3 files changed, 34 insertions, 1 deletions

diff --git a/src/video_core/shader/node.h b/src/video_core/shader/node.h
index 2f29b9506..db06767f6 100644
--- a/src/video_core/shader/node.h
+++ b/src/video_core/shader/node.h
@@ -212,6 +212,7 @@ enum class MetaStackClass {
 class OperationNode;
 class ConditionalNode;
 class GprNode;
+class CustomVarNode;
 class ImmediateNode;
 class InternalFlagNode;
 class PredicateNode;
@@ -223,7 +224,7 @@ class SmemNode;
 class GmemNode;
 class CommentNode;
 
-using NodeData = std::variant<OperationNode, ConditionalNode, GprNode, ImmediateNode,
+using NodeData = std::variant<OperationNode, ConditionalNode, GprNode, CustomVarNode, ImmediateNode,
                               InternalFlagNode, PredicateNode, AbufNode, PatchNode, CbufNode,
                               LmemNode, SmemNode, GmemNode, CommentNode>;
 using Node = std::shared_ptr<NodeData>;
@@ -550,6 +551,20 @@ private:
     Tegra::Shader::Register index{};
 };
 
+/// A custom variable
+class CustomVarNode final {
+public:
+    explicit constexpr CustomVarNode(u32 index) : index{index} {}
+
+    u32 GetIndex() const {
+        return index;
+    }
+
+private:
+    u32 index{};
+};
+
+
 /// A 32-bits value that represents an immediate value
 class ImmediateNode final {
 public:
diff --git a/src/video_core/shader/shader_ir.cpp b/src/video_core/shader/shader_ir.cpp
index a186e22b2..94972d57f 100644
--- a/src/video_core/shader/shader_ir.cpp
+++ b/src/video_core/shader/shader_ir.cpp
@@ -39,6 +39,10 @@ Node ShaderIR::GetRegister(Register reg) {
     return MakeNode<GprNode>(reg);
 }
 
+Node ShaderIR::GetCustomVariable(u32 id) {
+    return MakeNode<CustomVarNode>(id);
+}
+
 Node ShaderIR::GetImmediate19(Instruction instr) {
     return Immediate(instr.alu.GetImm20_19());
 }
@@ -453,4 +457,9 @@ std::size_t ShaderIR::DeclareAmend(Node new_amend) {
     return id;
 }
 
+u32 ShaderIR::NewCustomVariable() {
+    const u32 id = num_custom_variables++;
+    return id;
+}
+
 } // namespace VideoCommon::Shader
diff --git a/src/video_core/shader/shader_ir.h b/src/video_core/shader/shader_ir.h
index 121528346..2fe14e815 100644
--- a/src/video_core/shader/shader_ir.h
+++ b/src/video_core/shader/shader_ir.h
@@ -180,6 +180,10 @@ public:
         return amend_code[index];
     }
 
+    u32 GetCustomVariablesAmount() const {
+        return num_custom_variables;
+    }
+
 private:
     friend class ASTDecoder;
 
@@ -236,6 +240,8 @@ private:
 
     /// Generates a node for a passed register.
     Node GetRegister(Tegra::Shader::Register reg);
+    /// Generates a node for a custom variable
+    Node GetCustomVariable(u32 id);
     /// Generates a node representing a 19-bit immediate value
     Node GetImmediate19(Tegra::Shader::Instruction instr);
     /// Generates a node representing a 32-bit immediate value
@@ -403,6 +409,8 @@ private:
     /// Register new amending code and obtain the reference id.
     std::size_t DeclareAmend(Node new_amend);
 
+    u32 NewCustomVariable();
+
     const ProgramCode& program_code;
     const u32 main_offset;
     const CompilerSettings settings;
@@ -418,6 +426,7 @@ private:
     NodeBlock global_code;
     ASTManager program_manager{true, true};
     std::vector<Node> amend_code;
+    u32 num_custom_variables{};
 
     std::set<u32> used_registers;
     std::set<Tegra::Shader::Pred> used_predicates;