From f45177f2d325d76e0622109ddf4f534a05e721e8 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Thu, 20 Jun 2013 14:37:31 -0300
Subject: In the table that hashes constants, use a light userdata as keys to
integer values to avoid collisions with floats with the same numerical value
---
lcode.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
(limited to 'lcode.c')
diff --git a/lcode.c b/lcode.c
index ffb263f7..208b2f9a 100644
--- a/lcode.c
+++ b/lcode.c
@@ -1,5 +1,5 @@
/*
-** $Id: lcode.c,v 2.68 2013/05/02 12:37:24 roberto Exp roberto $
+** $Id: lcode.c,v 2.69 2013/05/06 17:22:16 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -333,9 +333,12 @@ int luaK_stringK (FuncState *fs, TString *s) {
int luaK_intK (FuncState *fs, lua_Integer n) {
- TValue o;
+ TValue k, o;
+ /* use userdata as key to avoid collision with float with same value;
+ conversion to 'void*' used only for hash, no "precision" problems */
+ setpvalue(&k, cast(void*, cast(size_t, n)));
setivalue(&o, n);
- return addk(fs, &o, &o);
+ return addk(fs, &k, &o);
}
@@ -344,17 +347,14 @@ static int luaK_numberK (FuncState *fs, lua_Number r) {
lua_State *L = fs->ls->L;
TValue o;
setnvalue(&o, r);
- if (r == 0 || luai_numisnan(NULL, r)) { /* handle -0 and NaN */
+ if (r != 0 && !luai_numisnan(NULL, r)) /* avoid -0 and NaN */
+ n = addk(fs, &o, &o); /* regular case */
+ else { /* handle -0 and NaN */
/* use raw representation as key to avoid numeric problems */
setsvalue(L, L->top++, luaS_newlstr(L, (char *)&r, sizeof(r)));
n = addk(fs, L->top - 1, &o);
L->top--;
}
- else {
- TValue k;
- setnvalue(&k, r + 0.5); /* ???? (avoid some collisions with ints) */
- n = addk(fs, &k, &o); /* regular case */
- }
return n;
}
--
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