bc: further simplify string-to-number conversion code

function                                             old     new   delta
bc_program_index                                      66      64      -2
bc_program_num                                       983     963     -20
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-22)             Total: -22 bytes
   text	   data	    bss	    dec	    hex	filename
 985706	    477	   7296	 993479	  f28c7	busybox_old
 985684	    477	   7296	 993457	  f28b1	busybox_unstripped

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

1 files changed, 7 insertions, 1 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index c36486414..ca9506929 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -2246,8 +2246,14 @@ static void bc_num_parseDecimal(BcNum *n, const char *val)
                 n->rdx = (size_t)((val + len) - (ptr + 1));
 
         if (!zero) {
-                for (i = len - 1; i < len; ++n->len, i -= 1 + (i && val[i - 1] == '.'))
+                i = len - 1;
+                for (;;) {
                         n->num[n->len] = val[i] - '0';
+                        ++n->len;
+ skip_dot:
+                        if ((ssize_t)--i == (ssize_t)-1) break;
+                        if (val[i] == '.') goto skip_dot;
+                }
         }
 }