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small optimizations.

v5-2
Roberto Ierusalimschy 25 years ago
parent
977b8f65f0
commit
3d0577f4b9
4 changed files with 89 additions and 50 deletions
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  1. 118
      lcode.c
  2. 14
      lstring.c
  3. 4
      lstring.h
  4. 3
      lvm.c

118
lcode.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lcode.c,v 1.5 2000/03/03 20:30:47 roberto Exp roberto $
** $Id: lcode.c,v 1.8 2000/03/09 13:57:37 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@ -100,6 +100,28 @@ static void luaK_conc (LexState *ls) {
}
static void luaK_eq (LexState *ls) {
Instruction *previous = previous_instruction(ls);
if (*previous == CREATE_U(PUSHNIL, 1)) {
*previous = CREATE_0(NOTOP);
luaK_deltastack(ls, -1); /* undo effect of PUSHNIL */
}
else
luaK_S(ls, IFEQJMP, 0, -2);
}
static void luaK_neq (LexState *ls) {
Instruction *previous = previous_instruction(ls);
if (*previous == CREATE_U(PUSHNIL, 1)) {
ls->fs->pc--; /* remove PUSHNIL */
luaK_deltastack(ls, -1); /* undo effect of PUSHNIL */
}
else
luaK_S(ls, IFNEQJMP, 0, -2);
}
void luaK_retcode (LexState *ls, int nlocals, int nexps) {
Instruction *previous = previous_instruction(ls);
if (nexps > 0 && GET_OPCODE(*previous) == CALL) {
@ -116,9 +138,7 @@ static void luaK_pushnil (LexState *ls, int n) {
Instruction *previous = previous_instruction(ls);
luaK_deltastack(ls, n);
switch(GET_OPCODE(*previous)) {
case PUSHNIL:
SETARG_U(*previous, GETARG_U(*previous)+n);
break;
case PUSHNIL: SETARG_U(*previous, GETARG_U(*previous)+n); break;
default: luaK_primitivecode(ls, CREATE_U(PUSHNIL, n));
}
}
@ -281,6 +301,8 @@ static OpCode invertjump (OpCode op) {
case IFLEJMP: return IFGTJMP;
case IFGTJMP: return IFLEJMP;
case IFGEJMP: return IFLTJMP;
case IFTJMP: case ONTJMP: return IFFJMP;
case IFFJMP: case ONFJMP: return IFTJMP;
default:
LUA_INTERNALERROR(NULL, "invalid jump instruction");
return ENDCODE; /* to avoid warnings */
@ -288,13 +310,23 @@ static OpCode invertjump (OpCode op) {
}
static void luaK_jump (LexState *ls, OpCode jump) {
Instruction *previous = previous_instruction(ls);
luaK_deltastack(ls, -1);
if (*previous == CREATE_0(NOTOP))
*previous = CREATE_S(invertjump(jump), 0);
else
luaK_primitivecode(ls, CREATE_S(jump, 0));
}
static void insert_last (FuncState *fs, int *list) {
int temp = *list;
*list = fs->pc-1;
if (temp == 0) /* chain list */
int first = *list;
*list = fs->pc-1; /* insert last instruction in the list */
if (first == 0)
SETARG_S(fs->f->code[*list], 0);
else
SETARG_S(fs->f->code[*list], temp-fs->pc);
SETARG_S(fs->f->code[*list], first-fs->pc);
}
@ -305,18 +337,18 @@ static void luaK_patchlistaux (LexState *ls, int list, int target,
for (;;) {
Instruction *i = &code[list];
OpCode op = GET_OPCODE(*i);
int temp = GETARG_S(*i);
if (op == special)
int next = GETARG_S(*i);
if (op == special) /* this `op' already has a value */
SETARG_S(*i, special_target-(list+1));
else {
SETARG_S(*i, target-(list+1));
if (op == ONTJMP)
SETARG_S(*i, target-(list+1)); /* do the patch */
if (op == ONTJMP) /* remove eventual values */
SET_OPCODE(*i, IFTJMP);
else if (op == ONFJMP)
SET_OPCODE(*i, IFFJMP);
}
if (temp == 0) return;
list += temp+1;
if (next == 0) return;
list += next+1;
}
}
}
@ -327,15 +359,15 @@ void luaK_patchlist (LexState *ls, int list, int target) {
}
static int has_jumps (FuncState *fs, int list, OpCode ignore) {
static int need_value (FuncState *fs, int list, OpCode hasvalue) {
if (list == 0) return 0;
else {
else { /* check whether list has a jump without a value */
Instruction *code = fs->f->code;
for (;;) {
int temp = GETARG_S(code[list]);
if (GET_OPCODE(code[list]) != ignore) return 1;
else if (temp == 0) return 0;
list += temp+1;
int next = GETARG_S(code[list]);
if (GET_OPCODE(code[list]) != hasvalue) return 1;
else if (next == 0) return 0;
list += next+1;
}
}
}
@ -348,12 +380,12 @@ static void concatlists (LexState *ls, int *l1, int l2) {
FuncState *fs = ls->fs;
int list = *l1;
for (;;) { /* traverse `l1' */
int temp = GETARG_S(fs->f->code[list]);
if (temp == 0) { /* end of list? */
int next = GETARG_S(fs->f->code[list]);
if (next == 0) { /* end of list? */
SETARG_S(fs->f->code[list], l2-(list+1)); /* end points to `l2' */
return;
}
list += temp+1;
list += next+1;
}
}
}
@ -368,7 +400,7 @@ void luaK_goiftrue (LexState *ls, expdesc *v, int keepvalue) {
SET_OPCODE(*previous, invertjump(GET_OPCODE(*previous)));
else {
OpCode jump = keepvalue ? ONFJMP : IFFJMP;
luaK_S(ls, jump, 0, -1);
luaK_jump(ls, jump);
}
insert_last(fs, &v->u.l.f);
luaK_patchlist(ls, v->u.l.t, luaK_getlabel(ls));
@ -378,12 +410,12 @@ void luaK_goiftrue (LexState *ls, expdesc *v, int keepvalue) {
void luaK_goiffalse (LexState *ls, expdesc *v, int keepvalue) {
FuncState *fs = ls->fs;
Instruction *previous;
Instruction previous;
discharge1(ls, v);
previous = &fs->f->code[fs->pc-1];
if (!ISJUMP(GET_OPCODE(*previous))) {
previous = fs->f->code[fs->pc-1];
if (!ISJUMP(GET_OPCODE(previous))) {
OpCode jump = keepvalue ? ONTJMP : IFTJMP;
luaK_S(ls, jump, 0, -1);
luaK_jump(ls, jump);
}
insert_last(fs, &v->u.l.t);
luaK_patchlist(ls, v->u.l.f, luaK_getlabel(ls));
@ -395,8 +427,8 @@ void luaK_tostack (LexState *ls, expdesc *v, int onlyone) {
if (discharge(ls, v)) return;
else { /* is an expression */
FuncState *fs = ls->fs;
Instruction *previous = &fs->f->code[fs->pc-1];
if (!ISJUMP(GET_OPCODE(*previous)) && v->u.l.f == 0 && v->u.l.t == 0) {
OpCode previous = GET_OPCODE(fs->f->code[fs->pc-1]);
if (!ISJUMP(previous) && v->u.l.f == 0 && v->u.l.t == 0) {
/* it is an expression without jumps */
if (onlyone && v->k == VEXP)
luaK_setcallreturns(ls, 1); /* call must return 1 value */
@ -406,25 +438,25 @@ void luaK_tostack (LexState *ls, expdesc *v, int onlyone) {
int p_nil = 0; /* position of an eventual PUSHNIL */
int p_1 = 0; /* position of an eventual PUSHINT */
int final; /* position after whole expression */
if (ISJUMP(GET_OPCODE(*previous))) {
insert_last(fs, &v->u.l.t);
if (ISJUMP(previous)) {
insert_last(fs, &v->u.l.t); /* put `previous' in true list */
p_nil = luaK_0(ls, PUSHNILJMP, 0);
p_1 = luaK_S(ls, PUSHINT, 1, 1);
}
else { /* still may need a PUSHNIL or a PUSHINT */
int need_nil = has_jumps(fs, v->u.l.f, ONFJMP); /* needs a PUSHNIL? */
int need_1 = has_jumps(fs, v->u.l.t, ONTJMP); /* needs a PUSHINT? */
int need_nil = need_value(fs, v->u.l.f, ONFJMP);
int need_1 = need_value(fs, v->u.l.t, ONTJMP);
if (need_nil && need_1) {
luaK_S(ls, JMP, 2, 0);
luaK_S(ls, JMP, 2, 0); /* skip both pushes */
p_nil = luaK_0(ls, PUSHNILJMP, 0);
p_1 = luaK_S(ls, PUSHINT, 1, 1);
p_1 = luaK_S(ls, PUSHINT, 1, 0);
}
else if (need_nil || need_1) {
luaK_S(ls, JMP, 1, 0);
luaK_S(ls, JMP, 1, 0); /* skip one push */
if (need_nil)
p_nil = luaK_0(ls, PUSHNIL, 1);
p_nil = luaK_U(ls, PUSHNIL, 1, 0);
else /* need_1 */
p_1 = luaK_S(ls, PUSHINT, 1, 1);
p_1 = luaK_S(ls, PUSHINT, 1, 0);
}
}
final = luaK_getlabel(ls);
@ -462,7 +494,7 @@ void luaK_infix (LexState *ls, int op, expdesc *v) {
else if (op == OR)
luaK_goiffalse(ls, v, 1);
else
luaK_tostack(ls, v, 1);
luaK_tostack(ls, v, 1); /* all other binary operators need a value */
}
@ -480,7 +512,7 @@ void luaK_posfix (LexState *ls, int op, expdesc *v1, expdesc *v2) {
concatlists(ls, &v1->u.l.t, v2->u.l.t);
}
else {
luaK_tostack(ls, v2, 1); /* `v2' must have a value */
luaK_tostack(ls, v2, 1); /* `v2' must be a value */
switch (op) {
case '+': luaK_add(ls); break;
case '-': luaK_sub(ls); break;
@ -488,8 +520,8 @@ void luaK_posfix (LexState *ls, int op, expdesc *v1, expdesc *v2) {
case '/': luaK_0(ls, DIVOP, -1); break;
case '^': luaK_0(ls, POWOP, -1); break;
case CONC: luaK_conc(ls); break;
case EQ: luaK_S(ls, IFEQJMP, 0, -2); break;
case NE: luaK_S(ls, IFNEQJMP, 0, -2); break;
case EQ: luaK_eq(ls); break;
case NE: luaK_neq(ls); break;
case '>': luaK_S(ls, IFGTJMP, 0, -2); break;
case '<': luaK_S(ls, IFLTJMP, 0, -2); break;
case GE: luaK_S(ls, IFGEJMP, 0, -2); break;

14
lstring.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lstring.c,v 1.31 1999/12/14 18:42:57 roberto Exp roberto $
** $Id: lstring.c,v 1.32 2000/03/03 14:58:26 roberto Exp roberto $
** String table (keeps all strings handled by Lua)
** See Copyright Notice in lua.h
*/
@ -46,8 +46,9 @@ void luaS_freeall (lua_State *L) {
static unsigned long hash_s (const char *s, long l) {
unsigned long h = l; /* seed */
while (l--)
h = h ^ ((h<<5)+(h>>2)+(unsigned char)*(s++));
long step = (l>>6)+1; /* if string is too long, don't hash all its chars */
for (; l>0; l-=step)
h = h ^ ((h<<5)+(h>>2)+(unsigned char)*(s++));
return h;
}
@ -120,7 +121,8 @@ static void newentry (lua_State *L, stringtable *tb, TaggedString *ts, int h) {
TaggedString *luaS_newlstr (lua_State *L, const char *str, long l) {
unsigned long h = hash_s(str, l);
stringtable *tb = &L->string_root[h%NUM_HASHSTR];
stringtable *tb = &L->string_root[(l==0) ? 0 :
((unsigned int)(str[0]+str[l-1]))&(NUM_HASHSTR-1)];
int h1 = h&(tb->size-1);
TaggedString *ts;
for (ts = tb->hash[h1]; ts; ts = ts->nexthash) {
@ -134,6 +136,10 @@ TaggedString *luaS_newlstr (lua_State *L, const char *str, long l) {
}
/*
** uses '%' for one hashing with userdata because addresses are too regular,
** so two '&' operations would be highly correlated
*/
TaggedString *luaS_createudata (lua_State *L, void *udata, int tag) {
unsigned long h = IntPoint(L, udata);
stringtable *tb = &L->string_root[(h%NUM_HASHUDATA)+NUM_HASHSTR];

4
lstring.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lstring.h,v 1.15 1999/12/14 18:42:57 roberto Exp roberto $
** $Id: lstring.h,v 1.16 2000/03/03 14:58:26 roberto Exp roberto $
** String table (keep all strings handled by Lua)
** See Copyright Notice in lua.h
*/
@ -12,7 +12,7 @@
#include "lstate.h"
#define NUM_HASHSTR 31
#define NUM_HASHSTR 32
#define NUM_HASHUDATA 31
#define NUM_HASHS (NUM_HASHSTR+NUM_HASHUDATA)

3
lvm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 1.90 2000/03/03 14:58:26 roberto Exp roberto $
** $Id: lvm.c,v 1.93 2000/03/09 13:57:37 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -360,6 +360,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, const TProtoFunc *tf,
case PUSHNIL: {
int n = GETARG_U(i);
LUA_ASSERT(L, n>0, "invalid argument");
do {
ttype(top++) = LUA_T_NIL;
} while (--n > 0);

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