From 9720e989ccdce77a2c45a8379d36ff4428e6c2bf Mon Sep 17 00:00:00 2001 From: Richard-Qin-X Date: Mon, 17 Aug 2026 03:04:21 +0800 Subject: [RISCV][GlobalISel] Generate direct branch selection --- backend/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp | 13 ------------- backend/lib/Target/RISCV/RISCVGISelInteger.rccdesc | 10 ++++++++++ 2 files changed, 10 insertions(+), 13 deletions(-) (limited to 'backend') diff --git a/backend/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp b/backend/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp index cde2c8d..89b6ecd 100644 --- a/backend/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp +++ b/backend/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp @@ -364,7 +364,6 @@ public: case GenericOpcode::G_FPEXTLOAD: case GenericOpcode::G_FPTRUNCSTORE: case GenericOpcode::G_STORE: - case GenericOpcode::G_BR: case GenericOpcode::G_BRCOND: return {}; case GenericOpcode::G_FCONSTANT: { @@ -441,8 +440,6 @@ public: return selectStore(Instruction, Function); case GenericOpcode::G_FPTRUNCSTORE: return selectFloatTruncStore(Instruction, Function, Target); - case GenericOpcode::G_BR: - return selectBranch(Instruction); case GenericOpcode::G_BRCOND: return selectConditionalBranch(Instruction); case GenericOpcode::G_CONSTANT: @@ -1425,16 +1422,6 @@ private: return makeUnexpected(ErrorCode::Unsupported, "RISC-V cannot select this generic store type"); } - [[nodiscard]] Expected selectBranch(MachineInstr &Instruction) const { - auto Zero = physicalRegister(PhysicalRegisterID::X0); - if (!Zero) - return std::unexpected(Zero.error()); - auto Inserted = insertPhysicalRegister(Instruction, 0, *Zero, RegisterOperandFlag::Define); - if (!Inserted) - return std::unexpected(Inserted.error()); - return Instruction.setOpcode(instructionOpcode(InstructionOpcode::JAL)); - } - [[nodiscard]] Expected selectConditionalBranch(MachineInstr &Instruction) const { auto Zero = physicalRegister(PhysicalRegisterID::X0); if (!Zero) diff --git a/backend/lib/Target/RISCV/RISCVGISelInteger.rccdesc b/backend/lib/Target/RISCV/RISCVGISelInteger.rccdesc index f40e5d4..6ba88ef 100644 --- a/backend/lib/Target/RISCV/RISCVGISelInteger.rccdesc +++ b/backend/lib/Target/RISCV/RISCVGISelInteger.rccdesc @@ -1,4 +1,14 @@ selection_rules: + - + id: select_g_br + priority: 100 + match: + opcode: G_BR + apply: + instructions: + - opcode: PseudoBR + root: true + operands: [{ operand: 0 }] - id: select_g_implicit_def priority: 100 -- cgit v1.2.3