1//===- InlinerPass.h - Code common to all inliners --------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines a simple policy-based bottom-up inliner.  This file
11// implements all of the boring mechanics of the bottom-up inlining, while the
12// subclass determines WHAT to inline, which is the much more interesting
13// component.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_TRANSFORMS_IPO_INLINERPASS_H
18#define LLVM_TRANSFORMS_IPO_INLINERPASS_H
19
20#include "llvm/CallGraphSCCPass.h"
21
22namespace llvm {
23  class CallSite;
24  class TargetData;
25  class InlineCost;
26  template<class PtrType, unsigned SmallSize>
27  class SmallPtrSet;
28
29/// Inliner - This class contains all of the helper code which is used to
30/// perform the inlining operations that do not depend on the policy.
31///
32struct Inliner : public CallGraphSCCPass {
33  explicit Inliner(char &ID);
34  explicit Inliner(char &ID, int Threshold, bool InsertLifetime);
35
36  /// getAnalysisUsage - For this class, we declare that we require and preserve
37  /// the call graph.  If the derived class implements this method, it should
38  /// always explicitly call the implementation here.
39  virtual void getAnalysisUsage(AnalysisUsage &Info) const;
40
41  // Main run interface method, this implements the interface required by the
42  // Pass class.
43  virtual bool runOnSCC(CallGraphSCC &SCC);
44
45  // doFinalization - Remove now-dead linkonce functions at the end of
46  // processing to avoid breaking the SCC traversal.
47  virtual bool doFinalization(CallGraph &CG);
48
49  /// This method returns the value specified by the -inline-threshold value,
50  /// specified on the command line.  This is typically not directly needed.
51  ///
52  unsigned getInlineThreshold() const { return InlineThreshold; }
53
54  /// Calculate the inline threshold for given Caller. This threshold is lower
55  /// if the caller is marked with OptimizeForSize and -inline-threshold is not
56  /// given on the comand line. It is higher if the callee is marked with the
57  /// inlinehint attribute.
58  ///
59  unsigned getInlineThreshold(CallSite CS) const;
60
61  /// getInlineCost - This method must be implemented by the subclass to
62  /// determine the cost of inlining the specified call site.  If the cost
63  /// returned is greater than the current inline threshold, the call site is
64  /// not inlined.
65  ///
66  virtual InlineCost getInlineCost(CallSite CS) = 0;
67
68  /// removeDeadFunctions - Remove dead functions.
69  ///
70  /// This also includes a hack in the form of the 'AlwaysInlineOnly' flag
71  /// which restricts it to deleting functions with an 'AlwaysInline'
72  /// attribute. This is useful for the InlineAlways pass that only wants to
73  /// deal with that subset of the functions.
74  bool removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly = false);
75
76private:
77  // InlineThreshold - Cache the value here for easy access.
78  unsigned InlineThreshold;
79
80  // InsertLifetime - Insert @llvm.lifetime intrinsics.
81  bool InsertLifetime;
82
83  /// shouldInline - Return true if the inliner should attempt to
84  /// inline at the given CallSite.
85  bool shouldInline(CallSite CS);
86};
87
88} // End llvm namespace
89
90#endif
91