Revert "Add xpu to getAccelerator (#129205)"

This reverts commit 3e2df3ca9d0a593e09bc94c14bbf2b213413cbf3.

Reverted https://github.com/pytorch/pytorch/pull/129205 on behalf of https://github.com/kit1980 due to Need to revert https://github.com/pytorch/pytorch/pull/129463 which breaks Meta builds ([comment](https://github.com/pytorch/pytorch/pull/129205#issuecomment-2207514346))

aten/src/ATen/DeviceAccelerator.cpp

@@ -1,37 +1,39 @@
-#include <ATen/Context.h>
 #include <ATen/DeviceAccelerator.h>
+#include <ATen/Context.h>
+
 namespace at {
 
 C10_API std::optional<DeviceType> getAccelerator(bool checked) {
-#define DETECT_AND_ASSIGN_ACCELERATOR(device_name) \
-  if (at::has##device_name()) {                    \
-    device_type = k##device_name;                  \
-    TORCH_CHECK(                                   \
-        !is_accelerator_detected,                  \
-        "Cannot have ",                            \
-        device_type.value(),                       \
-        " with other accelerators.");              \
-    is_accelerator_detected = true;                \
-  }
+#define CHECK_NO_CUDA \
+  TORCH_CHECK(!at::hasCUDA(), "Cannot have both CUDA and PrivateUse1");
 
-  if (is_privateuse1_backend_registered()) {
-    // We explicitly allow PrivateUse1 and another device at the same time as we
-    // use this for testing. Whenever a PrivateUse1 device is registered, use it
-    // first.
-    return kPrivateUse1;
-  }
-  std::optional<DeviceType> device_type = std::nullopt;
-  bool is_accelerator_detected = false;
-  DETECT_AND_ASSIGN_ACCELERATOR(CUDA)
-  DETECT_AND_ASSIGN_ACCELERATOR(MTIA)
-  DETECT_AND_ASSIGN_ACCELERATOR(XPU)
-  if (checked) {
-    TORCH_CHECK(
-        device_type, "Cannot access accelerator device when none is available.")
-  }
-  return device_type;
+#define CHECK_NO_PU1 \
+  TORCH_CHECK(!is_privateuse1_backend_registered(), "Cannot have both CUDA and PrivateUse1");
 
-#undef DETECT_AND_ASSIGN_ACCELERATOR
+#define CHECK_NO_MTIA \
+  TORCH_CHECK(!at::hasMTIA(), "Cannot have MTIA with other devices");
+
+    if (is_privateuse1_backend_registered()) {
+        // We explicitly allow PrivateUse1 and another device at the same time
+        // as we use this for testing.
+        // Whenever a PrivateUse1 device is registered, use it first.
+        return kPrivateUse1;
+    } else if (at::hasCUDA()) {
+        CHECK_NO_PU1
+        CHECK_NO_MTIA
+        return kCUDA;
+    } else if (at::hasMTIA()) {
+        CHECK_NO_CUDA
+        CHECK_NO_PU1
+        return kMTIA;
+    } else {
+        TORCH_CHECK(!checked, "Cannot access accelerator device when none is available.")
+        return std::nullopt;
+    }
+
+#undef CHECK_NO_CUDA
+#undef CHECK_NO_PU1
 }
 
+
 } // namespace at

aten/src/ATen/DeviceAccelerator.h

@@ -13,9 +13,9 @@
 // - It provides a set of common APIs as defined by AcceleratorHooksInterface
 //
 // As of today, accelerator devices are (in no particular order):
-// CUDA, MTIA, XPU, PrivateUse1
+// CUDA, MTIA, PrivateUse1
 // We want to add once all the proper APIs are supported and tested:
-// HIP, MPS
+// HIP, MPS, XPU
 
 namespace at {
 

test/test_cpp_extensions_stream_and_event.py

@@ -15,7 +15,6 @@ from torch.testing._internal.common_utils import (
     skipIfTorchDynamo,
     TEST_CUDA,
     TEST_PRIVATEUSE1,
-    TEST_XPU,
 )
 from torch.utils.cpp_extension import CUDA_HOME, ROCM_HOME
 
@@ -37,7 +36,7 @@ def remove_build_path():
 # Since we use a fake MTIA device backend to test generic Stream/Event, device backends are mutual exclusive to each other.
 # The test will be skipped if any of the following conditions are met:
 @unittest.skipIf(
-    IS_ARM64 or not IS_LINUX or TEST_CUDA or TEST_XPU or TEST_PRIVATEUSE1 or TEST_ROCM,
+    IS_ARM64 or not IS_LINUX or TEST_CUDA or TEST_PRIVATEUSE1 or TEST_ROCM,
     "Only on linux platform and mutual exclusive to other backends",
 )
 @torch.testing._internal.common_utils.markDynamoStrictTest