[Pytorch] Add Vulkan support for aten::unsqueeze for 2d to 3d (pytorc…

…h#101719)

Summary:
Pull Request resolved: pytorch#101719

Unsqueeze operator: https://pytorch.org/docs/stable/generated/torch.unsqueeze.html#torch.unsqueeze

Test Plan:
Unsqueeze tests:
https://www.internalfb.com/phabricator/paste/view/P738187802
```
lfq@lfq-mbp fbsource % buck run --target-platforms ovr_config//platform/macos:arm64-fbsource //xplat/caffe2:pt_vulkan_api_test_binAppleMac\#macosx-arm64 -c pt.vulkan_full_precision=1 -- --gtest_filter="*unsqueeze*"
Downloaded 0/2 artifacts, 0.00 bytes, 100.0% cache miss (for updated rules)
Building: finished in 15.0 sec (100%) 455/455 jobs, 2/455 updated
  Total time: 15.0 sec
BUILD SUCCEEDED
Running main() from xplat/third-party/gmock/googletest-1.12.1/googletest/src/gtest_main.cc
Note: Google Test filter = *unsqueeze*
[==========] Running 3 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 3 tests from VulkanAPITest
[ RUN      ] VulkanAPITest.unsqueeze_dim0
[       OK ] VulkanAPITest.unsqueeze_dim0 (96 ms)
[ RUN      ] VulkanAPITest.unsqueeze_dim1
[       OK ] VulkanAPITest.unsqueeze_dim1 (2 ms)
[ RUN      ] VulkanAPITest.unsqueeze_dim2
[       OK ] VulkanAPITest.unsqueeze_dim2 (3 ms)
[----------] 3 tests from VulkanAPITest (101 ms total)
[----------] Global test environment tear-down
[==========] 3 tests from 1 test suite ran. (101 ms total)
[  PASSED  ] 3 tests.
```
All tests:
buck run //xplat/caffe2:pt_vulkan_api_test_binAppleMac\#macosx-arm64

https://www.internalfb.com/phabricator/paste/view/P738255852

Reviewed By: SS-JIA

Differential Revision: D45893511

fbshipit-source-id: 6875e1dcebc928282d8d6a2c795d3167e1dfb2cd

aten/src/ATen/native/vulkan/glsl/unsqueeze_2dto3d.glsl

@@ -0,0 +1,60 @@
+#version 450 core
+#define PRECISION $precision
+#define FORMAT $format
+
+layout(std430) buffer;
+
+/*
+ * Output Image
+ */
+layout(set = 0, binding = 0, FORMAT) uniform PRECISION restrict writeonly image3D uOutput;
+
+/*
+ * Input Sampler
+ */
+layout(set = 0, binding = 1) uniform PRECISION sampler3D uImage;
+
+/*
+ * Params Buffer
+ */
+layout(set = 0, binding = 2) uniform PRECISION restrict Block {
+  // dim: dimension to insert at
+  ivec2 dim;
+}
+uBlock;
+
+/*
+ * Local Work Group Size
+ */
+layout(local_size_x_id = 0, local_size_y_id = 1, local_size_z_id = 2) in;
+
+/*
+ * Returns a new tensor with dimension of size one inserted at the specified
+ * position (dim)
+ */
+void main() {
+  const ivec3 pos = ivec3(gl_GlobalInvocationID);
+  const int dim = uBlock.dim.x;
+  vec4 out_texel = vec4(0, 0, 0, 0);
+  if (dim == 0 || dim == -3) {
+    imageStore(uOutput, pos, texelFetch(uImage, pos, 0));
+  } else if (dim == 1 || dim == -2) {
+    int src_x = pos.x;
+    int src_z = 0;
+    for (int i = 0; i < 4; i++) {
+      int src_y = pos.z * 4 + i;
+      const vec4 v = texelFetch(uImage, ivec3(src_x, src_y, src_z), 0);
+      out_texel[i] = v[0];
+    }
+    imageStore(uOutput, pos, out_texel);
+  } else if (dim == 2 || dim == -1) {
+    int src_x = pos.y;
+    int src_z = 0;
+    for (int i = 0; i < 4; i++) {
+      int src_y = pos.z * 4 + i;
+      const vec4 v = texelFetch(uImage, ivec3(src_x, src_y, src_z), 0);
+      out_texel[i] = v[0];
+    }
+    imageStore(uOutput, pos, out_texel);
+  }
+}

aten/src/ATen/native/vulkan/ops/Unsqueeze.cpp

@@ -0,0 +1,106 @@
+#include <ATen/native/vulkan/ops/Common.h>
+#include <ATen/native/vulkan/ops/Utils.h>
+#include <torch/library.h>
+
+namespace at {
+namespace native {
+namespace vulkan {
+namespace ops {
+namespace {
+
+using namespace api::utils;
+
+struct Block final {
+  ivec2 dim;
+};
+
+Tensor unsqueeze_2dto3d(const at::Tensor& input_arg, int64_t dim) {
+  // Get the global Vulkan context
+  api::Context* const context = api::context();
+
+  // Cast the input Tensor to a vTensor
+  const Tensor input = input_arg.is_vulkan() ? input_arg : input_arg.vulkan();
+  const vTensor& v_input = convert(input);
+
+  // Create the output texture. For unsqueeze, add a dimension.
+  std::vector<int64_t> output_size = input_arg.sizes().vec();
+  if (dim < 0)
+    dim += 3;
+  output_size.insert(output_size.begin() + dim, 1);
+  const IntArrayRef v_input_sizes = v_input.sizes();
+  // Create the output texture
+  vTensor v_output{
+      context,
+      output_size,
+      input_arg.scalar_type(),
+  };
+
+  // Required to determine how to insert memory barriers in the command buffer
+  api::PipelineBarrier pipeline_barrier{};
+
+  // Total number of work items is equal to the size of the output texture
+  uvec3 global_size = v_output.extents();
+  // Adaptively determine local work group size, will usually be {4, 4, 4}
+  uvec3 local_size = adaptive_work_group_size(global_size);
+
+  // Create the params buffer
+  struct Block block {
+    {
+      static_cast<int32_t>(dim)
+    }
+  };
+  api::UniformParamsBuffer params(context, block);
+
+  context->submit_compute_job(
+      // shader descriptor
+      VK_KERNEL(unsqueeze_2dto3d),
+      // pipeline barrier
+      pipeline_barrier,
+      // global work group size
+      global_size,
+      // local work group size
+      local_size,
+      // fence handle
+      VK_NULL_HANDLE,
+      // shader arguments
+      v_output.image(
+          pipeline_barrier,
+          api::PipelineStage::COMPUTE,
+          api::MemoryAccessType::WRITE),
+      v_input.image(pipeline_barrier, api::PipelineStage::COMPUTE),
+      // params buffer
+      params.buffer());
+
+  return convert(v_output);
+}
+
+Tensor unsqueeze(const at::Tensor& self, int64_t dim) {
+  TORCH_CHECK(
+      self.dim() >= 1 || self.dim() <= 3,
+      "Vulkan unsqueeze supports 1d, 2d, 3d tensors as input!");
+  TORCH_CHECK(
+      dim >= -self.dim() - 1 && dim <= self.dim(),
+      "Vulkan unsqueeze dimension out of range (expected to be in range of [",
+      -self.dim() - 1,
+      ",",
+      self.dim(),
+      "], but got ",
+      dim);
+  // Remove this when 1d->2d and 3d->4d are supported.
+  TORCH_CHECK(self.dim() == 2, "Vulkan unsqueeze expects input dimension = 2!");
+  return unsqueeze_2dto3d(self, dim);
+}
+
+#ifdef USE_VULKAN_API
+
+TORCH_LIBRARY_IMPL(aten, Vulkan, m) {
+  m.impl(TORCH_SELECTIVE_NAME("aten::unsqueeze"), TORCH_FN(unsqueeze));
+}
+
+#endif /* USE_VULKAN_API */
+
+} // namespace
+} // namespace ops
+} // namespace vulkan
+} // namespace native
+} // namespace at

aten/src/ATen/test/vulkan_api_test.cpp

@@ -3343,6 +3343,47 @@ TEST_F(VulkanAPITest, sub_to_scalar_wrapped) {
   ASSERT_TRUE(check);
 }
 
+void test_unsqueeze(const at::IntArrayRef input_shape, int64_t dim) {
+  at::TensorOptions options(at::kCPU);
+  options = options.dtype(at::kFloat);
+
+  const auto in_cpu = at::rand(input_shape, at::device(at::kCPU).dtype(at::kFloat));
+  const auto out_cpu = at::unsqueeze(in_cpu, dim);
+
+  const auto in_vulkan = in_cpu.vulkan();
+  const auto out_vulkan = at::unsqueeze(in_vulkan, dim);
+
+  const auto check = almostEqual(out_cpu, out_vulkan.cpu());
+  if (!check) {
+    showRtol(out_cpu, out_vulkan.cpu());
+  }
+  ASSERT_TRUE(check);
+}
+
+TEST_F(VulkanAPITest, unsqueeze_dim0) {
+  c10::InferenceMode mode;
+  test_unsqueeze({5, 7}, 0);
+  test_unsqueeze({5, 7}, -3);
+  test_unsqueeze({111, 222}, 0);
+  test_unsqueeze({111, 222}, -3);
+}
+
+TEST_F(VulkanAPITest, unsqueeze_dim1) {
+  c10::InferenceMode mode;
+  test_unsqueeze({5, 7}, 1);
+  test_unsqueeze({5, 7}, -2);
+  test_unsqueeze({111, 222}, 1);
+  test_unsqueeze({111, 222}, -2);
+}
+
+TEST_F(VulkanAPITest, unsqueeze_dim2) {
+  c10::InferenceMode mode;
+  test_unsqueeze({5, 7}, 2);
+  test_unsqueeze({5, 7}, -1);
+  test_unsqueeze({111, 222}, 2);
+  test_unsqueeze({111, 222}, -1);
+}
+
 TEST_F(VulkanAPITest, upsample_nearest2d) {
   const auto in_cpu = at::rand({1, 2, 2, 3}, at::TensorOptions(at::kCPU).dtype(at::kFloat));
   const auto out_cpu = at::upsample_nearest2d(in_cpu, {4, 6});