3 files changed, 7 insertions, 0 deletions
diff --git a/backend/include/rcc/CodeGen/GlobalISel/LegalizerHelper.h b/backend/include/rcc/CodeGen/GlobalISel/LegalizerHelper.h
index 07ee8bb..0fdc89f 100644
--- a/backend/include/rcc/CodeGen/GlobalISel/LegalizerHelper.h
+++ b/backend/include/rcc/CodeGen/GlobalISel/LegalizerHelper.h
@@ -29,6 +29,8 @@ public:
   [[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> lowerVAArg(MachineInstr &Instruction);
   [[nodiscard]] Expected<void> widenScalar(MachineInstr &Instruction, std::size_t TypeIndex,
                                            LowLevelType WideType);
diff --git a/backend/include/rcc/CodeGen/GlobalISel/LegalizerInfo.h b/backend/include/rcc/CodeGen/GlobalISel/LegalizerInfo.h
index 2981f8e..5deefd4 100644
--- a/backend/include/rcc/CodeGen/GlobalISel/LegalizerInfo.h
+++ b/backend/include/rcc/CodeGen/GlobalISel/LegalizerInfo.h
@@ -184,6 +184,10 @@ public:
 
   [[nodiscard]] virtual GenericOpcode getExtOpcodeForWideningConstant(LowLevelType SmallType) const;
 
+  [[nodiscard]] virtual bool isSExtCheaperThanZExt(LowLevelType, LowLevelType) const {
+    return false;
+  }
+
   // This hook performs read-only target checks before a lowering mutation is committed.
   [[nodiscard]] virtual Expected<void> validateLowering(const MachineInstr &,
                                                         const MachineFunction &,
diff --git a/backend/include/rcc/Target/RISCV/RISCVSubtarget.h b/backend/include/rcc/Target/RISCV/RISCVSubtarget.h
index 9594a34..34ed4bd 100644
--- a/backend/include/rcc/Target/RISCV/RISCVSubtarget.h
+++ b/backend/include/rcc/Target/RISCV/RISCVSubtarget.h
@@ -27,6 +27,7 @@ enum class RISCVExtension : std::uint8_t {
   F,
   D,
   C,
+  Zbb,
   Zicsr,
   Zifencei,
   Zacas,