From 16d8a6ce56fd066efa9ecb1d3fa3b3dab6d9613c Mon Sep 17 00:00:00 2001 From: Lukas Larsson Date: Mon, 22 Sep 2014 12:00:05 +0200 Subject: erts: Fix ub in list_to_integer and bignum div --- erts/emulator/beam/big.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'erts/emulator/beam/big.c') diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c index a8710dd910..de7d370938 100644 --- a/erts/emulator/beam/big.c +++ b/erts/emulator/beam/big.c @@ -274,10 +274,9 @@ _b = _b << _s; \ _vn1 = _b >> H_EXP; \ _vn0 = _b & LO_MASK; \ - /* Sometimes _s is 0 which triggers undefined behaviour for the \ - (_a0>>(D_EXP-_s)) shift, but this is ok because the \ - & -s will make it all to 0 later anyways. */ \ - _un32 = (_a1 << _s) | ((_a0>>(D_EXP-_s)) & (-_s >> (D_EXP-1))); \ + /* If needed to avoid undefined behaviour */ \ + if (_s) _un32 = (_a1 << _s) | ((_a0>>(D_EXP-_s)) & (-_s >> (D_EXP-1))); \ + else _un32 = _a1; \ _un10 = _a0 << _s; \ _un1 = _un10 >> H_EXP; \ _un0 = _un10 & LO_MASK; \ -- cgit v1.2.3