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X-Received-From: 2a00:1450:4864:20::344 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , QEMU Developers , Aurelien Jarno Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Aleksandar Markovic writes: > 11:53 Pet, 27.03.2020. Alex Benn=C3=A9e =D1=98= =D0=B5 =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BE/=D0=BB=D0=B0: >> >> The undefined behaviour checker > > Alex, what exactly is "undefined behaviour checker"? If this is a test, c= an > you give us a link? It's enabled by our sanitizers build: ../../configure --cc=3Dclang-8 --cxx=3Dclang++-8 --enable-sanitizers > > Sincerely, > Aleksandar > >> pointed out that a shift of 64 would >> lead to undefined behaviour. >> >> Signed-off-by: Alex Benn=C3=A9e >> --- >> fpu/softfloat.c | 11 ++++++++--- >> 1 file changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/fpu/softfloat.c b/fpu/softfloat.c >> index 301ce3b537b..444d35920dd 100644 >> --- a/fpu/softfloat.c >> +++ b/fpu/softfloat.c >> @@ -3834,9 +3834,14 @@ void normalizeFloatx80Subnormal(uint64_t aSig, > int32_t *zExpPtr, >> { >> int8_t shiftCount; >> >> - shiftCount =3D clz64(aSig); >> - *zSigPtr =3D aSig<> - *zExpPtr =3D 1 - shiftCount; >> + if (aSig) { >> + shiftCount =3D clz64(aSig); >> + *zSigPtr =3D aSig << shiftCount; >> + *zExpPtr =3D 1 - shiftCount; >> + } else { >> + *zSigPtr =3D 0; >> + *zExpPtr =3D 1 - 64; >> + } >> } >> >> > /*----------------------------------------------------------------------= ------ >> -- >> 2.20.1 >> >> --=20 Alex Benn=C3=A9e