[slimtensor] Add aoti_torch_item_bool for SlimTensor

backends/cuda/runtime/shims/memory_slim.cpp

@@ -219,6 +219,35 @@ aoti_torch_copy_(Tensor* self, Tensor* src, int32_t non_blocking) {
   return Error::Ok;
 }
 
+AOTITorchError aoti_torch_item_bool(Tensor* tensor, bool* ret_value) {
+  ET_CHECK_OR_RETURN_ERROR(
+      tensor != nullptr,
+      InvalidArgument,
+      "aoti_torch_item_bool: tensor is null");
+
+  ET_CHECK_OR_RETURN_ERROR(
+      ret_value != nullptr,
+      InvalidArgument,
+      "aoti_torch_item_bool: ret_value is null");
+
+  ET_CHECK_OR_RETURN_ERROR(
+      tensor->numel() == 1,
+      InvalidArgument,
+      "aoti_torch_item_bool: tensor must have exactly 1 element, got %zu",
+      tensor->numel());
+
+  ET_CHECK_OR_RETURN_ERROR(
+      tensor->dtype() == ScalarType::Bool,
+      InvalidArgument,
+      "aoti_torch_item_bool: tensor dtype must be Bool");
+
+  // SlimTensor::item<T>() handles both CPU and CUDA tensors.
+  // For CUDA tensors, it copies the value to CPU automatically.
+  *ret_value = tensor->item<bool>();
+
+  return Error::Ok;
+}
+
 AOTITorchError aoti_torch_assign_tensors_out(Tensor* src, Tensor** ret_dst) {
   ET_CHECK_OR_RETURN_ERROR(
       src != nullptr,

backends/cuda/runtime/shims/memory_slim.h

@@ -143,6 +143,19 @@ AOTI_SHIM_EXPORT AOTITorchError aoti_torch__reinterpret_tensor(
 AOTI_SHIM_EXPORT AOTITorchError
 aoti_torch_copy_(Tensor* self, Tensor* src, int32_t non_blocking);
 
+/**
+ * Extracts a boolean scalar value from a single-element tensor.
+ *
+ * The tensor must contain exactly one element and have Bool dtype.
+ * For CUDA tensors, this will synchronize to copy the value to CPU.
+ *
+ * @param tensor Single-element boolean tensor (must not be null)
+ * @param ret_value Output parameter for the extracted boolean value
+ * @return AOTITorchError error code (Error::Ok on success)
+ */
+AOTI_SHIM_EXPORT AOTITorchError
+aoti_torch_item_bool(Tensor* tensor, bool* ret_value);
+
 /**
  * Moves a tensor into a new handle and assigns it to the output parameter.
  *

backends/cuda/runtime/shims/tests/targets.bzl

@@ -77,4 +77,5 @@ def define_common_targets():
     cuda_shim_slim_cpp_unittest("aoti_torch_new_tensor_handle")
     cuda_shim_slim_cpp_unittest("aoti_torch__reinterpret_tensor")
     cuda_shim_slim_cpp_unittest("aoti_torch_copy_")
+    cuda_shim_slim_cpp_unittest("aoti_torch_item_bool")
     cuda_shim_slim_cpp_unittest("aoti_torch_assign_tensors_out")

backends/cuda/runtime/shims/tests/test_aoti_torch_item_bool_slim.cpp

@@ -0,0 +1,291 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <cuda_runtime.h>
+#include <gtest/gtest.h>
+#include <vector>
+
+#include <executorch/backends/aoti/slim/c10/core/Device.h>
+#include <executorch/backends/aoti/slim/c10/core/ScalarType.h>
+#include <executorch/backends/cuda/runtime/shims/memory_slim.h>
+#include <executorch/runtime/core/error.h>
+#include <executorch/runtime/platform/platform.h>
+
+using namespace executorch::backends::cuda;
+using executorch::runtime::Error;
+
+namespace slim_c10 = executorch::backends::aoti::slim::c10;
+
+namespace {
+
+bool isCudaAvailable() {
+  int device_count = 0;
+  cudaError_t err = cudaGetDeviceCount(&device_count);
+  return (err == cudaSuccess && device_count > 0);
+}
+
+} // namespace
+
+class AOTITorchItemBoolSlimTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    et_pal_init();
+  }
+
+  Tensor* createScalarBoolTensor(
+      bool value,
+      int32_t device_type = static_cast<int32_t>(slim_c10::DeviceType::CPU),
+      int32_t device_index = 0) {
+    Tensor* tensor = nullptr;
+
+    std::vector<int64_t> sizes = {1};
+    std::vector<int64_t> strides = {1};
+
+    AOTITorchError error = aoti_torch_empty_strided(
+        sizes.size(),
+        sizes.data(),
+        strides.data(),
+        static_cast<int32_t>(slim_c10::ScalarType::Bool),
+        device_type,
+        device_index,
+        &tensor);
+
+    if (error != Error::Ok || tensor == nullptr) {
+      return nullptr;
+    }
+
+    if (device_type == static_cast<int32_t>(slim_c10::DeviceType::CPU)) {
+      bool* data = static_cast<bool*>(tensor->data_ptr());
+      *data = value;
+    } else {
+      cudaMemcpy(
+          tensor->data_ptr(), &value, sizeof(bool), cudaMemcpyHostToDevice);
+    }
+
+    return tensor;
+  }
+
+  Tensor* createTestTensor(
+      const std::vector<int64_t>& sizes,
+      int32_t dtype = static_cast<int32_t>(slim_c10::ScalarType::Float),
+      int32_t device_type = static_cast<int32_t>(slim_c10::DeviceType::CPU),
+      int32_t device_index = 0) {
+    Tensor* tensor = nullptr;
+
+    std::vector<int64_t> strides(sizes.size());
+    if (!sizes.empty()) {
+      strides[sizes.size() - 1] = 1;
+      for (int64_t i = static_cast<int64_t>(sizes.size()) - 2; i >= 0; i--) {
+        strides[i] = strides[i + 1] * sizes[i + 1];
+      }
+    }
+
+    AOTITorchError error = aoti_torch_empty_strided(
+        sizes.size(),
+        sizes.data(),
+        strides.data(),
+        dtype,
+        device_type,
+        device_index,
+        &tensor);
+
+    return (error == Error::Ok) ? tensor : nullptr;
+  }
+};
+
+// ============================================================================
+// Basic Functionality Tests
+// ============================================================================
+
+TEST_F(AOTITorchItemBoolSlimTest, TrueValue_CPU) {
+  Tensor* tensor = createScalarBoolTensor(
+      true, static_cast<int32_t>(slim_c10::DeviceType::CPU), 0);
+  ASSERT_NE(tensor, nullptr);
+
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::Ok);
+  EXPECT_EQ(result, true);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, FalseValue_CPU) {
+  Tensor* tensor = createScalarBoolTensor(
+      false, static_cast<int32_t>(slim_c10::DeviceType::CPU), 0);
+  ASSERT_NE(tensor, nullptr);
+
+  bool result = true;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::Ok);
+  EXPECT_EQ(result, false);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+// ============================================================================
+// Error Handling Tests
+// ============================================================================
+
+TEST_F(AOTITorchItemBoolSlimTest, NullTensor) {
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(nullptr, &result);
+
+  EXPECT_EQ(error, Error::InvalidArgument);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, NullReturnValue) {
+  Tensor* tensor = createScalarBoolTensor(
+      true, static_cast<int32_t>(slim_c10::DeviceType::CPU), 0);
+  ASSERT_NE(tensor, nullptr);
+
+  AOTITorchError error = aoti_torch_item_bool(tensor, nullptr);
+
+  EXPECT_EQ(error, Error::InvalidArgument);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, MultiElementTensor) {
+  std::vector<int64_t> sizes = {2, 3};
+  Tensor* tensor = createTestTensor(
+      sizes,
+      static_cast<int32_t>(slim_c10::ScalarType::Bool),
+      static_cast<int32_t>(slim_c10::DeviceType::CPU),
+      0);
+  ASSERT_NE(tensor, nullptr);
+  EXPECT_GT(tensor->numel(), 1);
+
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::InvalidArgument);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, WrongDtype_Float) {
+  std::vector<int64_t> sizes = {1};
+  Tensor* tensor = createTestTensor(
+      sizes,
+      static_cast<int32_t>(slim_c10::ScalarType::Float),
+      static_cast<int32_t>(slim_c10::DeviceType::CPU),
+      0);
+  ASSERT_NE(tensor, nullptr);
+
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::InvalidArgument);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, WrongDtype_Long) {
+  std::vector<int64_t> sizes = {1};
+  Tensor* tensor = createTestTensor(
+      sizes,
+      static_cast<int32_t>(slim_c10::ScalarType::Long),
+      static_cast<int32_t>(slim_c10::DeviceType::CPU),
+      0);
+  ASSERT_NE(tensor, nullptr);
+
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::InvalidArgument);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+// ============================================================================
+// CUDA Tests
+// ============================================================================
+
+TEST_F(AOTITorchItemBoolSlimTest, TrueValue_CUDA) {
+  if (!isCudaAvailable()) {
+    GTEST_SKIP() << "CUDA not available";
+  }
+
+  Tensor* tensor = createScalarBoolTensor(
+      true, static_cast<int32_t>(slim_c10::DeviceType::CUDA), 0);
+  ASSERT_NE(tensor, nullptr);
+  EXPECT_TRUE(tensor->is_cuda());
+
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::Ok);
+  EXPECT_EQ(result, true);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, FalseValue_CUDA) {
+  if (!isCudaAvailable()) {
+    GTEST_SKIP() << "CUDA not available";
+  }
+
+  Tensor* tensor = createScalarBoolTensor(
+      false, static_cast<int32_t>(slim_c10::DeviceType::CUDA), 0);
+  ASSERT_NE(tensor, nullptr);
+  EXPECT_TRUE(tensor->is_cuda());
+
+  bool result = true;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::Ok);
+  EXPECT_EQ(result, false);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, MultiElementTensor_CUDA) {
+  if (!isCudaAvailable()) {
+    GTEST_SKIP() << "CUDA not available";
+  }
+
+  std::vector<int64_t> sizes = {2, 3};
+  Tensor* tensor = createTestTensor(
+      sizes,
+      static_cast<int32_t>(slim_c10::ScalarType::Bool),
+      static_cast<int32_t>(slim_c10::DeviceType::CUDA),
+      0);
+  ASSERT_NE(tensor, nullptr);
+  EXPECT_TRUE(tensor->is_cuda());
+
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::InvalidArgument);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}
+
+TEST_F(AOTITorchItemBoolSlimTest, WrongDtype_Float_CUDA) {
+  if (!isCudaAvailable()) {
+    GTEST_SKIP() << "CUDA not available";
+  }
+
+  std::vector<int64_t> sizes = {1};
+  Tensor* tensor = createTestTensor(
+      sizes,
+      static_cast<int32_t>(slim_c10::ScalarType::Float),
+      static_cast<int32_t>(slim_c10::DeviceType::CUDA),
+      0);
+  ASSERT_NE(tensor, nullptr);
+
+  bool result = false;
+  AOTITorchError error = aoti_torch_item_bool(tensor, &result);
+
+  EXPECT_EQ(error, Error::InvalidArgument);
+
+  EXPECT_EQ(aoti_torch_delete_tensor_object(tensor), Error::Ok);
+}