COMPMID-3637: Move utility headers from arm_compute to src

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: If9d6fa8c900b68c4b6fd373f2fc1f9abb83ea917
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4145
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Sang-Hoon Park <sang-hoon.park@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 205 insertions, 0 deletions

diff --git a/support/Rounding.h b/support/Rounding.h
new file mode 100644
index 0000000000..ba9266d323
--- /dev/null
+++ b/support/Rounding.h
@@ -0,0 +1,205 @@
+/*
+ * Copyright (c) 2018-2020 Arm Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef ARM_COMPUTE_UTILS_ROUNDING_H
+#define ARM_COMPUTE_UTILS_ROUNDING_H
+
+#include "arm_compute/core/Error.h"
+#include "arm_compute/core/utils/misc/Traits.h"
+#include "support/Requires.h"
+#include "support/ToolchainSupport.h"
+
+#include <cmath>
+
+namespace arm_compute
+{
+namespace utils
+{
+namespace rounding
+{
+/** Rounding mode */
+enum class RoundingMode
+{
+    TO_ZERO,             /**< Round towards zero */
+    AWAY_FROM_ZERO,      /**< Round away from zero */
+    HALF_TO_ZERO,        /**< Round half towards from zero */
+    HALF_AWAY_FROM_ZERO, /**< Round half away from zero */
+    HALF_UP,             /**< Round half towards positive infinity */
+    HALF_DOWN,           /**< Round half towards negative infinity */
+    HALF_EVEN            /**< Round half towards nearest even */
+};
+
+/** Round floating-point value with round to zero
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value floating-point value to be rounded.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round_to_zero(T value)
+{
+    T res = std::floor(std::fabs(value));
+    return (value < 0.f) ? -res : res;
+}
+
+/** Round floating-point value with round away from zero
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value floating-point value to be rounded.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round_away_from_zero(T value)
+{
+    T res = std::ceil(std::fabs(value));
+    return (value < 0.f) ? -res : res;
+}
+
+/** Round floating-point value with half value rounding towards zero.
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value floating-point value to be rounded.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round_half_to_zero(T value)
+{
+    T res = T(std::ceil(std::fabs(value) - 0.5f));
+    return (value < 0.f) ? -res : res;
+}
+
+/** Round floating-point value with half value rounding away from zero.
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value floating-point value to be rounded.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round_half_away_from_zero(T value)
+{
+    T res = T(std::floor(std::fabs(value) + 0.5f));
+    return (value < 0.f) ? -res : res;
+}
+
+/** Round floating-point value with half value rounding to positive infinity.
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value floating-point value to be rounded.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round_half_up(T value)
+{
+    return std::floor(value + 0.5f);
+}
+
+/** Round floating-point value with half value rounding to negative infinity.
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value floating-point value to be rounded.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round_half_down(T value)
+{
+    return std::ceil(value - 0.5f);
+}
+
+/** Round floating-point value with half value rounding to nearest even.
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value   floating-point value to be rounded.
+ * @param[in] epsilon precision.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round_half_even(T value, T epsilon = std::numeric_limits<T>::epsilon())
+{
+    T positive_value = std::abs(value);
+    T ipart          = 0;
+    std::modf(positive_value, &ipart);
+    // If 'value' is exactly halfway between two integers
+    if(std::abs(positive_value - (ipart + 0.5f)) < epsilon)
+    {
+        // If 'ipart' is even then return 'ipart'
+        if(std::fmod(ipart, 2.f) < epsilon)
+        {
+            return support::cpp11::copysign(ipart, value);
+        }
+        // Else return the nearest even integer
+        return support::cpp11::copysign(std::ceil(ipart + 0.5f), value);
+    }
+    // Otherwise use the usual round to closest
+    return support::cpp11::copysign(support::cpp11::round(positive_value), value);
+}
+
+/** Round floating-point value given a rounding mode
+ *
+ * @tparam T Parameter type. Should be of floating point type.
+ *
+ * @param[in] value         floating-point value to be rounded.
+ * @param[in] rounding_mode Rounding mode to use.
+ *
+ * @return Floating-point value of rounded @p value.
+ */
+template <typename T, REQUIRES_TA(traits::is_floating_point<T>::value)>
+inline T round(T value, RoundingMode rounding_mode)
+{
+    switch(rounding_mode)
+    {
+        case RoundingMode::TO_ZERO:
+            return round_to_zero(value);
+        case RoundingMode::AWAY_FROM_ZERO:
+            return round_away_from_zero(value);
+        case RoundingMode::HALF_TO_ZERO:
+            return round_half_to_zero(value);
+        case RoundingMode::HALF_AWAY_FROM_ZERO:
+            return round_half_away_from_zero(value);
+        case RoundingMode::HALF_UP:
+            return round_half_up(value);
+        case RoundingMode::HALF_DOWN:
+            return round_half_down(value);
+        case RoundingMode::HALF_EVEN:
+            return round_half_even(value);
+        default:
+            ARM_COMPUTE_ERROR("Unsupported rounding mode!");
+    }
+}
+} // namespace rounding
+} // namespace utils
+} // namespace arm_compute
+#endif /*ARM_COMPUTE_UTILS_ROUNDING_H */