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tightening up unifying equality in several small ways

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This commit is contained in:
Paul Driver 2018-03-15 15:06:53 -07:00
parent 3c54440c82
commit 93d54041a9
1 changed files with 56 additions and 46 deletions
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102
noun/retrieve.c
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@ -502,10 +502,14 @@ _sang_one(u3_noun* a, u3_noun* b)
}
}
#define SONG_NONE 0
#define SONG_HEAD 1
#define SONG_TAIL 2
typedef struct {
c3_y sat_y;
u3_noun a;
u3_noun b;
c3_y sat_y;
} eqframe;
static inline eqframe*
@ -513,9 +517,9 @@ _eq_push(c3_ys mov, c3_ys off, u3_noun a, u3_noun b)
{
u3R->cap_p += mov;
eqframe* cur = u3to(eqframe, u3R->cap_p + off);
cur->a = a;
cur->b = b;
cur->sat_y = 0;
cur->sat_y = SONG_NONE;
cur->a = a;
cur->b = b;
return cur;
}
@ -659,10 +663,6 @@ _song_atom(u3_atom a, u3_atom b)
return c3y;
}
/* knob: set lower to get more/earlier memoize-by-pointer,
* higher to avoid allocating the u3h as often */
#define EQ_WHISTLE 1024
/* _song_x(): yes if a and b are the same noun, use uni to unify
*/
static c3_o
@ -671,50 +671,39 @@ _song_x(u3_noun a, u3_noun b, void (*uni)(u3_noun*, u3_noun*))
u3p(eqframe) empty = u3R->cap_p;
u3p(u3h_root) har_p = 0;
c3_y wis_y = c3_wiseof(eqframe);
c3_o nor_o = u3a_is_north(u3R);
c3_ys mov = ( c3y == nor_o ? -wis_y : wis_y );
c3_ys off = ( c3y == nor_o ? 0 : -wis_y );
c3_w wis_w = 0;
c3_o r_o = c3n;
c3_y wis_y = c3_wiseof(eqframe);
c3_o nor_o = u3a_is_north(u3R);
c3_ys mov = ( c3y == nor_o ? -wis_y : wis_y );
c3_ys off = ( c3y == nor_o ? 0 : -wis_y );
c3_o r_o = c3n;
c3_w ovr_w = 0;
eqframe* fam = _eq_push(mov, off, a, b);
eqframe* don = u3to(eqframe, empty + off);
/* there's a while and a switch here. continues all mean "do the loop again"
** and breaks all mean "fall through this switch case". There are no breaks
** that early terminate the loop.
** and breaks all mean jump to end of switch. There are no breaks
** that terminate the loop.
*/
while ( empty != u3R->cap_p ) {
if ( (a = fam->a) == (b = fam->b) ) {
r_o = c3y;
}
else if ( c3y == u3a_is_atom(a) ) {
r_o = _song_atom(a, b);
}
else if ( c3y == u3a_is_atom(b) ) {
r_o = c3n;
}
else {
u3a_cell* a_u = u3a_to_ptr(a);
u3a_cell* b_u = u3a_to_ptr(b);
switch ( fam->sat_y ) {
case 2:
uni(&(a_u->tel), &(b_u->tel));
while ( don != fam ) {
switch ( fam->sat_y ) {
case SONG_NONE:
if ( (a = fam->a) == (b = fam->b) ) {
r_o = c3y;
break;
}
else if ( c3y == u3a_is_atom(a) ) {
r_o = _song_atom(a, b);
}
else if ( c3y == u3a_is_atom(b) ) {
r_o = c3n;
}
else {
u3a_cell* a_u = u3a_to_ptr(a);
u3a_cell* b_u = u3a_to_ptr(b);
case 1:
uni(&(a_u->hed), &(b_u->hed));
fam->sat_y = 2;
fam = _eq_push(mov, off, a_u->tel, b_u->tel);
continue;
case 0: {
if ( a_u->mug_w &&
b_u->mug_w &&
(a_u->mug_w != b_u->mug_w) ) {
r_o = c3n;
break;
}
else {
if ( har_p != 0 ) {
@ -728,14 +717,33 @@ _song_x(u3_noun a, u3_noun b, void (*uni)(u3_noun*, u3_noun*))
continue;
}
}
fam->sat_y = 1;
fam->sat_y = SONG_HEAD;
fam = _eq_push(mov, off, a_u->hed, b_u->hed);
continue;
}
}
default:
c3_assert(0);
break;
case SONG_HEAD: {
u3a_cell* a_u = u3a_to_ptr(fam->a);
u3a_cell* b_u = u3a_to_ptr(fam->b);
uni(&(a_u->hed), &(b_u->hed));
fam->sat_y = SONG_TAIL;
fam = _eq_push(mov, off, a_u->tel, b_u->tel);
continue;
}
case SONG_TAIL: {
u3a_cell* a_u = u3a_to_ptr(fam->a);
u3a_cell* b_u = u3a_to_ptr(fam->b);
uni(&(a_u->tel), &(b_u->tel));
r_o = c3y;
break;
}
default:
c3_assert(0);
break;
}
if ( c3n == r_o ) {
@ -746,7 +754,9 @@ _song_x(u3_noun a, u3_noun b, void (*uni)(u3_noun*, u3_noun*))
return c3n;
}
else {
if ( 0 == har_p && (wis_w++ > EQ_WHISTLE) ) {
// ovr_w counts iterations. when it overflows, we know we've hit a
// pathological case and MUST start de-duplicating comparisons.
if ( 0 == har_p && 0 == ++ovr_w ) {
har_p = u3h_new();
}
if ( 0 != har_p ) {