Add generic device; Initial support in portBLAS

* oneMKL Interfaces currently only supports known targets: Intel CPU/GPU, AMD GPU, Nvidia GPU
* This PR:
  * Enables a new generic target
  * Enables the generic target to use the portBLAS backend
  * Adds documentation

CMakeLists.txt

@@ -60,6 +60,9 @@ option(ENABLE_CUFFT_BACKEND "Enable the cuFFT backend for the DFT interface" OFF
 option(ENABLE_ROCFFT_BACKEND "Enable the rocFFT backend for the DFT interface" OFF)
 option(ENABLE_PORTFFT_BACKEND "Enable the portFFT DFT backend for the DFT interface. Cannot be used with other DFT backends." OFF)
 
+# Generic devices
+option(ENABLE_GENERIC_DEVICE "Enable generic devices. Requires the portBLAS backend." OFF)
+
 set(ONEMKL_SYCL_IMPLEMENTATION "dpc++" CACHE STRING "Name of the SYCL compiler")
 set(HIP_TARGETS "" CACHE STRING "Target HIP architectures")
 
@@ -123,6 +126,11 @@ if (ENABLE_PORTFFT_BACKEND
 	message(FATAL_ERROR "ENABLE_PORTFFT_BACKEND cannot be enabled at the same time as other DFT backends.")
 endif()
 
+if(ENABLE_GENERIC_DEVICE
+  AND NOT ENABLE_PORTBLAS_BACKEND)
+  message(FATAL_ERROR "ENABLE_GENERIC_DEVICE requires that the portBLAS backend is enabled.")
+endif()
+
 # Define required CXX compilers before project
 if(CMAKE_CXX_COMPILER OR NOT ONEMKL_SYCL_IMPLEMENTATION STREQUAL "dpc++")
   if(WIN32)

README.md

@@ -62,7 +62,7 @@ oneMKL is part of the [UXL Foundation](http://www.uxlfoundation.org).
         </tr>
         <tr>
             <td align="center"><a href="https://github.com/codeplaysoftware/portBLAS"> portBLAS </a></td>
-            <td align="center">x86 CPU, Intel GPU, NVIDIA GPU, AMD GPU</td>
+            <td align="center">x86 CPU, Intel GPU, NVIDIA GPU, AMD GPU, Other SYCL devices (unsupported)</td>
         </tr>
         <tr>
             <td align="center"><a href="https://github.com/codeplaysoftware/portFFT"> portFFT </a></td>
@@ -172,7 +172,7 @@ Supported compilers include:
     </thead>
     <tbody>
         <tr>
-            <td rowspan=9 align="center">BLAS</td>
+            <td rowspan=10 align="center">BLAS</td>
             <td rowspan=3 align="center">x86 CPU</td>
             <td align="center">Intel(R) oneMKL</td>
             <td align="center">Intel DPC++</br>AdaptiveCpp</td>
@@ -221,6 +221,12 @@ Supported compilers include:
             <td align="center">Open DPC++</td>
             <td align="center">Dynamic, Static</td>
         </tr>
+        <tr>
+            <td rowspan=1 align="center">Other SYCL devices (unsupported)</td>
+            <td align="center">portBLAS</td>
+            <td align="center">Intel DPC++</br>Open DPC++</td>
+            <td align="center">Dynamic, Static</td>
+        </tr>
         <tr>
             <td rowspan=4 align="center">LAPACK</td>
             <td align="center">x86 CPU</td>
@@ -405,6 +411,7 @@ Supported compilers include:
     - Intel(R) Data Center GPU Max Series
     - NVIDIA(R) A100 (Linux* only)
     - AMD(R) GPUs see [here](https://github.com/RadeonOpenCompute/ROCm#hardware-and-software-support) tested on AMD Vega 20 (gfx906)
+    - Other SYCL devices can be used, but are not supported
 
 ---
 ### Supported Operating Systems

docs/building_the_project_with_dpcpp.rst

@@ -128,6 +128,9 @@ The most important supported build options are:
    * - ENABLE_PORTFFT_BACKEND
      - True, False
      - False      
+   * - ENABLE_GENERIC_DEVICE
+     - True, False
+     - False
    * - BUILD_FUNCTIONAL_TESTS
      - True, False
      - True      
@@ -225,6 +228,23 @@ A few often-used architectures are listed below:
 For a host with ROCm installed, the device architecture can be retrieved via the
 ``rocminfo`` tool. The architecture will be displayed in the ``Name:`` row.
 
+.. _build_for_other_SYCL_devices:
+
+Building for other SYCL devices
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+SYCL enables portable heterogeneous computing on a wide range of accelerators.
+Consequently, it is possible to use oneMKL Interfaces with accelerators not
+anticipated by the oneMKL Interfaces team. This can be enabled using the
+``-DENABLE_GENERIC_DEVICE=ON`` option. However, this is not a supported
+configuration.
+
+For generic SYCL devices, only the portBLAS backend is enabled. The user must
+set the appropriate ``-fsycl-targets`` for their device, and also any
+``PORTBLAS_TUNING_TARGET`` required for performance. See
+`Building for portBLAS`_. Extensive testing is strongly advised for these
+unsupported configurations.
+
 .. _build_for_portlibs_dpcpp:
 
 Pure SYCL backends: portBLAS and portFFT
@@ -408,6 +428,22 @@ set, the backend libraries to enable the use of BLAS, LAPACK and RNG with MKLGPU
 and MKLCPU would also be enabled. The build of examples is disabled. Since
 functional testing was not disabled, tests would be built.
 
+Build oneMKL for the BLAS domain on a generic SYCL device:
+
+.. code-block:: bash
+
+  cmake $ONEMKL_DIR \ 
+      -DCMAKE_CXX_COMPILER=clang++ \
+      -DCMAKE_C_COMPILER=clang \ 
+      -DENABLE_MKLCPU_BACKEND=False \ 
+      -DENABLE_MKLGPU_BACKEND=False \
+      -DENABLE_PORTBLAS_BACKEND=True \
+      -DENABLE_GENERIC_DEVICE=True
+
+Note that this is not a supported configuration. This builds oneMKL Interfaces
+with the portBLAS backend only, for a generic SYCL device supported by the 
+Open DPC++ project.
+
 .. _project_cleanup:
 
 Project Cleanup

include/oneapi/mkl/detail/backends_table.hpp

@@ -40,7 +40,7 @@
 namespace oneapi {
 namespace mkl {
 
-enum class device : uint16_t { x86cpu, intelgpu, nvidiagpu, amdgpu };
+enum class device : uint16_t { x86cpu, intelgpu, nvidiagpu, amdgpu, generic_device };
 enum class domain : uint16_t { blas, dft, lapack, rng, sparse_blas };
 
 static std::map<domain, std::map<device, std::vector<const char*>>> libraries = {
@@ -82,6 +82,12 @@ static std::map<domain, std::map<device, std::vector<const char*>>> libraries =
 #endif
 #ifdef ENABLE_PORTBLAS_BACKEND_NVIDIA_GPU
               LIB_NAME("blas_portblas"),
+#endif
+          } },
+        { device::generic_device,
+          {
+#ifdef ENABLE_PORTBLAS_BACKEND_GENERIC_DEVICE
+              LIB_NAME("blas_portblas"),
 #endif
           } } } },
 

include/oneapi/mkl/detail/get_device_id.hpp

@@ -59,11 +59,19 @@ inline oneapi::mkl::device get_device_id(sycl::queue &queue) {
         else if (vendor_id == AMD_ID)
             device_id = device::amdgpu;
         else {
+#ifdef ENABLE_GENERIC_DEVICE
+            device_id = device::generic_device;
+#else
             throw unsupported_device("", "", queue.get_device());
+#endif // ENABLE_GENERIC_DEVICE
         }
     }
     else {
+#ifdef ENABLE_GENERIC_DEVICE
+        device_id = device::generic_device;
+#else
         throw unsupported_device("", "", queue.get_device());
+#endif // ENABLE_GENERIC_DEVICE
     }
     return device_id;
 }

src/CMakeLists.txt

@@ -29,6 +29,7 @@ set(ENABLE_PORTBLAS_BACKEND_INTEL_CPU OFF CACHE INTERNAL "")
 set(ENABLE_PORTBLAS_BACKEND_INTEL_GPU OFF CACHE INTERNAL "")
 set(ENABLE_PORTBLAS_BACKEND_AMD_GPU OFF CACHE INTERNAL "")
 set(ENABLE_PORTBLAS_BACKEND_NVIDIA_GPU OFF CACHE INTERNAL "")
+set(ENABLE_PORTBLAS_BACKEND_GENERIC_DEVICE OFF CACHE INTERNAL "")
 # store path to CMAKE_CURRENT_BINARY_DIR to use it later (makes FetchContent_Declare workable)
 set(ONEMKL_GENERATED_INCLUDE_PATH ${CMAKE_CURRENT_BINARY_DIR})
 

src/blas/backends/portblas/CMakeLists.txt

@@ -46,7 +46,14 @@ if(NUM_TARGETS EQUAL 0)
   list(LENGTH SYCL_TARGETS NUM_TARGETS)
 endif()
 
-if(PORTBLAS_TUNING_TARGET)
+if(ENABLE_GENERIC_DEVICE)
+  set(ENABLE_PORTBLAS_BACKEND_GENERIC_DEVICE "ON" CACHE INTERAL "")
+  if(NOT PORTBLAS_TUNING_TARGET)
+    # If a generic device is specified, set the tuning target to default for best compatibility.
+    message(STATUS "Setting DEFAULT portBLAS tuning target for generic device.")
+    set(PORTBLAS_TUNING_TARGET "DEFAULT")
+  endif()
+elseif (PORTBLAS_TUNING_TARGET)
   # Allow the user to manually enable a specific device type 
   # for tuned portBLAS configurations and sets sycl-target.
   if(PORTBLAS_TUNING_TARGET STREQUAL "INTEL_CPU")

src/config.hpp.in

@@ -32,12 +32,14 @@
 #cmakedefine ENABLE_PORTBLAS_BACKEND_INTEL_CPU
 #cmakedefine ENABLE_PORTBLAS_BACKEND_INTEL_GPU
 #cmakedefine ENABLE_PORTBLAS_BACKEND_NVIDIA_GPU
+#cmakedefine ENABLE_PORTBLAS_BACKEND_GENERIC_DEVICE
 #cmakedefine ENABLE_PORTFFT_BACKEND
 #cmakedefine ENABLE_ROCBLAS_BACKEND
 #cmakedefine ENABLE_ROCFFT_BACKEND
 #cmakedefine ENABLE_ROCRAND_BACKEND
 #cmakedefine ENABLE_ROCSOLVER_BACKEND
 #cmakedefine BUILD_SHARED_LIBS
+#cmakedefine ENABLE_GENERIC_DEVICE
 #cmakedefine REF_BLAS_LIBNAME "@REF_BLAS_LIBNAME@"
 #cmakedefine REF_CBLAS_LIBNAME "@REF_CBLAS_LIBNAME@"