[ET-VK] Introduce BufferMetadata GLSL struct to abstract tensor layout

Pull Request resolved: #13595

As title; introduce an consolidated metadata UBO for buffer storage that can be used to abstract tensor indexing operations for buffer-backed tensors.

This new metadata UBO is capable of representing tensors of up to 8 dimensions. This upper limit is hardcoded, but can be increased later on without needing to update callsites since everything is abstracted by the BufferMetadata struct.

Update the following ops to use this new metadata UBO:

* staging shaders (nchw_to_buffer and buffer_to_nchw)
* binary op


@imported-using-ghimport

Differential Revision: [D80800082](https://our.internmc.facebook.com/intern/diff/D80800082/)
ghstack-source-id: 304953694

Author: ssjia

backends/vulkan/runtime/api/containers/Tensor.cpp

@@ -566,6 +566,7 @@ vTensor::vTensor(
       max_ubo_nbytes_{
           calculate_max_ubo_nbytes(min_nbytes_per_ubo_, storage_type)},
       uniforms_(),
+      buffer_meta_(),
       // Construct Tensor storage
       storage_(std::make_shared<vTensorStorage>(
           context,
@@ -610,6 +611,7 @@ vTensor::vTensor(
       max_ubo_nbytes_{
           calculate_max_ubo_nbytes(min_nbytes_per_ubo_, utils::kTexture3D)},
       uniforms_(),
+      buffer_meta_(),
       // Construct Tensor storage
       storage_(std::make_shared<vTensorStorage>(context, image)) {
   uniform_data_ = std::make_shared<UniformData>(UniformData{
@@ -633,6 +635,7 @@ vTensor::vTensor(vTensor& other)
       min_nbytes_per_ubo_{other.min_nbytes_per_ubo_},
       max_ubo_nbytes_{other.max_ubo_nbytes_},
       uniforms_(),
+      buffer_meta_(),
       // Copy Tensor storage
       storage_(other.storage_) {
   uniform_data_ = std::make_shared<UniformData>(*other.get_uniform_data());
@@ -658,6 +661,7 @@ vTensor::vTensor(
       min_nbytes_per_ubo_{other.min_nbytes_per_ubo_},
       max_ubo_nbytes_{other.max_ubo_nbytes_},
       uniforms_(),
+      buffer_meta_(),
       // Copy Tensor storage
       storage_(other.storage_) {
   uniform_data_ = std::make_shared<UniformData>(UniformData{
@@ -710,6 +714,38 @@ uint32_t vTensor::UniformData::write_attribute(
   return 0;
 }
 
+vTensor::BufferMetadata::BufferMetadata(
+    std::vector<int64_t> src_sizes,
+    std::vector<int64_t> src_dim_order,
+    std::vector<int64_t> src_strides,
+    size_t src_numel) {
+  update(src_sizes, src_dim_order, src_strides, src_numel);
+}
+
+void vTensor::BufferMetadata::update(
+    std::vector<int64_t> src_sizes,
+    std::vector<int64_t> src_dim_order,
+    std::vector<int64_t> src_strides,
+    size_t src_numel) {
+  int32_t fixed_ndim = utils::safe_downcast<int32_t>(kTensorDimLimit);
+
+  std::vector<uint32_t> fu_sizes = flip_and_unsqueeze<uint32_t>(
+      src_sizes, kTensorSizes, src_numel, fixed_ndim);
+  std::vector<uint32_t> fu_dim_order = flip_and_unsqueeze<uint32_t>(
+      src_dim_order, kTensorDimOrder, src_numel, fixed_ndim);
+  std::vector<uint32_t> fu_strides = flip_and_unsqueeze<uint32_t>(
+      src_strides, kTensorStrides, src_numel, fixed_ndim);
+
+  for (int i = 0; i < fixed_ndim; ++i) {
+    sizes[i] = fu_sizes.at(i);
+    dim_order[i] = fu_dim_order.at(i);
+    strides[i] = fu_strides.at(i);
+  }
+
+  ndim = utils::safe_downcast<uint32_t>(src_sizes.size());
+  numel = utils::safe_downcast<uint32_t>(src_numel);
+}
+
 vkapi::VulkanImage& vTensor::image(
     vkapi::PipelineBarrier& pipeline_barrier,
     const vkapi::PipelineStageFlags stage) & {
@@ -798,6 +834,15 @@ const vkapi::BufferBindInfo vTensor::numel_ubo() {
   return metadata_ubo_impl(&numel_uniform_offset_, uniform_data_->numel);
 }
 
+const vkapi::BufferBindInfo vTensor::buffer_meta_ubo() {
+  size_t ubo_nbytes = std::min(sizeof(BufferMetadata), min_nbytes_per_ubo_);
+  if (!buffer_meta_.buffer()) {
+    BufferMetadata data(sizes_, dim_order_, strides_, numel_);
+    buffer_meta_ = ParamsBuffer(storage_->context_, data);
+  }
+  return vkapi::BufferBindInfo(buffer_meta_.buffer(), 0, ubo_nbytes);
+}
+
 VkMemoryRequirements vTensor::get_memory_requirements() const {
   switch (storage_type()) {
     case utils::kBuffer:
@@ -874,6 +919,11 @@ void vTensor::update_metadata() {
     uniforms_.update(
         uniform_data_->logical_limits.limits, logical_limits_uniform_offset_);
   }
+
+  if (buffer_meta_.buffer()) {
+    BufferMetadata data(sizes_, dim_order_, strides_, numel_);
+    buffer_meta_.update(data);
+  }
 }
 
 void vTensor::check_sizes(const std::vector<int64_t>& sizes) const {

backends/vulkan/runtime/api/containers/Tensor.h

@@ -19,6 +19,8 @@
 namespace vkcompute {
 namespace api {
 
+static constexpr size_t kTensorDimLimit = 8;
+
 /*
  * Given a GPUMemoryLayout value, produce a dim order vector that matches the
  * given memory layout. The produced dim order vector will be in the NCHW
@@ -262,6 +264,26 @@ class vTensor final {
         const Attribute attr);
   };
 
+  struct BufferMetadata {
+    uint32_t sizes[kTensorDimLimit];
+    uint32_t dim_order[kTensorDimLimit];
+    uint32_t strides[kTensorDimLimit];
+    uint32_t ndim;
+    uint32_t numel;
+
+    BufferMetadata(
+        std::vector<int64_t> sizes,
+        std::vector<int64_t> dim_order,
+        std::vector<int64_t> strides,
+        size_t numel);
+
+    void update(
+        std::vector<int64_t> sizes,
+        std::vector<int64_t> dim_order,
+        std::vector<int64_t> strides,
+        size_t numel);
+  };
+
  private:
   /*
    * "Core" tensor metadata. They are the minimum amount of information required
@@ -332,6 +354,11 @@ class vTensor final {
    */
   ParamsBuffer uniforms_;
 
+  /*
+   * TODO: explain
+   */
+  ParamsBuffer buffer_meta_;
+
   uint32_t uniforms_size_ = 0u;
   uint32_t sizes_uniform_offset_ = kUniformOffsetUnset;
   uint32_t dim_order_uniform_offset_ = kUniformOffsetUnset;
@@ -557,6 +584,8 @@ class vTensor final {
 
   const vkapi::BufferBindInfo numel_ubo();
 
+  const vkapi::BufferBindInfo buffer_meta_ubo();
+
  public:
   inline size_t staging_buffer_numel() const {
     return storage_->buffer_len();

backends/vulkan/runtime/graph/ComputeGraph.h

@@ -357,6 +357,10 @@ class ComputeGraph final {
     return values_.at(idx).toConstTensor().has_buffer_storage();
   }
 
+  inline bool is_texture_storage(const ValueRef idx) const {
+    return !is_buffer_storage(idx);
+  }
+
   /*
    * Checks that the following is true:
    * 1. The value at `idx` is a tensor
@@ -411,6 +415,10 @@ class ComputeGraph final {
     return values_.at(idx).toTensor().sizes_ubo();
   }
 
+  inline vkapi::BufferBindInfo buffer_meta_ubo(const ValueRef idx) {
+    return values_.at(idx).toTensor().buffer_meta_ubo();
+  }
+
   inline vkapi::BufferBindInfo strides_ubo(const ValueRef idx) {
     return values_.at(idx).toTensor().strides_ubo();
   }

backends/vulkan/runtime/graph/ops/glsl/binary_op.glsl

@@ -34,6 +34,8 @@ $if IS_COMPARISON_OP:
 
 layout(std430) buffer;
 
+#include "indexing.glslh"
+
 $if IS_COMPARISON_OP:
   ${layout_declare_tensor(B, "w", "t_out", "uint8", STORAGE)}
 $else:
@@ -43,13 +45,11 @@ ${layout_declare_tensor(B, "r", "t_in", DTYPE, STORAGE)}
 ${layout_declare_tensor(B, "r", "t_other", DTYPE, STORAGE)}
 
 $if STORAGE == "buffer":
+  ${layout_declare_ubo(B, "BufferMetadata", "outp")}
+  ${layout_declare_ubo(B, "BufferMetadata", "inp")}
+  ${layout_declare_ubo(B, "BufferMetadata", "other")}
+
   layout(push_constant) uniform restrict Block {
-    ivec4 in_sizes;
-    ivec4 other_sizes;
-    ivec4 out_strides;
-    ivec4 in_strides;
-    ivec4 other_strides;
-    int out_numel;
     float alpha;
   };
 $else:
@@ -83,25 +83,30 @@ $else:
 #ifdef USING_BUFFER
 
 void main() {
-  const int out_bufi = ivec3(gl_GlobalInvocationID).x;
-  if (out_bufi >= out_numel) {
+  const uint out_bufi = gl_GlobalInvocationID.x;
+  if (out_bufi >= numel(outp)) {
     return;
   }
 
   // Simple case; no broadcasting
-  if (in_sizes == other_sizes) {
+  if (are_equal(inp, other)) {
     t_out[out_bufi] = T(op(t_in[out_bufi], t_other[out_bufi], T(alpha)));
     return;
   }
 
-  const ivec4 out_tidx = bufi_to_tidx(out_bufi, out_strides, out_dim_order);
-  const ivec4 in_tidx = min(out_tidx, in_sizes - 1);
-  const ivec4 other_tidx = min(out_tidx, other_sizes - 1);
+  TensorIndex outp_tidx;
+  linear_idx_to_tensor_idx(outp, out_bufi, outp_tidx);
+
+  TensorIndex inp_tidx = outp_tidx;
+  clamp_tensor_idx(inp, inp_tidx);
+
+  TensorIndex other_tidx = outp_tidx;
+  clamp_tensor_idx(other, other_tidx);
 
-  const int in_bufi = tidx_to_bufi(in_tidx, in_strides);
-  const int other_bufi = tidx_to_bufi(other_tidx, other_strides);
+  uint inp_bufi = tensor_idx_to_linear_idx(inp, inp_tidx);
+  uint other_bufi = tensor_idx_to_linear_idx(other, other_tidx);
 
-  t_out[out_bufi] = T(op(t_in[in_bufi], t_other[other_bufi], T(alpha)));
+  t_out[out_bufi] = T(op(t_in[inp_bufi], t_other[other_bufi], T(alpha)));
 }
 
 #else // USING_TEXTURE

backends/vulkan/runtime/graph/ops/glsl/buffer_to_nchw.glsl

@@ -4,40 +4,33 @@
 
 #define T ${buffer_scalar_type(DTYPE)}
 
-#include "indexing_utils.h"
-
 ${define_required_extensions(DTYPE)}
 
 layout(std430) buffer;
 
-${layout_declare_tensor(0, "w", "nchw_buf", DTYPE, STORAGE)}
-${layout_declare_tensor(1, "r", "t_in", DTYPE, STORAGE)}
+#include "indexing.glslh"
+
+${layout_declare_tensor(B, "w", "nchw_buf", DTYPE, STORAGE)}
+${layout_declare_tensor(B, "r", "t_inp", DTYPE, STORAGE)}
 
-$if USE_PUSH_CONST:
-  layout(push_constant) uniform restrict Block {
-    ivec4 in_sizes;
-    ivec4 in_strides;
-    int numel;
-  };
-$else:
-  ${layout_declare_ubo(2, "ivec4", "in_sizes")}
-  ${layout_declare_ubo(3, "ivec4", "in_strides")}
-  ${layout_declare_ubo(4, "int", "numel")}
+${layout_declare_ubo(B, "BufferMetadata", "inp")}
 
 layout(local_size_x_id = 0, local_size_y_id = 1, local_size_z_id = 2) in;
 
 // This constant is unused in this shader but is kept so that the signature is
 // consistent with image_to_nchw.
-layout(constant_id = 3) const int UNUSED_packed_dim = W_DIM;
+${layout_declare_spec_const(C, "int", "unused", "0")}
 
 void main() {
-  int nchwi = int(gl_GlobalInvocationID.x);
-  if (nchwi >= numel) {
+  uint inp_bufi = gl_GlobalInvocationID.x;
+  if (inp_bufi>= numel(inp)) {
     return;
   }
 
-  ivec4 in_tidx = nchwi_to_tidx(nchwi, in_sizes);
-  const int in_bufi = tidx_to_bufi(in_tidx, in_strides);
+  TensorIndex inp_tidx;
+  linear_idx_to_tensor_idx(inp, inp_bufi, inp_tidx);
+
+  uint nchwi = tensor_idx_to_contiguous_idx(inp, inp_tidx);
 
-  nchw_buf[nchwi] = t_in[in_bufi];
+  nchw_buf[nchwi] = t_inp[inp_bufi];
 }

backends/vulkan/runtime/graph/ops/glsl/buffer_to_nchw.yaml

@@ -19,5 +19,3 @@ buffer_to_nchw:
       - VALUE: int32
   shader_variants:
     - NAME: buffer_to_nchw
-    - NAME: buffer_to_nchw_no_pc
-      USE_PUSH_CONST: False