Clean implementation of fpga_simulator_selector

Document fpga_simulator_selector in official documentation. Bump the
version to 2.

Author: mendell27

sycl/doc/extensions/supported/sycl_ext_intel_fpga_device_selector.md

@@ -1,7 +1,7 @@
 # FPGA selector
 
 Intel FPGA users can use header file: `#include<sycl/ext/intel/fpga_device_selector.hpp>` to simplify their code
-when they want to specify FPGA hardware device or FPGA emulation device.
+when they want to specify FPGA hardware device, FPGA simulator device or FPGA emulation device.
 
 ## Implementation
 
@@ -17,6 +17,15 @@ sycl::queue deviceQueue{sycl::ext::intel::fpga_selector{}};
 ...
 ```
 
+## Usage: select FPGA simulator device
+```c++
+#include <sycl/ext/intel/fpga_device_selector.hpp>
+...
+// force FPGA simulator device
+sycl::queue deviceQueue{sycl::ext::intel::fpga_simulator_selector{}};
+...
+```
+
 ## Usage: select FPGA emulator device
 ```c++
 #include <sycl/ext/intel/fpga_device_selector.hpp>
@@ -39,3 +48,4 @@ extension
 |Value |Description|
 |:---- |:---------:|
 |1     |Initial extension version. Base features are supported.|
+|2     |fpga_simulator_selector added.|

sycl/include/sycl/ext/intel/fpga_device_selector.hpp

@@ -34,10 +34,6 @@ class platform_selector : public device_selector {
     const platform &pf = device.get_platform();
     const std::string &platform_name = pf.get_info<info::platform::name>();
     if (platform_name == device_platform_name) {
-      const std::string name = device.get_info<sycl::info::device::name>();
-      // Prefer hardware devices over simulator ones.
-      if (name.find("SimulatorDevice") != std::string::npos)
-        return 9000;
       return 10000;
     }
     return -1;
@@ -61,16 +57,12 @@ class fpga_emulator_selector : public platform_selector {
 
 class fpga_simulator_selector : public fpga_selector {
 public:
-  fpga_simulator_selector(unsigned int numDevices = 1) {
-    // Tell the runtime to start a simulator device
-    // Notes:
-    //   This replaces any hardware devices present
-    //   Currently only 1 simulator device is supported
-    auto devices = std::to_string(numDevices);
+  fpga_simulator_selector() {
+    // Tell the runtime to use a simulator device rather than hardware
 #ifdef _WIN32
-    _putenv_s("CL_CONTEXT_MPSIM_DEVICE_INTELFPGA", devices.c_str());
+    _putenv_s("CL_CONTEXT_MPSIM_DEVICE_INTELFPGA", "1");
 #else
-    setenv("CL_CONTEXT_MPSIM_DEVICE_INTELFPGA", devices.c_str(), 0);
+    setenv("CL_CONTEXT_MPSIM_DEVICE_INTELFPGA", "1", 0);
 #endif
   }
 };

sycl/include/sycl/feature_test.hpp.in

@@ -62,7 +62,9 @@ __SYCL_INLINE_VER_NAMESPACE(_V1) {
 #define SYCL_EXT_INTEL_EXTENDED_ATOMICS 1
 #endif
 #endif
-#define SYCL_EXT_INTEL_FPGA_DEVICE_SELECTOR 1
+#ifndef SYCL_EXT_INTEL_FPGA_DEVICE_SELECTOR
+#define SYCL_EXT_INTEL_FPGA_DEVICE_SELECTOR 2
+#endif
 #define SYCL_EXT_INTEL_FPGA_LSU 1
 #define SYCL_EXT_INTEL_FPGA_REG 1
 #define SYCL_EXT_INTEL_KERNEL_ARGS_RESTRICT 1