1 files changed, 158 insertions, 0 deletions
diff --git a/backend/include/rcc/CodeGen/GlobalISel/LegalizerHelper.h b/backend/include/rcc/CodeGen/GlobalISel/LegalizerHelper.h
new file mode 100644
index 0000000..fa4e5e2
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GlobalISel/LegalizerHelper.h
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GLOBALISEL_LEGALIZERHELPER_H
+#define RCC_CODEGEN_GLOBALISEL_LEGALIZERHELPER_H
+
+#include "rcc/CodeGen/GenericOpcodes.h"
+#include "rcc/CodeGen/GlobalISel/LegalizerInfo.h"
+#include "rcc/CodeGen/MachineIRBuilder.h"
+#include "rcc/Support/Error.h"
+
+#include <vector>
+
+namespace rcc {
+
+class MachineFunction;
+class MachineInstr;
+class GISelChangeObserver;
+struct LibcallLoweringInfo;
+
+class LegalizerHelper final {
+public:
+  MachineIRBuilder &MIRBuilder;
+  GISelChangeObserver &Observer;
+
+  LegalizerHelper(MachineFunction &Function, const LegalizerInfo &Info,
+                  GISelChangeObserver &Observer, MachineIRBuilder &MIRBuilder,
+                  const LibcallLoweringInfo *Libcalls = nullptr);
+
+  [[nodiscard]] Expected<void> legalize(MachineInstr &Instruction,
+                                        const LegalizationDecision &Decision);
+  [[nodiscard]] Expected<void> lower(MachineInstr &Instruction,
+                                     const LegalizationDecision &Decision);
+  [[nodiscard]] Expected<void> lowerAbsToAddXor(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerAbsDiffToSelect(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerAbsDiffToMinMax(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerMinMax(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerThreewayCompare(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerDivRem(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerHighMultiply(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerBitCount(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerBswap(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerFunnelShift(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerRotate(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerDynStackAlloc(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerStackSave(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerStackRestore(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerMemcpyInline(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerVAArg(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> libcall(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> widenScalar(MachineInstr &Instruction, std::size_t TypeIndex,
+                                           LowLevelType WideType);
+  [[nodiscard]] Expected<void> widenScalarSrc(MachineInstr &Instruction, LowLevelType WideType,
+                                              std::size_t OperandIndex,
+                                              GenericOpcode ExtensionOpcode);
+  [[nodiscard]] Expected<void> narrowScalarSrc(MachineInstr &Instruction, LowLevelType NarrowType,
+                                               std::size_t OperandIndex);
+  [[nodiscard]] Expected<void> narrowScalarDst(MachineInstr &Instruction, LowLevelType NarrowType,
+                                               std::size_t OperandIndex,
+                                               GenericOpcode ExtensionOpcode);
+  [[nodiscard]] Expected<void> widenScalarDst(MachineInstr &Instruction, LowLevelType WideType,
+                                              std::size_t OperandIndex = 0,
+                                              GenericOpcode TruncOpcode = GenericOpcode::G_TRUNC);
+
+  [[nodiscard]] Expected<void> narrowScalar(MachineInstr &Instruction, std::size_t TypeIndex,
+                                            LowLevelType NarrowType);
+
+private:
+  [[nodiscard]] Expected<void> widenScalarMergeValues(MachineInstr &Instruction,
+                                                      std::size_t TypeIndex, LowLevelType WideType);
+  [[nodiscard]] Expected<void>
+  widenScalarUnmergeValues(MachineInstr &Instruction, std::size_t TypeIndex, LowLevelType WideType);
+  [[nodiscard]] Expected<void> insertParts(Register Destination, LowLevelType ResultType,
+                                           LowLevelType PartType,
+                                           const std::vector<Register> &PartRegisters,
+                                           LowLevelType LeftoverType = {},
+                                           const std::vector<Register> &LeftoverRegisters = {});
+  [[nodiscard]] Expected<void> extractGCDType(std::vector<Register> &Parts, LowLevelType GCDType,
+                                              Register Source);
+  [[nodiscard]] Expected<LowLevelType> extractGCDType(std::vector<Register> &Parts,
+                                                      LowLevelType DestinationType,
+                                                      LowLevelType NarrowType, Register Source);
+  [[nodiscard]] Expected<LowLevelType>
+  buildLCMMergePieces(LowLevelType DestinationType, LowLevelType NarrowType, LowLevelType GCDType,
+                      std::vector<Register> &Registers,
+                      GenericOpcode PadStrategy = GenericOpcode::G_ANYEXT);
+  [[nodiscard]] Expected<void>
+  buildWidenedRemergeToDst(Register Destination, LowLevelType LCMType,
+                           const std::vector<Register> &RemergeRegisters);
+  [[nodiscard]] Expected<void> multiplyRegisters(std::vector<Register> &Destinations,
+                                                 const std::vector<Register> &FirstSources,
+                                                 const std::vector<Register> &SecondSources,
+                                                 LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> narrowScalarAddSub(MachineInstr &Instruction, std::size_t TypeIndex,
+                                                  LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> narrowScalarMul(MachineInstr &Instruction, std::size_t TypeIndex,
+                                               LowLevelType NarrowType);
+  [[nodiscard]] Expected<void>
+  narrowScalarLoadStore(MachineInstr &Instruction, std::size_t TypeIndex, LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> reduceLoadStoreWidth(MachineInstr &Instruction,
+                                                    std::size_t TypeIndex, LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> lowerLoad(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerStore(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> narrowScalarBasic(MachineInstr &Instruction, std::size_t TypeIndex,
+                                                 LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> narrowScalarExt(MachineInstr &Instruction, std::size_t TypeIndex,
+                                               LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> narrowScalarSelect(MachineInstr &Instruction, std::size_t TypeIndex,
+                                                  LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> narrowScalarShift(MachineInstr &Instruction, std::size_t TypeIndex,
+                                                 LowLevelType NarrowType);
+  [[nodiscard]] Expected<void> narrowScalarShiftByConstant(MachineInstr &Instruction,
+                                                           const APInt &Amount,
+                                                           LowLevelType HalfType,
+                                                           LowLevelType AmountType);
+  [[nodiscard]] Expected<void> narrowScalarShiftMultiway(MachineInstr &Instruction,
+                                                         LowLevelType TargetType);
+  [[nodiscard]] Expected<void> narrowScalarShiftByConstantMultiway(MachineInstr &Instruction,
+                                                                   const APInt &Amount,
+                                                                   LowLevelType TargetType,
+                                                                   LowLevelType AmountType);
+  [[nodiscard]] Expected<void> fewerElements(MachineInstr &Instruction, std::size_t TypeIndex,
+                                             LowLevelType NarrowType);
+
+  struct ShiftParameters final {
+    Register WordShift;
+    Register BitShift;
+    Register InverseBitShift;
+    Register Zero;
+    Register SignBit;
+  };
+
+  [[nodiscard]] Expected<Register>
+  buildConstantShiftPart(GenericOpcode Generic, std::size_t PartIndex, std::size_t PartCount,
+                         const std::vector<Register> &SourceParts,
+                         const ShiftParameters &Parameters, LowLevelType TargetType);
+  [[nodiscard]] Expected<Register>
+  buildVariableShiftPart(GenericOpcode Generic, Register MainOperand, Register ShiftAmount,
+                         LowLevelType TargetType, Register CarryOperand = {});
+  [[nodiscard]] Expected<void> widenScalarAddSubOverflow(MachineInstr &Instruction,
+                                                         std::size_t TypeIndex,
+                                                         LowLevelType WideType);
+  [[nodiscard]] Expected<void> widenScalarMulo(MachineInstr &Instruction, std::size_t TypeIndex,
+                                               LowLevelType WideType);
+  [[nodiscard]] Expected<void> lowerSignedAddSubOverflow(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerSaturatingAddSubToMinMax(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerSaturatingAddSubToOverflow(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerSaturatingShiftLeft(MachineInstr &Instruction);
+  [[nodiscard]] Expected<void> lowerMulo(MachineInstr &Instruction);
+
+  MachineFunction &Function;
+  MachineRegisterInfo &MRI;
+  const LegalizerInfo &Info;
+  const LibcallLoweringInfo *Libcalls = nullptr;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GLOBALISEL_LEGALIZERHELPER_H