COMPMID-1719 CL: Implement RSqrt, Exp

Change-Id: I827b26239043a9e90d26c2583122648d2a45303a
Reviewed-on: https://review.mlplatform.org/317
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/CL/cl_kernels/elementwise_unary.cl b/src/core/CL/cl_kernels/elementwise_unary.cl
new file mode 100644
index 0000000..bccb47e
--- /dev/null
+++ b/src/core/CL/cl_kernels/elementwise_unary.cl
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2018 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.
+ */
+#include "helpers.h"
+#include "warp_helpers.h"
+
+#if defined(DATA_TYPE) && defined(VEC_SIZE) && defined(OPERATION)
+/** Calculate reverse square root
+ *
+ * @param[in] input Pointer to the first element.
+ *
+ * @return reverse square root
+ */
+inline VEC_DATA_TYPE(DATA_TYPE, VEC_SIZE) inverse_sqrt(const VEC_DATA_TYPE(DATA_TYPE, VEC_SIZE) input)
+{
+    return rsqrt(input);
+}
+
+/** Calculate exponential
+ *
+ * @param[in] input Pointer to the first element.
+ *
+ * @return exponential
+ */
+inline VEC_DATA_TYPE(DATA_TYPE, VEC_SIZE) exponential(const VEC_DATA_TYPE(DATA_TYPE, VEC_SIZE) input)
+{
+    return exp(input);
+}
+
+/** Applies element wise unary operator in a tensor.
+ *
+ * @param[in]  in_ptr                            Pointer to the source image. Supported data types: F16/32.
+ * @param[in]  in_stride_x                       Stride of the source image in X dimension (in bytes)
+ * @param[in]  in_step_x                         in_stride_x * number of elements along X processed per work item (in bytes)
+ * @param[in]  in_offset_first_element_in_bytes  Offset of the first element in the source image
+ * @param[out] out_ptr                           Pointer to the destination image. Supported data types: F16/32.
+ * @param[in]  out_stride_x                      Stride of the destination image in X dimension (in bytes)
+ * @param[in]  out_step_y                        out_stride_y * number of elements along Y processed per work item (in bytes)
+ * @param[in]  out_offset_first_element_in_bytes Offset of the first element in the destination image
+ */
+__kernel void elementwise_unary(
+    VECTOR_DECLARATION(in),
+    VECTOR_DECLARATION(out))
+{
+    Vector in  = CONVERT_TO_VECTOR_STRUCT(in);
+    Vector out = CONVERT_TO_VECTOR_STRUCT(out);
+
+#if defined(VEC_SIZE) && defined(LAST_ACCESSED_X)
+    // Check if access on width gets out of bounds
+    // If it does shift access vector to access elements within bounds
+    const int xi = (int)(get_global_id(0) * VEC_SIZE);
+    in.ptr -= max(xi - (int)LAST_ACCESSED_X, 0) * in_stride_x;
+    out.ptr -= max(xi - (int)LAST_ACCESSED_X, 0) * out_stride_x;
+
+    VEC_DATA_TYPE(DATA_TYPE, VEC_SIZE)
+    data = VLOAD(VEC_SIZE)(0, (__global DATA_TYPE *)in.ptr);
+
+    VSTORE(VEC_SIZE)
+    (OPERATION(data), 0, (__global DATA_TYPE *)out.ptr);
+#else  // !defined(VEC_SIZE) || !defined(LAST_ACCESSED_X)
+    VEC_DATA_TYPE(DATA_TYPE, VEC_SIZE)
+    data = VLOAD(VEC_SIZE)(0, (__global DATA_TYPE *)in.ptr);
+    VSTORE(VEC_SIZE)
+    (OPERATION(data), 0, (__global DATA_TYPE *)out.ptr);
+#endif // defined(VEC_SIZE) && defined(LAST_ACCESSED_X)
+}
+#endif // defined(DATA_TYPE) && defined(VEC_SIZE) && defined(OPERATION)