InlinerPass.h revision 3251e81d793a293b78f4914be6093b405c24fc2a 
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/Analysis/CallGraphSCCPass.h"
21
22namespace llvm {
23  class CallSite;
24  class DataLayout;
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  using llvm::Pass::doFinalization;
46  // doFinalization - Remove now-dead linkonce functions at the end of
47  // processing to avoid breaking the SCC traversal.
48  virtual bool doFinalization(CallGraph &CG);
49
50  /// This method returns the value specified by the -inline-threshold value,
51  /// specified on the command line.  This is typically not directly needed.
52  ///
53  unsigned getInlineThreshold() const { return InlineThreshold; }
54
55  /// Calculate the inline threshold for given Caller. This threshold is lower
56  /// if the caller is marked with OptimizeForSize and -inline-threshold is not
57  /// given on the comand line. It is higher if the callee is marked with the
58  /// inlinehint attribute.
59  ///
60  unsigned getInlineThreshold(CallSite CS) const;
61
62  /// getInlineCost - This method must be implemented by the subclass to
63  /// determine the cost of inlining the specified call site.  If the cost
64  /// returned is greater than the current inline threshold, the call site is
65  /// not inlined.
66  ///
67  virtual InlineCost getInlineCost(CallSite CS) = 0;
68
69  /// removeDeadFunctions - Remove dead functions.
70  ///
71  /// This also includes a hack in the form of the 'AlwaysInlineOnly' flag
72  /// which restricts it to deleting functions with an 'AlwaysInline'
73  /// attribute. This is useful for the InlineAlways pass that only wants to
74  /// deal with that subset of the functions.
75  bool removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly = false);
76
77private:
78  // InlineThreshold - Cache the value here for easy access.
79  unsigned InlineThreshold;
80
81  // InsertLifetime - Insert @llvm.lifetime intrinsics.
82  bool InsertLifetime;
83
84  /// shouldInline - Return true if the inliner should attempt to
85  /// inline at the given CallSite.
86  bool shouldInline(CallSite CS);
87};
88
89} // End llvm namespace
90
91#endif
92