bc: no need to "set to zero" BcNum after bc_num_init(), it already is

function                                             old     new   delta
bc_num_init                                           48      49      +1
bc_program_num                                      1115    1108      -7
bc_program_exec                                     4098    4081     -17
bc_vm_init                                           786     768     -18
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/3 up/down: 1/-42)             Total: -41 bytes
   text	   data	    bss	    dec	    hex	filename
 985872	    477	   7296	 993645	  f296d	busybox_old
 985831	    477	   7296	 993604	  f2944	busybox_unstripped

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

1 files changed, 10 insertions, 7 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 2e3c4139e..71b419d8f 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -1399,12 +1399,16 @@ static void bc_num_ten(BcNum *n)
         n->num[1] = 1;
 }
 
+// Note: this also sets BcNum to zero
 static void bc_num_init(BcNum *n, size_t req)
 {
         req = req >= BC_NUM_DEF_SIZE ? req : BC_NUM_DEF_SIZE;
-        memset(n, 0, sizeof(BcNum));
+        //memset(n, 0, sizeof(BcNum)); - cleared by assignments below
         n->num = xmalloc(req);
         n->cap = req;
+        n->rdx = 0;
+        n->len = 0;
+        n->neg = false;
 }
 
 static void bc_num_init_DEF_SIZE(BcNum *n)
@@ -2288,7 +2292,7 @@ static void bc_num_parseBase(BcNum *n, const char *val, BcNum *base)
         }
 
         bc_num_init(&result, base->len);
-        bc_num_zero(&result);
+        //bc_num_zero(&result); - already is
         bc_num_one(&mult);
 
         for (i += 1, digits = 0; i < len; ++i, ++digits) {
@@ -6209,7 +6213,7 @@ static BcStatus bc_program_return(char inst)
         }
         else {
                 bc_num_init_DEF_SIZE(&res.d.n);
-                bc_num_zero(&res.d.n);
+                //bc_num_zero(&res.d.n); - already is
         }
 
         // We need to pop arguments as well, so this takes that into account.
@@ -6768,8 +6772,7 @@ static BcStatus bc_program_exec(void)
                                 bc_num_init_DEF_SIZE(&r.d.n);
                                 if (!bc_num_cmp(num, &G.prog.zero))
                                         bc_num_one(&r.d.n);
-                                else
-                                        bc_num_zero(&r.d.n);
+                                //else bc_num_zero(&r.d.n); - already is
                                 bc_program_retire(&r, BC_RESULT_TEMP);
                                 break;
                         case BC_INST_NEG:
@@ -7379,10 +7382,10 @@ static void bc_program_init(void)
 #endif
 
         bc_num_init_DEF_SIZE(&G.prog.last);
-        bc_num_zero(&G.prog.last);
+        //bc_num_zero(&G.prog.last); - already is
 
         bc_num_init_DEF_SIZE(&G.prog.zero);
-        bc_num_zero(&G.prog.zero);
+        //bc_num_zero(&G.prog.zero); - already is
 
         bc_num_init_DEF_SIZE(&G.prog.one);
         bc_num_one(&G.prog.one);