commit 1b4480003b1bfa7e1d34e587ebd19a9de63c6467
parent 42167804b89b26428dea98b97549892c24623d71
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 10 Aug 2009 12:31:20 -0300
"stange numbers" (-0 and NaN) also go to the constant table (as
strings with their binary representation). Therefore, constant
folding may produce these results.
Diffstat:
M | lcode.c | | | 45 | +++++++++++++++++++++++++++++---------------- |
1 file changed, 29 insertions(+), 16 deletions(-)
diff --git a/lcode.c b/lcode.c
@@ -1,5 +1,5 @@
/*
-** $Id: lcode.c,v 2.39 2009/06/17 17:49:09 roberto Exp roberto $
+** $Id: lcode.c,v 2.40 2009/06/18 16:35:05 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -21,6 +21,7 @@
#include "lobject.h"
#include "lopcodes.h"
#include "lparser.h"
+#include "lstring.h"
#include "ltable.h"
@@ -224,22 +225,24 @@ static int addk (FuncState *fs, TValue *key, TValue *v) {
lua_State *L = fs->L;
TValue *idx = luaH_set(L, fs->h, key);
Proto *f = fs->f;
- int k;
+ int k, oldsize;
if (ttisnumber(idx)) {
lua_Number n = nvalue(idx);
lua_number2int(k, n);
- lua_assert(luaO_rawequalObj(&f->k[k], v));
- }
- else { /* constant not found; create a new entry */
- int oldsize = f->sizek;
- k = fs->nk;
- setnvalue(idx, cast_num(k));
- luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Bx, "constants");
- while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
- setobj(L, &f->k[k], v);
- fs->nk++;
- luaC_barrier(L, f, v);
+ if (luaO_rawequalObj(&f->k[k], v))
+ return k;
+ /* else may be a collision (e.g., between 0.0 and "\0\0\0\0\0\0\0\0");
+ go through and create a new entry for this value */
}
+ /* constant not found; create a new entry */
+ oldsize = f->sizek;
+ k = fs->nk;
+ setnvalue(idx, cast_num(k));
+ luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Bx, "constants");
+ while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
+ setobj(L, &f->k[k], v);
+ fs->nk++;
+ luaC_barrier(L, f, v);
return k;
}
@@ -252,9 +255,20 @@ int luaK_stringK (FuncState *fs, TString *s) {
int luaK_numberK (FuncState *fs, lua_Number r) {
+ int n;
+ lua_State *L = fs->L;
TValue o;
setnvalue(&o, r);
- return addk(fs, &o, &o);
+ if (r == 0 || luai_numisnan(NULL, r)) { /* handle -0 and NaN */
+ /* use raw representation as key to avoid numeric problems */
+ setsvalue(L, L->top, luaS_newlstr(L, (char *)&r, sizeof(r)));
+ incr_top(L);
+ n = addk(fs, L->top - 1, &o);
+ L->top--;
+ }
+ else
+ n = addk(fs, &o, &o); /* regular case */
+ return n;
}
@@ -643,7 +657,6 @@ static int constfolding (OpCode op, expdesc *e1, expdesc *e2) {
if ((op == OP_DIV || op == OP_MOD) && e2->u.nval == 0)
return 0; /* do not attempt to divide by 0 */
r = luaO_arith(op - OP_ADD + LUA_OPADD, e1->u.nval, e2->u.nval);
- if (luai_numisnan(NULL, r)) return 0; /* do not attempt to produce NaN */
e1->u.nval = r;
return 1;
}
@@ -690,7 +703,7 @@ void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e) {
e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0;
switch (op) {
case OPR_MINUS: {
- if (isnumeral(e) && e->u.nval != 0) /* minus non-zero constant? */
+ if (isnumeral(e)) /* minus constant? */
e->u.nval = luai_numunm(NULL, e->u.nval); /* fold it */
else {
luaK_exp2anyreg(fs, e);