src/tests/end2end/ComputeLayoutMemoryBufferTests.cpp - dawn - Git at Google

 // Copyright 2021 The Dawn Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #include "tests/DawnTest.h"

 #include "common/Math.h"
 #include "utils/WGPUHelpers.h"

 #include <array>
 #include <functional>

 namespace {

     // Helper for replacing all occurrences of substr in str with replacement
     std::string ReplaceAll(std::string str,
                            const std::string& substr,
                            const std::string& replacement) {
         size_t pos = 0;
         while ((pos = str.find(substr, pos)) != std::string::npos) {
             str.replace(pos, substr.length(), replacement);
             pos += replacement.length();
         }
         return str;
     }

     // DataMatcherCallback is the callback function by DataMatcher.
     // It is called for each contiguous sequence of bytes that should be checked
     // for equality.
     // offset and size are in units of bytes.
     using DataMatcherCallback = std::function<void(uint32_t offset, uint32_t size)>;

     // DataMatcher is a function pointer to a data matching function.
     // size is the total number of bytes being considered for matching.
     // The callback may be called once or multiple times, and may only consider
     // part of the interval [0, size)
     using DataMatcher = void (*)(uint32_t size, DataMatcherCallback);

     // FullDataMatcher is a DataMatcher that calls callback with the interval
     // [0, size)
     void FullDataMatcher(uint32_t size, DataMatcherCallback callback) {
         callback(0, size);
     }

     // StridedDataMatcher is a DataMatcher that calls callback with the strided
     // intervals of length BYTES_TO_MATCH, skipping BYTES_TO_SKIP.
     // For example: StridedDataMatcher<2, 4>(18, callback) will call callback
     // with the intervals: [0, 2), [6, 8), [12, 14)
     template <int BYTES_TO_MATCH, int BYTES_TO_SKIP>
     void StridedDataMatcher(uint32_t size, DataMatcherCallback callback) {
         uint32_t offset = 0;
         while (offset < size) {
             callback(offset, BYTES_TO_MATCH);
             offset += BYTES_TO_MATCH + BYTES_TO_SKIP;
         }
     }

     // Align returns the WGSL decoration for an explicit structure field alignment
     std::string AlignDeco(uint32_t value) {
         return "[[align(" + std::to_string(value) + ")]] ";
     }

 }  // namespace

 // Field holds test parameters for ComputeLayoutMemoryBufferTests.Fields
 struct Field {
     const char* type;  // Type of the field
     uint32_t align;    // Alignment of the type in bytes
     uint32_t size;     // Natural size of the type in bytes

     uint32_t padded_size = 0;                // Decorated (extended) size of the type in bytes
     DataMatcher matcher = &FullDataMatcher;  // The matching method
     bool storage_buffer_only = false;        // This should only be used for storage buffer tests

     // Sets the padded_size to value.
     // Returns this Field so calls can be chained.
     Field& PaddedSize(uint32_t value) {
         padded_size = value;
         return *this;
     }

     // Sets the matcher to a StridedDataMatcher<BYTES_TO_MATCH, BYTES_TO_SKIP>.
     // Returns this Field so calls can be chained.
     template <int BYTES_TO_MATCH, int BYTES_TO_SKIP>
     Field& Strided() {
         matcher = &StridedDataMatcher<BYTES_TO_MATCH, BYTES_TO_SKIP>;
         return *this;
     }

     // Marks that this should only be used for storage buffer tests.
     // Returns this Field so calls can be chained.
     Field& StorageBufferOnly() {
         storage_buffer_only = true;
         return *this;
     }
 };

 // StorageClass is an enumerator of storage classes used by ComputeLayoutMemoryBufferTests.Fields
 enum class StorageClass {
     Uniform,
     Storage,
 };

 std::ostream& operator<<(std::ostream& o, StorageClass storageClass) {
     switch (storageClass) {
         case StorageClass::Uniform:
             o << "uniform";
             break;
         case StorageClass::Storage:
             o << "storage";
             break;
     }
     return o;
 }

 std::ostream& operator<<(std::ostream& o, Field field) {
     o << "[[align(" << field.align << "), size("
       << (field.padded_size > 0 ? field.padded_size : field.size) << ")]] " << field.type;
     return o;
 }

 DAWN_TEST_PARAM_STRUCT(ComputeLayoutMemoryBufferTestParams, StorageClass, Field);

 class ComputeLayoutMemoryBufferTests
     : public DawnTestWithParams<ComputeLayoutMemoryBufferTestParams> {
     void SetUp() override {
         DawnTestBase::SetUp();
     }
 };

 TEST_P(ComputeLayoutMemoryBufferTests, Fields) {
     // Sentinel value markers codes used to check that the start and end of
     // structures are correctly aligned. Each of these codes are distinct and
     // are not likely to be confused with data.
     constexpr uint32_t kDataHeaderCode = 0xa0b0c0a0u;
     constexpr uint32_t kDataFooterCode = 0x40302010u;
     constexpr uint32_t kInputHeaderCode = 0x91827364u;
     constexpr uint32_t kInputFooterCode = 0x19283764u;

     // Byte codes used for field padding. The MSB is set for each of these.
     // The field data has the MSB 0.
     constexpr uint8_t kDataAlignPaddingCode = 0xfeu;
     constexpr uint8_t kFieldAlignPaddingCode = 0xfdu;
     constexpr uint8_t kFieldSizePaddingCode = 0xdcu;
     constexpr uint8_t kDataSizePaddingCode = 0xdbu;
     constexpr uint8_t kInputFooterAlignPaddingCode = 0xdau;
     constexpr uint8_t kInputTailPaddingCode = 0xd9u;

     // Status codes returned by the shader.
     constexpr uint32_t kStatusBadInputHeader = 100u;
     constexpr uint32_t kStatusBadInputFooter = 101u;
     constexpr uint32_t kStatusBadDataHeader = 102u;
     constexpr uint32_t kStatusBadDataFooter = 103u;
     constexpr uint32_t kStatusOk = 200u;

     const Field& field = GetParam().mField;

     const bool isUniform = GetParam().mStorageClass == StorageClass::Uniform;

     std::string shader = R"(
 struct Data {
     header : u32;
     [[align({field_align}), size({field_size})]] field : {field_type};
     footer : u32;
 };

 [[block]] struct Input {
     header : u32;
     {data_align}data : Data;
     {footer_align}footer : u32;
 };

 [[block]] struct Output {
     data : {field_type};
 };

 [[block]] struct Status {
     code : u32;
 };

 [[group(0), binding(0)]] var<{input_qualifiers}> input : Input;
 [[group(0), binding(1)]] var<storage, read_write> output : Output;
 [[group(0), binding(2)]] var<storage, read_write> status : Status;

 [[stage(compute), workgroup_size(1,1,1)]]
 fn main() {
     if (input.header != {input_header_code}u) {
         status.code = {status_bad_input_header}u;
     } elseif (input.footer != {input_footer_code}u) {
         status.code = {status_bad_input_footer}u;
     } elseif (input.data.header != {data_header_code}u) {
         status.code = {status_bad_data_header}u;
     } elseif (input.data.footer != {data_footer_code}u) {
         status.code = {status_bad_data_footer}u;
     } else {
         status.code = {status_ok}u;
         output.data = input.data.field;
     }
 })";

     // https://www.w3.org/TR/WGSL/#alignment-and-size
     // Structure size: roundUp(AlignOf(S), OffsetOf(S, L) + SizeOf(S, L))
     // https://www.w3.org/TR/WGSL/#storage-class-constraints
     // RequiredAlignOf(S, uniform): roundUp(16, max(AlignOf(T0), ..., AlignOf(TN)))
     uint32_t dataAlign = isUniform ? std::max(16u, field.align) : field.align;

     // https://www.w3.org/TR/WGSL/#structure-layout-rules
     // Note: When underlying the target is a Vulkan device, we assume the device does not support
     // the scalarBlockLayout feature. Therefore, a data value must not be placed in the padding at
     // the end of a structure or matrix, nor in the padding at the last element of an array.
     uint32_t footerAlign = isUniform ? 16 : 4;

     shader = ReplaceAll(shader, "{data_align}", isUniform ? AlignDeco(dataAlign) : "");
     shader = ReplaceAll(shader, "{field_align}", std::to_string(field.align));
     shader = ReplaceAll(shader, "{footer_align}", isUniform ? AlignDeco(footerAlign) : "");
     shader = ReplaceAll(shader, "{field_size}",
                         std::to_string(field.padded_size > 0 ? field.padded_size : field.size));
     shader = ReplaceAll(shader, "{field_type}", field.type);
     shader = ReplaceAll(shader, "{input_header_code}", std::to_string(kInputHeaderCode));
     shader = ReplaceAll(shader, "{input_footer_code}", std::to_string(kInputFooterCode));
     shader = ReplaceAll(shader, "{data_header_code}", std::to_string(kDataHeaderCode));
     shader = ReplaceAll(shader, "{data_footer_code}", std::to_string(kDataFooterCode));
     shader = ReplaceAll(shader, "{status_bad_input_header}", std::to_string(kStatusBadInputHeader));
     shader = ReplaceAll(shader, "{status_bad_input_footer}", std::to_string(kStatusBadInputFooter));
     shader = ReplaceAll(shader, "{status_bad_data_header}", std::to_string(kStatusBadDataHeader));
     shader = ReplaceAll(shader, "{status_bad_data_footer}", std::to_string(kStatusBadDataFooter));
     shader = ReplaceAll(shader, "{status_ok}", std::to_string(kStatusOk));
     shader = ReplaceAll(shader, "{input_qualifiers}",
                         isUniform ? "uniform"  //
                                   : "storage, read_write");

     // Set up shader and pipeline
     auto module = utils::CreateShaderModule(device, shader.c_str());

     wgpu::ComputePipelineDescriptor csDesc;
     csDesc.compute.module = module;
     csDesc.compute.entryPoint = "main";

     wgpu::ComputePipeline pipeline = device.CreateComputePipeline(&csDesc);

     // Build the input and expected data.
     std::vector<uint8_t> inputData;     // The whole SSBO data
     std::vector<uint8_t> expectedData;  // The expected data to be copied by the shader
     {
         auto PushU32 = [&inputData](uint32_t u32) {
             inputData.emplace_back((u32 >> 0) & 0xff);
             inputData.emplace_back((u32 >> 8) & 0xff);
             inputData.emplace_back((u32 >> 16) & 0xff);
             inputData.emplace_back((u32 >> 24) & 0xff);
         };
         auto AlignTo = [&inputData](uint32_t alignment, uint8_t code) {
             uint32_t target = Align(inputData.size(), alignment);
             uint32_t bytes = target - inputData.size();
             for (uint32_t i = 0; i < bytes; i++) {
                 inputData.emplace_back(code);
             }
         };
         PushU32(kInputHeaderCode);                  // Input.header
         AlignTo(dataAlign, kDataAlignPaddingCode);  // Input.data
         {
             PushU32(kDataHeaderCode);                      // Input.data.header
             AlignTo(field.align, kFieldAlignPaddingCode);  // Input.data.field
             for (uint32_t i = 0; i < field.size; i++) {
                 // The data has the MSB cleared to distinguish it from the
                 // padding codes.
                 uint8_t code = i & 0x7f;
                 inputData.emplace_back(code);  // Input.data.field
                 expectedData.emplace_back(code);
             }
             for (uint32_t i = field.size; i < field.padded_size; i++) {
                 inputData.emplace_back(kFieldSizePaddingCode);  // Input.data.field padding
             }
             PushU32(kDataFooterCode);                    // Input.data.footer
             AlignTo(field.align, kDataSizePaddingCode);  // Input.data padding
         }
         AlignTo(footerAlign, kInputFooterAlignPaddingCode);  // Input.footer [[align]]
         PushU32(kInputFooterCode);                           // Input.footer
         AlignTo(256, kInputTailPaddingCode);                 // Input padding
     }

     // Set up input storage buffer
     wgpu::Buffer inputBuf = utils::CreateBufferFromData(
         device, inputData.data(), inputData.size(),
         wgpu::BufferUsage::CopySrc | wgpu::BufferUsage::CopyDst |
             (isUniform ? wgpu::BufferUsage::Uniform : wgpu::BufferUsage::Storage));

     // Set up output storage buffer
     wgpu::BufferDescriptor outputDesc;
     outputDesc.size = field.size;
     outputDesc.usage =
         wgpu::BufferUsage::Storage | wgpu::BufferUsage::CopySrc | wgpu::BufferUsage::CopyDst;
     wgpu::Buffer outputBuf = device.CreateBuffer(&outputDesc);

     // Set up status storage buffer
     wgpu::BufferDescriptor statusDesc;
     statusDesc.size = 4u;
     statusDesc.usage =
         wgpu::BufferUsage::Storage | wgpu::BufferUsage::CopySrc | wgpu::BufferUsage::CopyDst;
     wgpu::Buffer statusBuf = device.CreateBuffer(&statusDesc);

     // Set up bind group and issue dispatch
     wgpu::BindGroup bindGroup = utils::MakeBindGroup(device, pipeline.GetBindGroupLayout(0),
                                                      {
                                                          {0, inputBuf},
                                                          {1, outputBuf},
                                                          {2, statusBuf},
                                                      });

     wgpu::CommandBuffer commands;
     {
         wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
         wgpu::ComputePassEncoder pass = encoder.BeginComputePass();
         pass.SetPipeline(pipeline);
         pass.SetBindGroup(0, bindGroup);
         pass.Dispatch(1);
         pass.EndPass();

         commands = encoder.Finish();
     }

     queue.Submit(1, &commands);

     // Check the status
     EXPECT_BUFFER_U32_EQ(kStatusOk, statusBuf, 0) << "status code error" << std::endl
                                                   << "Shader: " << shader;

     // Check the data
     field.matcher(field.size, [&](uint32_t offset, uint32_t size) {
         EXPECT_BUFFER_U8_RANGE_EQ(expectedData.data() + offset, outputBuf, offset, size)
             << "offset: " << offset;
     });
 }

 namespace {

     auto GenerateParams() {
         auto params = MakeParamGenerator<ComputeLayoutMemoryBufferTestParams>(
             {
                 D3D12Backend(), MetalBackend(), VulkanBackend(),
                 // TODO(crbug.com/dawn/942)
                 // There was a compiler error: Buffer block cannot be expressed as any of std430,
                 // std140, scalar, even with enhanced layouts. You can try flattening this block to
                 // support a more flexible layout.
                 // OpenGLBackend(),
                 // OpenGLESBackend(),
             },
             {StorageClass::Storage, StorageClass::Uniform},
             {
                 // See https://www.w3.org/TR/WGSL/#alignment-and-size
                 // Scalar types with no custom alignment or size
                 Field{"i32", /* align */ 4, /* size */ 4},
                 Field{"u32", /* align */ 4, /* size */ 4},
                 Field{"f32", /* align */ 4, /* size */ 4},

                 // Scalar types with custom alignment
                 Field{"i32", /* align */ 16, /* size */ 4},
                 Field{"u32", /* align */ 16, /* size */ 4},
                 Field{"f32", /* align */ 16, /* size */ 4},

                 // Scalar types with custom size
                 Field{"i32", /* align */ 4, /* size */ 4}.PaddedSize(24),
                 Field{"u32", /* align */ 4, /* size */ 4}.PaddedSize(24),
                 Field{"f32", /* align */ 4, /* size */ 4}.PaddedSize(24),

                 // Vector types with no custom alignment or size
                 Field{"vec2<i32>", /* align */ 8, /* size */ 8},
                 Field{"vec2<u32>", /* align */ 8, /* size */ 8},
                 Field{"vec2<f32>", /* align */ 8, /* size */ 8},
                 Field{"vec3<i32>", /* align */ 16, /* size */ 12},
                 Field{"vec3<u32>", /* align */ 16, /* size */ 12},
                 Field{"vec3<f32>", /* align */ 16, /* size */ 12},
                 Field{"vec4<i32>", /* align */ 16, /* size */ 16},
                 Field{"vec4<u32>", /* align */ 16, /* size */ 16},
                 Field{"vec4<f32>", /* align */ 16, /* size */ 16},

                 // Vector types with custom alignment
                 Field{"vec2<i32>", /* align */ 32, /* size */ 8},
                 Field{"vec2<u32>", /* align */ 32, /* size */ 8},
                 Field{"vec2<f32>", /* align */ 32, /* size */ 8},
                 Field{"vec3<i32>", /* align */ 32, /* size */ 12},
                 Field{"vec3<u32>", /* align */ 32, /* size */ 12},
                 Field{"vec3<f32>", /* align */ 32, /* size */ 12},
                 Field{"vec4<i32>", /* align */ 32, /* size */ 16},
                 Field{"vec4<u32>", /* align */ 32, /* size */ 16},
                 Field{"vec4<f32>", /* align */ 32, /* size */ 16},

                 // Vector types with custom size
                 Field{"vec2<i32>", /* align */ 8, /* size */ 8}.PaddedSize(24),
                 Field{"vec2<u32>", /* align */ 8, /* size */ 8}.PaddedSize(24),
                 Field{"vec2<f32>", /* align */ 8, /* size */ 8}.PaddedSize(24),
                 Field{"vec3<i32>", /* align */ 16, /* size */ 12}.PaddedSize(24),
                 Field{"vec3<u32>", /* align */ 16, /* size */ 12}.PaddedSize(24),
                 Field{"vec3<f32>", /* align */ 16, /* size */ 12}.PaddedSize(24),
                 Field{"vec4<i32>", /* align */ 16, /* size */ 16}.PaddedSize(24),
                 Field{"vec4<u32>", /* align */ 16, /* size */ 16}.PaddedSize(24),
                 Field{"vec4<f32>", /* align */ 16, /* size */ 16}.PaddedSize(24),

                 // Matrix types with no custom alignment or size
                 Field{"mat2x2<f32>", /* align */ 8, /* size */ 16},
                 Field{"mat3x2<f32>", /* align */ 8, /* size */ 24},
                 Field{"mat4x2<f32>", /* align */ 8, /* size */ 32},
                 Field{"mat2x3<f32>", /* align */ 16, /* size */ 32}.Strided<12, 4>(),
                 Field{"mat3x3<f32>", /* align */ 16, /* size */ 48}.Strided<12, 4>(),
                 Field{"mat4x3<f32>", /* align */ 16, /* size */ 64}.Strided<12, 4>(),
                 Field{"mat2x4<f32>", /* align */ 16, /* size */ 32},
                 Field{"mat3x4<f32>", /* align */ 16, /* size */ 48},
                 Field{"mat4x4<f32>", /* align */ 16, /* size */ 64},

                 // Matrix types with custom alignment
                 Field{"mat2x2<f32>", /* align */ 32, /* size */ 16},
                 Field{"mat3x2<f32>", /* align */ 32, /* size */ 24},
                 Field{"mat4x2<f32>", /* align */ 32, /* size */ 32},
                 Field{"mat2x3<f32>", /* align */ 32, /* size */ 32}.Strided<12, 4>(),
                 Field{"mat3x3<f32>", /* align */ 32, /* size */ 48}.Strided<12, 4>(),
                 Field{"mat4x3<f32>", /* align */ 32, /* size */ 64}.Strided<12, 4>(),
                 Field{"mat2x4<f32>", /* align */ 32, /* size */ 32},
                 Field{"mat3x4<f32>", /* align */ 32, /* size */ 48},
                 Field{"mat4x4<f32>", /* align */ 32, /* size */ 64},

                 // Matrix types with custom size
                 Field{"mat2x2<f32>", /* align */ 8, /* size */ 16}.PaddedSize(128),
                 Field{"mat3x2<f32>", /* align */ 8, /* size */ 24}.PaddedSize(128),
                 Field{"mat4x2<f32>", /* align */ 8, /* size */ 32}.PaddedSize(128),
                 Field{"mat2x3<f32>", /* align */ 16, /* size */ 32}
                     .PaddedSize(128)
                     .Strided<12, 4>(),
                 Field{"mat3x3<f32>", /* align */ 16, /* size */ 48}
                     .PaddedSize(128)
                     .Strided<12, 4>(),
                 Field{"mat4x3<f32>", /* align */ 16, /* size */ 64}
                     .PaddedSize(128)
                     .Strided<12, 4>(),
                 Field{"mat2x4<f32>", /* align */ 16, /* size */ 32}.PaddedSize(128),
                 Field{"mat3x4<f32>", /* align */ 16, /* size */ 48}.PaddedSize(128),
                 Field{"mat4x4<f32>", /* align */ 16, /* size */ 64}.PaddedSize(128),

                 // Array types with no custom alignment, size or stride
                 // Note: The use of StorageBufferOnly() is due to UBOs requiring 16 byte alignment
                 // of array elements. See https://www.w3.org/TR/WGSL/#storage-class-constraints
                 Field{"array<u32, 1>", /* align */ 4, /* size */ 4}.StorageBufferOnly(),
                 Field{"array<u32, 2>", /* align */ 4, /* size */ 8}.StorageBufferOnly(),
                 Field{"array<u32, 3>", /* align */ 4, /* size */ 12}.StorageBufferOnly(),
                 Field{"array<u32, 4>", /* align */ 4, /* size */ 16}.StorageBufferOnly(),
                 Field{"[[stride(16)]] array<u32, 1>", /* align */ 4, /* size */ 16}
                     .StorageBufferOnly()
                     .Strided<4, 12>(),
                 Field{"[[stride(16)]] array<u32, 2>", /* align */ 4, /* size */ 32}
                     .StorageBufferOnly()
                     .Strided<4, 12>(),
                 Field{"[[stride(16)]] array<u32, 3>", /* align */ 4, /* size */ 48}
                     .StorageBufferOnly()
                     .Strided<4, 12>(),
                 Field{"[[stride(16)]] array<u32, 4>", /* align */ 4, /* size */ 64}
                     .StorageBufferOnly()
                     .Strided<4, 12>(),
                 Field{"array<vec3<u32>, 4>", /* align */ 16, /* size */ 64}.Strided<12, 4>(),
                 Field{"[[stride(32)]] array<vec3<u32>, 4>", /* align */ 16, /* size */ 128}
                     .Strided<12, 20>(),

                 // Array types with custom alignment
                 Field{"array<u32, 1>", /* align */ 32, /* size */ 4}.StorageBufferOnly(),
                 Field{"array<u32, 2>", /* align */ 32, /* size */ 8}.StorageBufferOnly(),
                 Field{"array<u32, 3>", /* align */ 32, /* size */ 12}.StorageBufferOnly(),
                 Field{"array<u32, 4>", /* align */ 32, /* size */ 16}.StorageBufferOnly(),
                 Field{"[[stride(16)]] array<u32, 1>", /* align */ 32, /* size */ 16}
                     .Strided<4, 12>(),
                 Field{"[[stride(16)]] array<u32, 2>", /* align */ 32, /* size */ 32}
                     .Strided<4, 12>(),
                 Field{"[[stride(16)]] array<u32, 3>", /* align */ 32, /* size */ 48}
                     .Strided<4, 12>(),
                 Field{"[[stride(16)]] array<u32, 4>", /* align */ 32, /* size */ 64}
                     .Strided<4, 12>(),
                 Field{"array<vec3<u32>, 4>", /* align */ 32, /* size */ 64}.Strided<12, 4>(),

                 // Array types with custom size
                 Field{"array<u32, 1>", /* align */ 4, /* size */ 4}
                     .PaddedSize(128)
                     .StorageBufferOnly(),
                 Field{"array<u32, 2>", /* align */ 4, /* size */ 8}
                     .PaddedSize(128)
                     .StorageBufferOnly(),
                 Field{"array<u32, 3>", /* align */ 4, /* size */ 12}
                     .PaddedSize(128)
                     .StorageBufferOnly(),
                 Field{"array<u32, 4>", /* align */ 4, /* size */ 16}
                     .PaddedSize(128)
                     .StorageBufferOnly(),
                 Field{"array<vec3<u32>, 4>", /* align */ 16, /* size */ 64}
                     .PaddedSize(128)
                     .Strided<12, 4>(),
             });

         std::vector<ComputeLayoutMemoryBufferTestParams> filtered;
         for (auto param : params) {
             if (param.mStorageClass != StorageClass::Storage && param.mField.storage_buffer_only) {
                 continue;
             }
             filtered.emplace_back(param);
         }
         return filtered;
     }

     INSTANTIATE_TEST_SUITE_P(
         ,
         ComputeLayoutMemoryBufferTests,
         ::testing::ValuesIn(GenerateParams()),
         DawnTestBase::PrintToStringParamName("ComputeLayoutMemoryBufferTests"));
     GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(ComputeLayoutMemoryBufferTests);

 }  // namespace
	// Copyright 2021 The Dawn Authors
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#include "tests/DawnTest.h"

	#include "common/Math.h"
	#include "utils/WGPUHelpers.h"

	#include <array>
	#include <functional>

	namespace {

	// Helper for replacing all occurrences of substr in str with replacement
	std::string ReplaceAll(std::string str,
	const std::string& substr,
	const std::string& replacement) {
	size_t pos = 0;
	while ((pos = str.find(substr, pos)) != std::string::npos) {
	str.replace(pos, substr.length(), replacement);
	pos += replacement.length();
	}
	return str;
	}

	// DataMatcherCallback is the callback function by DataMatcher.
	// It is called for each contiguous sequence of bytes that should be checked
	// for equality.
	// offset and size are in units of bytes.
	using DataMatcherCallback = std::function<void(uint32_t offset, uint32_t size)>;

	// DataMatcher is a function pointer to a data matching function.
	// size is the total number of bytes being considered for matching.
	// The callback may be called once or multiple times, and may only consider
	// part of the interval [0, size)
	using DataMatcher = void (*)(uint32_t size, DataMatcherCallback);

	// FullDataMatcher is a DataMatcher that calls callback with the interval
	// [0, size)
	void FullDataMatcher(uint32_t size, DataMatcherCallback callback) {
	callback(0, size);
	}

	// StridedDataMatcher is a DataMatcher that calls callback with the strided
	// intervals of length BYTES_TO_MATCH, skipping BYTES_TO_SKIP.
	// For example: StridedDataMatcher<2, 4>(18, callback) will call callback
	// with the intervals: [0, 2), [6, 8), [12, 14)
	template <int BYTES_TO_MATCH, int BYTES_TO_SKIP>
	void StridedDataMatcher(uint32_t size, DataMatcherCallback callback) {
	uint32_t offset = 0;
	while (offset < size) {
	callback(offset, BYTES_TO_MATCH);
	offset += BYTES_TO_MATCH + BYTES_TO_SKIP;
	}
	}

	// Align returns the WGSL decoration for an explicit structure field alignment
	std::string AlignDeco(uint32_t value) {
	return "[[align(" + std::to_string(value) + ")]] ";
	}

	} // namespace

	// Field holds test parameters for ComputeLayoutMemoryBufferTests.Fields
	struct Field {
	const char* type; // Type of the field
	uint32_t align; // Alignment of the type in bytes
	uint32_t size; // Natural size of the type in bytes

	uint32_t padded_size = 0; // Decorated (extended) size of the type in bytes
	DataMatcher matcher = &FullDataMatcher; // The matching method
	bool storage_buffer_only = false; // This should only be used for storage buffer tests

	// Sets the padded_size to value.
	// Returns this Field so calls can be chained.
	Field& PaddedSize(uint32_t value) {
	padded_size = value;
	return *this;
	}

	// Sets the matcher to a StridedDataMatcher<BYTES_TO_MATCH, BYTES_TO_SKIP>.
	// Returns this Field so calls can be chained.
	template <int BYTES_TO_MATCH, int BYTES_TO_SKIP>
	Field& Strided() {
	matcher = &StridedDataMatcher<BYTES_TO_MATCH, BYTES_TO_SKIP>;
	return *this;
	}

	// Marks that this should only be used for storage buffer tests.
	// Returns this Field so calls can be chained.
	Field& StorageBufferOnly() {
	storage_buffer_only = true;
	return *this;
	}
	};

	// StorageClass is an enumerator of storage classes used by ComputeLayoutMemoryBufferTests.Fields
	enum class StorageClass {
	Uniform,
	Storage,
	};

	std::ostream& operator<<(std::ostream& o, StorageClass storageClass) {
	switch (storageClass) {
	case StorageClass::Uniform:
	o << "uniform";
	break;
	case StorageClass::Storage:
	o << "storage";
	break;
	}
	return o;
	}

	std::ostream& operator<<(std::ostream& o, Field field) {
	o << "[[align(" << field.align << "), size("
	<< (field.padded_size > 0 ? field.padded_size : field.size) << ")]] " << field.type;
	return o;
	}

	DAWN_TEST_PARAM_STRUCT(ComputeLayoutMemoryBufferTestParams, StorageClass, Field);

	class ComputeLayoutMemoryBufferTests
	: public DawnTestWithParams<ComputeLayoutMemoryBufferTestParams> {
	void SetUp() override {
	DawnTestBase::SetUp();
	}
	};

	TEST_P(ComputeLayoutMemoryBufferTests, Fields) {
	// Sentinel value markers codes used to check that the start and end of
	// structures are correctly aligned. Each of these codes are distinct and
	// are not likely to be confused with data.
	constexpr uint32_t kDataHeaderCode = 0xa0b0c0a0u;
	constexpr uint32_t kDataFooterCode = 0x40302010u;
	constexpr uint32_t kInputHeaderCode = 0x91827364u;
	constexpr uint32_t kInputFooterCode = 0x19283764u;

	// Byte codes used for field padding. The MSB is set for each of these.
	// The field data has the MSB 0.
	constexpr uint8_t kDataAlignPaddingCode = 0xfeu;
	constexpr uint8_t kFieldAlignPaddingCode = 0xfdu;
	constexpr uint8_t kFieldSizePaddingCode = 0xdcu;
	constexpr uint8_t kDataSizePaddingCode = 0xdbu;
	constexpr uint8_t kInputFooterAlignPaddingCode = 0xdau;
	constexpr uint8_t kInputTailPaddingCode = 0xd9u;

	// Status codes returned by the shader.
	constexpr uint32_t kStatusBadInputHeader = 100u;
	constexpr uint32_t kStatusBadInputFooter = 101u;
	constexpr uint32_t kStatusBadDataHeader = 102u;
	constexpr uint32_t kStatusBadDataFooter = 103u;
	constexpr uint32_t kStatusOk = 200u;

	const Field& field = GetParam().mField;

	const bool isUniform = GetParam().mStorageClass == StorageClass::Uniform;

	std::string shader = R"(
	struct Data {
	header : u32;
	[[align({field_align}), size({field_size})]] field : {field_type};
	footer : u32;
	};

	[[block]] struct Input {
	header : u32;
	{data_align}data : Data;
	{footer_align}footer : u32;
	};

	[[block]] struct Output {
	data : {field_type};
	};

	[[block]] struct Status {
	code : u32;
	};

	[[group(0), binding(0)]] var<{input_qualifiers}> input : Input;
	[[group(0), binding(1)]] var<storage, read_write> output : Output;
	[[group(0), binding(2)]] var<storage, read_write> status : Status;

	[[stage(compute), workgroup_size(1,1,1)]]
	fn main() {
	if (input.header != {input_header_code}u) {
	status.code = {status_bad_input_header}u;
	} elseif (input.footer != {input_footer_code}u) {
	status.code = {status_bad_input_footer}u;
	} elseif (input.data.header != {data_header_code}u) {
	status.code = {status_bad_data_header}u;
	} elseif (input.data.footer != {data_footer_code}u) {
	status.code = {status_bad_data_footer}u;
	} else {
	status.code = {status_ok}u;
	output.data = input.data.field;
	}
	})";

	// https://www.w3.org/TR/WGSL/#alignment-and-size
	// Structure size: roundUp(AlignOf(S), OffsetOf(S, L) + SizeOf(S, L))
	// https://www.w3.org/TR/WGSL/#storage-class-constraints
	// RequiredAlignOf(S, uniform): roundUp(16, max(AlignOf(T0), ..., AlignOf(TN)))
	uint32_t dataAlign = isUniform ? std::max(16u, field.align) : field.align;

	// https://www.w3.org/TR/WGSL/#structure-layout-rules
	// Note: When underlying the target is a Vulkan device, we assume the device does not support
	// the scalarBlockLayout feature. Therefore, a data value must not be placed in the padding at
	// the end of a structure or matrix, nor in the padding at the last element of an array.
	uint32_t footerAlign = isUniform ? 16 : 4;

	shader = ReplaceAll(shader, "{data_align}", isUniform ? AlignDeco(dataAlign) : "");
	shader = ReplaceAll(shader, "{field_align}", std::to_string(field.align));
	shader = ReplaceAll(shader, "{footer_align}", isUniform ? AlignDeco(footerAlign) : "");
	shader = ReplaceAll(shader, "{field_size}",
	std::to_string(field.padded_size > 0 ? field.padded_size : field.size));
	shader = ReplaceAll(shader, "{field_type}", field.type);
	shader = ReplaceAll(shader, "{input_header_code}", std::to_string(kInputHeaderCode));
	shader = ReplaceAll(shader, "{input_footer_code}", std::to_string(kInputFooterCode));
	shader = ReplaceAll(shader, "{data_header_code}", std::to_string(kDataHeaderCode));
	shader = ReplaceAll(shader, "{data_footer_code}", std::to_string(kDataFooterCode));
	shader = ReplaceAll(shader, "{status_bad_input_header}", std::to_string(kStatusBadInputHeader));
	shader = ReplaceAll(shader, "{status_bad_input_footer}", std::to_string(kStatusBadInputFooter));
	shader = ReplaceAll(shader, "{status_bad_data_header}", std::to_string(kStatusBadDataHeader));
	shader = ReplaceAll(shader, "{status_bad_data_footer}", std::to_string(kStatusBadDataFooter));
	shader = ReplaceAll(shader, "{status_ok}", std::to_string(kStatusOk));
	shader = ReplaceAll(shader, "{input_qualifiers}",
	isUniform ? "uniform" //
	: "storage, read_write");

	// Set up shader and pipeline
	auto module = utils::CreateShaderModule(device, shader.c_str());

	wgpu::ComputePipelineDescriptor csDesc;
	csDesc.compute.module = module;
	csDesc.compute.entryPoint = "main";

	wgpu::ComputePipeline pipeline = device.CreateComputePipeline(&csDesc);

	// Build the input and expected data.
	std::vector<uint8_t> inputData; // The whole SSBO data
	std::vector<uint8_t> expectedData; // The expected data to be copied by the shader
	{
	auto PushU32 = [&inputData](uint32_t u32) {
	inputData.emplace_back((u32 >> 0) & 0xff);
	inputData.emplace_back((u32 >> 8) & 0xff);
	inputData.emplace_back((u32 >> 16) & 0xff);
	inputData.emplace_back((u32 >> 24) & 0xff);
	};
	auto AlignTo = [&inputData](uint32_t alignment, uint8_t code) {
	uint32_t target = Align(inputData.size(), alignment);
	uint32_t bytes = target - inputData.size();
	for (uint32_t i = 0; i < bytes; i++) {
	inputData.emplace_back(code);
	}
	};
	PushU32(kInputHeaderCode); // Input.header
	AlignTo(dataAlign, kDataAlignPaddingCode); // Input.data
	{
	PushU32(kDataHeaderCode); // Input.data.header
	AlignTo(field.align, kFieldAlignPaddingCode); // Input.data.field
	for (uint32_t i = 0; i < field.size; i++) {
	// The data has the MSB cleared to distinguish it from the
	// padding codes.
	uint8_t code = i & 0x7f;
	inputData.emplace_back(code); // Input.data.field
	expectedData.emplace_back(code);
	}
	for (uint32_t i = field.size; i < field.padded_size; i++) {
	inputData.emplace_back(kFieldSizePaddingCode); // Input.data.field padding
	}
	PushU32(kDataFooterCode); // Input.data.footer
	AlignTo(field.align, kDataSizePaddingCode); // Input.data padding
	}
	AlignTo(footerAlign, kInputFooterAlignPaddingCode); // Input.footer [[align]]
	PushU32(kInputFooterCode); // Input.footer
	AlignTo(256, kInputTailPaddingCode); // Input padding
	}

	// Set up input storage buffer
	wgpu::Buffer inputBuf = utils::CreateBufferFromData(
	device, inputData.data(), inputData.size(),
	wgpu::BufferUsage::CopySrc \| wgpu::BufferUsage::CopyDst \|
	(isUniform ? wgpu::BufferUsage::Uniform : wgpu::BufferUsage::Storage));

	// Set up output storage buffer
	wgpu::BufferDescriptor outputDesc;
	outputDesc.size = field.size;
	outputDesc.usage =
	wgpu::BufferUsage::Storage \| wgpu::BufferUsage::CopySrc \| wgpu::BufferUsage::CopyDst;
	wgpu::Buffer outputBuf = device.CreateBuffer(&outputDesc);

	// Set up status storage buffer
	wgpu::BufferDescriptor statusDesc;
	statusDesc.size = 4u;
	statusDesc.usage =
	wgpu::BufferUsage::Storage \| wgpu::BufferUsage::CopySrc \| wgpu::BufferUsage::CopyDst;
	wgpu::Buffer statusBuf = device.CreateBuffer(&statusDesc);

	// Set up bind group and issue dispatch
	wgpu::BindGroup bindGroup = utils::MakeBindGroup(device, pipeline.GetBindGroupLayout(0),
	{
	{0, inputBuf},
	{1, outputBuf},
	{2, statusBuf},
	});

	wgpu::CommandBuffer commands;
	{
	wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
	wgpu::ComputePassEncoder pass = encoder.BeginComputePass();
	pass.SetPipeline(pipeline);
	pass.SetBindGroup(0, bindGroup);
	pass.Dispatch(1);
	pass.EndPass();

	commands = encoder.Finish();
	}

	queue.Submit(1, &commands);

	// Check the status
	EXPECT_BUFFER_U32_EQ(kStatusOk, statusBuf, 0) << "status code error" << std::endl
	<< "Shader: " << shader;

	// Check the data
	field.matcher(field.size, [&](uint32_t offset, uint32_t size) {
	EXPECT_BUFFER_U8_RANGE_EQ(expectedData.data() + offset, outputBuf, offset, size)
	<< "offset: " << offset;
	});
	}

	namespace {

	auto GenerateParams() {
	auto params = MakeParamGenerator<ComputeLayoutMemoryBufferTestParams>(
	{
	D3D12Backend(), MetalBackend(), VulkanBackend(),
	// TODO(crbug.com/dawn/942)
	// There was a compiler error: Buffer block cannot be expressed as any of std430,
	// std140, scalar, even with enhanced layouts. You can try flattening this block to
	// support a more flexible layout.
	// OpenGLBackend(),
	// OpenGLESBackend(),
	},
	{StorageClass::Storage, StorageClass::Uniform},
	{
	// See https://www.w3.org/TR/WGSL/#alignment-and-size
	// Scalar types with no custom alignment or size
	Field{"i32", /* align / 4, / size */ 4},
	Field{"u32", /* align / 4, / size */ 4},
	Field{"f32", /* align / 4, / size */ 4},

	// Scalar types with custom alignment
	Field{"i32", /* align / 16, / size */ 4},
	Field{"u32", /* align / 16, / size */ 4},
	Field{"f32", /* align / 16, / size */ 4},

	// Scalar types with custom size
	Field{"i32", /* align / 4, / size */ 4}.PaddedSize(24),
	Field{"u32", /* align / 4, / size */ 4}.PaddedSize(24),
	Field{"f32", /* align / 4, / size */ 4}.PaddedSize(24),

	// Vector types with no custom alignment or size
	Field{"vec2<i32>", /* align / 8, / size */ 8},
	Field{"vec2<u32>", /* align / 8, / size */ 8},
	Field{"vec2<f32>", /* align / 8, / size */ 8},
	Field{"vec3<i32>", /* align / 16, / size */ 12},
	Field{"vec3<u32>", /* align / 16, / size */ 12},
	Field{"vec3<f32>", /* align / 16, / size */ 12},
	Field{"vec4<i32>", /* align / 16, / size */ 16},
	Field{"vec4<u32>", /* align / 16, / size */ 16},
	Field{"vec4<f32>", /* align / 16, / size */ 16},

	// Vector types with custom alignment
	Field{"vec2<i32>", /* align / 32, / size */ 8},
	Field{"vec2<u32>", /* align / 32, / size */ 8},
	Field{"vec2<f32>", /* align / 32, / size */ 8},
	Field{"vec3<i32>", /* align / 32, / size */ 12},
	Field{"vec3<u32>", /* align / 32, / size */ 12},
	Field{"vec3<f32>", /* align / 32, / size */ 12},
	Field{"vec4<i32>", /* align / 32, / size */ 16},
	Field{"vec4<u32>", /* align / 32, / size */ 16},
	Field{"vec4<f32>", /* align / 32, / size */ 16},

	// Vector types with custom size
	Field{"vec2<i32>", /* align / 8, / size */ 8}.PaddedSize(24),
	Field{"vec2<u32>", /* align / 8, / size */ 8}.PaddedSize(24),
	Field{"vec2<f32>", /* align / 8, / size */ 8}.PaddedSize(24),
	Field{"vec3<i32>", /* align / 16, / size */ 12}.PaddedSize(24),
	Field{"vec3<u32>", /* align / 16, / size */ 12}.PaddedSize(24),
	Field{"vec3<f32>", /* align / 16, / size */ 12}.PaddedSize(24),
	Field{"vec4<i32>", /* align / 16, / size */ 16}.PaddedSize(24),
	Field{"vec4<u32>", /* align / 16, / size */ 16}.PaddedSize(24),
	Field{"vec4<f32>", /* align / 16, / size */ 16}.PaddedSize(24),

	// Matrix types with no custom alignment or size
	Field{"mat2x2<f32>", /* align / 8, / size */ 16},
	Field{"mat3x2<f32>", /* align / 8, / size */ 24},
	Field{"mat4x2<f32>", /* align / 8, / size */ 32},
	Field{"mat2x3<f32>", /* align / 16, / size */ 32}.Strided<12, 4>(),
	Field{"mat3x3<f32>", /* align / 16, / size */ 48}.Strided<12, 4>(),
	Field{"mat4x3<f32>", /* align / 16, / size */ 64}.Strided<12, 4>(),
	Field{"mat2x4<f32>", /* align / 16, / size */ 32},
	Field{"mat3x4<f32>", /* align / 16, / size */ 48},
	Field{"mat4x4<f32>", /* align / 16, / size */ 64},

	// Matrix types with custom alignment
	Field{"mat2x2<f32>", /* align / 32, / size */ 16},
	Field{"mat3x2<f32>", /* align / 32, / size */ 24},
	Field{"mat4x2<f32>", /* align / 32, / size */ 32},
	Field{"mat2x3<f32>", /* align / 32, / size */ 32}.Strided<12, 4>(),
	Field{"mat3x3<f32>", /* align / 32, / size */ 48}.Strided<12, 4>(),
	Field{"mat4x3<f32>", /* align / 32, / size */ 64}.Strided<12, 4>(),
	Field{"mat2x4<f32>", /* align / 32, / size */ 32},
	Field{"mat3x4<f32>", /* align / 32, / size */ 48},
	Field{"mat4x4<f32>", /* align / 32, / size */ 64},

	// Matrix types with custom size
	Field{"mat2x2<f32>", /* align / 8, / size */ 16}.PaddedSize(128),
	Field{"mat3x2<f32>", /* align / 8, / size */ 24}.PaddedSize(128),
	Field{"mat4x2<f32>", /* align / 8, / size */ 32}.PaddedSize(128),
	Field{"mat2x3<f32>", /* align / 16, / size */ 32}
	.PaddedSize(128)
	.Strided<12, 4>(),
	Field{"mat3x3<f32>", /* align / 16, / size */ 48}
	.PaddedSize(128)
	.Strided<12, 4>(),
	Field{"mat4x3<f32>", /* align / 16, / size */ 64}
	.PaddedSize(128)
	.Strided<12, 4>(),
	Field{"mat2x4<f32>", /* align / 16, / size */ 32}.PaddedSize(128),
	Field{"mat3x4<f32>", /* align / 16, / size */ 48}.PaddedSize(128),
	Field{"mat4x4<f32>", /* align / 16, / size */ 64}.PaddedSize(128),

	// Array types with no custom alignment, size or stride
	// Note: The use of StorageBufferOnly() is due to UBOs requiring 16 byte alignment
	// of array elements. See https://www.w3.org/TR/WGSL/#storage-class-constraints
	Field{"array<u32, 1>", /* align / 4, / size */ 4}.StorageBufferOnly(),
	Field{"array<u32, 2>", /* align / 4, / size */ 8}.StorageBufferOnly(),
	Field{"array<u32, 3>", /* align / 4, / size */ 12}.StorageBufferOnly(),
	Field{"array<u32, 4>", /* align / 4, / size */ 16}.StorageBufferOnly(),
	Field{"[[stride(16)]] array<u32, 1>", /* align / 4, / size */ 16}
	.StorageBufferOnly()
	.Strided<4, 12>(),
	Field{"[[stride(16)]] array<u32, 2>", /* align / 4, / size */ 32}
	.StorageBufferOnly()
	.Strided<4, 12>(),
	Field{"[[stride(16)]] array<u32, 3>", /* align / 4, / size */ 48}
	.StorageBufferOnly()
	.Strided<4, 12>(),
	Field{"[[stride(16)]] array<u32, 4>", /* align / 4, / size */ 64}
	.StorageBufferOnly()
	.Strided<4, 12>(),
	Field{"array<vec3<u32>, 4>", /* align / 16, / size */ 64}.Strided<12, 4>(),
	Field{"[[stride(32)]] array<vec3<u32>, 4>", /* align / 16, / size */ 128}
	.Strided<12, 20>(),

	// Array types with custom alignment
	Field{"array<u32, 1>", /* align / 32, / size */ 4}.StorageBufferOnly(),
	Field{"array<u32, 2>", /* align / 32, / size */ 8}.StorageBufferOnly(),
	Field{"array<u32, 3>", /* align / 32, / size */ 12}.StorageBufferOnly(),
	Field{"array<u32, 4>", /* align / 32, / size */ 16}.StorageBufferOnly(),
	Field{"[[stride(16)]] array<u32, 1>", /* align / 32, / size */ 16}
	.Strided<4, 12>(),
	Field{"[[stride(16)]] array<u32, 2>", /* align / 32, / size */ 32}
	.Strided<4, 12>(),
	Field{"[[stride(16)]] array<u32, 3>", /* align / 32, / size */ 48}
	.Strided<4, 12>(),
	Field{"[[stride(16)]] array<u32, 4>", /* align / 32, / size */ 64}
	.Strided<4, 12>(),
	Field{"array<vec3<u32>, 4>", /* align / 32, / size */ 64}.Strided<12, 4>(),

	// Array types with custom size
	Field{"array<u32, 1>", /* align / 4, / size */ 4}
	.PaddedSize(128)
	.StorageBufferOnly(),
	Field{"array<u32, 2>", /* align / 4, / size */ 8}
	.PaddedSize(128)
	.StorageBufferOnly(),
	Field{"array<u32, 3>", /* align / 4, / size */ 12}
	.PaddedSize(128)
	.StorageBufferOnly(),
	Field{"array<u32, 4>", /* align / 4, / size */ 16}
	.PaddedSize(128)
	.StorageBufferOnly(),
	Field{"array<vec3<u32>, 4>", /* align / 16, / size */ 64}
	.PaddedSize(128)
	.Strided<12, 4>(),
	});

	std::vector<ComputeLayoutMemoryBufferTestParams> filtered;
	for (auto param : params) {
	if (param.mStorageClass != StorageClass::Storage && param.mField.storage_buffer_only) {
	continue;
	}
	filtered.emplace_back(param);
	}
	return filtered;
	}

	INSTANTIATE_TEST_SUITE_P(
	,
	ComputeLayoutMemoryBufferTests,
	::testing::ValuesIn(GenerateParams()),
	DawnTestBase::PrintToStringParamName("ComputeLayoutMemoryBufferTests"));
	GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(ComputeLayoutMemoryBufferTests);

	} // namespace