commit c3d72096c4841ebc04a0615917d71f22aaa5e5ff
parent 7afc74ff07907294a2162600023a9c61a64cdbd5
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 27 Aug 2001 12:16:06 -0300
use a table to find (and reuse) constants when parsing
Diffstat:
6 files changed, 32 insertions(+), 38 deletions(-)
diff --git a/lcode.c b/lcode.c
@@ -1,5 +1,5 @@
/*
-** $Id: lcode.c,v 1.77 2001/07/17 14:30:44 roberto Exp roberto $
+** $Id: lcode.c,v 1.78 2001/07/24 17:19:07 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -18,6 +18,7 @@
#include "lobject.h"
#include "lopcodes.h"
#include "lparser.h"
+#include "ltable.h"
#define hasjumps(e) ((e)->t != (e)->f)
@@ -222,38 +223,33 @@ static void freeexp (FuncState *fs, expdesc *e) {
static int addk (FuncState *fs, TObject *k) {
- Proto *f = fs->f;
- luaM_growvector(fs->L, f->k, fs->nk, f->sizek, TObject,
- MAXARG_Bc, l_s("constant table overflow"));
- setobj(&f->k[fs->nk], k);
- return fs->nk++;
+ const TObject *index = luaH_get(fs->h, k);
+ if (ttype(index) == LUA_TNUMBER) {
+ lua_assert(luaO_equalObj(&fs->f->k[(int)nvalue(index)], k));
+ return (int)nvalue(index);
+ }
+ else { /* constant not found; create a new entry */
+ TObject o;
+ Proto *f = fs->f;
+ luaM_growvector(fs->L, f->k, fs->nk, f->sizek, TObject,
+ MAXARG_Bc, l_s("constant table overflow"));
+ setobj(&f->k[fs->nk], k);
+ setnvalue(&o, fs->nk);
+ setobj(luaH_set(fs->L, fs->h, k), &o);
+ return fs->nk++;
+ }
}
int luaK_stringk (FuncState *fs, TString *s) {
- Proto *f = fs->f;
- int c = s->tsv.constindex;
- if (c >= fs->nk || ttype(&f->k[c]) != LUA_TSTRING || tsvalue(&f->k[c]) != s) {
- TObject o;
- setsvalue(&o, s);
- c = addk(fs, &o);
- s->tsv.constindex = (unsigned short)c; /* hint for next time */
- }
- return c;
+ TObject o;
+ setsvalue(&o, s);
+ return addk(fs, &o);
}
static int number_constant (FuncState *fs, lua_Number r) {
- /* check whether `r' has appeared within the last LOOKBACKNUMS entries */
TObject o;
- Proto *f = fs->f;
- int c = fs->nk;
- int lim = c < LOOKBACKNUMS ? 0 : c-LOOKBACKNUMS;
- while (--c >= lim) {
- if (ttype(&f->k[c]) == LUA_TNUMBER && nvalue(&f->k[c]) == r)
- return c;
- }
- /* not found; create a new entry */
setnvalue(&o, r);
return addk(fs, &o);
}
diff --git a/llimits.h b/llimits.h
@@ -1,5 +1,5 @@
/*
-** $Id: llimits.h,v 1.29 2001/06/05 18:17:01 roberto Exp roberto $
+** $Id: llimits.h,v 1.30 2001/06/05 20:01:09 roberto Exp roberto $
** Limits, basic types, and some other `installation-dependent' definitions
** See Copyright Notice in lua.h
*/
@@ -124,10 +124,4 @@ typedef unsigned long Instruction;
-/* maximum lookback to find a real constant (for code generation) */
-#ifndef LOOKBACKNUMS
-#define LOOKBACKNUMS 40 /* arbitrary constant */
-#endif
-
-
#endif
diff --git a/lobject.h b/lobject.h
@@ -1,5 +1,5 @@
/*
-** $Id: lobject.h,v 1.108 2001/06/28 14:48:44 roberto Exp roberto $
+** $Id: lobject.h,v 1.109 2001/06/28 14:56:25 roberto Exp roberto $
** Type definitions for Lua objects
** See Copyright Notice in lua.h
*/
@@ -90,8 +90,7 @@ typedef union TString {
struct {
lu_hash hash;
size_t len;
- unsigned short constindex; /* hint to reuse constants */
- short marked;
+ int marked;
union TString *nexthash; /* chain for hash table */
} tsv;
} TString;
diff --git a/lparser.c b/lparser.c
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.c,v 1.152 2001/07/10 20:02:22 roberto Exp roberto $
+** $Id: lparser.c,v 1.153 2001/08/10 20:53:03 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@@ -318,6 +318,7 @@ static void open_func (LexState *ls, FuncState *fs) {
fs->jlt = NO_JUMP;
fs->freereg = 0;
fs->nk = 0;
+ fs->h = luaH_new(ls->L, 0);
fs->np = 0;
fs->nlineinfo = 0;
fs->nlocvars = 0;
@@ -339,6 +340,9 @@ static void close_func (LexState *ls) {
luaK_codeABC(fs, OP_RETURN, 0, 0, 0); /* final return */
luaK_getlabel(fs); /* close eventual list of pending jumps */
removelocalvars(ls, fs->nactloc);
+ lua_assert(G(L)->roottable == fs->h);
+ G(L)->roottable = fs->h->next;
+ luaH_free(L, fs->h);
luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
f->sizecode = fs->pc;
luaM_reallocvector(L, f->k, f->sizek, fs->nk, TObject);
diff --git a/lparser.h b/lparser.h
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.h,v 1.32 2001/06/28 14:56:25 roberto Exp roberto $
+** $Id: lparser.h,v 1.33 2001/08/10 20:53:03 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@@ -8,6 +8,7 @@
#define lparser_h
#include "lobject.h"
+#include "ltable.h"
#include "lzio.h"
@@ -53,6 +54,7 @@ typedef struct FuncState {
int jlt; /* list of jumps to `lasttarget' */
int freereg; /* first free register */
int nk; /* number of elements in `k' */
+ Hash *h; /* table to find (and reuse) elements in `k' */
int np; /* number of elements in `p' */
int nlineinfo; /* number of elements in `lineinfo' */
int nlocvars; /* number of elements in `locvars' */
diff --git a/lstring.c b/lstring.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstring.c,v 1.64 2001/06/07 15:01:21 roberto Exp roberto $
+** $Id: lstring.c,v 1.65 2001/06/15 20:36:57 roberto Exp roberto $
** String table (keeps all strings handled by Lua)
** See Copyright Notice in lua.h
*/
@@ -54,7 +54,6 @@ static TString *newlstr (lua_State *L, const l_char *str, size_t l, lu_hash h) {
ts->tsv.len = l;
ts->tsv.hash = h;
ts->tsv.marked = 0;
- ts->tsv.constindex = 0;
memcpy(getstr(ts), str, l*sizeof(l_char));
getstr(ts)[l] = l_c('\0'); /* ending 0 */
tb = &G(L)->strt;
