1 //===---------------- lib/CodeGen/CalcSpillWeights.h ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 #ifndef LLVM_CODEGEN_CALCSPILLWEIGHTS_H
12 #define LLVM_CODEGEN_CALCSPILLWEIGHTS_H
14 #include "llvm/CodeGen/MachineFunctionPass.h"
15 #include "llvm/ADT/DenseMap.h"
21 class MachineLoopInfo;
23 /// VirtRegAuxInfo - Calculate auxiliary information for a virtual
24 /// register such as its spill weight and allocation hint.
25 class VirtRegAuxInfo {
28 const MachineLoopInfo &loops_;
29 DenseMap<unsigned, float> hint_;
31 VirtRegAuxInfo(MachineFunction &mf, LiveIntervals &lis,
32 const MachineLoopInfo &loops) :
33 mf_(mf), lis_(lis), loops_(loops) {}
35 /// CalculateRegClass - recompute the register class for reg from its uses.
36 /// Since the register class can affect the allocation hint, this function
37 /// should be called before CalculateWeightAndHint if both are called.
38 void CalculateRegClass(unsigned reg);
40 /// CalculateWeightAndHint - (re)compute li's spill weight and allocation
42 void CalculateWeightAndHint(LiveInterval &li);
45 /// CalculateSpillWeights - Compute spill weights for all virtual register
47 class CalculateSpillWeights : public MachineFunctionPass {
51 CalculateSpillWeights() : MachineFunctionPass(ID) {
52 initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
55 virtual void getAnalysisUsage(AnalysisUsage &au) const;
57 virtual bool runOnMachineFunction(MachineFunction &fn);
60 /// Returns true if the given live interval is zero length.
61 bool isZeroLengthInterval(LiveInterval *li) const;
66 #endif // LLVM_CODEGEN_CALCSPILLWEIGHTS_H