From b7716aba458fb3d49742f7a3c169deee7345396e Mon Sep 17 00:00:00 2001
From: Richard-Qin-X <richard.qin.001@gmail.com>
Date: Tue, 11 Aug 2026 19:36:06 +0800
Subject: [RISCV] Honor invocation subtarget features

---
 .../include/rcc/CodeGen/MachinePipelinePasses.h    |  7 +++-
 backend/include/rcc/Target/RISCV/RISCVCodeGen.h    |  5 +++
 backend/include/rcc/Target/RISCV/RISCVPipeline.h   |  6 +++
 backend/include/rcc/Target/RISCV/RISCVSubtarget.h  | 47 ++++++++++++++++++++++
 4 files changed, 64 insertions(+), 1 deletion(-)
 create mode 100644 backend/include/rcc/Target/RISCV/RISCVSubtarget.h

(limited to 'backend/include/rcc')

diff --git a/backend/include/rcc/CodeGen/MachinePipelinePasses.h b/backend/include/rcc/CodeGen/MachinePipelinePasses.h
index 08f0dac..1187e4a 100644
--- a/backend/include/rcc/CodeGen/MachinePipelinePasses.h
+++ b/backend/include/rcc/CodeGen/MachinePipelinePasses.h
@@ -6,12 +6,16 @@
 #include "rcc/CodeGen/MachinePass.h"
 #include "rcc/CodeGen/TargetCodeGen.h"
 
+#include <memory>
+
 namespace rcc {
 
 class LegalizerPass final : public MachineFunctionPass {
 public:
   explicit LegalizerPass(const TargetLegalizerInfo *Info) : Info(Info) {}
   explicit LegalizerPass(const TargetLegalizerInfo &Info) : Info(&Info) {}
+  explicit LegalizerPass(std::unique_ptr<TargetLegalizerInfo> Info)
+      : OwnedInfo(std::move(Info)), Info(OwnedInfo.get()) {}
 
   [[nodiscard]] const MachinePassContract &contract() const noexcept override;
   [[nodiscard]] Expected<MachinePassResult> run(MachineFunction &Function,
@@ -23,7 +27,8 @@ private:
                                                               const TargetDescription &Target,
                                                               MachineActionReplay &Actions);
 
-  const TargetLegalizerInfo *Info;
+  std::unique_ptr<TargetLegalizerInfo> OwnedInfo;
+  const TargetLegalizerInfo *Info = nullptr;
 };
 
 class RegisterBankSelectPass final : public MachineFunctionPass {
diff --git a/backend/include/rcc/Target/RISCV/RISCVCodeGen.h b/backend/include/rcc/Target/RISCV/RISCVCodeGen.h
index b6b207c..a39a3fa 100644
--- a/backend/include/rcc/Target/RISCV/RISCVCodeGen.h
+++ b/backend/include/rcc/Target/RISCV/RISCVCodeGen.h
@@ -12,10 +12,15 @@
 #include "rcc/CodeGen/TargetPseudoExpansion.h"
 #include "rcc/CodeGen/TargetRegisterAllocationInfo.h"
 #include "rcc/CodeGen/TargetSchedulingModel.h"
+#include "rcc/Target/RISCV/RISCVSubtarget.h"
+
+#include <memory>
 
 namespace rcc::riscv {
 
 [[nodiscard]] const TargetLegalizerInfo &legalizerInfo() noexcept;
+[[nodiscard]] std::unique_ptr<TargetLegalizerInfo>
+createLegalizerInfo(RISCVSubtargetFeatures Features);
 [[nodiscard]] const TargetRegisterBankInfo &registerBankInfo() noexcept;
 [[nodiscard]] const TargetInstructionSelector &instructionSelector() noexcept;
 [[nodiscard]] const TargetSSAInfo &ssaInfo() noexcept;
diff --git a/backend/include/rcc/Target/RISCV/RISCVPipeline.h b/backend/include/rcc/Target/RISCV/RISCVPipeline.h
index 8bd79e9..fa2cb45 100644
--- a/backend/include/rcc/Target/RISCV/RISCVPipeline.h
+++ b/backend/include/rcc/Target/RISCV/RISCVPipeline.h
@@ -5,6 +5,7 @@
 
 #include "rcc/CodeGen/MachinePass.h"
 #include "rcc/Support/Error.h"
+#include "rcc/Target/RISCV/RISCVSubtarget.h"
 
 #include <memory>
 #include <string>
@@ -20,8 +21,13 @@ namespace riscv {
 
 [[nodiscard]] Expected<void> addCanonicalPipeline(MachinePassManager &Pipeline,
                                                   const MachineFunction &Function);
+[[nodiscard]] Expected<void> addCanonicalPipeline(MachinePassManager &Pipeline,
+                                                  const MachineFunction &Function,
+                                                  RISCVSubtargetFeatures Features);
 [[nodiscard]] Expected<std::unique_ptr<MachineFunctionPass>>
 createCanonicalPipelinePass(std::string_view Name);
+[[nodiscard]] Expected<std::unique_ptr<MachineFunctionPass>>
+createCanonicalPipelinePass(std::string_view Name, RISCVSubtargetFeatures Features);
 [[nodiscard]] Expected<std::vector<std::string>>
 canonicalPipelinePassNames(const MachineFunction &Function);
 [[nodiscard]] Expected<void>
diff --git a/backend/include/rcc/Target/RISCV/RISCVSubtarget.h b/backend/include/rcc/Target/RISCV/RISCVSubtarget.h
new file mode 100644
index 0000000..d5f088f
--- /dev/null
+++ b/backend/include/rcc/Target/RISCV/RISCVSubtarget.h
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_TARGET_RISCV_RISCVSUBTARGET_H
+#define RCC_TARGET_RISCV_RISCVSUBTARGET_H
+
+#include "rcc/Support/Error.h"
+
+#include <cstdint>
+#include <span>
+#include <string>
+
+namespace rcc::riscv {
+
+enum class RISCVExtension : std::uint8_t {
+  I,
+  M,
+  A,
+  F,
+  D,
+  C,
+  Zicsr,
+  Zifencei,
+  Zacas,
+  Zabha,
+  Count,
+};
+
+class RISCVSubtargetFeatures final {
+public:
+  [[nodiscard]] static Expected<RISCVSubtargetFeatures>
+  fromFeatureList(std::span<const std::string> Features);
+  [[nodiscard]] static RISCVSubtargetFeatures rv64gc() noexcept;
+
+  [[nodiscard]] bool has(RISCVExtension Extension) const noexcept;
+
+  friend bool operator==(const RISCVSubtargetFeatures &Left,
+                         const RISCVSubtargetFeatures &Right) = default;
+
+private:
+  explicit constexpr RISCVSubtargetFeatures(std::uint16_t Enabled) noexcept : Enabled(Enabled) {}
+
+  std::uint16_t Enabled = 0;
+};
+
+} // namespace rcc::riscv
+
+#endif // RCC_TARGET_RISCV_RISCVSUBTARGET_H
-- 
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