Ck tiled main fixing for building xformers (#44)

* Add include/ck/config.h to support xformers c++ extension building

* Disable exp() and log() overloading for half_t to support xformers C++ extension building

* config.h.default

---------
Co-authored-by: Chao Liu <chao.liu2@amd.com>

include/ck/config.h.default

+/*******************************************************************************
+ *
+ * MIT License
+ *
+ * Copyright (c) 2023 Advanced Micro Devices, Inc.
+ *
+ * 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 CK_CONFIG_H_IN
+#define CK_CONFIG_H_IN
+
+// clang-format off
+//
+// DataType supports in the current CK build
+//
+#ifndef DTYPES
+/* #undef DTYPES */
+#endif
+// if DTYPES is not defined, enable all datatypes in headerfiles
+#ifndef CK_ENABLE_ALL_DTYPES
+#define CK_ENABLE_ALL_DTYPES ON
+#if defined(CK_ENABLE_ALL_DTYPES)
+#ifndef CK_ENABLE_INT8
+#define CK_ENABLE_INT8 "ON"
+#endif
+#ifndef CK_ENABLE_FP8
+#define CK_ENABLE_FP8 "ON"
+#endif
+#ifndef CK_ENABLE_BF8
+#define CK_ENABLE_BF8 "ON"
+#endif
+#ifndef CK_ENABLE_FP16
+#define CK_ENABLE_FP16 "ON"
+#endif
+#ifndef CK_ENABLE_BF16
+#define CK_ENABLE_BF16 "ON"
+#endif
+#ifndef CK_ENABLE_FP32
+#define CK_ENABLE_FP32 "ON"
+#endif
+#ifndef CK_ENABLE_FP64
+#define CK_ENABLE_FP64 "ON"
+#endif
+#endif
+#endif
+// if DTYPES are selectively enabled
+#ifndef CK_ENABLE_INT8
+/* #undef CK_ENABLE_INT8 */
+#endif
+
+#ifndef CK_ENABLE_FP8
+/* #undef CK_ENABLE_FP8 */
+#endif
+
+#ifndef CK_ENABLE_BF8
+/* #undef CK_ENABLE_BF8 */
+#endif
+
+#ifndef CK_ENABLE_FP16
+/* #undef CK_ENABLE_FP16 */
+#endif
+
+#ifndef CK_ENABLE_BF16
+/* #undef CK_ENABLE_BF16 */
+#endif
+
+#ifndef CK_ENABLE_FP32
+/* #undef CK_ENABLE_FP32 */
+#endif
+
+#ifndef CK_ENABLE_FP64
+/* #undef CK_ENABLE_FP64 */
+#endif
+
+//
+// Legacy DL kernel supports in the current CK build
+// by default DL kernels are turned OFF
+//
+#ifndef CK_ENABLE_DL_KERNELS
+/* #undef CK_ENABLE_DL_KERNELS */
+#endif
+
+//
+// Instances supports in the current CK build
+//
+#ifndef CK_ENABLE_INSTANCES_ONLY
+/* #undef CK_ENABLE_INSTANCES_ONLY */
+#endif
+
+// clang-format on
+
+#endif // CK_CONFIG_H_IN

include/ck/utility/math_v2.hpp

@@ -312,11 +312,13 @@ inline __device__ float exp<float>(float x)
     return __expf(x);
 }
 
+/*
 template <>
 inline __device__ half_t exp<half_t>(half_t x)
 {
     return hexp(x);
 };
+*/
 
 template <>
 inline __device__ double exp<double>(double x)
@@ -346,11 +348,13 @@ inline __device__ T log(T x)
     return ck::type_convert<T>(__logf(ck::type_convert<float>(x)));
 };
 
+/*
 template <>
 inline __device__ half_t log<half_t>(half_t x)
 {
     return hlog(x);
 };
+*/
 
 template <>
 inline __device__ float log<float>(float x)