Unify scalar, batch, and batch_bool in some places

docs/source/api/type_traits.rst

@@ -32,9 +32,15 @@ Type Traits
 ===========
 
 `xsimd` provides a few type traits to interact with scalar and batch types in an
-uniformeous manner.
+uniform manner.
 
 
+Combined traits:
+
++---------------------------------------+----------------------------------------------------+
+| :cpp:class:`batch_traits`             | batch types and proprties                          |
++---------------------------------------+----------------------------------------------------+
+
 Type check:
 
 +---------------------------------------+----------------------------------------------------+

include/xsimd/arch/common/xsimd_common_logical.hpp

@@ -212,6 +212,35 @@ namespace xsimd
                     res |= 1ul << i;
             return res;
         }
+
+        // select
+        namespace detail
+        {
+            template <typename T, typename A>
+            using is_batch_bool_register_same = std::is_same<typename batch_bool<T, A>::register_type, typename batch<T, A>::register_type>;
+        }
+
+        template <class A, class T, typename std::enable_if<detail::is_batch_bool_register_same<T, A>::value, int>::type = 3>
+        XSIMD_INLINE batch_bool<T, A> select(batch_bool<T, A> const& cond, batch_bool<T, A> const& true_br, batch_bool<T, A> const& false_br, requires_arch<common>)
+        {
+            using register_type = typename batch_bool<T, A>::register_type;
+            // Do not cast, but rather reinterpret the masks as batches.
+            const auto true_v = batch<T, A> { static_cast<register_type>(true_br) };
+            const auto false_v = batch<T, A> { static_cast<register_type>(false_br) };
+            return batch_bool<T, A> { select(cond, true_v, false_v) };
+        }
+
+        template <class A, class T, typename std::enable_if<!detail::is_batch_bool_register_same<T, A>::value, int>::type = 3>
+        XSIMD_INLINE batch_bool<T, A> select(batch_bool<T, A> const& cond, batch_bool<T, A> const& true_br, batch_bool<T, A> const& false_br, requires_arch<common>)
+        {
+            return (true_br & cond) | (bitwise_andnot(false_br, cond));
+        }
+
+        template <class A, class T, bool... Values>
+        XSIMD_INLINE batch_bool<T, A> select(batch_bool_constant<T, A, Values...> const& cond, batch_bool<T, A> const& true_br, batch_bool<T, A> const& false_br, requires_arch<common>)
+        {
+            return (true_br & cond) | (false_br & ~cond);
+        }
     }
 }
 

include/xsimd/arch/xsimd_scalar.hpp

@@ -83,53 +83,16 @@ namespace xsimd
     using std::tgamma;
     using std::trunc;
 
-    XSIMD_INLINE signed char abs(signed char v)
+    template <typename T>
+    XSIMD_INLINE constexpr typename std::enable_if<std::is_integral<T>::value && std::is_signed<T>::value, T>::type
+    abs(T v) noexcept
     {
         return v < 0 ? -v : v;
     }
 
-    namespace detail
-    {
-        // Use templated type here to prevent automatic instantiation that may
-        // ends up in a warning
-        template <typename char_type>
-        XSIMD_INLINE char abs(char_type v, std::true_type)
-        {
-            return v;
-        }
-        template <typename char_type>
-        XSIMD_INLINE char abs(char_type v, std::false_type)
-        {
-            return v < 0 ? -v : v;
-        }
-    }
-
-    XSIMD_INLINE char abs(char v)
-    {
-        return detail::abs(v, std::is_unsigned<char>::type {});
-    }
-
-    XSIMD_INLINE short abs(short v)
-    {
-        return v < 0 ? -v : v;
-    }
-    XSIMD_INLINE unsigned char abs(unsigned char v)
-    {
-        return v;
-    }
-    XSIMD_INLINE unsigned short abs(unsigned short v)
-    {
-        return v;
-    }
-    XSIMD_INLINE unsigned int abs(unsigned int v)
-    {
-        return v;
-    }
-    XSIMD_INLINE unsigned long abs(unsigned long v)
-    {
-        return v;
-    }
-    XSIMD_INLINE unsigned long long abs(unsigned long long v)
+    template <typename T>
+    XSIMD_INLINE constexpr typename std::enable_if<std::is_integral<T>::value && std::is_unsigned<T>::value, T>::type
+    abs(T v) noexcept
     {
         return v;
     }
@@ -1235,6 +1198,19 @@ namespace xsimd
     {
         return cond ? true_br : false_br;
     }
+
+    template <class T>
+    XSIMD_INLINE constexpr bool batch_bool_cast(bool b) noexcept
+    {
+        return b;
+    }
+
+    template <class T_out, class T_in>
+    XSIMD_INLINE constexpr T_out batch_cast(T_in const& val) noexcept
+    {
+        static_assert(!std::is_same<T_out, bool>::value, "cannot convert to bool, use !x or x != 0");
+        return static_cast<T_out>(val);
+    }
 }
 
 #endif

include/xsimd/types/xsimd_api.hpp

@@ -2099,6 +2099,27 @@ namespace xsimd
         return kernel::select<A>(cond, true_br, false_br, A {});
     }
 
+    /**
+     * @ingroup batch_bool_logical
+     *
+     * Ternary operator for conditions: selects values from the batches \c true_br or \c false_br
+     * depending on the boolean values in the constant batch \c cond. Equivalent to
+     * \code{.cpp}
+     * for(std::size_t i = 0; i < N; ++i)
+     *     res[i] = cond[i] ? true_br[i] : false_br[i];
+     * \endcode
+     * @param cond batch condition.
+     * @param true_br batch values for truthy condition.
+     * @param false_br batch value for falsy condition.
+     * @return the result of the selection.
+     */
+    template <class T, class A>
+    XSIMD_INLINE batch_bool<T, A> select(batch_bool<T, A> const& cond, batch_bool<T, A> const& true_br, batch_bool<T, A> const& false_br) noexcept
+    {
+        detail::static_check_supported_config<T, A>();
+        return kernel::select<A>(cond, true_br, false_br, A {});
+    }
+
     /**
      * @ingroup batch_cond
      *
@@ -2141,6 +2162,27 @@ namespace xsimd
         return kernel::select<A>(cond, true_br, false_br, A {});
     }
 
+    /**
+     * @ingroup batch_cond
+     *
+     * Ternary operator for mask batches: selects values from the masks \c true_br or \c false_br
+     * depending on the boolean values in the constant batch \c cond. Equivalent to
+     * \code{.cpp}
+     * for(std::size_t i = 0; i < N; ++i)
+     *     res[i] = cond[i] ? true_br[i] : false_br[i];
+     * \endcode
+     * @param cond constant batch condition.
+     * @param true_br batch values for truthy condition.
+     * @param false_br batch value for falsy condition.
+     * @return the result of the selection.
+     */
+    template <class T, class A, bool... Values>
+    XSIMD_INLINE batch_bool<T, A> select(batch_bool_constant<T, A, Values...> const& cond, batch_bool<T, A> const& true_br, batch_bool<T, A> const& false_br) noexcept
+    {
+        detail::static_check_supported_config<T, A>();
+        return kernel::select<A>(cond, true_br, false_br, A {});
+    }
+
     /**
      * @ingroup batch_data_transfer
      *

include/xsimd/types/xsimd_traits.hpp

@@ -233,59 +233,133 @@ namespace xsimd
     /**
      * @ingroup batch_traits
      *
-     * type traits that inherits from @c std::true_type for @c batch<...> types and from
-     * @c std::false_type otherwise.
+     * type traits that provide information about a batch or scalar type.
      *
      * @tparam T type to analyze.
      */
+
     template <class T>
-    struct is_batch;
+    struct batch_traits
+    {
+        using scalar_type = T; ///< T if scalar, or type of the scalar element for the batch T.
+        using mask_type = bool; ///< Mask type for T: bool for scalars, or batch_bool for batch types.
 
+        static constexpr bool is_batch = false; ///< True if T is @c batch<...>.
+        static constexpr bool is_batch_bool = false; ///< True if T is @c batch_bool<...>.
+        static constexpr bool is_any_batch = false; ///< True if T is @c batch<...> or @c batch_bool<...>.
+        static constexpr bool is_complex = detail::is_complex<T>::value; ///< True if T is complex or a batch of complex values.
+    };
+
+#if __cplusplus < 201703L
+    template <class T>
+    constexpr bool batch_traits<T>::is_batch;
     template <class T>
-    struct is_batch : std::false_type
+    constexpr bool batch_traits<T>::is_batch_bool;
+    template <class T>
+    constexpr bool batch_traits<T>::is_any_batch;
+    template <class T>
+    constexpr bool batch_traits<T>::is_complex;
+#endif
+
+    template <class T, class A>
+    struct batch_traits<batch<T, A>>
     {
+        using scalar_type = T;
+        using mask_type = typename batch<T, A>::batch_bool_type;
+
+        static constexpr bool is_batch = true;
+        static constexpr bool is_batch_bool = false;
+        static constexpr bool is_any_batch = true;
+        static constexpr bool is_complex = detail::is_complex<T>::value;
     };
 
+#if __cplusplus < 201703L
+    template <class T, class A>
+    constexpr bool batch_traits<batch<T, A>>::is_batch;
+    template <class T, class A>
+    constexpr bool batch_traits<batch<T, A>>::is_batch_bool;
+    template <class T, class A>
+    constexpr bool batch_traits<batch<T, A>>::is_any_batch;
+    template <class T, class A>
+    constexpr bool batch_traits<batch<T, A>>::is_complex;
+#endif
+
     template <class T, class A>
-    struct is_batch<batch<T, A>> : std::true_type
+    struct batch_traits<batch_bool<T, A>>
     {
+        using scalar_type = bool;
+        using mask_type = batch_bool<T, A>;
+
+        static constexpr bool is_batch = false;
+        static constexpr bool is_batch_bool = true;
+        static constexpr bool is_any_batch = true;
+        static constexpr bool is_complex = false;
     };
 
+#if __cplusplus < 201703L
+    template <class T, class A>
+    constexpr bool batch_traits<batch_bool<T, A>>::is_batch;
+    template <class T, class A>
+    constexpr bool batch_traits<batch_bool<T, A>>::is_batch_bool;
+    template <class T, class A>
+    constexpr bool batch_traits<batch_bool<T, A>>::is_any_batch;
+    template <class T, class A>
+    constexpr bool batch_traits<batch_bool<T, A>>::is_complex;
+#endif
+
     /**
      * @ingroup batch_traits
      *
-     * type traits that inherits from @c std::true_type for @c batch_bool<...> types and from
+     * type traits that inherits from @c std::true_type for @c batch<...> types and from
      * @c std::false_type otherwise.
      *
      * @tparam T type to analyze.
      */
 
     template <class T>
-    struct is_batch_bool : std::false_type
+    struct is_batch : std::integral_constant<bool, batch_traits<T>::is_batch>
     {
     };
 
-    template <class T, class A>
-    struct is_batch_bool<batch_bool<T, A>> : std::true_type
+    /**
+     * @ingroup batch_traits
+     *
+     * type traits that inherits from @c std::true_type for @c batch_bool<...> types and from
+     * @c std::false_type otherwise.
+     *
+     * @tparam T type to analyze.
+     */
+
+    template <class T>
+    struct is_batch_bool : std::integral_constant<bool, batch_traits<T>::is_batch_bool>
     {
     };
 
     /**
      * @ingroup batch_traits
      *
-     * type traits that inherits from @c std::true_type for @c batch<std::complex<...>>
+     * type traits that inherits from @c std::true_type for @c batch<...> or batch_bool<...>
      * types and from @c std::false_type otherwise.
      *
      * @tparam T type to analyze.
      */
 
     template <class T>
-    struct is_batch_complex : std::false_type
+    struct is_any_batch : std::integral_constant<bool, batch_traits<T>::is_any_batch>
     {
     };
 
-    template <class T, class A>
-    struct is_batch_complex<batch<std::complex<T>, A>> : std::true_type
+    /**
+     * @ingroup batch_traits
+     *
+     * type traits that inherits from @c std::true_type for @c batch<std::complex<...>>
+     * types and from @c std::false_type otherwise.
+     *
+     * @tparam T type to analyze.
+     */
+
+    template <class T>
+    struct is_batch_complex : std::integral_constant<bool, batch_traits<T>::is_batch && batch_traits<T>::is_complex>
     {
     };
 
@@ -300,12 +374,7 @@ namespace xsimd
     template <class T>
     struct scalar_type
     {
-        using type = T;
-    };
-    template <class T, class A>
-    struct scalar_type<batch<T, A>>
-    {
-        using type = T;
+        using type = typename batch_traits<T>::scalar_type;
     };
 
     template <class T>
@@ -322,12 +391,7 @@ namespace xsimd
     template <class T>
     struct mask_type
     {
-        using type = bool;
-    };
-    template <class T, class A>
-    struct mask_type<batch<T, A>>
-    {
-        using type = typename batch<T, A>::batch_bool_type;
+        using type = typename batch_traits<T>::mask_type;
     };
 
     template <class T>
@@ -364,7 +428,6 @@ namespace xsimd
     }
     template <typename T>
     using widen_t = typename detail::widen<T>::type;
-
 }
 
 #endif

test/test_batch_cast.cpp

@@ -341,6 +341,7 @@ struct batch_cast_test
             T_out scalar_ref = static_cast<T_out>(in_test_value);
             T_out scalar_res = res.get(0);
             CHECK_SCALAR_EQ(scalar_ref, scalar_res);
+            CHECK_SCALAR_EQ(scalar_ref, xsimd::batch_cast<T_out>(in_test_value));
         }
     }
 
@@ -356,11 +357,13 @@ struct batch_cast_test
         B_common_out all_true_res = xsimd::batch_bool_cast<T_out>(all_true_in);
         INFO(name);
         CHECK_SCALAR_EQ(all_true_res.get(0), true);
+        CHECK_SCALAR_EQ(xsimd::batch_bool_cast<B_out>(true), true);
 
         B_common_in all_false_in(false);
         B_common_out all_false_res = xsimd::batch_bool_cast<T_out>(all_false_in);
         INFO(name);
         CHECK_SCALAR_EQ(all_false_res.get(0), false);
+        CHECK_SCALAR_EQ(xsimd::batch_bool_cast<B_out>(false), false);
     }
 };