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optimize alt epsilon transition offsets

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This commit is contained in:
Kyryl Melekhin
2021-10-02 09:27:54 +00:00
parent f32e9c4478
commit 2bdc92d6ec
1 changed files with 8 additions and 2 deletions
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10
pike.c
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@@ -191,6 +191,7 @@ static int _compilecode(const char **re_loc, rcode *prog, int sizecode)
int *code = sizecode ? NULL : prog->insts;
int start = PC, term = PC;
int alt_label = 0, c;
int alt_stack[5000], altc = 0;
for (; *re && *re != ')';) {
switch (*re) {
@@ -362,7 +363,7 @@ static int _compilecode(const char **re_loc, rcode *prog, int sizecode)
break;
case '|':
if (alt_label)
EMIT(alt_label, REL(alt_label, PC) + 1);
alt_stack[altc++] = alt_label;
INSERT_CODE(start, 3, PC);
EMIT(PC++, JMP);
alt_label = PC++;
@@ -386,8 +387,13 @@ static int _compilecode(const char **re_loc, rcode *prog, int sizecode)
}
uc_len(c, re) re += c;
}
if (alt_label)
if (alt_label) {
EMIT(alt_label, REL(alt_label, PC) + 1);
for (int alts = altc; altc; altc--) {
int at = alt_stack[alts-altc]+altc*3;
EMIT(at, REL(at, PC) + 1);
}
}
*re_loc = re;
return RE_SUCCESS;
syntax_error: