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>

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 2feaf7bf3fb2085ac033b3a4f0b7ac98b2aa4a2c..aeb29a9712c8dc52ccd6b20f420f4d2fe7a6d82a 100644 (file)
--- 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;