From 08c033c406e2ef1ef9209b1ea09864928e2158ab Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 5 Dec 2018 16:55:08 +0100 Subject: [PATCH] bc: optimize pushing zero bytes to vectors function old new delta bc_vec_pushZeroByte - 10 +10 bc_vm_run 1919 1917 -2 bc_vec_string 61 59 -2 bc_vec_concat 68 66 -2 bc_parse_create 170 168 -2 bc_lex_number 298 296 -2 dc_lex_token 691 687 -4 bc_read_line 314 303 -11 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/7 up/down: 10/-25) Total: -15 bytes Signed-off-by: Denys Vlasenko --- miscutils/bc.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/miscutils/bc.c b/miscutils/bc.c index 171bc8858..97adeaa53 100644 --- a/miscutils/bc.c +++ b/miscutils/bc.c @@ -1068,6 +1068,13 @@ static void bc_vec_pushByte(BcVec *v, char data) bc_vec_push(v, &data); } +static void bc_vec_pushZeroByte(BcVec *v) +{ + //bc_vec_pushByte(v, '\0'); + // better: + bc_vec_push(v, &const_int_0); +} + static void bc_vec_pushAt(BcVec *v, const void *data, size_t idx) { if (idx == v->len) @@ -1092,14 +1099,14 @@ static void bc_vec_string(BcVec *v, size_t len, const char *str) memcpy(v->v, str, len); v->len = len; - bc_vec_pushByte(v, '\0'); + bc_vec_pushZeroByte(v); } static void bc_vec_concat(BcVec *v, const char *str) { size_t len; - if (v->len == 0) bc_vec_pushByte(v, '\0'); + if (v->len == 0) bc_vec_pushZeroByte(v); len = v->len + strlen(str); @@ -1173,7 +1180,6 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt) do { int i; - char c; bad_chars = 0; bc_vec_pop_all(vec); @@ -1222,12 +1228,11 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt) bc_error_fmt("illegal character 0x%02x", i); bad_chars = 1; } - c = (char) i; - bc_vec_push(vec, &c); + bc_vec_pushByte(vec, (char)i); } while (i != '\n'); } while (bad_chars); - bc_vec_pushByte(vec, '\0'); + bc_vec_pushZeroByte(vec); return BC_STATUS_SUCCESS; } @@ -2833,7 +2838,7 @@ static BcStatus bc_lex_number(BcLex *l, char start) bc_vec_push(&l->t.v, &c); } - bc_vec_pushByte(&l->t.v, '\0'); + bc_vec_pushZeroByte(&l->t.v); l->i += i; return BC_STATUS_SUCCESS; @@ -3307,7 +3312,7 @@ static BcStatus dc_lex_register(BcLex *l) else { bc_vec_pop_all(&l->t.v); bc_vec_pushByte(&l->t.v, l->buf[l->i - 1]); - bc_vec_pushByte(&l->t.v, '\0'); + bc_vec_pushZeroByte(&l->t.v); l->t.t = BC_LEX_NAME; } @@ -3336,7 +3341,7 @@ static BcStatus dc_lex_string(BcLex *l) return bc_error("string end could not be found"); } - bc_vec_pushByte(&l->t.v, '\0'); + bc_vec_pushZeroByte(&l->t.v); if (i - l->i > BC_MAX_STRING) return bc_error("string too long: must be [1, BC_STRING_MAX]"); @@ -3558,7 +3563,7 @@ static void bc_parse_create(BcParse *p, size_t func, bc_vec_init(&p->flags, sizeof(uint8_t), NULL); bc_vec_init(&p->exits, sizeof(BcInstPtr), NULL); bc_vec_init(&p->conds, sizeof(size_t), NULL); - bc_vec_pushByte(&p->flags, 0); + bc_vec_pushZeroByte(&p->flags); bc_vec_init(&p->ops, sizeof(BcLexType), NULL); p->parse = parse; @@ -6915,7 +6920,7 @@ static BcStatus bc_vm_stdin(void) bc_char_vec_init(&buffer); bc_char_vec_init(&buf); - bc_vec_pushByte(&buffer, '\0'); + bc_vec_pushZeroByte(&buffer); // This loop is complex because the vm tries not to send any lines that end // with a backslash to the parser. The reason for that is because the parser -- 2.25.1