[CodeGen] Complete register allocation infrastructure

1 files changed, 58 insertions, 0 deletions

diff --git a/backend/include/rcc/CodeGen/TargetRegisterAllocationInfo.h b/backend/include/rcc/CodeGen/TargetRegisterAllocationInfo.h
new file mode 100644
index 0000000..6e25465
--- /dev/null
+++ b/backend/include/rcc/CodeGen/TargetRegisterAllocationInfo.h
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_TARGETREGISTERALLOCATIONINFO_H
+#define RCC_CODEGEN_TARGETREGISTERALLOCATIONINFO_H
+
+#include "rcc/CodeGen/MachineFrameInfo.h"
+#include "rcc/CodeGen/MachineLiveness.h"
+#include "rcc/CodeGen/TargetRegisterInfo.h"
+
+#include <cstdint>
+
+namespace rcc {
+
+class MachineIRBuilder;
+class MachineInstr;
+class TargetDescription;
+
+class TargetRegisterAllocationInfo {
+public:
+  virtual ~TargetRegisterAllocationInfo() = default;
+
+  [[nodiscard]] virtual Expected<void>
+  validateSpillReload(RegisterClassID Class, const TargetDescription &Target) const = 0;
+  [[nodiscard]] virtual Expected<MachineInstr *>
+  emitReload(MachineIRBuilder &Builder, Register Destination, RegisterClassID Class,
+             FrameIndex StackSlot, LaneMask Lanes) const = 0;
+  [[nodiscard]] virtual Expected<MachineInstr *> emitSpill(MachineIRBuilder &Builder,
+                                                           Register Source, RegisterClassID Class,
+                                                           FrameIndex StackSlot,
+                                                           LaneMask Lanes) const = 0;
+
+  [[nodiscard]] virtual Expected<bool> isRematerializable(const MachineInstr &, Register,
+                                                          const MachineFunction &,
+                                                          const TargetDescription &) const {
+    return false;
+  }
+  [[nodiscard]] virtual Expected<MachineInstr *> rematerialize(MachineIRBuilder &,
+                                                               const MachineInstr &, Register,
+                                                               Register,
+                                                               const TargetDescription &) const {
+    return makeUnexpected(ErrorCode::InternalError,
+                          "target accepted rematerialization without implementing it");
+  }
+
+  [[nodiscard]] virtual std::uint64_t physicalRegisterCost(const MachineFunction &, Register,
+                                                           PhysicalRegister, RegisterClassID,
+                                                           bool) const noexcept {
+    return 0;
+  }
+  [[nodiscard]] virtual std::uint64_t spillCost(const MachineFunction &, const LiveInterval &,
+                                                RegisterClassID) const noexcept {
+    return 1;
+  }
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_TARGETREGISTERALLOCATIONINFO_H