1 files changed, 51 insertions, 0 deletions
diff --git a/backend/include/rcc/CodeGen/RegisterBankInfo.h b/backend/include/rcc/CodeGen/RegisterBankInfo.h
new file mode 100644
index 0000000..bc918cc
--- /dev/null
+++ b/backend/include/rcc/CodeGen/RegisterBankInfo.h
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_REGISTERBANKINFO_H
+#define RCC_CODEGEN_REGISTERBANKINFO_H
+
+#include "rcc/CodeGen/MachineIRTypes.h"
+#include "rcc/CodeGen/Register.h"
+#include "rcc/Support/Error.h"
+
+#include <optional>
+#include <vector>
+
+namespace rcc {
+
+class MachineFunction;
+class MachineInstr;
+class TargetDescription;
+struct VirtualRegisterInfo;
+
+struct RegisterBankSelection final {
+  RegisterBankID Bank;
+  bool IsConstrained = false;
+};
+
+using RegisterBankInstructionMapping = std::vector<std::optional<RegisterBankID>>;
+
+class RegisterBankInfo {
+public:
+  virtual ~RegisterBankInfo() = default;
+
+  [[nodiscard]] virtual Expected<RegisterBankSelection>
+  selectBank(const MachineFunction &Function, Register Reg, const VirtualRegisterInfo &Info,
+             const MachineInstr *Context, const TargetDescription &Target) const = 0;
+
+  [[nodiscard]] virtual Expected<RegisterBankInstructionMapping>
+  getInstructionMapping(const MachineInstr &, const MachineFunction &,
+                        const TargetDescription &) const {
+    return RegisterBankInstructionMapping{};
+  }
+
+  // This hook rejects invalid mappings before register-bank state is published.
+  [[nodiscard]] virtual Expected<void> validateInstruction(const MachineInstr &,
+                                                           const MachineFunction &,
+                                                           const TargetDescription &) const {
+    return {};
+  }
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_REGISTERBANKINFO_H