddr;
if (NOf > 3)
*WhereTo = ThourthAddr;
}
/* Places in a space pairs 0 -> Fail */
static void
ClrSpace(CELL *StSpace, int NBytes)
{
int i;
NBytes /= 2 * CellSize;
for (i = 0; i < NBytes; i++) {
*StSpace++ = Zero;
*StSpace++ = (CELL)FailAddress;
}
}
/* Evaluates the number of groups and builds the clause and group arrays */
static int
NGroupsIn(PredEntry *ap)
{
int x, y, PresentGroup;
ClauseDef *ActualCl = ArOfCl, *LastClauses[MaxOptions];
GroupDef *Group = Groups;
yamop *q = (yamop *)(ap->FirstClause), *LastOne = (yamop *)(ap->LastClause);
NGroups = 1;
LastClauses[VarCl] = NIL;
LastClauses[AtCl] = NIL;
LastClauses[ApplCl] = NIL;
LastClauses[ListCl] = NIL;
Group = Groups;
NClauses = 0;
while (IsVarClause(q)) {
RemovedCl = TRUE;
if (q == LastOne)
return (NGroups);
else
q = (yamop *)NextClause(q);
}
x = KindOfArg(q);
if (NonVarCl(x))
PresentGroup = 1;
else
PresentGroup = 0;
LastClauses[x] = Group->Start = ActualCl;
Group->NCl = 0;
Group->First = q;
Group->Type[VarCl] = 0;
Group->Type[AtCl] = 0;
Group->Type[ApplCl] = 0;
Group->Type[ListCl] = 0;
Group->SInfo = OnlyNils;
do {
while (IsVarClause(q)) {
RemovedCl = TRUE;
if (q == LastOne)
return (NGroups);
else
q = (yamop *)NextClause(q);
}
x = KindOfArg(q);
NClauses++;
ActualCl->Kind = x;
ActualCl->Code = q;
if (x == ListCl) {
ActualCl->Name = HeadOfList(q);
y = 1;
} else if (NonVarCl(x)) {
ActualCl->Name = TermOfCl(q);
y = 1;
} else {
y = 0;
}
if (y != PresentGroup) {
Group++->Last = (ActualCl - 1)->Code;
NGroups++;
if ((ADDR)Group > TrailTop-1024)
growtrail(64 * 1024L);
Group->First = q;
Group->Start = ActualCl;
Group->NCl = 0;
Group->Type[VarCl] = 0;
Group->Type[AtCl] = 0;
Group->Type[ApplCl] = 0;
Group->Type[ListCl] = 0;
Group->SInfo = OnlyNils;
LastClauses[VarCl] = NIL;
LastClauses[AtCl] = NIL;
LastClauses[ApplCl] = NIL;
LastClauses[ListCl] = NIL;
PresentGroup = y;
}
if (x == AtCl) {
if (ActualCl->Name != MkAtomTerm(AtomNil))
Group->SInfo &= ~OnlyNils;
if (KindOfBipArg(q) & (FIsAtom|FIsNum|FIsPrimi)) {
Group->SInfo |= UsesBips;
ActualCl->Name = 0x0;
}
}
ActualCl->Next = NIL;
if (LastClauses[x] != NIL)
LastClauses[x]->Next = ActualCl;
LastClauses[x] = ActualCl++;
/* check for overflow in case we have a really big database */
if (ASP <= CellPtr (ActualCl) + 256) {
freep = (char *)ActualCl;
save_machine_regs();
longjmp(CompilerBotch, 3);
}
(Group->Type[x])++;
(Group->NCl)++;
if (q == LastOne)
q = NIL;
else
q = (yamop *)NextClause(q);
} while (q != NIL);
return (NGroups);
}
/* for each group find out how many clauses follow that group */
static void
CountGroups(GroupDef *Gr, int NGr)
{
GroupDef *grp = Gr+NGr;
int cls = 0;
do {
grp--;
grp->NofClausesAfter = cls;
cls += grp->NCl;
} while(grp > Gr);
}
/* Finds the first clause whose arg is neither a list or a var */
static yamop *
FindFirst(int i, int kind)
{
ClauseDef *GrClaus = Groups[i].Start;
while (GrClaus->Kind != kind)
GrClaus++;
if (AtomsOnlyNil)
return (SecB(GrClaus->Code));
return (Body(GrClaus->Code));
}
/* evaluates the size (power of two) necessary for a table */
static int
SizeTable(int Cases)
{
register int i = 2;
if (Cases <= MinHashEntries)
return (Cases);
while ((Cases /= 2) > 0)
i *= 2;
return (i * 2);
}
#define HASH_SHIFT 6
/*
* creates the hash table works if TableSize is a power of two
*/
static void
BuildHash(CELL *WhereTo, int NOfEntries, int TableSize, int Gend)
{
register int hash;
register int i;
#ifdef DEBUG
#ifdef CLASHES
int clashes = 0;
#endif /* CLASHES */
#endif /* DEBUG */
Term WorkTerm;
EntryDef *EntryP = Entries;
yamop *Base = (yamop *)CodePtr(WhereTo);
yamop *EndSpace = (yamop *)((char *)Base + TableSize * 2 * CellSize);
ClrSpace(WhereTo, ((int) ((char *)EndSpace - (char *)Base)));
TableSize--;
for (i = 0; i < NOfEntries; ++i) {
register Int d;
CELL *hentry;
WorkTerm = EntryP->Class;
hash = (Unsigned(WorkTerm) >> HASH_SHIFT) & TableSize;
hentry = (CELL *)Base + hash * 2;
d = TableSize & (Unsigned(WorkTerm) | 1);
while (*hentry) {
#ifdef DEBUG
#ifdef CLASHES
++clashes;
#endif /* CLASHES */
#endif /* DEBUG */
hash = (hash + d) & TableSize;
hentry = (CELL *)Base + hash * 2;
}
hentry[0] = Unsigned(WorkTerm);
hentry[1] = (CELL)((EntryP++)->Code);
}
#ifdef DEBUG
#ifdef CLASHES
YP_fprintf(YP_stderr,"hash table clashes: %d %d\n", clashes, NOfEntries);
#endif /* CLASHES */
#endif /* DEBUG */
}
static void
BuildIfTable(CELL *WhereTo, int NOfEntries)
{
register EntryDef *EntryP = Entries;
register int j;
*WhereTo++ = (CELL)FailAddress;
for (j = 0; j < NOfEntries; ++j) {
*WhereTo++ = Unsigned(EntryP->Class);
*WhereTo++ = (CELL)((EntryP++)->Code);
}
}
/* Creates the code for each entry in a group */
static void
TreatEntry(EntryDef *Entrance, int Gender, int PositionFlag, GroupDef *Gr)
{
if (Entrance->Last == Entrance->First) {
if (PositionFlag & LastGroup) {
/* last group, meaning we already have a choice point set */
register yamop * k = (Entrance->First)->Code;
labelno += 2;
emit(label_op, Entrance->Code = labelno, Zero);
if (PositionFlag & HeadIndex) {
emit_tr(trust_op, ThiB(k), 1, clause_has_cut(k));
} else {
/* we cannot emit to SecLB because switch might have already
set SREG :-(, hence making us jump one step ahead. This
is not a problem with a direct jump, in this case the
work on S will just have been squandered */
emit_tr(trust_op, Body(k), 1, clause_has_cut(k));
}
} else if (ExtendedSingle) {
/* a single alternative and a catchall clause */
register yamop * k = (Entrance->First)->Code;
labelno += 2;
emit(label_op, Entrance->Code = labelno, Zero);
/* if we are in a list */
if (PositionFlag & HeadIndex) {
/* we cannot emit to SecLB because switch might have already
set SREG :-( */
emit_try(try_op, 0, Body(k), 1, clause_has_cut(k));
if (indexed_code_for_cut != NIL) {
Entrance->Code =
(CELL)indexed_code_for_cut;
} else {
emit_tr(trust_op, FailAddress, 1, clause_has_cut(k));
Entrance->Code = labelno;
}
} else {
emit_try(try_op, 0, SecB(k), 2, clause_has_cut(k));
if (indexed_code_for_cut != NIL) {
Entrance->Code =
(CELL)indexed_code_for_cut;
} else {
emit_tr(trust_op, FailAddress, 1, clause_has_cut(k));
Entrance->Code = labelno;
}
}
} else if (PositionFlag & HeadIndex) {
/* single clause in the middle of code, no need to worry about
choicepoints */
Entrance->Code = Unsigned(ThiB((Entrance->First)->Code));
} else {
Entrance->Code = Unsigned(SecB((Entrance->First)->Code));
}
} else {
ClauseDef *k = Entrance->First;
int nofentries = 1, nofalts;
while (k != Entrance->Last) {
nofentries++;
k = k->Next;
}
nofalts = Gr->NofClausesAfter+nofentries;
k = Entrance->First;
labelno += 2;
emit(label_op, (Entrance->Code = labelno), Zero);
emit_cp_inst(try_op, k->Code, PositionFlag, nofalts);
nofalts--;
if (indexed_code_for_cut != NIL) {
Entrance->Code = (CELL)indexed_code_for_cut;
} else {
while ((k = k->Next) != Entrance->Last) {
emit_cp_inst(retry_op, k->Code, PositionFlag, nofalts);
nofalts--;
}
emit_cp_inst(trust_op, k->Code, PositionFlag, nofalts);
/* emit a jump with the place to jump to after finishing this group */
if (NGroups > 1 && !(PositionFlag & LastGroup) && !ExtendedSingle)
emit(jump_op, (CELL)((Gr+1)->First), Zero);
}
}
}
/* Creates the code for either appl or atomic cases */
static CELL
DealFixed(ClauseDef *j, int Gender, compiler_vm_op op, int Flag, GroupDef *Gr)
{
int NDiffTerms = 1;
int TableSize, k;
ClauseDef *NextInChain;
Term HeadName;
CELL LFixed;
CELL *WhereToStore;
EntryDef *Entry = Entries;
Entry->Class = j->Name;
Entry->Last = Entry->First = j;
do {
int l = 0;
HeadName = j->Name;
NextInChain = j->Next;
j->Next = NIL;
Entry = Entries;
while (l < NDiffTerms && Entry->Class != HeadName)
Entry++, l++;
if (l == NDiffTerms) {
if ((ADDR)Entry > TrailTop-1024)
growtrail(64 * 1024L);
Entry->Class = HeadName;
Entry->Last = Entry->First = j;
NDiffTerms++;
} else {
(Entry->Last)->Next = j;
Entry->Last = j;
}
} while ((j = NextInChain) != NIL && j->Name != 0x0);
Entry = Entries;
if (NDiffTerms == 1) {
CELL *WhereToStore;
if (AtomsOnlyNil) {
TreatEntry(Entry, Gender, Flag, Gr);
return ((CELL)(Entry->Code));
}
LFixed = emit_go(Gender, Entry->Class);
WhereToStore = StorePoint;
TreatEntry(Entry, Gender, Flag, Gr);
fill_go(WhereToStore, (CELL)(Entry->Code));
return (LFixed);
}
TableSize = SizeTable(NDiffTerms);
if (NDiffTerms <= MinHashEntries) {
if (op == switch_c_op)
op = if_c_op;
else
op = if_f_op;
LFixed = emit_space(op, CellSize + TableSize * 2 * CellSize, TableSize);
} else
LFixed = emit_space(op, TableSize * 2 * CellSize, TableSize);
WhereToStore = StorePoint;
for (k = 0; k < NDiffTerms; k++) {
TreatEntry(Entry, Gender, Flag, Gr);
Entry++;
}
if (NDiffTerms > MinHashEntries)
BuildHash(WhereToStore, NDiffTerms, TableSize, Gender);
else
BuildIfTable(WhereToStore, NDiffTerms);
return (LFixed);
}
/*
If atom(X) and friends are around, and for the moment, just forget
about doing indexing for constants and generate a traditional try,
retry chain.
*/
static CELL
DealFixedWithBips(ClauseDef *j, int NClauses, int Flag, GroupDef *Gr)
{
int i = 2;
CELL my_labelno;
int nofalts = Gr->NofClausesAfter+NClauses;
labelno += 2;
my_labelno = labelno;
emit(label_op, labelno, Zero);
#ifdef AGRESSIVE_BIPS
if (j->Name != 0x0 && j->Next->Name != 0x0) {
/*
we've got a sequence of i clauses with known argument. Can
index as normal for them
*/
CELL old_labelno;
yamop *old_FailAddress;
int old_ExtendedSingle, old_NAlts;
ClauseDef *j0 = j;
labelno += 2;
old_labelno = labelno;
old_FailAddress = FailAddress;
FailAddress = labelno;
/* the clauses behaves as if a new group */
NGroups++;
old_ExtendedSingle = ExtendedSingle;
ExtendedSingle = FALSE;
j = j->Next;
old_NAlts = Gr->NofClausesAfter;
while (j->Name != 0x0) i++, j = j->Next;
Gr->NofClausesAfter = old_NAlts + G->NCl - i;
DealFixed(j0, AtCl, switch_c_op, FirstIndex | IsAtom, Gr);
emit(label_op, old_labelno, Zero);
FailAddress = old_FailAddress;
ExtendedSingle = old_ExtendedSingle;
Gr->NofClausesAfter = old_NAlts;
NGroups--;
} else {
#endif /* AGRESSIVE_BIPS */
emit_cp_inst(try_op, j->Code, Flag, nofalts);
if (indexed_code_for_cut != NIL) {
/* Unfortunately, this is bound never to happen */
return((CELL)indexed_code_for_cut);
}
else j = j->Next;
nofalts--;
#ifdef AGRESSIVE_BIPS
}
#endif /* AGRESSIVE_BIPS */
/* we handled a group */
for (; i < NClauses; i++) {
emit_cp_inst(retry_op, j->Code, Flag, nofalts);
j = j->Next;
nofalts--;
}
emit_cp_inst(trust_op, j->Code, Flag, nofalts);
/* emit a jump with the place to jump to after finishing this group */
if (NGroups > 1 && !(Flag & LastGroup) && !ExtendedSingle)
emit(jump_op, (CELL)((Gr+1)->First), Zero);
return(my_labelno);
}
static CELL
DealCons(int i)
{
int NAtCl = Groups[i].Type[AtCl];
ClauseDef *Cla = Groups[i].Start;
if (NAtCl == 1) {
if (FinalGr(i)) {
yamop * Cl = FindFirst(i, AtCl);
labelno += 2;
emit(label_op, labelno, Zero);
emit_tr(trust_op, Cl, 1, clause_has_cut(Cl));
return (labelno);
} else if (ExtendedSingle) {
yamop * Cl = FindFirst(i, AtCl);
labelno += 2;
emit(label_op, labelno, Zero);
emit_tr(try_op, Cl, 2, clause_has_cut(Cl));
emit_tr(trust_op, FailAddress, 1, clause_has_cut(FailAddress));
return (labelno);
}
return ((CELL)FindFirst(i, AtCl));
} else if (NAtCl == 0)
return ((CELL)FailAddress);
while (Cla->Kind != AtCl)
Cla++;
if (FinalGr(i)) {
if (Groups[i].SInfo & UsesBips)
return(DealFixedWithBips(Cla, NAtCl, LastGroup, Groups+i));
else
return (DealFixed(Cla, AtCl, switch_c_op,
FirstIndex | IsAtom | LastGroup, Groups+i));
} else {
if (Groups[i].SInfo & UsesBips)
return(DealFixedWithBips(Cla, NAtCl, 0, Groups+i));
else
return (DealFixed(Cla, AtCl, switch_c_op,
FirstIndex | IsAtom, Groups+i));
}
}
static CELL
DealAppl(int i)
{
int NApCl = Groups[i].Type[ApplCl];
ClauseDef *Cla = Groups[i].Start;
if (NApCl == 1) {
if (FinalGr(i)) {
yamop * Cl = FindFirst(i, ApplCl);
labelno += 2;
emit(label_op, labelno, Zero);
emit_tr(trust_op, Cl, 1, clause_has_cut(Cl));
return (labelno);
} else if (ExtendedSingle) {
yamop * Cl = FindFirst(i, ApplCl);
labelno += 2;
emit(label_op, labelno, Zero);
emit_tr(try_op, Cl, 2, clause_has_cut(Cl));
emit_tr(trust_op, FailAddress, 1, clause_has_cut(FailAddress));
return (labelno);
}
return ((CELL)FindFirst(i, ApplCl));
} else if (NApCl == 0)
return ((CELL)FailAddress);
while (Cla->Kind != ApplCl)
Cla++;
if (FinalGr(i)) {
int Flag = FirstIndex | LastGroup;
return (DealFixed(Cla, ApplCl, switch_f_op, Flag, Groups+i));
}
return (DealFixed(Cla, ApplCl, switch_f_op, FirstIndex, Groups+i));
}
/* Finds the body of the first clause of a group whose first arg is a list */
static CELL
StartList(int i)
{
ClauseDef *j = Groups[i].Start;
while (j->Kind != ListCl)
j++;
if (FinalGr(i)) {
labelno += 2;
emit(label_op, labelno, Zero);
emit_tr(trust_op, SecLB(j->Code), 1, clause_has_cut(j->Code));
return (labelno);
} else if (ExtendedSingle) {
labelno += 2;
emit(label_op, labelno, Zero);
emit_tr(try_op, SecLB(j->Code), 2, clause_has_cut(j->Code));
emit_tr(trust_op, FailAddress, 1, clause_has_cut(FailAddress));
return (labelno);
} else {
return (Unsigned(SecLB(j->Code)));
}
}
static CELL
DealLAt(ClauseDef *Cla, int NOfClau, int NG)
{
if (NOfClau == 0)
return ((CELL)FailAddress);
if (FinalGr(NG)) {
int Flag = HeadIndex | IsAtom | LastGroup;
return (DealFixed(Cla, AtCl, switch_c_op, Flag, Groups+NG));
}
return (DealFixed(Cla, AtCl, switch_c_op, HeadIndex | IsAtom, Groups+NG));
}
static CELL
DealLAppl(ClauseDef *Cla, int NOfClauses, int NG)
{
if (NOfClauses == 0)
return ((CELL)FailAddress);
if (FinalGr(NG)) {
int Flag = HeadIndex | LastGroup;
return (DealFixed(Cla, ApplCl, switch_f_op, Flag, Groups+NG));
}
return (DealFixed(Cla, ApplCl, switch_f_op, HeadIndex, Groups+NG));
}
static CELL
DealLList(ClauseDef *j, int NOfClauses, int PositionFlag, int NG)
{
int k, nofalts = 1;
if (NOfClauses == 0)
return ((CELL)FailAddress);
else if (NOfClauses == 1) {
if (FinalGr(NG)) {
labelno += 2;
emit(label_op, labelno, Zero);
if (PositionFlag & FirstIndex)
emit_tr(trust_op, SecLB(j->Code), 1, clause_has_cut(j->Code));
else
emit_tr(trust_op, ThiLB(j->Code), 1, clause_has_cut(j->Code));
return (labelno);
} else if (ExtendedSingle) {
labelno += 2;
emit(label_op, labelno, Zero);
if (PositionFlag & FirstIndex)
emit_tr(try_op, SecLB(j->Code), 2, clause_has_cut(j->Code));
else
emit_tr(try_op, ThiLB(j->Code), 2, clause_has_cut(j->Code));
emit_tr(trust_op, FailAddress, 1, clause_has_cut(FailAddress));
return (labelno);
}
if (PositionFlag & FirstIndex)
return (Unsigned(SecLB(j->Code)));
return (Unsigned(ThiLB(j->Code)));
}
if (FinalGr(NG))
PositionFlag |= LastGroup;
labelno += 2;
emit(label_op, labelno, Zero);
nofalts = Groups[NG].NofClausesAfter+NOfClauses;
emit_cp_inst(try_op, j->Code, PositionFlag, nofalts);
nofalts--;
if (indexed_code_for_cut != NIL) {
return((CELL)indexed_code_for_cut);
} else {
j = j->Next;
for (k = 2; k < NOfClauses; ++k) {
emit_cp_inst(retry_op, j->Code, PositionFlag, nofalts);
nofalts--;
j = j->Next;
}
emit_cp_inst(trust_op, j->Code, PositionFlag, nofalts);
/* emit a jump with the place to jump to after finishing this group */
if (NGroups > 1 && !(PositionFlag & LastGroup) && !ExtendedSingle)
emit(jump_op, (CELL)(Groups[NG+1].First), Zero);
return (labelno);
}
}
static int
NoHeadVar(ClauseDef *CInfo, int NClauses)
{
while (NClauses--) {
if (KindOfListArg(CInfo->Code) == VarCl)
return (FALSE);
CInfo = CInfo->Next;
}
return (TRUE);
}
/* Creates code when several clauses first arg is a list */
static CELL
DealList(int i)
{
int k;
ClauseDef *j;
CELL LLFirst;
CELL *WhereToStore;
int NListCl = Groups[i].Type[ListCl];
int VFlags;
int nofalts = Groups[i].NofClausesAfter+NListCl;
if (NListCl == 0)
return ((CELL)FailAddress);
if (NListCl == 1)
return (StartList(i));
j = Groups[i].Start;
while (j->Kind != ListCl)
j++;
if (NoHeadVar(j, NListCl)) {
CELL LLVar, LLAt, LLList, LLAppl;
ClauseDef *Firsts[MaxOptions], *Lasts[MaxOptions];
int NOfSameCl[MaxOptions], l;
NOfSameCl[AtCl] = 0;
NOfSameCl[VarCl] = 0;
NOfSameCl[ListCl] = 0;
NOfSameCl[ApplCl] = 0;
LLFirst = emit_space(switch_h_op, 4 * CellSize, 0);
WhereToStore = StorePoint;
LLVar = DealLList(j, NListCl, LastFoundList | FirstIndex, i);
for (l = 0; l < NListCl; ++l) {
int z = KindOfListArg(j->Code);
if (NOfSameCl[z] != 0)
Lasts[z]->Next = j;
else
Firsts[z] = j;
Lasts[z] = j;
(NOfSameCl[z])++;
j = j->Next;
}
if (NOfSameCl[AtCl])
Lasts[AtCl]->Next = NIL;
if (NOfSameCl[VarCl])
Lasts[VarCl]->Next = NIL;
if (NOfSameCl[ListCl])
Lasts[ListCl]->Next = NIL;
if (NOfSameCl[ApplCl])
Lasts[ApplCl]->Next = NIL;
LLAppl = DealLAppl(Firsts[ApplCl], NOfSameCl[ApplCl], i);
LLAt = DealLAt(Firsts[AtCl], NOfSameCl[AtCl], i);
LLList = DealLList(Firsts[ListCl], NOfSameCl[ListCl],
LastFoundList | HeadIndex, i);
fill_switch_slots(WhereToStore, LLList, LLAt, LLAppl, LLVar, 4);
return (LLFirst);
}
if (FinalGr(i))
VFlags = FirstIndex | LastFoundList | LastGroup;
else
VFlags = FirstIndex | LastFoundList;
labelno += 2;
emit(label_op, labelno, Zero);
emit_cp_inst(try_op, j->Code, VFlags, nofalts);
nofalts--;
if (indexed_code_for_cut != NIL) {
return((CELL)indexed_code_for_cut);
} else {
j = j->Next;
for (k = 2; k < NListCl; ++k) {
emit_cp_inst(retry_op, j->Code, VFlags, nofalts);
j = j->Next;
nofalts--;
}
emit_cp_inst(trust_op, j->Code, VFlags, nofalts);
/* emit a jump with the place to jump to after finishing this group */
if (NGroups > 1 && !(VFlags & LastGroup) && !ExtendedSingle)
emit(jump_op, (CELL)(Groups[i+1].First), Zero);
return (labelno);
}
}
/* Finds the place where to go if we have a flop */
static CELL
GetFailToGo(int NG)
{
if (NGroups == 1)
return (Unsigned(FAILCODE));
if (FinalGr(NG))
return (Unsigned(TRUSTFAILCODE));
if (ExtendedSingle)
return (Unsigned(Body(Groups[NG + 1].Start->Code)));
return (Unsigned(FAILCODE));
}
/* Verifies if we have a group and a var first clause (catchall, usually) */
static int
IsExtendedSingle(int NG)
{
if (NGroups == 2 && NG == 0 && Groups[1].NCl == 1 &&
NClauses <= CLAUSES_FOR_EXTENDED_SINGLE)
return (TRUE);
return (FALSE);
}
static int
gr_has_cuts(GroupDef *gr)
{
return(0);
}
static void
EmitGrSwitch(int Count)
{
GroupDef Gr;
Gr = Groups[Count];
if (!Gr.Type[ApplCl] && (Gr.SInfo & OnlyNils)) {
AtomsOnlyNil = TRUE;
if (FinalGr(Count)) {
emit_space(switch_ll_op, 3 * CellSize,
((Gr.NCl) << 1)+gr_has_cuts(Groups+Count));
} else if (NGroups == 1 || ExtendedSingle)
emit_space(switch_lnl_op, 4 * CellSize, 0);
else
emit_space(switch_nvl_op, 3 * CellSize, 0);
} else {
AtomsOnlyNil = FALSE;
if (FinalGr(Count))
emit_space(switch_l_op, 3 * CellSize,
((Gr.NCl) << 1)+gr_has_cuts(Groups+Count));
else if (NGroups == 1 || ExtendedSingle)
emit_space(switch_t_op, 4 * CellSize, 0);
else
emit_space(switch_nv_op, 3 * CellSize, 0);
}
}
/* Creates the indexation code for a non var group */
static int
IndexNonVarGr(int Count)
{
CELL LVar, LCons, LA, LL;
GroupDef Gr;
CELL *WhereToStore;
Gr = Groups[Count];
ExtendedSingle = IsExtendedSingle(Count);
FailAddress = (yamop *)GetFailToGo(Count);
if (NGroups > 1 && !(ExtendedSingle) && Count < NGroups - 1) {
labelno += 2;
Groups[Count + 1].First = (yamop *)labelno;
}
if (Gr.NCl == 1) {
yamop * Cl = (Gr.Start)->Code;
if (Count == 0)
emit_tr(try_op, Body(Cl), Gr.NofClausesAfter+1, clause_has_cut(Cl));
else if (FinalGr(Count))
emit_tr(trust_op, Body(Cl), Gr.NofClausesAfter+1, clause_has_cut(Cl));
else
emit_tr(retry_op, Body(Cl), Gr.NofClausesAfter+1, clause_has_cut(Cl));
return (FALSE); /* Indexation is not necessary */
}
if (NGroups > 1 && !(ExtendedSingle) && Count < NGroups - 1) {
if (Count == 0)
emit_tr(tryme_op, (yamop *) labelno,
Gr.NofClausesAfter+1, clause_has_cut((Gr.Start)->Code));
else
emit_tr(retryme_op, (yamop *) labelno,
Gr.NofClausesAfter+1, clause_has_cut((Gr.Start)->Code));
}
EmitGrSwitch(Count);
WhereToStore = StorePoint;
LCons = DealCons(Count);
AtomsOnlyNil = FALSE;
LA = DealAppl(Count);
LL = DealList(Count);
if (log_update) {
LVar = log_update;
} else
LVar = Unsigned(FirstCl);
if (NGroups == 1 || ExtendedSingle)
fill_switch_slots(WhereToStore, LL, LCons, LA, LVar, 4);
else
fill_switch_slots(WhereToStore, LL, LCons, LA, LVar, 3);
return (TRUE);
}
static void
IndexVarGr(int Count)
{
GroupDef *Gr;
ClauseDef *Cla;
int j;
int nofalts;
Gr = Groups + Count;
Cla = Gr->Start;
nofalts = Gr->NofClausesAfter+Gr->NCl;
if (Count == 0) {
emit_tr(try_op, Body((Cla)->Code), nofalts, clause_has_cut(Cla->Code));
Cla++;
nofalts--;
} else if (Count == NGroups - 1 && Gr->NCl == 1) {
emit(label_op, Unsigned(Gr->First), Zero);
emit_tr(trust_op, Body((Cla)->Code), 1, clause_has_cut(Cla->Code));
return;
} else {
emit(label_op, Unsigned(Gr->First), Zero);
emit_tr(retry_op, Body((Cla)->Code), nofalts, clause_has_cut(Cla->Code));
Cla++;
nofalts--;
}
for (j = 2; j < Gr->NCl; ++j) {
emit_tr(retry_op, Body((Cla)->Code), nofalts, clause_has_cut(Cla->Code));
Cla++;
nofalts--;
}
if (Gr->NCl > 1) {
if (Count == NGroups - 1)
emit_tr(trust_op, Body(Cla->Code), 1, clause_has_cut(Cla->Code));
else
emit_tr(retry_op, Body(Cla->Code), nofalts, clause_has_cut(Cla->Code));
}
}
static int
SimpleCase(void)
{
if (Groups[0].Type[VarCl] != 0)
return (FALSE);
return (IndexNonVarGr(0));
}
static int
ComplexCase(void)
{
int Indexable = FALSE, i;
if (IsExtendedSingle(0))
return (SimpleCase());
emit(jump_v_op, (CELL) FirstCl, Zero);
if (Groups[0].Type[VarCl] == 0)
i = 0;
else {
IndexVarGr(0);
i = 1;
}
for (; i < NGroups; i += 2) {
Indexable |= IndexNonVarGr(i);
if (i < NGroups - 1)
IndexVarGr(i + 1);
}
return (Indexable);
}
static int
SpecialCases(void)
{
CELL LVar;
if (log_update) {
LVar = log_update;
} else {
LVar = (CELL)(ArOfCl->Code);
}
/* Clear what was left before */
freep = (char *) (ArOfCl + NClauses);
CodeStart = cpc = NIL;
/* For now just a special case */
if (NGroups == 2 && NClauses == 2 && Groups[0].Type[AtCl] == 1 &&
!RemovedCl && !(Groups[0].SInfo & UsesBips)) {
emit_if_not(ArOfCl->Name, Unsigned(Body(ArOfCl[1].Code)),
LVar);
return (TRUE);
} else
return (FALSE);
}
CODEADDR
PredIsIndexable(PredEntry *ap)
{
int NGr, Indexable = 0;
CODEADDR indx_out = NIL;
log_update = 0;
if (setjmp(CompilerBotch) == 3) {
/* just duplicate the stack */
restore_machine_regs();
gc(ap->ArityOfPE, ENV, CP);
}
restart_index:
labelno = 1;
RemovedCl = FALSE;
FirstCl = (yamop *)(ap->FirstClause);
CurrentPred = ap;
if (CurrentPred->PredFlags & ProfiledPredFlag)
profiling = TRUE;
else
profiling = FALSE;
IPredArity = ap->ArityOfPE;
/* Store the clauses in the Global */
ArOfCl = (ClauseDef *) H;
/* and the groups in the Auxiliary */
Groups = (GroupDef *) TR;
NGr = NGroupsIn(ap);
CountGroups(Groups, NGr);
/* store entries after groups */
Entries = (EntryDef *) (Groups + NGroups);
CodeStart = cpc = NIL;
freep = (char *) (ArOfCl + NClauses);
if (ErrorMessage != NIL) {
return (NIL);
}
if (CurrentPred->PredFlags & LogUpdatePredFlag) {
log_update = labelno;
labelno += 2;
}
if (NClauses == 0) {
Indexable = FALSE;
return(NIL);
} else {
if (NGr == 1)
Indexable = SimpleCase();
else
Indexable = ComplexCase();
if (!Indexable)
Indexable = SpecialCases();
}
if (CellPtr(freep) >= ASP) {
Error(SYSTEM_ERROR, TermNil, "out of stack space while indexing");
return(NIL);
}
if (log_update && NClauses > 1) {
int i;
Clause *cl;
Indexable = TRUE;
emit(label_op, log_update, Zero);
emit(try_op, Unsigned(Body(ArOfCl[0].Code)), Zero);
cl = ClauseCodeToClause(ArOfCl[0].Code);
if (cl->ClFlags & LogUpdRuleMask) {
cl->u2.ClExt->u.EC.ClRefs++;
} else {
cl->u2.ClUse++;
}
for (i = 1; i < NClauses-1; i++) {
emit(retry_op, Unsigned(Body(ArOfCl[i].Code)), Zero);
cl = ClauseCodeToClause(ArOfCl[0].Code);
if (cl->ClFlags & LogUpdRuleMask) {
cl->u2.ClExt->u.EC.ClRefs++;
} else {
cl->u2.ClUse++;
}
}
emit(trust_op, Unsigned(Body(ArOfCl[i].Code)), Zero);
cl = ClauseCodeToClause(ArOfCl[i].Code);
if (cl->ClFlags & LogUpdRuleMask) {
cl->u2.ClExt->u.EC.ClRefs++;
} else {
cl->u2.ClUse++;
}
}
if (!Indexable) {
return (NIL);
} else {
#ifdef DEBUG
if (Option['i' - 'a' + 1]) {
ShowCode();
}
#endif
if ((indx_out = assemble(ASSEMBLING_INDEX)) == NIL) {
if (!growheap(FALSE)) {
Abort("[ SYSTEM ERROR: YAP failed to reserve space in growheap ]\n");
return(FALSE);
}
goto restart_index;
}
}
return(indx_out);
}
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