COMPMID-3927 CTS failure for OpenCL ElementwiseOperation

Change-Id: I1a82315dfa9b021f72e0b687da658e2e02c9bb34
Signed-off-by: Giorgio Arena <giorgio.arena@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4257
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/CL/cl_kernels/elementwise_operation.cl b/src/core/CL/cl_kernels/elementwise_operation.cl
index 211eb38..3519ef8 100644
--- a/src/core/CL/cl_kernels/elementwise_operation.cl
+++ b/src/core/CL/cl_kernels/elementwise_operation.cl
@@ -38,7 +38,7 @@
 #define SQUARED_DIFF(x, y) (x - y) * (x - y)
 #define DIV(x, y) (x / y)
 #define POWER(x, y) pow(x, y)
-#define PRELU(x, y) (select(y * x, x, x > (DATA_TYPE_OUT)0))
+#define PRELU(x, y) (select(y * x, x, CONVERT((x > (DATA_TYPE_OUT)0), SELECT_DATA_TYPE(DATA_TYPE_OUT, VEC_SIZE_OUT))))
 
 #define OP_FUN_NAME_STR(op) elementwise_operation_##op
 #define OP_FUN_NAME(op) OP_FUN_NAME_STR(op)