pedroediaz/lexvm
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

optimize alt epsilon transition offsets

Browse Source
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
Download Patch File Download Diff File Expand all files Collapse all files

10
pike.c
View File

@@ -191,6 +191,7 @@ static int _compilecode(const char **re_loc, rcode *prog, int sizecode)
int *code = sizecode ? NULL : prog->insts; int *code = sizecode ? NULL : prog->insts;
int start = PC, term = PC; int start = PC, term = PC;
int alt_label = 0, c; int alt_label = 0, c;
int alt_stack[5000], altc = 0;
for (; *re && *re != ')';) { for (; *re && *re != ')';) {
switch (*re) { switch (*re) {
@@ -362,7 +363,7 @@ static int _compilecode(const char **re_loc, rcode *prog, int sizecode)
break; break;
case '|': case '|':
if (alt_label) if (alt_label)
EMIT(alt_label, REL(alt_label, PC) + 1); alt_stack[altc++] = alt_label;
INSERT_CODE(start, 3, PC); INSERT_CODE(start, 3, PC);
EMIT(PC++, JMP); EMIT(PC++, JMP);
alt_label = PC++; alt_label = PC++;
@@ -386,8 +387,13 @@ static int _compilecode(const char **re_loc, rcode *prog, int sizecode)
} }
uc_len(c, re) re += c; uc_len(c, re) re += c;
} }
if (alt_label) if (alt_label) {
EMIT(alt_label, REL(alt_label, PC) + 1); 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; *re_loc = re;
return RE_SUCCESS; return RE_SUCCESS;
syntax_error: syntax_error: