[Fix, Test] (ShaderTranspiler, DirectGLES): make every array-of-storage-blocks index a constant for ESSL

2026-09-11 13:48:30 +09:00 · 2026-08-20 23:08:38 -04:00
parent 50efa4410a
commit f7dfa01c18
8 changed files with 1087 additions and 0 deletions
@@ -12,6 +12,7 @@ add_executable(
        UniquifyIoBlockNamesTest.cpp
        LowerViewportIndexTest.cpp
        ClampMultisampleFetchTest.cpp
+        LegalizeStorageBlockArrayIndexTest.cpp
 )

 target_include_directories(SpirvPassTest PRIVATE
@@ -0,0 +1,251 @@
+// MobileGL - MobileGL/MG_Test/ShaderTranspiler/LegalizeStorageBlockArrayIndexTest.cpp
+// Copyright (c) 2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#include <gtest/gtest.h>
+
+#define SPV_ENABLE_UTILITY_CODE
+#include "glslang/SPIRV/spirv.hpp11"
+#undef SPV_ENABLE_UTILITY_CODE
+
+#include "Includes.h"
+#include <MG_Util/ShaderTranspiler/ShaderCompiler.h>
+#include <MG_Util/ShaderTranspiler/Types.h>
+
+#include <spirv-tools/libspirv.hpp>
+
+#include <set>
+#include <vector>
+
+using namespace MobileGL;
+using MobileGL::MG_Util::ShaderTranspiler::ShaderCompiler;
+
+namespace {
+    constexpr SizeT kSpirvHeaderWordCount = 5u;
+
+    template <typename Visitor>
+    void ForEachInstruction(const Vector<Uint32>& spirv, Visitor&& visit) {
+        for (SizeT offset = kSpirvHeaderWordCount; offset < spirv.size();) {
+            const Uint32 wordCount = spirv[offset] >> 16u;
+            if (wordCount == 0u || offset + wordCount > spirv.size()) break;
+            visit(static_cast<spv::Op>(spirv[offset] & 0xffffu), &spirv[offset], wordCount);
+            offset += wordCount;
+        }
+    }
+
+    Vector<Uint32> CompileCompute(const String& source) {
+        using namespace MobileGL::MG_Util::ShaderTranspiler;
+        ShaderAttrib shaderAttrib{.shaderType = GL_COMPUTE_SHADER, .sourceStr = source};
+        auto shaderResult = ShaderCompiler::CompileShader(shaderAttrib);
+        EXPECT_TRUE(shaderResult) << (shaderResult ? String{} : shaderResult.error().log);
+        if (!shaderResult) return {};
+
+        ProgramAttrib programAttrib{.shaders = {shaderResult.value()}};
+        auto programResult = ShaderCompiler::LinkProgram(programAttrib);
+        EXPECT_TRUE(programResult) << (programResult ? String{} : programResult.error().log);
+        if (!programResult) return {};
+
+        ProgramBinaryAttrib binaryAttrib{.shaderTypes = {GL_COMPUTE_SHADER}, .program = *programResult.value()};
+        auto binaryResult = ShaderCompiler::GetSpirvBinaryFromProgram(binaryAttrib);
+        EXPECT_TRUE(binaryResult) << (binaryResult ? String{} : binaryResult.error().log);
+        if (!binaryResult || binaryResult->empty()) return {};
+        return binaryResult->front();
+    }
+
+    bool Validates(const Vector<Uint32>& spirv) {
+        spvtools::SpirvTools tools(SPV_ENV_VULKAN_1_1);
+        tools.SetMessageConsumer(
+            [](spv_message_level_t, const char*, const spv_position_t& position, const char* message) {
+                ADD_FAILURE() << "spirv-val at word " << position.index << ": " << message;
+            });
+        return tools.Validate(spirv);
+    }
+
+    Uint32 CountOpcode(const Vector<Uint32>& spirv, spv::Op wanted) {
+        Uint32 count = 0u;
+        ForEachInstruction(spirv, [&](spv::Op opcode, const Uint32*, Uint32) {
+            if (opcode == wanted) ++count;
+        });
+        return count;
+    }
+
+    // Test-side reference walker, deliberately independent of the production detection so a
+    // bug in the pass cannot hide behind the same helper: true when some access chain rooted
+    // at an array-of-storage-blocks variable carries a non-constant FIRST index, which is
+    // exactly what the Qualcomm ES compiler refuses.
+    bool HasDynamicBlockArrayIndex(const Vector<Uint32>& spirv) {
+        std::set<Uint32> blockStructs;      // OpTypeStruct ids decorated Block / BufferBlock
+        std::set<Uint32> constants;         // OpConstant / OpConstantNull result ids
+        std::set<Uint32> blockArrayTypes;   // OpTypeArray ids whose element is such a struct
+        std::set<Uint32> blockArrayPointers;// OpTypePointer ids pointing at one of those arrays
+        std::set<Uint32> blockArrayVars;    // OpVariable ids of one of those pointer types
+
+        ForEachInstruction(spirv, [&](spv::Op opcode, const Uint32* words, Uint32 wordCount) {
+            switch (opcode) {
+            case spv::Op::OpDecorate:
+                if (wordCount >= 3u) {
+                    const auto decoration = static_cast<spv::Decoration>(words[2]);
+                    if (decoration == spv::Decoration::Block ||
+                        decoration == spv::Decoration::BufferBlock) {
+                        blockStructs.insert(words[1]);
+                    }
+                }
+                break;
+            case spv::Op::OpConstant:
+                if (wordCount >= 3u) constants.insert(words[2]);
+                break;
+            case spv::Op::OpConstantNull:
+                if (wordCount >= 3u) constants.insert(words[2]);
+                break;
+            case spv::Op::OpTypeArray:
+                // OpTypeArray <result> <element type> <length>
+                if (wordCount >= 4u && blockStructs.count(words[2]) != 0u) {
+                    blockArrayTypes.insert(words[1]);
+                }
+                break;
+            case spv::Op::OpTypePointer:
+                // OpTypePointer <result> <storage class> <pointee>
+                if (wordCount >= 4u && blockArrayTypes.count(words[3]) != 0u) {
+                    blockArrayPointers.insert(words[1]);
+                }
+                break;
+            case spv::Op::OpVariable:
+                // OpVariable <result type> <result> <storage class>
+                if (wordCount >= 4u && blockArrayPointers.count(words[1]) != 0u) {
+                    blockArrayVars.insert(words[2]);
+                }
+                break;
+            default:
+                break;
+            }
+        });
+
+        bool dynamic = false;
+        ForEachInstruction(spirv, [&](spv::Op opcode, const Uint32* words, Uint32 wordCount) {
+            if (opcode != spv::Op::OpAccessChain && opcode != spv::Op::OpInBoundsAccessChain) return;
+            // OpAccessChain <result type> <result> <base> <index 0> ...
+            if (wordCount < 5u) return;
+            if (blockArrayVars.count(words[3]) == 0u) return;
+            if (constants.count(words[4]) != 0u) return;
+            dynamic = true;
+        });
+        return dynamic;
+    }
+
+    // `for (i = 0; i < 4; ++i)` over an array of storage blocks - the shape
+    // KHR-GL43.shader_storage_buffer_object.basic-stdLayout-case1 uses. Foldable: the
+    // induction variable is a literal after unrolling.
+    constexpr const char* kLoopIndexedBlockArray = R"(#version 450 core
+layout(local_size_x = 1) in;
+layout(std430, binding = 0) buffer Blk { uint data[4]; } g_blocks[4];
+layout(std430, binding = 8) buffer Out { uint data[4]; } g_out;
+void main() {
+    for (int i = 0; i < 4; ++i) {
+        g_out.data[i] = g_blocks[i].data[0];
+    }
+}
+)";
+
+    // A uniform-sourced index - the shape
+    // KHR-GL43.shader_storage_buffer_object.advanced-indirectAddressing-case2 uses. Nothing
+    // can fold it, so the switch/select lowering is what has to carry it.
+    constexpr const char* kUniformIndexedBlockArray = R"(#version 450 core
+layout(local_size_x = 1) in;
+layout(std430, binding = 0) buffer Blk { uint data[4]; } g_blocks[4];
+layout(std430, binding = 8) buffer Out { uint value; } g_out;
+uniform int g_index;
+void main() {
+    g_blocks[g_index].data[0] = 7u;
+    g_out.value = g_blocks[g_index].data[1];
+}
+)";
+
+    // The positive control from the device run: dynamic addressing through an array MEMBER of
+    // ONE block is legal ES and must not be rewritten.
+    constexpr const char* kArrayMemberInsideOneBlock = R"(#version 450 core
+layout(local_size_x = 1) in;
+layout(std430, binding = 0) buffer Blk { uint data[4]; } g_block;
+layout(std430, binding = 8) buffer Out { uint value; } g_out;
+uniform int g_index;
+void main() {
+    g_out.value = g_block.data[g_index];
+}
+)";
+
+    // A block array indexed only with literals is already legal ES.
+    constexpr const char* kConstantIndexedBlockArray = R"(#version 450 core
+layout(local_size_x = 1) in;
+layout(std430, binding = 0) buffer Blk { uint data[4]; } g_blocks[4];
+layout(std430, binding = 8) buffer Out { uint value; } g_out;
+void main() {
+    g_out.value = g_blocks[2].data[0] + g_blocks[3].data[1];
+}
+)";
+} // namespace
+
+TEST(LegalizeStorageBlockArrayIndexPass, FoldsALoopIndexedBlockArray) {
+    const Vector<Uint32> input = CompileCompute(kLoopIndexedBlockArray);
+    ASSERT_FALSE(input.empty());
+    EXPECT_TRUE(HasDynamicBlockArrayIndex(input));
+
+    Vector<Uint32> output;
+    ASSERT_TRUE(ShaderCompiler::LegalizeStorageBlockArrayIndexingForEssl(input, output, true));
+    ASSERT_FALSE(output.empty());
+    // Either half of the legalization is an acceptable outcome here - what the ES driver
+    // cares about is only that no dynamic subscript survives.
+    EXPECT_FALSE(HasDynamicBlockArrayIndex(output));
+    EXPECT_TRUE(Validates(output));
+}
+
+TEST(LegalizeStorageBlockArrayIndexPass, LowersAUniformIndexedWriteToASwitchAndAReadToSelects) {
+    const Vector<Uint32> input = CompileCompute(kUniformIndexedBlockArray);
+    ASSERT_FALSE(input.empty());
+    EXPECT_TRUE(HasDynamicBlockArrayIndex(input));
+    EXPECT_EQ(CountOpcode(input, spv::Op::OpSwitch), 0u);
+
+    Vector<Uint32> output;
+    ASSERT_TRUE(ShaderCompiler::LegalizeStorageBlockArrayIndexingForEssl(input, output, true));
+    ASSERT_FALSE(output.empty());
+    EXPECT_FALSE(HasDynamicBlockArrayIndex(output));
+    // One switch for the store, and one select per element past the first for the load.
+    EXPECT_EQ(CountOpcode(output, spv::Op::OpSwitch), 1u);
+    EXPECT_EQ(CountOpcode(output, spv::Op::OpSelect), 3u);
+    EXPECT_TRUE(Validates(output));
+}
+
+TEST(LegalizeStorageBlockArrayIndexPass, LeavesADynamicMemberOfOneBlockByteIdentical) {
+    const Vector<Uint32> input = CompileCompute(kArrayMemberInsideOneBlock);
+    ASSERT_FALSE(input.empty());
+    EXPECT_FALSE(HasDynamicBlockArrayIndex(input));
+
+    Vector<Uint32> output;
+    ASSERT_TRUE(ShaderCompiler::LegalizeStorageBlockArrayIndexingForEssl(input, output, true));
+    EXPECT_EQ(output, input);
+}
+
+TEST(LegalizeStorageBlockArrayIndexPass, LeavesAConstantIndexedBlockArrayByteIdentical) {
+    const Vector<Uint32> input = CompileCompute(kConstantIndexedBlockArray);
+    ASSERT_FALSE(input.empty());
+    EXPECT_FALSE(HasDynamicBlockArrayIndex(input));
+
+    Vector<Uint32> output;
+    ASSERT_TRUE(ShaderCompiler::LegalizeStorageBlockArrayIndexingForEssl(input, output, true));
+    EXPECT_EQ(output, input);
+}
+
+TEST(LegalizeStorageBlockArrayIndexPass, IsIdempotent) {
+    const Vector<Uint32> input = CompileCompute(kUniformIndexedBlockArray);
+    ASSERT_FALSE(input.empty());
+
+    Vector<Uint32> once;
+    ASSERT_TRUE(ShaderCompiler::LegalizeStorageBlockArrayIndexingForEssl(input, once, true));
+    ASSERT_FALSE(once.empty());
+
+    Vector<Uint32> twice;
+    ASSERT_TRUE(ShaderCompiler::LegalizeStorageBlockArrayIndexingForEssl(once, twice, true));
+    EXPECT_EQ(twice, once);
+}