gl_shader_decompiler: Implement GLSL physical attributes

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -165,6 +165,7 @@ public:
         DeclareConstantBuffers();
         DeclareGlobalMemory();
         DeclareSamplers();
+        DeclarePhysicalAttributeReader();
 
         code.AddLine("void execute_" + suffix + "() {");
         ++code.scope;
@@ -330,8 +331,7 @@ private:
 
     void DeclareInputAttributes() {
         if (ir.HasPhysicalAttributes()) {
-            const u32 num_inputs{stage == ShaderStage::Vertex ? GetNumPhysicalAttributes()
-                                                              : GetNumPhysicalVaryings()};
+            const u32 num_inputs{GetNumPhysicalInputAttributes()};
             for (u32 i = 0; i < num_inputs; ++i) {
                 DeclareInputAttribute(ToGenericAttribute(i));
             }
@@ -374,7 +374,7 @@ private:
     }
 
     void DeclareOutputAttributes() {
-        if (ir.HasPhysicalAttributes()) {
+        if (ir.HasPhysicalAttributes() && stage != ShaderStage::Fragment) {
             for (u32 i = 0; i < GetNumPhysicalVaryings(); ++i) {
                 DeclareOutputAttribute(ToGenericAttribute(i));
             }
@@ -461,6 +461,31 @@ private:
             code.AddNewLine();
     }
 
+    void DeclarePhysicalAttributeReader() {
+        if (!ir.HasPhysicalAttributes()) {
+            return;
+        }
+        code.AddLine("float readPhysicalAttribute(uint physical_address) {");
+        ++code.scope;
+        code.AddLine("switch (physical_address) {");
+
+        // Just declare generic attributes for now.
+        const auto num_attributes{static_cast<u32>(GetNumPhysicalAttributes())};
+        for (u32 index = 0; index < num_attributes; ++index) {
+            for (u32 element = 0; element < 4; ++element) {
+                code.AddLine(fmt::format("case 0x{:x}: return {};", 0x80 + index * 16 + element * 4,
+                                         ReadAttribute(ToGenericAttribute(index), element)));
+            }
+        }
+
+        code.AddLine("default: return 0;");
+
+        code.AddLine('}');
+        --code.scope;
+        code.AddLine('}');
+        code.AddNewLine();
+    }
+
     void VisitBlock(const NodeBlock& bb) {
         for (const Node node : bb) {
             if (const std::string expr = Visit(node); !expr.empty()) {
@@ -515,16 +540,70 @@ private:
             return value;
 
         } else if (const auto abuf = std::get_if<AbufNode>(node)) {
-            const auto attribute = abuf->GetIndex();
-            const auto element = abuf->GetElement();
+            UNIMPLEMENTED_IF_MSG(abuf->IsPhysicalBuffer() && stage == ShaderStage::Geometry,
+                                 "Physical attributes in geometry shaders are not implemented");
+            if (abuf->IsPhysicalBuffer()) {
+                return "readPhysicalAttribute(ftou(" + Visit(abuf->GetPhysicalAddress()) + "))";
+            }
+            return ReadAttribute(abuf->GetIndex(), abuf->GetElement(), abuf->GetBuffer());
+
+        } else if (const auto cbuf = std::get_if<CbufNode>(node)) {
+            const Node offset = cbuf->GetOffset();
+            if (const auto immediate = std::get_if<ImmediateNode>(offset)) {
+                // Direct access
+                const u32 offset_imm = immediate->GetValue();
+                ASSERT_MSG(offset_imm % 4 == 0, "Unaligned cbuf direct access");
+                return fmt::format("{}[{}][{}]", GetConstBuffer(cbuf->GetIndex()),
+                                   offset_imm / (4 * 4), (offset_imm / 4) % 4);
+
+            } else if (std::holds_alternative<OperationNode>(*offset)) {
+                // Indirect access
+                const std::string final_offset = code.GenerateTemporary();
+                code.AddLine("uint " + final_offset + " = (ftou(" + Visit(offset) + ") / 4);");
+                return fmt::format("{}[{} / 4][{} % 4]", GetConstBuffer(cbuf->GetIndex()),
+                                   final_offset, final_offset);
+
+            } else {
+                UNREACHABLE_MSG("Unmanaged offset node type");
+            }
+
+        } else if (const auto gmem = std::get_if<GmemNode>(node)) {
+            const std::string real = Visit(gmem->GetRealAddress());
+            const std::string base = Visit(gmem->GetBaseAddress());
+            const std::string final_offset = "(ftou(" + real + ") - ftou(" + base + ")) / 4";
+            return fmt::format("{}[{}]", GetGlobalMemory(gmem->GetDescriptor()), final_offset);
+
+        } else if (const auto lmem = std::get_if<LmemNode>(node)) {
+            return fmt::format("{}[ftou({}) / 4]", GetLocalMemory(), Visit(lmem->GetAddress()));
+
+        } else if (const auto internal_flag = std::get_if<InternalFlagNode>(node)) {
+            return GetInternalFlag(internal_flag->GetFlag());
+
+        } else if (const auto conditional = std::get_if<ConditionalNode>(node)) {
+            // It's invalid to call conditional on nested nodes, use an operation instead
+            code.AddLine("if (" + Visit(conditional->GetCondition()) + ") {");
+            ++code.scope;
+
+            VisitBlock(conditional->GetCode());
+
+            --code.scope;
+            code.AddLine('}');
+            return {};
 
-            const auto GeometryPass = [&](const std::string& name) {
-                if (stage == ShaderStage::Geometry && abuf->GetBuffer()) {
+        } else if (const auto comment = std::get_if<CommentNode>(node)) {
+            return "// " + comment->GetText();
+        }
+        UNREACHABLE();
+        return {};
+    }
+
+    std::string ReadAttribute(Attribute::Index attribute, u32 element, Node buffer = {}) {
+        const auto GeometryPass = [&](std::string name) {
+            if (stage == ShaderStage::Geometry && buffer) {
                 // TODO(Rodrigo): Guard geometry inputs against out of bound reads. Some games
                 // set an 0x80000000 index for those and the shader fails to build. Find out why
                 // this happens and what's its intent.
-                    return "gs_" + name + "[ftou(" + Visit(abuf->GetBuffer()) +
-                           ") % MAX_VERTEX_INPUT]";
+                return "gs_" + std::move(name) + "[ftou(" + Visit(buffer) + ") % MAX_VERTEX_INPUT]";
             }
             return name;
         };
@@ -578,55 +657,7 @@ private:
             break;
         }
         UNIMPLEMENTED_MSG("Unhandled input attribute: {}", static_cast<u32>(attribute));
-
-        } else if (const auto cbuf = std::get_if<CbufNode>(node)) {
-            const Node offset = cbuf->GetOffset();
-            if (const auto immediate = std::get_if<ImmediateNode>(offset)) {
-                // Direct access
-                const u32 offset_imm = immediate->GetValue();
-                ASSERT_MSG(offset_imm % 4 == 0, "Unaligned cbuf direct access");
-                return fmt::format("{}[{}][{}]", GetConstBuffer(cbuf->GetIndex()),
-                                   offset_imm / (4 * 4), (offset_imm / 4) % 4);
-
-            } else if (std::holds_alternative<OperationNode>(*offset)) {
-                // Indirect access
-                const std::string final_offset = code.GenerateTemporary();
-                code.AddLine("uint " + final_offset + " = (ftou(" + Visit(offset) + ") / 4);");
-                return fmt::format("{}[{} / 4][{} % 4]", GetConstBuffer(cbuf->GetIndex()),
-                                   final_offset, final_offset);
-
-            } else {
-                UNREACHABLE_MSG("Unmanaged offset node type");
-            }
-
-        } else if (const auto gmem = std::get_if<GmemNode>(node)) {
-            const std::string real = Visit(gmem->GetRealAddress());
-            const std::string base = Visit(gmem->GetBaseAddress());
-            const std::string final_offset = "(ftou(" + real + ") - ftou(" + base + ")) / 4";
-            return fmt::format("{}[{}]", GetGlobalMemory(gmem->GetDescriptor()), final_offset);
-
-        } else if (const auto lmem = std::get_if<LmemNode>(node)) {
-            return fmt::format("{}[ftou({}) / 4]", GetLocalMemory(), Visit(lmem->GetAddress()));
-
-        } else if (const auto internal_flag = std::get_if<InternalFlagNode>(node)) {
-            return GetInternalFlag(internal_flag->GetFlag());
-
-        } else if (const auto conditional = std::get_if<ConditionalNode>(node)) {
-            // It's invalid to call conditional on nested nodes, use an operation instead
-            code.AddLine("if (" + Visit(conditional->GetCondition()) + ") {");
-            ++code.scope;
-
-            VisitBlock(conditional->GetCode());
-
-            --code.scope;
-            code.AddLine('}');
-            return {};
-
-        } else if (const auto comment = std::get_if<CommentNode>(node)) {
-            return "// " + comment->GetText();
-        }
-        UNREACHABLE();
-        return {};
+        return "0";
     }
 
     std::string ApplyPrecise(Operation operation, const std::string& value) {
@@ -1677,6 +1708,10 @@ private:
         return name + '_' + std::to_string(index) + '_' + suffix;
     }
 
+    u32 GetNumPhysicalInputAttributes() const {
+        return stage == ShaderStage::Vertex ? GetNumPhysicalAttributes() : GetNumPhysicalVaryings();
+    }
+
     u32 GetNumPhysicalAttributes() const {
         return std::min<u32>(device.GetMaxVertexAttributes(), Maxwell::NumVertexAttributes);
     }

src/video_core/shader/shader_ir.h

@@ -885,7 +885,7 @@ private:
     std::set<Sampler> used_samplers;
     std::array<bool, Tegra::Engines::Maxwell3D::Regs::NumClipDistances> used_clip_distances{};
     std::map<GlobalMemoryBase, GlobalMemoryUsage> used_global_memory;
-    bool use_physical_attributes = true; // Shader uses AL2P
+    bool use_physical_attributes{}; // Shader uses AL2P or physical attribute read/writes
 
     Tegra::Shader::Header header;
 };