nik/lush
1
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Changes in opcodes for generic 'for'

Browse Source 
Again, as the control variable is read only, the code doesn't need
to keep an internal copy of it.
This commit is contained in:
Roberto Ierusalimschy
2022-12-22 13:52:53 -03:00
parent 873588dc5f
commit 7d4c7ae2af
3 changed files with 38 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
lparser.c
View File

@@ -1558,6 +1558,7 @@ static void forbody (LexState *ls, int base, int line, int nvars, int isgen) {
int prep, endfor;
checknext(ls, TK_DO);
prep = luaK_codeABx(fs, forprep[isgen], base, 0);
fs->freereg--; /* both 'forprep' remove one register from the stack */
enterblock(fs, &bl, 0); /* scope for declared variables */
adjustlocalvars(ls, nvars);
luaK_reserveregs(fs, nvars);
@@ -1591,8 +1592,7 @@ static void fornum (LexState *ls, TString *varname, int line) {
luaK_int(fs, fs->freereg, 1);
luaK_reserveregs(fs, 1);
}
adjustlocalvars(ls, 2); /* start scope for internal state variables */
fs->freereg--; /* OP_FORPREP removes one register from the stack */
adjustlocalvars(ls, 2); /* start scope for internal variables */
forbody(ls, base, line, 1, 0);
}
@@ -1601,14 +1601,13 @@ static void forlist (LexState *ls, TString *indexname) {
/* forlist -> NAME {,NAME} IN explist forbody */
FuncState *fs = ls->fs;
expdesc e;
int nvars = 5; /* gen, state, control, toclose, 'indexname' */
int nvars = 4; /* function, state, closing, control */
int line;
int base = fs->freereg;
/* create control variables */
new_localvarliteral(ls, "(for state)");
new_localvarliteral(ls, "(for state)");
new_localvarliteral(ls, "(for state)");
new_localvarliteral(ls, "(for state)");
/* create internal variables */
new_localvarliteral(ls, "(for state)"); /* iterator function */
new_localvarliteral(ls, "(for state)"); /* state */
new_localvarliteral(ls, "(for state)"); /* closing var. (after swap) */
new_localvarkind(ls, indexname, RDKCONST); /* control variable */
/* other declared variables */
while (testnext(ls, ',')) {
@@ -1618,10 +1617,10 @@ static void forlist (LexState *ls, TString *indexname) {
checknext(ls, TK_IN);
line = ls->linenumber;
adjust_assign(ls, 4, explist(ls, &e), &e);
adjustlocalvars(ls, 4); /* control variables */
marktobeclosed(fs); /* last control var. must be closed */
luaK_checkstack(fs, 3); /* extra space to call generator */
forbody(ls, base, line, nvars - 4, 1);
adjustlocalvars(ls, 3); /* start scope for internal variables */
marktobeclosed(fs); /* last internal var. must be closed */
luaK_checkstack(fs, 2); /* extra space to call iterator */
forbody(ls, base, line, nvars - 3, 1);
}