Added DPCTLDeviceMgr_GetRelativeId(DRef)

This computes the relative id (position in the vector) inside
p.get_devices( sycl_device_type(DRef) ).

Returns -1 is the device was not found (expected to happen for
sub-devices).

Author: oleksandr-pavlyk

dpctl-capi/include/dpctl_sycl_device_manager.h

@@ -116,4 +116,15 @@ size_t DPCTLDeviceMgr_GetNumDevices(int device_identifier);
 DPCTL_API
 void DPCTLDeviceMgr_PrintDeviceInfo(__dpctl_keep const DPCTLSyclDeviceRef DRef);
 
+/*!
+ * @brief Gives the index of the given device in the vector returned get_devices
+ * for the platform associated with DRef for the device type of DRef.
+ *
+ * @param    DRef           A #DPCTLSyclDeviceRef opaque pointer.
+ * @ingroup DeviceManager
+ */
+DPCTL_API
+int64_t
+DPCTLDeviceMgr_GetRelativeId(__dpctl_keep const DPCTLSyclDeviceRef DRef);
+
 DPCTL_C_EXTERN_C_END

dpctl-capi/source/dpctl_sycl_device_manager.cpp

@@ -194,3 +194,22 @@ void DPCTLDeviceMgr_PrintDeviceInfo(__dpctl_keep const DPCTLSyclDeviceRef DRef)
         std::cout << "Device is not valid (NULL). Cannot print device info.\n";
     }
 }
+
+int64_t DPCTLDeviceMgr_GetRelativeId(__dpctl_keep const DPCTLSyclDeviceRef DRef)
+{
+    auto Device = unwrap(DRef);
+
+    if (Device) {
+        auto p = Device->get_platform();
+        auto dt = Device->get_info<sycl::info::device::device_type>();
+        auto dev_vec = p.get_devices(dt);
+        int64_t id = 0;
+        for (auto &d_i : dev_vec) {
+            if (*Device == d_i)
+                return id;
+            ++id;
+        }
+        return -1;
+    }
+    return -1;
+}

dpctl-capi/tests/test_sycl_device_manager.cpp

@@ -56,6 +56,13 @@ struct TestDPCTLDeviceManager : public ::testing::TestWithParam<const char *>
     }
 };
 
+TEST_P(TestDPCTLDeviceManager, Chk_GetRelativeId)
+{
+    int64_t rel_id = -1;
+    EXPECT_NO_FATAL_FAILURE(rel_id = DPCTLDeviceMgr_GetRelativeId(DRef));
+    EXPECT_FALSE(rel_id == -1);
+}
+
 TEST_P(TestDPCTLDeviceManager, Chk_PrintDeviceInfo)
 {
     EXPECT_NO_FATAL_FAILURE(DPCTLDeviceMgr_PrintDeviceInfo(DRef));