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multiple values in single value context are returned as tuples

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ESL 2023-03-12 17:32:16 -04:00
parent c72ac73743
commit 90944d25b8
1 changed files with 27 additions and 6 deletions
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33
i.c
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@ -103,11 +103,20 @@ static obj *init_modules(obj *r, obj *sp, obj *hp);
#define hpushvmclo(c) hendblk(c)
#endif
/* vm tuple representation (c != 1) */
#define istuple(x) (isrecord(x) && recordrtd(x) == 0)
#define tupleref recordref
#define tuplelen recordlen
#define tuplebsz(c) hbsz((c)+2)
#define hpushtuple(c) (*--hp = 0, *--hp = obj_from_size(RECORD_BTAG), hendblk((c)+2))
/* in/re-loading gc-save shadow registers */
#define unload_ip() (rx = obj_from_fixnum(ip - &vectorref(vmcloref(rd, 0), 0)))
#define reload_ip() (ip = &vectorref(vmcloref(rd, 0), fixnum_from_obj(rx)))
#define unload_sp() (rs = obj_from_fixnum(sp - r))
#define reload_sp() (sp = r + fixnum_from_obj(rs))
/* access to stack, display, global cells */
#define sref(i) (sp[-(i)-1])
#define dref(i) (vmcloref(rd, (i)+1))
#define gref(p) (boxref(p))
@ -476,15 +485,21 @@ define_instruction(sdmv) {
retfromi();
} else {
/* can only pseudo-return to rcmv */
int n = fixnum_from_obj(ac), m = 3;
int n = fixnum_from_obj(ac), m = 3, i;
if (sref(n) == obj_from_fixnum(0) && sref(n+1) == cx_callmv_2Dadapter_2Dclosure) {
/* tail-call the consumer with the produced values */
rd = sref(n+2); rx = obj_from_fixnum(0); /* cns */
/* NB: can be sped up for popular cases: n == 0, n == 2 */
memmove((void*)(sp-n-m), (void*)(sp-n), (size_t)n*sizeof(obj));
sdrop(m); callsubi();
} else {
fail("multiple values returned to single value context");
} else { /* return args as a tuple (n != 1) */
hp_reserve(tuplebsz(n));
for (i = n-1; i >= 0; --i) *--hp = sref(i);
ac = hpushtuple(n);
sdrop(n);
rx = spop();
rd = spop();
retfromi();
}
}
}
@ -545,7 +560,7 @@ define_instruction(rck) {
ac = rd;
goi(wckr);
} else { /* multiple results case */
int c = fixnum_from_obj(ac), n = vmclolen(rd) - 1;
int c = fixnum_from_obj(ac), n = vmclolen(rd) - 1, i;
obj *ks = &vmcloref(rd, 1), *ke = ks + n;
if (ke-ks > 3 && *--ke == obj_from_fixnum(0) && *--ke == cx_callmv_2Dadapter_2Dclosure) {
obj *sb = r + VM_REGC;
@ -555,8 +570,14 @@ define_instruction(rck) {
if (c) memmove(sb+n, sp-c, c*sizeof(obj));
memcpy(sb, ks, n*sizeof(obj));
sp = sb+n+c; callsubi();
} else {
fail("multiple values returned to single value continuation");
} else { /* return args as a tuple (c != 1) */
hp_reserve(tuplebsz(c));
for (i = c-1; i >= 0; --i) *--hp = sref(i);
ac = hpushtuple(c);
sdrop(c);
spush(ac);
ac = rd;
goi(wckr);
}
}
}