From a2f8d7c5e22b510965327383410bd576f7cf28e7 Mon Sep 17 00:00:00 2001
From: Richard-Qin-X <richard.qin.001@gmail.com>
Date: Thu, 13 Aug 2026 04:17:52 +0800
Subject: [CodeGen] Split machine liveness components

---
 backend/include/rcc/CodeGen/LiveIntervals.h | 73 +++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 backend/include/rcc/CodeGen/LiveIntervals.h

(limited to 'backend/include/rcc/CodeGen/LiveIntervals.h')

diff --git a/backend/include/rcc/CodeGen/LiveIntervals.h b/backend/include/rcc/CodeGen/LiveIntervals.h
new file mode 100644
index 0000000..a45c593
--- /dev/null
+++ b/backend/include/rcc/CodeGen/LiveIntervals.h
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_CODEGEN_LIVEINTERVALS_H
+#define RCC_CODEGEN_LIVEINTERVALS_H
+
+#include "rcc/CodeGen/LiveInterval.h"
+#include "rcc/CodeGen/MachinePass.h"
+#include "rcc/CodeGen/RegisterMask.h"
+
+#include <cstdint>
+#include <memory>
+#include <optional>
+#include <span>
+#include <string_view>
+#include <unordered_map>
+#include <vector>
+
+namespace rcc {
+
+class MachineFunction;
+class MachineInstr;
+class TargetDescription;
+
+struct RegMaskPosition final {
+  SlotIndex Position;
+  MachineInstrStableID Instruction;
+  std::shared_ptr<const RegisterMask> Mask;
+};
+
+class LiveIntervalsAnalysis final {
+public:
+  class Result final {
+  public:
+    [[nodiscard]] const SlotIndexesAnalysis::Result &slotIndexes() const noexcept {
+      return Indexes;
+    }
+    [[nodiscard]] SlotIndex slot(const MachineInstr &Instruction) const noexcept {
+      return Indexes.instructionIndex(Instruction);
+    }
+    [[nodiscard]] const LiveInterval *interval(Register Reg) const noexcept;
+    [[nodiscard]] LiveInterval *interval(Register Reg) noexcept;
+    [[nodiscard]] const LiveRange *regUnitRange(RegisterUnitID Unit) const noexcept;
+    [[nodiscard]] std::span<const RegMaskPosition> regMaskPositions() const noexcept {
+      return RegMasks;
+    }
+    [[nodiscard]] bool interferes(Register Left, Register Right) const noexcept;
+    [[nodiscard]] bool regMaskClobbers(const LiveInterval &Interval,
+                                       PhysicalRegister Candidate) const noexcept;
+    [[nodiscard]] Expected<void> shrinkToUses(Register Reg, std::span<const SlotIndex> Uses);
+
+    [[nodiscard]] bool invalidate(const MachineFunction &,
+                                  const PreservedAnalyses &Preserved) const noexcept;
+
+  private:
+    SlotIndexesAnalysis::Result Indexes;
+    std::unordered_map<Register, LiveInterval> Intervals;
+    std::unordered_map<RegisterUnitID, LiveRange> RegisterUnitRanges;
+    std::vector<RegMaskPosition> RegMasks;
+
+    friend class LiveIntervalsAnalysis;
+  };
+
+  [[nodiscard]] static constexpr std::string_view name() noexcept {
+    return "LiveIntervals";
+  }
+
+  [[nodiscard]] static Expected<Result>
+  run(MachineFunction &Function, const TargetDescription &Target, MachineAnalysisManager &Analyses);
+};
+
+} // namespace rcc
+
+#endif // RCC_CODEGEN_LIVEINTERVALS_H
-- 
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