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bc: remove redundant JUMP generation when parsing 'while'

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function                                             old     new   delta
zbc_parse_stmt_possibly_auto                        2065    2025     -40
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-40)             Total: -40 bytes
   text	   data	    bss	    dec	    hex	filename
 982035	    485	   7296	 989816	  f1a78	busybox_old
 981995	    485	   7296	 989776	  f1a50	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-16 23:02:22 +01:00
parent 06ade77002
commit de24e9d366
2 changed files with 32 additions and 11 deletions
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16
miscutils/bc.c
View File

@ -4175,7 +4175,7 @@ static BC_STATUS zbc_parse_while(BcParse *p)
BcStatus s;
BcInstPtr ip;
size_t *label;
size_t n;
size_t cond_idx;
s = zbc_lex_next(&p->l);
if (s) RETURN_STATUS(s);
@ -4183,10 +4183,10 @@ static BC_STATUS zbc_parse_while(BcParse *p)
s = zbc_lex_next(&p->l);
if (s) RETURN_STATUS(s);
ip.idx = p->func->labels.len;
cond_idx = p->func->labels.len;
bc_vec_push(&p->func->labels, &p->func->code.len);
bc_vec_push(&p->conds, &ip.idx);
bc_vec_push(&p->conds, &cond_idx);
ip.idx = p->func->labels.len;
ip.func = 1;
@ -4209,15 +4209,9 @@ static BC_STATUS zbc_parse_while(BcParse *p)
s = zbc_parse_stmt_fail_if_bare_NLINE(p, false, "while");
if (s) RETURN_STATUS(s);
n = *((size_t *) bc_vec_top(&p->conds));
dbg_lex("%s:%d BC_INST_JUMP to %d", __func__, __LINE__, cond_idx);
bc_parse_push(p, BC_INST_JUMP);
bc_parse_pushIndex(p, n);
label = bc_vec_top(&p->conds);
dbg_lex("%s:%d BC_INST_JUMP to %d", __func__, __LINE__, *label);
bc_parse_push(p, BC_INST_JUMP);
bc_parse_pushIndex(p, *label);
bc_parse_pushIndex(p, cond_idx);
label = bc_vec_item(&p->func->labels, ip.idx);
dbg_lex("%s:%d rewriting label: %d -> %d", __func__, __LINE__, *label, p->func->code.len);

27
testsuite/bc.tests
View File

@ -107,6 +107,33 @@ if(1) {
99
"
testing "bc continue in if" \
"bc" \
"\
11
21
11
31
99
" \
"" "\
i=2
while(i--) {
11
if(i) {
21
continue
22
} else {
31
continue
32
}
12
}
99
"
tar xJf bc_large.tar.xz
for f in bc*.bc; do