1 files changed, 37 insertions, 2 deletions
diff --git a/include/llvm/CodeGen/RegisterPressure.h b/include/llvm/CodeGen/RegisterPressure.h
index 987634fb36c3..9bbdf3e071bd 100644
--- a/include/llvm/CodeGen/RegisterPressure.h
+++ b/include/llvm/CodeGen/RegisterPressure.h
@@ -141,6 +141,28 @@ public:
   LLVM_DUMP_METHOD void dump(const TargetRegisterInfo &TRI) const;
 };
 
+/// List of registers defined and used by a machine instruction.
+class RegisterOperands {
+public:
+  /// List of virtual regiserts and register units read by the instruction.
+  SmallVector<unsigned, 8> Uses;
+  /// \brief List of virtual registers and register units defined by the
+  /// instruction which are not dead.
+  SmallVector<unsigned, 8> Defs;
+  /// \brief List of virtual registers and register units defined by the
+  /// instruction but dead.
+  SmallVector<unsigned, 8> DeadDefs;
+
+  /// Analyze the given instruction \p MI and fill in the Uses, Defs and
+  /// DeadDefs list based on the MachineOperand flags.
+  void collect(const MachineInstr &MI, const TargetRegisterInfo &TRI,
+               const MachineRegisterInfo &MRI, bool IgnoreDead = false);
+
+  /// Use liveness information to find dead defs not marked with a dead flag
+  /// and move them to the DeadDefs vector.
+  void detectDeadDefs(const MachineInstr &MI, const LiveIntervals &LIS);
+};
+
 /// Array of PressureDiffs.
 class PressureDiffs {
   PressureDiff *PDiffArray;
@@ -161,6 +183,10 @@ public:
   const PressureDiff &operator[](unsigned Idx) const {
     return const_cast<PressureDiffs*>(this)->operator[](Idx);
   }
+  /// \brief Record pressure difference induced by the given operand list to
+  /// node with index \p Idx.
+  void addInstruction(unsigned Idx, const RegisterOperands &RegOpers,
+                      const MachineRegisterInfo &MRI);
 };
 
 /// Store the effects of a change in pressure on things that MI scheduler cares
@@ -329,8 +355,17 @@ public:
   void setPos(MachineBasicBlock::const_iterator Pos) { CurrPos = Pos; }
 
   /// Recede across the previous instruction.
-  void recede(SmallVectorImpl<unsigned> *LiveUses = nullptr,
-              PressureDiff *PDiff = nullptr);
+  void recede(SmallVectorImpl<unsigned> *LiveUses = nullptr);
+
+  /// Recede across the previous instruction.
+  /// This "low-level" variant assumes that recedeSkipDebugValues() was
+  /// called previously and takes precomputed RegisterOperands for the
+  /// instruction.
+  void recede(const RegisterOperands &RegOpers,
+              SmallVectorImpl<unsigned> *LiveUses = nullptr);
+
+  /// Recede until we find an instruction which is not a DebugValue.
+  void recedeSkipDebugValues();
 
   /// Advance across the current instruction.
   void advance();