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authorDenys Vlasenko2018-12-19 12:35:27 +0100
committerDenys Vlasenko2018-12-19 12:35:27 +0100
commitb80d7aad1b001479942c314690e6979d8290bdfb (patch)
tree45e53f1aca73e38b6bfc42e803e310906a163065 /miscutils
parentd6e24bd795d5d1d00c2414efe2e5d9e1152c5f5b (diff)
downloadbusybox-b80d7aad1b001479942c314690e6979d8290bdfb.zip
busybox-b80d7aad1b001479942c314690e6979d8290bdfb.tar.gz
bc: in execution loop, reload stack only after insts which can change it
Only these functions affect G.prog.exestack: zbc_program_read zbc_program_call zbc_program_return zbc_program_nquit zbc_program_execStr function old new delta zbc_program_exec 3995 4093 +98 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/0 up/down: 98/0) Total: 98 bytes text data bss dec hex filename 981364 485 7296 989145 f17d9 busybox_old 981462 485 7296 989243 f183b busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'miscutils')
-rw-r--r--miscutils/bc.c77
1 files changed, 44 insertions, 33 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c
index 7ddae34..92bf1df 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -167,8 +167,9 @@
# include "dc.c"
#else
-#define DEBUG_LEXER 0
-#define DEBUG_EXEC 0
+#define DEBUG_LEXER 0
+#define DEBUG_COMPILE 0
+#define DEBUG_EXEC 0
#if DEBUG_LEXER
static uint8_t lex_indent;
@@ -193,6 +194,12 @@ static uint8_t lex_indent;
# define dbg_lex_done(...) ((void)0)
#endif
+#if DEBUG_COMPILE
+# define dbg_compile(...) bb_error_msg(__VA_ARGS__)
+#else
+# define dbg_compile(...) ((void)0)
+#endif
+
#if DEBUG_EXEC
# define dbg_exec(...) bb_error_msg(__VA_ARGS__)
#else
@@ -683,7 +690,7 @@ typedef struct BcProgram {
#endif
BcVec results;
- BcVec stack;
+ BcVec exestack;
BcVec fns;
BcVec fn_map;
@@ -3448,7 +3455,7 @@ static void bc_parse_addFunc(BcParse *p, char *name, size_t *idx)
static void bc_parse_push(BcParse *p, char i)
{
- dbg_lex("%s:%d pushing opcode %d", __func__, __LINE__, i);
+ dbg_compile("%s:%d pushing bytecode %zd:%d", __func__, __LINE__, p->func->code.len, i);
bc_vec_pushByte(&p->func->code, i);
}
@@ -3537,11 +3544,11 @@ static void bc_program_reset(void)
BcFunc *f;
BcInstPtr *ip;
- bc_vec_npop(&G.prog.stack, G.prog.stack.len - 1);
+ bc_vec_npop(&G.prog.exestack, G.prog.exestack.len - 1);
bc_vec_pop_all(&G.prog.results);
f = bc_program_func(0);
- ip = bc_vec_top(&G.prog.stack);
+ ip = bc_vec_top(&G.prog.exestack);
ip->idx = f->code.len;
}
@@ -5145,7 +5152,7 @@ static BC_STATUS zbc_program_read(void)
f = bc_program_func(BC_PROG_READ);
bc_vec_pushByte(&f->code, BC_INST_POP_EXEC);
- bc_vec_push(&G.prog.stack, &ip);
+ bc_vec_push(&G.prog.exestack, &ip);
exec_err:
bc_parse_free(&parse);
G.in_read = 0;
@@ -5824,12 +5831,13 @@ static BC_STATUS zbc_program_incdec(char inst)
static BC_STATUS zbc_program_call(char *code, size_t *idx)
{
BcInstPtr ip;
- size_t i, nparams = bc_program_index(code, idx);
+ size_t i, nparams;
BcFunc *func;
BcId *a;
BcResultData param;
BcResult *arg;
+ nparams = bc_program_index(code, idx);
ip.idx = 0;
ip.func = bc_program_index(code, idx);
func = bc_program_func(ip.func);
@@ -5870,7 +5878,7 @@ static BC_STATUS zbc_program_call(char *code, size_t *idx)
}
}
- bc_vec_push(&G.prog.stack, &ip);
+ bc_vec_push(&G.prog.exestack, &ip);
RETURN_STATUS(BC_STATUS_SUCCESS);
}
@@ -5881,7 +5889,7 @@ static BC_STATUS zbc_program_return(char inst)
BcResult res;
BcFunc *f;
size_t i;
- BcInstPtr *ip = bc_vec_top(&G.prog.stack);
+ BcInstPtr *ip = bc_vec_top(&G.prog.exestack);
if (!BC_PROG_STACK(&G.prog.results, ip->len + inst == BC_INST_RET))
RETURN_STATUS(bc_error_stack_has_too_few_elements());
@@ -5914,7 +5922,7 @@ static BC_STATUS zbc_program_return(char inst)
bc_vec_npop(&G.prog.results, G.prog.results.len - ip->len);
bc_vec_push(&G.prog.results, &res);
- bc_vec_pop(&G.prog.stack);
+ bc_vec_pop(&G.prog.exestack);
RETURN_STATUS(BC_STATUS_SUCCESS);
}
@@ -6184,13 +6192,13 @@ static BC_STATUS zbc_program_nquit(void)
bc_vec_pop(&G.prog.results);
- if (G.prog.stack.len < val)
+ if (G.prog.exestack.len < val)
RETURN_STATUS(bc_error_stack_has_too_few_elements());
- if (G.prog.stack.len == val) {
+ if (G.prog.exestack.len == val) {
QUIT_OR_RETURN_TO_MAIN;
}
- bc_vec_npop(&G.prog.stack, val);
+ bc_vec_npop(&G.prog.exestack, val);
RETURN_STATUS(s);
}
@@ -6283,7 +6291,7 @@ static BC_STATUS zbc_program_execStr(char *code, size_t *bgn, bool cond)
ip.func = fidx;
bc_vec_pop(&G.prog.results);
- bc_vec_push(&G.prog.stack, &ip);
+ bc_vec_push(&G.prog.exestack, &ip);
RETURN_STATUS(BC_STATUS_SUCCESS);
err:
@@ -6348,15 +6356,16 @@ static BC_STATUS zbc_program_exec(void)
{
BcResult r, *ptr;
BcNum *num;
- BcInstPtr *ip = bc_vec_top(&G.prog.stack);
+ BcInstPtr *ip = bc_vec_top(&G.prog.exestack);
BcFunc *func = bc_program_func(ip->func);
char *code = func->code.v;
+ dbg_exec("func:%zd bytes:%zd ip:%zd", ip->func, func->code.len, ip->idx);
while (ip->idx < func->code.len) {
BcStatus s = BC_STATUS_SUCCESS;
- char inst = code[(ip->idx)++];
+ char inst = code[ip->idx++];
- dbg_exec("inst:%d", inst);
+ dbg_exec("inst at %zd:%d", ip->idx - 1, inst);
switch (inst) {
#if ENABLE_BC
case BC_INST_JUMP_ZERO: {
@@ -6382,7 +6391,7 @@ static BC_STATUS zbc_program_exec(void)
case BC_INST_CALL:
dbg_exec("BC_INST_CALL:");
s = zbc_program_call(code, &ip->idx);
- break;
+ goto read_updated_ip;
case BC_INST_INC_PRE:
case BC_INST_DEC_PRE:
case BC_INST_INC_POST:
@@ -6398,7 +6407,7 @@ static BC_STATUS zbc_program_exec(void)
case BC_INST_RET0:
dbg_exec("BC_INST_RET[0]:");
s = zbc_program_return(inst);
- break;
+ goto read_updated_ip;
case BC_INST_BOOL_OR:
case BC_INST_BOOL_AND:
#endif // ENABLE_BC
@@ -6414,7 +6423,7 @@ static BC_STATUS zbc_program_exec(void)
case BC_INST_READ:
dbg_exec("BC_INST_READ:");
s = zbc_program_read();
- break;
+ goto read_updated_ip;
case BC_INST_VAR:
dbg_exec("BC_INST_VAR:");
s = zbc_program_pushVar(code, &ip->idx, false, false);
@@ -6454,7 +6463,7 @@ static BC_STATUS zbc_program_exec(void)
break;
case BC_INST_POP_EXEC:
dbg_exec("BC_INST_POP_EXEC:");
- bc_vec_pop(&G.prog.stack);
+ bc_vec_pop(&G.prog.exestack);
break;
case BC_INST_PRINT:
case BC_INST_PRINT_POP:
@@ -6513,7 +6522,7 @@ static BC_STATUS zbc_program_exec(void)
case BC_INST_EXECUTE:
case BC_INST_EXEC_COND:
s = zbc_program_execStr(code, &ip->idx, inst == BC_INST_EXEC_COND);
- break;
+ goto read_updated_ip;
case BC_INST_PRINT_STACK: {
size_t idx;
for (idx = 0; idx < G.prog.results.len; ++idx) {
@@ -6566,14 +6575,20 @@ static BC_STATUS zbc_program_exec(void)
}
case BC_INST_QUIT:
dbg_exec("BC_INST_NEG:");
- if (G.prog.stack.len <= 2)
+ if (G.prog.exestack.len <= 2)
QUIT_OR_RETURN_TO_MAIN;
- bc_vec_npop(&G.prog.stack, 2);
+ bc_vec_npop(&G.prog.exestack, 2);
break;
case BC_INST_NQUIT:
s = zbc_program_nquit();
- break;
+ //goto read_updated_ip; - just fall through to it
#endif // ENABLE_DC
+ read_updated_ip:
+ // Instruction stack has changed, read new pointers
+ ip = bc_vec_top(&G.prog.exestack);
+ func = bc_program_func(ip->func);
+ code = func->code.v;
+ dbg_exec("func:%zd bytes:%zd ip:%zd", ip->func, func->code.len, ip->idx);
}
if (s || G_interrupt) {
@@ -6583,10 +6598,6 @@ static BC_STATUS zbc_program_exec(void)
fflush_and_check();
- // If the stack has changed, pointers may be invalid.
- ip = bc_vec_top(&G.prog.stack);
- func = bc_program_func(ip->func);
- code = func->code.v;
}
RETURN_STATUS(BC_STATUS_SUCCESS);
@@ -6957,7 +6968,7 @@ static void bc_program_free(void)
bc_vec_free(&G.prog.strs);
bc_vec_free(&G.prog.consts);
bc_vec_free(&G.prog.results);
- bc_vec_free(&G.prog.stack);
+ bc_vec_free(&G.prog.exestack);
bc_num_free(&G.prog.last);
bc_num_free(&G.prog.zero);
bc_num_free(&G.prog.one);
@@ -7009,8 +7020,8 @@ static void bc_program_init(void)
bc_vec_init(&G.prog.strs, sizeof(char *), bc_string_free);
bc_vec_init(&G.prog.consts, sizeof(char *), bc_string_free);
bc_vec_init(&G.prog.results, sizeof(BcResult), bc_result_free);
- bc_vec_init(&G.prog.stack, sizeof(BcInstPtr), NULL);
- bc_vec_push(&G.prog.stack, &ip);
+ bc_vec_init(&G.prog.exestack, sizeof(BcInstPtr), NULL);
+ bc_vec_push(&G.prog.exestack, &ip);
bc_char_vec_init(&G.input_buffer);
}