bc: simplify BC_INST_JUMP[_ZERO] handling

function                                             old     new   delta
zbc_program_exec                                    4063    4050     -13

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

1 files changed, 12 insertions, 9 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 2feaf7bf3..aeb29a971 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -6715,7 +6715,6 @@ static BC_STATUS zbc_program_exec(void)
         BcInstPtr *ip = bc_vec_top(&G.prog.stack);
         BcFunc *func = bc_program_func(ip->func);
         char *code = func->code.v;
-        bool cond = false;
 
         while (ip->idx < func->code.len) {
                 BcStatus s = BC_STATUS_SUCCESS;
@@ -6723,17 +6722,22 @@ static BC_STATUS zbc_program_exec(void)
 
                 switch (inst) {
 #if ENABLE_BC
-                        case BC_INST_JUMP_ZERO:
+                        case BC_INST_JUMP_ZERO: {
+                                bool zero;
                                 s = zbc_program_prep(&ptr, &num);
                                 if (s) RETURN_STATUS(s);
-                                cond = !bc_num_cmp(num, &G.prog.zero);
+                                zero = (bc_num_cmp(num, &G.prog.zero) == 0);
                                 bc_vec_pop(&G.prog.results);
-                                // Fallthrough.
+                                if (!zero) {
+                                        bc_program_index(code, &ip->idx);
+                                        break;
+                                }
+                                // else: fall through
+                        }
                         case BC_INST_JUMP: {
-                                size_t *addr;
                                 size_t idx = bc_program_index(code, &ip->idx);
-                                addr = bc_vec_item(&func->labels, idx);
-                                if (inst == BC_INST_JUMP || cond) ip->idx = *addr;
+                                size_t *addr = bc_vec_item(&func->labels, idx);
+                                ip->idx = *addr;
                                 break;
                         }
                         case BC_INST_CALL:
@@ -6851,8 +6855,7 @@ static BC_STATUS zbc_program_exec(void)
                                 break;
                         case BC_INST_EXECUTE:
                         case BC_INST_EXEC_COND:
-                                cond = inst == BC_INST_EXEC_COND;
-                                s = zbc_program_execStr(code, &ip->idx, cond);
+                                s = zbc_program_execStr(code, &ip->idx, inst == BC_INST_EXEC_COND);
                                 break;
                         case BC_INST_PRINT_STACK: {
                                 size_t idx;