From b80d7aad1b001479942c314690e6979d8290bdfb Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 19 Dec 2018 12:35:27 +0100 Subject: 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 --- miscutils/bc.c | 77 +++++++++++++++++++++++++++++++++------------------------- 1 file changed, 44 insertions(+), 33 deletions(-) (limited to 'miscutils/bc.c') diff --git a/miscutils/bc.c b/miscutils/bc.c index 7ddae341f..92bf1df57 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); } -- cgit v1.2.3