Initial Commit

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

@@ -0,0 +1,106 @@
+//===- MachineBlockFrequencyInfo.h - MBB Frequency Analysis -----*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Loops should be simplified before this analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
+#define LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
+
+#include "llvm/ADT/Optional.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/Support/BlockFrequency.h"
+#include <cstdint>
+#include <memory>
+
+namespace llvm {
+
+template <class BlockT> class BlockFrequencyInfoImpl;
+class MachineBasicBlock;
+class MachineBranchProbabilityInfo;
+class MachineFunction;
+class MachineLoopInfo;
+class raw_ostream;
+
+/// MachineBlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation
+/// to estimate machine basic block frequencies.
+class MachineBlockFrequencyInfo : public MachineFunctionPass {
+  using ImplType = BlockFrequencyInfoImpl<MachineBasicBlock>;
+  std::unique_ptr<ImplType> MBFI;
+
+public:
+  static char ID;
+
+  MachineBlockFrequencyInfo();
+  explicit MachineBlockFrequencyInfo(MachineFunction &F,
+                                     MachineBranchProbabilityInfo &MBPI,
+                                     MachineLoopInfo &MLI);
+  ~MachineBlockFrequencyInfo() override;
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+  bool runOnMachineFunction(MachineFunction &F) override;
+
+  /// calculate - compute block frequency info for the given function.
+  void calculate(const MachineFunction &F,
+                 const MachineBranchProbabilityInfo &MBPI,
+                 const MachineLoopInfo &MLI);
+
+  void releaseMemory() override;
+
+  /// getblockFreq - Return block frequency. Return 0 if we don't have the
+  /// information. Please note that initial frequency is equal to 1024. It means
+  /// that we should not rely on the value itself, but only on the comparison to
+  /// the other block frequencies. We do this to avoid using of floating points.
+  /// For example, to get the frequency of a block relative to the entry block,
+  /// divide the integral value returned by this function (the
+  /// BlockFrequency::getFrequency() value) by getEntryFreq().
+  BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const;
+
+  /// Compute the frequency of the block, relative to the entry block.
+  /// This API assumes getEntryFreq() is non-zero.
+  float getBlockFreqRelativeToEntryBlock(const MachineBasicBlock *MBB) const {
+    return getBlockFreq(MBB).getFrequency() * (1.0f / getEntryFreq());
+  }
+
+  Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const;
+  Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const;
+
+  bool isIrrLoopHeader(const MachineBasicBlock *MBB) const;
+
+  /// incrementally calculate block frequencies when we split edges, to avoid
+  /// full CFG traversal.
+  void onEdgeSplit(const MachineBasicBlock &NewPredecessor,
+                   const MachineBasicBlock &NewSuccessor,
+                   const MachineBranchProbabilityInfo &MBPI);
+
+  const MachineFunction *getFunction() const;
+  const MachineBranchProbabilityInfo *getMBPI() const;
+
+  /// Pop up a ghostview window with the current block frequency propagation
+  /// rendered using dot.
+  void view(const Twine &Name, bool isSimple = true) const;
+
+  // Print the block frequency Freq to OS using the current functions entry
+  // frequency to convert freq into a relative decimal form.
+  raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
+
+  // Convenience method that attempts to look up the frequency associated with
+  // BB and print it to OS.
+  raw_ostream &printBlockFreq(raw_ostream &OS,
+                              const MachineBasicBlock *MBB) const;
+
+  /// Divide a block's BlockFrequency::getFrequency() value by this value to
+  /// obtain the entry block - relative frequency of said block.
+  uint64_t getEntryFreq() const;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H