bc: code shrink in bc_num_cmp()

function                                             old     new   delta
bc_num_cmp                                           275     231     -44

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-12 11:51:32 +01:00
parent 16494f557f
commit 251fbb57be

View File

@ -1601,46 +1601,44 @@ static ssize_t bc_num_cmp(BcNum *a, BcNum *b)
{
size_t i, min, a_int, b_int, diff;
BcDig *max_num, *min_num;
bool a_max, neg = false;
bool a_max, neg;
ssize_t cmp;
if (a == b) return 0;
if (a->len == 0) return BC_NUM_NEG(!!b->len, !b->neg);
if (b->len == 0) return BC_NUM_NEG(1, a->neg);
if (a->neg) {
if (b->neg)
neg = true;
else
return -1;
}
else if (b->neg)
return 1;
if (a->neg != b->neg) // signs of a and b differ
// +a,-b = a>b = 1 or -a,+b = a<b = -1
return (int)b->neg - (int)a->neg;
neg = a->neg; // 1 if both negative, 0 if both positive
a_int = BC_NUM_INT(a);
b_int = BC_NUM_INT(b);
a_int -= b_int;
a_max = (a->rdx > b->rdx);
if (a_int != 0) return (ssize_t) a_int;
a_max = (a->rdx > b->rdx);
if (a_max) {
min = b->rdx;
diff = a->rdx - b->rdx;
max_num = a->num + diff;
min_num = b->num;
}
else {
// neg = (a_max == neg); - NOP (maps 1->1 and 0->0)
} else {
min = a->rdx;
diff = b->rdx - a->rdx;
max_num = b->num + diff;
min_num = a->num;
neg = !neg; // same as "neg = (a_max == neg)"
}
cmp = bc_num_compare(max_num, min_num, b_int + min);
if (cmp != 0) return BC_NUM_NEG(cmp, (!a_max) != neg);
if (cmp != 0) return BC_NUM_NEG(cmp, neg);
for (max_num -= diff, i = diff - 1; i < diff; --i) {
if (max_num[i]) return BC_NUM_NEG(1, (!a_max) != neg);
if (max_num[i]) return BC_NUM_NEG(1, neg);
}
return 0;