bc: use unsigned division by 10 instead of signed

function                                             old     new   delta
bc_num_k                                             990     988      -2

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 07793e9d4..6dc79118a 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -1657,7 +1657,7 @@ static BcStatus bc_num_k(BcNum *restrict a, BcNum *restrict b,
             a->len < BC_NUM_KARATSUBA_LEN || b->len < BC_NUM_KARATSUBA_LEN)
         {
                 size_t i, j, len;
-                int carry;
+                unsigned carry;
 
                 bc_num_expand(c, a->len + b->len + 1);
 
@@ -1668,8 +1668,9 @@ static BcStatus bc_num_k(BcNum *restrict a, BcNum *restrict b,
 
                         carry = 0;
                         for (j = 0; j < a->len; ++j) {
-                                int in = (int) c->num[i + j];
-                                in += ((int) a->num[j]) * ((int) b->num[i]) + carry;
+                                unsigned in = c->num[i + j];
+                                in += ((unsigned) a->num[j]) * ((unsigned) b->num[i]) + carry;
+                                // note: compilers prefer _unsigned_ div/const
                                 carry = in / 10;
                                 c->num[i + j] = (BcDig)(in % 10);
                         }