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Fix UB in bool packetmath test.

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This commit is contained in:
Antonio Sánchez 2024-02-09 19:46:45 +00:00 committed by Rasmus Munk Larsen
parent 431e4a913b
commit 7b87b21910
3 changed files with 44 additions and 28 deletions
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32
Eigen/src/Core/GenericPacketMath.h
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@ -376,6 +376,12 @@ struct ptrue_impl {
}
};
// For booleans, we can only directly set a valid `bool` value to avoid UB.
template <>
struct ptrue_impl<bool, void> {
static EIGEN_DEVICE_FUNC inline bool run(const bool& /*a*/) { return true; }
};
// For non-trivial scalars, set to Scalar(1) (i.e. a non-zero value).
// Although this is technically not a valid bitmask, the scalar path for pselect
// uses a comparison to zero, so this should still work in most cases. We don't
@ -458,6 +464,32 @@ struct bit_not {
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR EIGEN_ALWAYS_INLINE T operator()(const T& a) const { return ~a; }
};
template <>
struct bit_and<bool> {
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR EIGEN_ALWAYS_INLINE bool operator()(const bool& a, const bool& b) const {
return a && b;
}
};
template <>
struct bit_or<bool> {
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR EIGEN_ALWAYS_INLINE bool operator()(const bool& a, const bool& b) const {
return a || b;
}
};
template <>
struct bit_xor<bool> {
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR EIGEN_ALWAYS_INLINE bool operator()(const bool& a, const bool& b) const {
return a != b;
}
};
template <>
struct bit_not<bool> {
EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR EIGEN_ALWAYS_INLINE bool operator()(const bool& a) const { return !a; }
};
// Use operators &, |, ^, ~.
template <typename T>
struct operator_bitwise_helper {

24
Eigen/src/Core/arch/SSE/PacketMath.h
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@ -527,7 +527,7 @@ EIGEN_STRONG_INLINE Packet4i pnegate(const Packet4i& a) {
template <>
EIGEN_STRONG_INLINE Packet16b pnegate(const Packet16b& a) {
return psub(pset1<Packet16b>(false), a);
return a;
}
template <>
@ -677,18 +677,6 @@ template <>
EIGEN_DEVICE_FUNC inline Packet2d pselect(const Packet2d& mask, const Packet2d& a, const Packet2d& b) {
return _mm_blendv_pd(b, a, mask);
}
template <>
EIGEN_DEVICE_FUNC inline Packet16b pselect(const Packet16b& mask, const Packet16b& a, const Packet16b& b) {
return _mm_blendv_epi8(b, a, mask);
}
#else
template <>
EIGEN_DEVICE_FUNC inline Packet16b pselect(const Packet16b& mask, const Packet16b& a, const Packet16b& b) {
Packet16b a_part = _mm_and_si128(mask, a);
Packet16b b_part = _mm_andnot_si128(mask, b);
return _mm_or_si128(a_part, b_part);
}
#endif
template <>
@ -696,8 +684,8 @@ EIGEN_STRONG_INLINE Packet4i ptrue<Packet4i>(const Packet4i& a) {
return _mm_cmpeq_epi32(a, a);
}
template <>
EIGEN_STRONG_INLINE Packet16b ptrue<Packet16b>(const Packet16b& a) {
return _mm_cmpeq_epi8(a, a);
EIGEN_STRONG_INLINE Packet16b ptrue<Packet16b>(const Packet16b& /*a*/) {
return pset1<Packet16b>(true);
}
template <>
EIGEN_STRONG_INLINE Packet4f ptrue<Packet4f>(const Packet4f& a) {
@ -838,7 +826,9 @@ EIGEN_STRONG_INLINE Packet4ui pcmp_eq(const Packet4ui& a, const Packet4ui& b) {
}
template <>
EIGEN_STRONG_INLINE Packet16b pcmp_eq(const Packet16b& a, const Packet16b& b) {
return _mm_cmpeq_epi8(a, b);
// Mask out invalid bool bits to avoid UB.
const Packet16b kBoolMask = pset1<Packet16b>(true);
return _mm_and_si128(_mm_cmpeq_epi8(a, b), kBoolMask);
}
template <>
EIGEN_STRONG_INLINE Packet4i pcmp_le(const Packet4i& a, const Packet4i& b) {
@ -1377,7 +1367,7 @@ EIGEN_STRONG_INLINE void pstoreu<uint32_t>(uint32_t* to, const Packet4ui& from)
}
template <>
EIGEN_STRONG_INLINE void pstoreu<bool>(bool* to, const Packet16b& from) {
EIGEN_DEBUG_ALIGNED_STORE _mm_storeu_si128(reinterpret_cast<__m128i*>(to), from);
EIGEN_DEBUG_UNALIGNED_STORE _mm_storeu_si128(reinterpret_cast<__m128i*>(to), from);
}
template <typename Scalar, typename Packet>

16
test/packetmath.cpp
View File

@ -382,12 +382,6 @@ struct packetmath_boolean_mask_ops_notcomplex_test<
}
};
// Packet16b representing bool does not support ptrue, pandnot or pcmp_eq, since
// the scalar path (for some compilers) compute the bitwise and with 0x1 of the
// results to keep the value in [0,1].
template <>
void packetmath_boolean_mask_ops<bool, internal::packet_traits<bool>::type>() {}
template <typename Scalar, typename Packet, typename EnableIf = void>
struct packetmath_minus_zero_add_test {
static void run() {}
@ -662,11 +656,11 @@ void packetmath() {
{
for (int i = 0; i < PacketSize; ++i) {
// "if" mask
unsigned char v = internal::random<bool>() ? 0xff : 0;
char* bytes = (char*)(data1 + i);
for (int k = 0; k < int(sizeof(Scalar)); ++k) {
bytes[k] = v;
}
// Note: it's UB to load 0xFF directly into a `bool`.
uint8_t v =
internal::random<bool>() ? (std::is_same<Scalar, bool>::value ? static_cast<uint8_t>(true) : 0xff) : 0;
// Avoid strict aliasing violation by using memset.
memset(data1 + i, v, sizeof(Scalar));
// "then" packet
data1[i + PacketSize] = internal::random<Scalar>();
// "else" packet