[GlobalISel] Split the generic pipeline components

5 files changed, 183 insertions, 0 deletions

diff --git a/backend/include/rcc/CodeGen/GlobalISel/InstructionSelect.h b/backend/include/rcc/CodeGen/GlobalISel/InstructionSelect.h
new file mode 100644
index 0000000..0c034cd
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GlobalISel/InstructionSelect.h
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GLOBALISEL_INSTRUCTIONSELECT_H
+#define RCC_CODEGEN_GLOBALISEL_INSTRUCTIONSELECT_H
+
+#include "rcc/CodeGen/GlobalISel/InstructionSelector.h"
+#include "rcc/CodeGen/MachinePass.h"
+
+namespace rcc {
+
+class InstructionSelect final : public MachineFunctionPass {
+public:
+  explicit InstructionSelect(const InstructionSelector *Info) : Info(Info) {}
+  explicit InstructionSelect(const InstructionSelector &Info) : Info(&Info) {}
+
+  [[nodiscard]] const MachinePassContract &contract() const noexcept override;
+  [[nodiscard]] Expected<MachinePassResult> run(MachineFunction &Function,
+                                                const TargetDescription &Target,
+                                                MachineAnalysisManager &Analyses) override;
+
+private:
+  [[nodiscard]] Expected<MachinePassResult> runImplementation(MachineFunction &Function,
+                                                              const TargetDescription &Target,
+                                                              MachineActionReplay &Actions);
+
+  const InstructionSelector *Info;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GLOBALISEL_INSTRUCTIONSELECT_H
diff --git a/backend/include/rcc/CodeGen/GlobalISel/InstructionSelector.h b/backend/include/rcc/CodeGen/GlobalISel/InstructionSelector.h
new file mode 100644
index 0000000..4c69606
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GlobalISel/InstructionSelector.h
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GLOBALISEL_INSTRUCTIONSELECTOR_H
+#define RCC_CODEGEN_GLOBALISEL_INSTRUCTIONSELECTOR_H
+
+#include "rcc/Support/Error.h"
+
+namespace rcc {
+
+class MachineFunction;
+class MachineInstr;
+class TargetDescription;
+
+class InstructionSelector {
+public:
+  virtual ~InstructionSelector() = default;
+
+  [[nodiscard]] virtual Expected<void> select(MachineInstr &Instruction, MachineFunction &Function,
+                                              const TargetDescription &Target) const = 0;
+
+  // Selection matching is read-only and completes before select() mutates MachineIR.
+  [[nodiscard]] virtual Expected<void> canSelect(const MachineInstr &, const MachineFunction &,
+                                                 const TargetDescription &) const {
+    return {};
+  }
+
+  [[nodiscard]] virtual Expected<void>
+  constrainSelectedInstruction(MachineInstr &, MachineFunction &, const TargetDescription &) const {
+    return {};
+  }
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GLOBALISEL_INSTRUCTIONSELECTOR_H
diff --git a/backend/include/rcc/CodeGen/GlobalISel/Legalizer.h b/backend/include/rcc/CodeGen/GlobalISel/Legalizer.h
new file mode 100644
index 0000000..7f86d16
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GlobalISel/Legalizer.h
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GLOBALISEL_LEGALIZER_H
+#define RCC_CODEGEN_GLOBALISEL_LEGALIZER_H
+
+#include "rcc/CodeGen/GlobalISel/LegalizerInfo.h"
+#include "rcc/CodeGen/MachinePass.h"
+
+#include <memory>
+
+namespace rcc {
+
+class Legalizer final : public MachineFunctionPass {
+public:
+  explicit Legalizer(const LegalizerInfo *Info) : Info(Info) {}
+  explicit Legalizer(const LegalizerInfo &Info) : Info(&Info) {}
+  explicit Legalizer(std::unique_ptr<LegalizerInfo> Info)
+      : OwnedInfo(std::move(Info)), Info(OwnedInfo.get()) {}
+
+  [[nodiscard]] const MachinePassContract &contract() const noexcept override;
+  [[nodiscard]] Expected<MachinePassResult> run(MachineFunction &Function,
+                                                const TargetDescription &Target,
+                                                MachineAnalysisManager &Analyses) override;
+
+private:
+  [[nodiscard]] Expected<MachinePassResult> runImplementation(MachineFunction &Function,
+                                                              const TargetDescription &Target,
+                                                              MachineActionReplay &Actions);
+
+  std::unique_ptr<LegalizerInfo> OwnedInfo;
+  const LegalizerInfo *Info = nullptr;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GLOBALISEL_LEGALIZER_H
diff --git a/backend/include/rcc/CodeGen/GlobalISel/LegalizerInfo.h b/backend/include/rcc/CodeGen/GlobalISel/LegalizerInfo.h
new file mode 100644
index 0000000..218a4c6
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GlobalISel/LegalizerInfo.h
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GLOBALISEL_LEGALIZERINFO_H
+#define RCC_CODEGEN_GLOBALISEL_LEGALIZERINFO_H
+
+#include "rcc/Support/Error.h"
+
+#include <cstdint>
+
+namespace rcc {
+
+class MachineFunction;
+class MachineInstr;
+class TargetDescription;
+
+enum class LegalizationAction : std::uint8_t {
+  Legal,
+  Unsupported,
+  Custom,
+  Lower,
+  Libcall,
+  WidenScalar,
+  NarrowScalar,
+  MoreElements,
+  FewerElements,
+  Bitcast,
+  ChangeElementType,
+  ChangeAddressSpace,
+};
+
+class LegalizerInfo {
+public:
+  virtual ~LegalizerInfo() = default;
+
+  [[nodiscard]] virtual Expected<LegalizationAction>
+  classify(const MachineInstr &Instruction, const MachineFunction &Function,
+           const TargetDescription &Target) const = 0;
+
+  [[nodiscard]] virtual Expected<void> lower(MachineInstr &Instruction, MachineFunction &Function,
+                                             const TargetDescription &Target,
+                                             LegalizationAction Action) const = 0;
+
+  // This hook performs read-only target checks before a lowering mutation is committed.
+  [[nodiscard]] virtual Expected<void> validateLowering(const MachineInstr &,
+                                                        const MachineFunction &,
+                                                        const TargetDescription &,
+                                                        LegalizationAction) const {
+    return {};
+  }
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GLOBALISEL_LEGALIZERINFO_H
diff --git a/backend/include/rcc/CodeGen/GlobalISel/RegBankSelect.h b/backend/include/rcc/CodeGen/GlobalISel/RegBankSelect.h
new file mode 100644
index 0000000..256d748
--- /dev/null
+++ b/backend/include/rcc/CodeGen/GlobalISel/RegBankSelect.h
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_GLOBALISEL_REGBANKSELECT_H
+#define RCC_CODEGEN_GLOBALISEL_REGBANKSELECT_H
+
+#include "rcc/CodeGen/MachinePass.h"
+#include "rcc/CodeGen/RegisterBankInfo.h"
+
+namespace rcc {
+
+class RegBankSelect final : public MachineFunctionPass {
+public:
+  explicit RegBankSelect(const RegisterBankInfo *Info) : Info(Info) {}
+  explicit RegBankSelect(const RegisterBankInfo &Info) : Info(&Info) {}
+
+  [[nodiscard]] const MachinePassContract &contract() const noexcept override;
+  [[nodiscard]] Expected<MachinePassResult> run(MachineFunction &Function,
+                                                const TargetDescription &Target,
+                                                MachineAnalysisManager &Analyses) override;
+
+private:
+  const RegisterBankInfo *Info;
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_GLOBALISEL_REGBANKSELECT_H