COMPMID-2800: Add support for QASYMM8_SIGNED in NEDepthwiseConvolutionLayer3x3Kernel

Change-Id: Ia5d23ff2c9e59c80ded2fac5ca02704214f0a01a
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-on: https://review.mlplatform.org/c/2537
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Pablo Marquez <pablo.tello@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/arm_compute/core/NEON/wrapper/intrinsics/ext.h b/arm_compute/core/NEON/wrapper/intrinsics/ext.h
new file mode 100644
index 0000000..70bc91a
--- /dev/null
+++ b/arm_compute/core/NEON/wrapper/intrinsics/ext.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 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_WRAPPER_EXT_H
+#define ARM_COMPUTE_WRAPPER_EXT_H
+
+#include <arm_neon.h>
+
+namespace arm_compute
+{
+namespace wrapper
+{
+#define VEXT_IMPL(vtype, prefix, postfix, size)            \
+    inline vtype vext_##size(vtype value_a, vtype value_b) \
+    {                                                      \
+        return prefix##_##postfix(value_a, value_b, size); \
+    }
+
+VEXT_IMPL(int32x4_t, vextq, s32, 1)
+VEXT_IMPL(int32x4_t, vextq, s32, 2)
+
+#undef VEXT_IMPL
+} // namespace wrapper
+} // namespace arm_compute
+#endif /* ARM_COMPUTE_WRAPPER_EXT_H */