bc: shrink bc_program_index()

function                                             old     new   delta
bc_program_index                                      66      47     -19
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-19)             Total: -19 bytes
   text	   data	    bss	    dec	    hex	filename
 981418	    485	   7296	 989199	  f180f	busybox_old
 981399	    485	   7296	 989180	  f17fc	busybox_unstripped

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

1 files changed, 11 insertions, 4 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index eaa28a94a..2da7c317c 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -5256,11 +5256,18 @@ exec_err:
 
 static size_t bc_program_index(char *code, size_t *bgn)
 {
-        char amt = code[(*bgn)++], i = 0;
-        size_t res = 0;
+        unsigned char *bytes = (void*)(code + *bgn);
+        unsigned amt;
+        unsigned i;
+        size_t res;
+
+        amt = *bytes++;
+        *bgn += amt + 1;
 
-        for (; i < amt; ++i, ++(*bgn))
-                res |= (((size_t)((int) code[*bgn]) & UCHAR_MAX) << (i * CHAR_BIT));
+        amt *= 8;
+        res = 0;
+        for (i = 0; i < amt; i += 8)
+                res |= (size_t)(*bytes++) << i;
 
         return res;
 }