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authorDenys Vlasenko <vda.linux@googlemail.com>2018-12-12 11:51:32 +0100
committerDenys Vlasenko <vda.linux@googlemail.com>2018-12-12 11:51:32 +0100
commit251fbb57be45a8c4835f90f7126fa9fd27176373 (patch)
tree32627f771381c5e139a1a0caffa94dffdc1d5324 /miscutils
parent16494f557fd742ca484943407888fb8a349c01ee (diff)
downloadbusybox-251fbb57be45a8c4835f90f7126fa9fd27176373.tar.gz
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>
Diffstat (limited to 'miscutils')
-rw-r--r--miscutils/bc.c26
1 files changed, 12 insertions, 14 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c
index 8426998d0..8f326d20e 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -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;