Initial Commit

thirdparty/capstone/suite/synctools/tablegen/include/llvm/CodeGen/MacroFusion.h

@@ -0,0 +1,63 @@
+//===- MacroFusion.h - Macro Fusion -----------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file This file contains the definition of the DAG scheduling mutation to
+/// pair instructions back to back.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACROFUSION_H
+#define LLVM_CODEGEN_MACROFUSION_H
+
+#include <functional>
+#include <memory>
+
+namespace llvm {
+
+class MachineInstr;
+class ScheduleDAGMutation;
+class TargetInstrInfo;
+class TargetSubtargetInfo;
+class ScheduleDAGInstrs;
+class SUnit;
+
+/// Check if the instr pair, FirstMI and SecondMI, should be fused
+/// together. Given SecondMI, when FirstMI is unspecified, then check if
+/// SecondMI may be part of a fused pair at all.
+using ShouldSchedulePredTy = std::function<bool(const TargetInstrInfo &TII,
+                                                const TargetSubtargetInfo &TSI,
+                                                const MachineInstr *FirstMI,
+                                                const MachineInstr &SecondMI)>;
+
+/// Checks if the number of cluster edges between SU and its predecessors is
+/// less than FuseLimit
+bool hasLessThanNumFused(const SUnit &SU, unsigned FuseLimit);
+
+/// Create an artificial edge between FirstSU and SecondSU.
+/// Make data dependencies from the FirstSU also dependent on the SecondSU to
+/// prevent them from being scheduled between the FirstSU and the SecondSU
+/// and vice-versa.
+/// Fusing more than 2 instructions is not currently supported.
+bool fuseInstructionPair(ScheduleDAGInstrs &DAG, SUnit &FirstSU,
+                         SUnit &SecondSU);
+
+/// Create a DAG scheduling mutation to pair instructions back to back
+/// for instructions that benefit according to the target-specific
+/// shouldScheduleAdjacent predicate function.
+std::unique_ptr<ScheduleDAGMutation>
+createMacroFusionDAGMutation(ShouldSchedulePredTy shouldScheduleAdjacent);
+
+/// Create a DAG scheduling mutation to pair branch instructions with one
+/// of their predecessors back to back for instructions that benefit according
+/// to the target-specific shouldScheduleAdjacent predicate function.
+std::unique_ptr<ScheduleDAGMutation>
+createBranchMacroFusionDAGMutation(ShouldSchedulePredTy shouldScheduleAdjacent);
+
+} // end namespace llvm
+
+#endif // LLVM_CODEGEN_MACROFUSION_H