1 files changed, 82 insertions, 0 deletions
diff --git a/backend/include/rcc/CodeGen/MachineCombinerPattern.h b/backend/include/rcc/CodeGen/MachineCombinerPattern.h
new file mode 100644
index 0000000..69df70a
--- /dev/null
+++ b/backend/include/rcc/CodeGen/MachineCombinerPattern.h
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_MACHINECOMBINERPATTERN_H
+#define RCC_CODEGEN_MACHINECOMBINERPATTERN_H
+
+#include "rcc/CodeGen/MachineIRTypes.h"
+#include "rcc/Support/Error.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <span>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace rcc {
+
+enum class MachineCombinerStage : std::uint8_t {
+  SelectedSSA,
+  PreRegisterAllocation,
+  PostRegisterAllocation,
+  PostFrame,
+};
+
+using MachineCombinerStageMask = std::uint8_t;
+
+[[nodiscard]] constexpr MachineCombinerStageMask
+machineCombinerStageMask(MachineCombinerStage Stage) noexcept {
+  return static_cast<MachineCombinerStageMask>(1U << static_cast<std::uint8_t>(Stage));
+}
+
+enum class MachineCombinerPredicateKind : std::uint8_t {
+  ImmediateEquals,
+  RegisterEquals,
+  PhysicalRegisterEquals,
+  RegisterIsVirtual,
+  RegisterIsPhysical,
+};
+
+struct MachineCombinerPredicate final {
+  MachineCombinerPredicateKind Kind = MachineCombinerPredicateKind::ImmediateEquals;
+  std::size_t Operand = 0;
+  std::size_t OtherOperand = 0;
+  std::int64_t Value = 0;
+};
+
+enum class MachineCombinerActionKind : std::uint8_t {
+  ReplaceDefWithOperandAndErase,
+};
+
+struct MachineCombinerAction final {
+  MachineCombinerActionKind Kind = MachineCombinerActionKind::ReplaceDefWithOperandAndErase;
+  std::size_t DefinitionOperand = 0;
+  std::size_t SourceOperand = 0;
+};
+
+struct MachineCombinerPattern final {
+  std::string Name;
+  Opcode RootOpcode;
+  MachineCombinerStageMask Stages = 0;
+  std::vector<MachineCombinerPredicate> Predicates;
+  MachineCombinerAction Action;
+};
+
+class TargetMachineCombinerInfo final {
+public:
+  [[nodiscard]] static Expected<TargetMachineCombinerInfo>
+  create(std::vector<MachineCombinerPattern> Patterns);
+
+  [[nodiscard]] std::span<const MachineCombinerPattern> patterns(Opcode RootOpcode) const noexcept;
+
+private:
+  explicit TargetMachineCombinerInfo(std::vector<MachineCombinerPattern> Patterns)
+      : Patterns(std::move(Patterns)) {}
+
+  std::vector<MachineCombinerPattern> Patterns;
+  std::unordered_map<Opcode, std::vector<MachineCombinerPattern>> MatchTable;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_MACHINECOMBINERPATTERN_H