cfd3683891
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@971 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
636 lines
14 KiB
C
636 lines
14 KiB
C
/*************************************************************************
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* *
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* YAP Prolog *
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* *
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* Yap Prolog was developed at NCCUP - Universidade do Porto *
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* *
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* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
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* *
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**************************************************************************
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* *
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* File: unify.c *
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* Last rev: *
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* mods: *
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* comments: Unification and other auxiliary routines for absmi *
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* *
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*************************************************************************/
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#define IN_UNIFY_C 1
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#include "absmi.h"
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STATIC_PROTO(Int OCUnify_complex, (register CELL *, register CELL *, register CELL *));
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STATIC_PROTO(int OCUnify, (register CELL, register CELL));
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STATIC_PROTO(Int p_ocunify, (void));
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#ifdef THREADED_CODE
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STATIC_PROTO(int rtable_hash_op, (OPCODE));
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STATIC_PROTO(void InitReverseLookupOpcode, (void));
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#endif
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static int
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rational_tree_loop(CELL *pt0, CELL *pt0_end, CELL **to_visit0)
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{
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CELL **to_visit = to_visit0;
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loop:
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while (pt0 < pt0_end) {
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register CELL *ptd0;
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register CELL d0;
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ptd0 = ++pt0;
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pt0 = ptd0;
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d0 = *ptd0;
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deref_head(d0, rtree_loop_unk);
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rtree_loop_nvar:
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{
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if (d0 == TermFoundVar)
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goto cufail;
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if (IsPairTerm(d0)) {
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to_visit[0] = pt0;
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to_visit[1] = pt0_end;
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to_visit[2] = (CELL *)d0;
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to_visit += 3;
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*pt0 = TermFoundVar;
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pt0_end = (pt0 = RepPair(d0) - 1) + 2;
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continue;
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}
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if (IsApplTerm(d0)) {
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register Functor f;
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register CELL *ap2;
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/* store the terms to visit */
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ap2 = RepAppl(d0);
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f = (Functor) (*ap2);
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/* compare functors */
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if (IsExtensionFunctor(f)) {
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continue;
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}
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to_visit[0] = pt0;
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to_visit[1] = pt0_end;
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to_visit[2] = (CELL *)d0;
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to_visit += 3;
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*pt0 = TermFoundVar;
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d0 = ArityOfFunctor(f);
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pt0 = ap2;
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pt0_end = ap2 + d0;
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continue;
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}
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continue;
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}
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derefa_body(d0, ptd0, rtree_loop_unk, rtree_loop_nvar);
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}
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/* Do we still have compound terms to visit */
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if (to_visit > to_visit0) {
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to_visit -= 3;
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pt0 = to_visit[0];
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pt0_end = to_visit[1];
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*pt0 = (CELL)to_visit[2];
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goto loop;
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}
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return (FALSE);
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cufail:
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#ifdef RATIONAL_TREES
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/* we found an infinite term */
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while (to_visit > to_visit) {
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CELL *pt0;
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to_visit -= 3;
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pt0 = to_visit[0];
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*pt0 = (CELL)to_visit[2];
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}
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#endif
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return (TRUE);
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}
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static inline int
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rational_tree(Term d0) {
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if (IsPairTerm(d0)) {
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CELL *pt0 = RepPair(d0);
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CELL **to_visit = (CELL **)H;
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return(rational_tree_loop(pt0-1, pt0+1, to_visit));
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} else if (IsApplTerm(d0)) {
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CELL *pt0 = RepAppl(d0);
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Functor f = (Functor)(*pt0);
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CELL **to_visit = (CELL **)H;
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return(rational_tree_loop(pt0, pt0+ArityOfFunctor(f), to_visit));
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} else
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return(FALSE);
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}
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static Int
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OCUnify_complex(register CELL *pt0, register CELL *pt0_end,
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register CELL *pt1
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)
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{
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register CELL **to_visit;
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#if SHADOW_HB
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register CELL *HBREG;
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HBREG = HB;
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#endif
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to_visit = (CELL **) H;
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loop:
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while (pt0 < pt0_end) {
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register CELL *ptd0 = ++pt0;
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register CELL d0 = *ptd0;
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++pt1;
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deref_head(d0, unify_comp_unk);
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unify_comp_nvar:
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{
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register CELL *ptd1 = pt1;
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register CELL d1 = *ptd1;
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deref_head(d1, unify_comp_nvar_unk);
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unify_comp_nvar_nvar:
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if (d0 == d1) {
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if (rational_tree_loop(pt0-1, pt0, to_visit))
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goto cufail;
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continue;
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} if (IsPairTerm(d0)) {
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if (!IsPairTerm(d1)) {
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goto cufail;
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}
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/* now link the two structures so that no one else will */
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/* come here */
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to_visit[0] = pt0;
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to_visit[1] = pt0_end;
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to_visit[2] = pt1;
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/* we want unification of rational trees to fail */
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to_visit[3] = (CELL *)*pt0;
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to_visit[4] = (CELL *)*pt1;
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to_visit += 5;
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*pt0 = TermFoundVar;
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*pt1 = TermFoundVar;
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pt0_end = (pt0 = RepPair(d0) - 1) + 2;
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pt0_end = RepPair(d0) + 1;
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pt1 = RepPair(d1) - 1;
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continue;
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}
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else if (IsApplTerm(d0)) {
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register Functor f;
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register CELL *ap2, *ap3;
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/* store the terms to visit */
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ap2 = RepAppl(d0);
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f = (Functor) (*ap2);
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if (!IsApplTerm(d1)) {
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goto cufail;
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}
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ap3 = RepAppl(d1);
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/* compare functors */
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if (f != (Functor) *ap3) {
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goto cufail;
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}
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if (IsExtensionFunctor(f)) {
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switch((CELL)f) {
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case (CELL)FunctorDBRef:
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if (d0 == d1) continue;
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goto cufail;
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case (CELL)FunctorLongInt:
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if (ap2[1] == ap3[1]) continue;
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goto cufail;
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case (CELL)FunctorDouble:
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if (FloatOfTerm(d0) == FloatOfTerm(d1)) continue;
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goto cufail;
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#ifdef USE_GMP
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case (CELL)FunctorBigInt:
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if (mpz_cmp(Yap_BigIntOfTerm(d0),Yap_BigIntOfTerm(d1)) == 0) continue;
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goto cufail;
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#endif /* USE_GMP */
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default:
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goto cufail;
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}
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}
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/* now link the two structures so that no one else will */
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/* come here */
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to_visit[0] = pt0;
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to_visit[1] = pt0_end;
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to_visit[2] = pt1;
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to_visit[3] = (CELL *)*pt0;
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to_visit[4] = (CELL *)*pt1;
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to_visit += 5;
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*pt0 = TermFoundVar;
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*pt1 = TermFoundVar;
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d0 = ArityOfFunctor(f);
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pt0 = ap2;
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pt0_end = ap2 + d0;
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pt1 = ap3;
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continue;
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} else {
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if (d0 == d1)
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continue;
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else goto cufail;
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}
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derefa_body(d1, ptd1, unify_comp_nvar_unk, unify_comp_nvar_nvar);
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/* d1 and pt2 have the unbound value, whereas d0 is bound */
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BIND_GLOBAL(ptd1, d0, bind_ocunify1);
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#ifdef COROUTINING
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DO_TRAIL(ptd1, d0);
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if (ptd1 < H0) Yap_WakeUp(ptd1);
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bind_ocunify1:
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#endif
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if (rational_tree_loop(ptd1-1, ptd1, to_visit))
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goto cufail;
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continue;
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}
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derefa_body(d0, ptd0, unify_comp_unk, unify_comp_nvar);
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{
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register CELL d1;
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register CELL *ptd1 = NULL;
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d1 = *(ptd1 = pt1);
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/* pt2 is unbound */
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deref_head(d1, unify_comp_var_unk);
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unify_comp_var_nvar:
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/* pt2 is unbound and d1 is bound */
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BIND_GLOBAL(ptd0, d1, bind_ocunify2);
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#ifdef COROUTINING
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DO_TRAIL(ptd0, d1);
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if (ptd0 < H0) Yap_WakeUp(ptd0);
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bind_ocunify2:
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#endif
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if (rational_tree_loop(ptd0-1, ptd0, to_visit))
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goto cufail;
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continue;
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derefa_body(d1, ptd1, unify_comp_var_unk, unify_comp_var_nvar);
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/* ptd0 and ptd1 are unbound */
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UnifyGlobalCells(ptd0, ptd1);
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}
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}
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/* Do we still have compound terms to visit */
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if (to_visit > (CELL **) H) {
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to_visit -= 5;
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pt0 = to_visit[0];
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pt0_end = to_visit[1];
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pt1 = to_visit[2];
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*pt0 = (CELL)to_visit[3];
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*pt1 = (CELL)to_visit[4];
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goto loop;
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}
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/* successful exit */
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return (TRUE);
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cufail:
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/* failure */
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while (to_visit > (CELL **) H) {
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CELL *pt0;
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to_visit -= 5;
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pt0 = to_visit[0];
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pt1 = to_visit[2];
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*pt0 = (CELL)to_visit[3];
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*pt1 = (CELL)to_visit[4];
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}
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/* failure */
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return (FALSE);
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#if SHADOW_REGS
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#if defined(B) || defined(TR)
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#undef Yap_REGS
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#endif /* defined(B) || defined(TR) */
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#endif
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}
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static int
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OCUnify(register CELL d0, register CELL d1)
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{
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register CELL *pt0, *pt1;
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#if SHADOW_HB
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register CELL *HBREG = HB;
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#endif
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deref_head(d0, oc_unify_unk);
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oc_unify_nvar:
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/* d0 is bound */
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deref_head(d1, oc_unify_nvar_unk);
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oc_unify_nvar_nvar:
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if (d0 == d1) {
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if (rational_tree(d0))
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return(FALSE);
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return(TRUE);
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}
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/* both arguments are bound */
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if (IsPairTerm(d0)) {
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if (!IsPairTerm(d1)) {
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return (FALSE);
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}
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pt0 = RepPair(d0);
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pt1 = RepPair(d1);
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return (OCUnify_complex(pt0 - 1, pt0 + 1, pt1 - 1));
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}
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else if (IsApplTerm(d0)) {
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if (!IsApplTerm(d1))
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return (FALSE);
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pt0 = RepAppl(d0);
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d0 = *pt0;
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pt1 = RepAppl(d1);
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d1 = *pt1;
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if (d0 != d1) {
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return (FALSE);
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} else {
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if (IsExtensionFunctor((Functor)d0)) {
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switch(d0) {
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case (CELL)FunctorDBRef:
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return(pt0 == pt1);
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case (CELL)FunctorLongInt:
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return(pt0[1] == pt1[1]);
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case (CELL)FunctorDouble:
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return(FloatOfTerm(AbsAppl(pt0)) == FloatOfTerm(AbsAppl(pt1)));
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#ifdef USE_GMP
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case (CELL)FunctorBigInt:
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return(mpz_cmp(Yap_BigIntOfTerm(AbsAppl(pt0)),Yap_BigIntOfTerm(AbsAppl(pt0))) == 0);
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#endif /* USE_GMP */
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default:
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return(FALSE);
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}
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}
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return (OCUnify_complex(pt0, pt0 + ArityOfFunctor((Functor) d0),
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pt1));
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}
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} else {
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return(FALSE);
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}
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deref_body(d1, pt1, oc_unify_nvar_unk, oc_unify_nvar_nvar);
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/* d0 is bound and d1 is unbound */
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BIND(pt1, d0, bind_ocunify4);
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#ifdef COROUTINING
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DO_TRAIL(pt1, d0);
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if (pt1 < H0) Yap_WakeUp(pt1);
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bind_ocunify4:
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#endif
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if (rational_tree(d0))
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return(FALSE);
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return (TRUE);
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deref_body(d0, pt0, oc_unify_unk, oc_unify_nvar);
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/* pt0 is unbound */
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deref_head(d1, oc_unify_var_unk);
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oc_unify_var_nvar:
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/* pt0 is unbound and d1 is bound */
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BIND(pt0, d1, bind_ocunify5);
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#ifdef COROUTINING
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DO_TRAIL(pt0, d1);
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if (pt0 < H0) Yap_WakeUp(pt0);
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bind_ocunify5:
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#endif
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if (rational_tree(d1))
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return(FALSE);
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return (TRUE);
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deref_body(d1, pt1, oc_unify_var_unk, oc_unify_var_nvar);
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/* d0 and pt1 are unbound */
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UnifyCells(pt0, pt1, uc1, uc2);
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#ifdef COROUTINING
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DO_TRAIL(pt0, (CELL)pt1);
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if (pt0 < H0) Yap_WakeUp(pt0);
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uc1:
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#endif
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return (TRUE);
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#ifdef COROUTINING
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uc2:
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DO_TRAIL(pt1, (CELL)pt0);
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if (pt1 < H0) {
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Yap_WakeUp(pt1);
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}
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#endif
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return (TRUE);
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}
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static Int
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p_ocunify(void)
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{
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return(OCUnify(ARG1,ARG2));
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}
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static Int
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p_cyclic(void)
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{
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Term t = Deref(ARG1);
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if (IsVarTerm(t))
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return(FALSE);
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return(rational_tree(t));
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}
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static Int
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p_acyclic(void)
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{
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Term t = Deref(ARG1);
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if (IsVarTerm(t))
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return(TRUE);
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return(!rational_tree(t));
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}
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int
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Yap_IUnify(register CELL d0, register CELL d1)
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{
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#if THREADS
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#undef Yap_REGS
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register REGSTORE *regp = Yap_regp;
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#define Yap_REGS (*regp)
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#elif SHADOW_REGS
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#if defined(B) || defined(TR)
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register REGSTORE *regp = &Yap_REGS;
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#define Yap_REGS (*regp)
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#endif /* defined(B) || defined(TR) */
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#endif
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#if SHADOW_HB
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register CELL *HBREG = HB;
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#endif
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register CELL *pt0, *pt1;
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deref_head(d0, unify_unk);
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unify_nvar:
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/* d0 is bound */
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deref_head(d1, unify_nvar_unk);
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unify_nvar_nvar:
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/* both arguments are bound */
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if (d0 == d1)
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return (TRUE);
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if (IsPairTerm(d0)) {
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if (!IsPairTerm(d1)) {
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return (FALSE);
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}
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pt0 = RepPair(d0);
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pt1 = RepPair(d1);
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return (IUnify_complex(pt0 - 1, pt0 + 1, pt1 - 1));
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}
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else if (IsApplTerm(d0)) {
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pt0 = RepAppl(d0);
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d0 = *pt0;
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if (!IsApplTerm(d1))
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return (FALSE);
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pt1 = RepAppl(d1);
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d1 = *pt1;
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if (d0 != d1) {
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return (FALSE);
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} else {
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if (IsExtensionFunctor((Functor)d0)) {
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switch(d0) {
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case (CELL)FunctorDBRef:
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return(pt0 == pt1);
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case (CELL)FunctorLongInt:
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return(pt0[1] == pt1[1]);
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case (CELL)FunctorDouble:
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return(FloatOfTerm(AbsAppl(pt0)) == FloatOfTerm(AbsAppl(pt1)));
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#ifdef USE_GMP
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case (CELL)FunctorBigInt:
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return(mpz_cmp(Yap_BigIntOfTerm(AbsAppl(pt0)),Yap_BigIntOfTerm(AbsAppl(pt0))) == 0);
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#endif /* USE_GMP */
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default:
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return(FALSE);
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}
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}
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return (IUnify_complex(pt0, pt0 + ArityOfFunctor((Functor) d0),
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pt1));
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}
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} else {
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return (FALSE);
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}
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deref_body(d1, pt1, unify_nvar_unk, unify_nvar_nvar);
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/* d0 is bound and d1 is unbound */
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BIND(pt1, d0, bind_unify3);
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#ifdef COROUTINING
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DO_TRAIL(pt1, d0);
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if (pt1 < H0) Yap_WakeUp(pt1);
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bind_unify3:
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#endif
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return (TRUE);
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|
|
deref_body(d0, pt0, unify_unk, unify_nvar);
|
|
/* pt0 is unbound */
|
|
deref_head(d1, unify_var_unk);
|
|
unify_var_nvar:
|
|
/* pt0 is unbound and d1 is bound */
|
|
BIND(pt0, d1, bind_unify4);
|
|
#ifdef COROUTINING
|
|
DO_TRAIL(pt0, d1);
|
|
if (pt0 < H0) Yap_WakeUp(pt0);
|
|
bind_unify4:
|
|
#endif
|
|
return (TRUE);
|
|
|
|
#if TRAILING_REQUIRES_BRANCH
|
|
unify_var_nvar_trail:
|
|
DO_TRAIL(pt0);
|
|
return (TRUE);
|
|
#endif
|
|
|
|
deref_body(d1, pt1, unify_var_unk, unify_var_nvar);
|
|
/* d0 and pt1 are unbound */
|
|
UnifyCells(pt0, pt1, uc1, uc2);
|
|
#ifdef COROUTINING
|
|
DO_TRAIL(pt0, (CELL)pt1);
|
|
if (pt0 < H0) Yap_WakeUp(pt0);
|
|
uc1:
|
|
#endif
|
|
return (TRUE);
|
|
#ifdef COROUTINING
|
|
uc2:
|
|
DO_TRAIL(pt1, (CELL)pt0);
|
|
if (pt1 < H0) {
|
|
Yap_WakeUp(pt1);
|
|
}
|
|
return (TRUE);
|
|
#endif
|
|
#if THREADS
|
|
#undef Yap_REGS
|
|
#define Yap_REGS (*Yap_regp)
|
|
#elif SHADOW_REGS
|
|
#if defined(B) || defined(TR)
|
|
#undef Yap_REGS
|
|
#endif /* defined(B) || defined(TR) */
|
|
#endif
|
|
}
|
|
|
|
/**********************************************************************
|
|
* *
|
|
* Conversion from Label to Op *
|
|
* *
|
|
**********************************************************************/
|
|
|
|
#if USE_THREADED_CODE
|
|
|
|
/* mask a hash table that allows for fast reverse translation from
|
|
instruction address to corresponding opcode */
|
|
static void
|
|
InitReverseLookupOpcode(void)
|
|
{
|
|
opentry *opeptr;
|
|
op_numbers i;
|
|
/* 2 K should be OK */
|
|
int hash_size_mask = OP_HASH_SIZE-1;
|
|
|
|
if (OP_RTABLE == NULL)
|
|
OP_RTABLE = (opentry *)Yap_AllocCodeSpace(OP_HASH_SIZE*sizeof(struct opcode_tab_entry));
|
|
if (OP_RTABLE == NULL) {
|
|
Yap_Error(FATAL_ERROR, TermNil,
|
|
"Couldn't obtain space for the reverse translation opcode table");
|
|
}
|
|
opeptr = OP_RTABLE;
|
|
/* clear up table */
|
|
{
|
|
int j;
|
|
for (j=0; j<OP_HASH_SIZE; j++) {
|
|
opeptr[j].opc = 0;
|
|
opeptr[j].opnum = _Ystop;
|
|
}
|
|
}
|
|
opeptr = OP_RTABLE;
|
|
opeptr[rtable_hash_op(Yap_opcode(_Ystop),hash_size_mask)].opc
|
|
= Yap_opcode(_Ystop);
|
|
/* now place entries */
|
|
for (i = _std_top; i > _Ystop; i--) {
|
|
OPCODE opc = Yap_opcode(i);
|
|
int j = rtable_hash_op(opc,hash_size_mask);
|
|
|
|
while (opeptr[j].opc) {
|
|
if (++j > hash_size_mask)
|
|
j = 0;
|
|
}
|
|
/* clear entry, no conflict */
|
|
opeptr[j].opnum = i;
|
|
opeptr[j].opc = opc;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
void
|
|
Yap_InitUnify(void)
|
|
{
|
|
Yap_InitCPred("unify_with_occurs_check", 2, p_ocunify, SafePredFlag);
|
|
CurrentModule = TERMS_MODULE;
|
|
Yap_InitCPred("cyclic_term", 1, p_cyclic, SafePredFlag|TestPredFlag);
|
|
Yap_InitCPred("acyclic_term", 1, p_acyclic, SafePredFlag|TestPredFlag);
|
|
CurrentModule = PROLOG_MODULE;
|
|
}
|
|
|
|
|
|
void
|
|
Yap_InitAbsmi(void)
|
|
{
|
|
/* initialise access to abstract machine instructions */
|
|
#if USE_THREADED_CODE
|
|
Yap_absmi(1);
|
|
InitReverseLookupOpcode();
|
|
#endif
|
|
}
|
|
|