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author | Mike Pall <mike> | 2022-12-22 00:03:06 +0100 |
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committer | Mike Pall <mike> | 2022-12-22 00:03:06 +0100 |
commit | 8a5e398c52c7f8ca3e1a0e574cc2ba38224b759b (patch) | |
tree | dae089564f58db2963bae8e3530c1faae104cc61 /src/lj_carith.c | |
parent | b2791179ef96d652d00d78d2a8780af690537f6a (diff) | |
download | luajit2-8a5e398c52c7f8ca3e1a0e574cc2ba38224b759b.tar.gz |
Avoid negation of signed integers in C that may hold INT*_MIN.
Reported by minoki.
Recent C compilers 'take advantage' of the undefined behavior.
This completely changes the meaning of expressions like (k == -k).
Diffstat (limited to 'src/lj_carith.c')
-rw-r--r-- | src/lj_carith.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/lj_carith.c b/src/lj_carith.c index 462dbae4..231d7a8a 100644 --- a/src/lj_carith.c +++ b/src/lj_carith.c @@ -205,7 +205,7 @@ static int carith_int64(lua_State *L, CTState *cts, CDArith *ca, MMS mm) else *up = lj_carith_powu64(u0, u1); break; - case MM_unm: *up = (uint64_t)-(int64_t)u0; break; + case MM_unm: *up = ~u0+1u; break; default: lua_assert(0); break; } lj_gc_check(L); |