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yap-6.3/C/unifyi.c

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/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: unify.c *
* Last rev: *
* mods: *
* comments: Unification and other auxiliary routines for absmi *
* *
*************************************************************************/
int
IUnify_complex(register CELL *pt0, register CELL *pt0_end,
register CELL *pt1
)
{
#if SHADOW_REGS
#if defined(B) || defined(TR)
register REGSTORE *regp = &REGS;
#define REGS (*regp)
#endif /* defined(B) || defined(TR) || defined(HB) */
#endif
#if SHADOW_HB
register CELL *HBREG = HB;
#endif /* SHADOW_HB */
CELL **to_visit = (CELL **)H;
loop:
while (pt0 < pt0_end) {
register CELL *ptd0 = pt0+1;
register CELL d0;
++pt1;
pt0 = ptd0;
d0 = *ptd0;
deref_head(d0, unify_comp_unk);
unify_comp_nvar:
{
register CELL *ptd1 = pt1;
register CELL d1 = *ptd1;
deref_head(d1, unify_comp_nvar_unk);
unify_comp_nvar_nvar:
if (d0 == d1)
continue;
if (IsPairTerm(d0)) {
if (!IsPairTerm(d1)) {
goto cufail;
}
#ifdef RATIONAL_TREES
/* now link the two structures so that no one else will */
/* come here */
if (pt0 < pt1) {
to_visit[0] = pt0;
to_visit[1] = pt0_end;
to_visit[2] = pt1;
to_visit[3] = (CELL *)d0;
to_visit += 4;
*pt0 = d1;
}
else {
to_visit[0] = pt1;
to_visit[1] = pt1+(pt0_end-pt0);
to_visit[2] = pt0;
to_visit[3] = (CELL *)d1;
to_visit += 4;
*pt1 = d0;
}
#else
/* store the terms to visit */
if (pt0 < pt0_end) {
to_visit[0] = pt0;
to_visit[1] = pt0_end;
to_visit[2] = pt1;
to_visit += 3;
}
#endif
pt0_end = (pt0 = RepPair(d0) - 1) + 2;
pt1 = RepPair(d1) - 1;
continue;
}
if (IsApplTerm(d0)) {
register Functor f;
register CELL *ap2, *ap3;
if (!IsApplTerm(d1)) {
goto cufail;
}
/* store the terms to visit */
ap2 = RepAppl(d0);
ap3 = RepAppl(d1);
f = (Functor) (*ap2);
/* compare functors */
if (f != (Functor) *ap3)
goto cufail;
if (IsExtensionFunctor(f)) {
if (unify_extension(f, d0, ap2, d1))
continue;
goto cufail;
}
#ifdef RATIONAL_TREES
/* now link the two structures so that no one else will */
/* come here */
if (pt0 < pt1) {
to_visit[0] = pt0;
to_visit[1] = pt0_end;
to_visit[2] = pt1;
to_visit[3] = (CELL *)d0;
to_visit += 4;
*pt0 = d1;
}
else {
to_visit[0] = pt1;
to_visit[1] = pt1+(pt0_end-pt0);
to_visit[2] = pt0;
to_visit[3] = (CELL *)d1;
to_visit += 4;
*pt1 = d0;
}
#else
/* store the terms to visit */
if (pt0 < pt0_end) {
to_visit[0] = pt0;
to_visit[1] = pt0_end;
to_visit[2] = pt1;
to_visit += 3;
}
#endif
d0 = ArityOfFunctor(f);
pt0 = ap2;
pt0_end = ap2 + d0;
pt1 = ap3;
continue;
}
goto cufail;
derefa_body(d1, ptd1, unify_comp_nvar_unk, unify_comp_nvar_nvar);
/* d1 and pt2 have the unbound value, whereas d0 is bound */
Bind_Global(ptd1, d0, bind_unify1);
#ifdef COROUTINING
DO_TRAIL(ptd1, d0);
if (ptd1 < H0) WakeUp(ptd1);
bind_unify1:
#endif
continue;
}
derefa_body(d0, ptd0, unify_comp_unk, unify_comp_nvar);
{
register CELL d1;
register CELL *ptd1;
d1 = pt1[0];
/* pt2 is unbound */
ptd1 = pt1;
deref_head(d1, unify_comp_var_unk);
unify_comp_var_nvar:
/* pt2 is unbound and d1 is bound */
Bind_Global(ptd0, d1, bind_unify2);
#ifdef COROUTINING
DO_TRAIL(ptd0, d1);
if (ptd0 < H0) WakeUp(ptd0);
bind_unify2:
#endif
continue;
{
derefa_body(d1, ptd1, unify_comp_var_unk, unify_comp_var_nvar);
/* ptd0 and ptd1 are unbound */
UnifyGlobalCells(ptd0, ptd1, ugc1, ugc2);
#ifdef COROUTINING
DO_TRAIL(ptd0, (CELL)ptd1);
if (ptd0 < H0) WakeUp(ptd0);
ugc1:
#endif
continue;
#ifdef COROUTINING
ugc2:
DO_TRAIL(ptd1, (CELL)ptd0);
if (ptd1 < H0) WakeUp(ptd1);
continue;
#endif
}
}
}
/* Do we still have compound terms to visit */
if (to_visit > (CELL **) H) {
#ifdef RATIONAL_TREES
to_visit -= 4;
pt0 = to_visit[0];
pt0_end = to_visit[1];
pt1 = to_visit[2];
*pt0 = (CELL)to_visit[3];
#else
to_visit -= 3;
pt0 = to_visit[0];
pt0_end = to_visit[1];
pt1 = to_visit[2];
#endif
goto loop;
}
return (TRUE);
cufail:
#ifdef RATIONAL_TREES
/* failure */
while (to_visit > (CELL **) H) {
CELL *pt0;
to_visit -= 4;
pt0 = to_visit[0];
*pt0 = (CELL)to_visit[3];
}
#endif
return (FALSE);
#if SHADOW_REGS
#if defined(B) || defined(TR)
#undef REGS
#endif /* defined(B) || defined(TR) */
#endif
}
int
IUnify(register CELL d0, register CELL d1)
{
#if SHADOW_REGS
#if defined(B) || defined(TR)
register REGSTORE *regp = &REGS;
#define REGS (*regp)
#endif /* defined(B) || defined(TR) */
#endif
#if SHADOW_HB
register CELL *HBREG = HB;
#endif
register CELL *pt0, *pt1;
deref_head(d0, unify_unk);
unify_nvar:
/* d0 is bound */
deref_head(d1, unify_nvar_unk);
unify_nvar_nvar:
/* both arguments are bound */
if (d0 == d1)
return (TRUE);
if (IsPairTerm(d0)) {
if (!IsPairTerm(d1)) {
return (FALSE);
}
pt0 = RepPair(d0);
pt1 = RepPair(d1);
return (IUnify_complex(pt0 - 1, pt0 + 1, pt1 - 1));
}
else if (IsApplTerm(d0)) {
pt0 = RepAppl(d0);
d0 = *pt0;
if (!IsApplTerm(d1))
return (FALSE);
pt1 = RepAppl(d1);
d1 = *pt1;
if (d0 != d1) {
return (FALSE);
} else {
if (IsExtensionFunctor((Functor)d0)) {
switch(d0) {
case (CELL)FunctorDBRef:
return(pt0 == pt1);
case (CELL)FunctorLongInt:
return(pt0[1] == pt1[1]);
case (CELL)FunctorDouble:
return(FloatOfTerm(AbsAppl(pt0)) == FloatOfTerm(AbsAppl(pt1)));
#ifdef USE_GMP
case (CELL)FunctorBigInt:
return(mpz_cmp(BigIntOfTerm(AbsAppl(pt0)),BigIntOfTerm(AbsAppl(pt0))) == 0);
#endif /* USE_GMP */
default:
return(FALSE);
}
}
return (IUnify_complex(pt0, pt0 + ArityOfFunctor((Functor) d0),
pt1));
}
} else {
return (FALSE);
}
deref_body(d1, pt1, unify_nvar_unk, unify_nvar_nvar);
/* d0 is bound and d1 is unbound */
Bind(pt1, d0, bind_unify3);
#ifdef COROUTINING
DO_TRAIL(pt1, d0);
if (pt1 < H0) WakeUp(pt1);
bind_unify3:
#endif
return (TRUE);
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) 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) WakeUp(pt0);
uc1:
#endif
return (TRUE);
#ifdef COROUTINING
uc2:
DO_TRAIL(pt1, (CELL)pt0);
if (pt1 < H0) {
WakeUp(pt1);
}
return (TRUE);
#endif
#if SHADOW_REGS
#if defined(B) || defined(TR)
#undef REGS
#endif /* defined(B) || defined(TR) */
#endif
}