• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // llvm/Transforms/IPO/PassManagerBuilder.h - Build Standard Pass -*- 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 the PassManagerBuilder class, which is used to set up a
11 // "standard" optimization sequence suitable for languages like C and C++.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_SUPPORT_PASSMANAGERBUILDER_H
16 #define LLVM_SUPPORT_PASSMANAGERBUILDER_H
17 
18 #include <vector>
19 
20 namespace llvm {
21   class TargetLibraryInfo;
22   class PassManagerBase;
23   class Pass;
24   class FunctionPassManager;
25 
26 /// PassManagerBuilder - This class is used to set up a standard optimization
27 /// sequence for languages like C and C++, allowing some APIs to customize the
28 /// pass sequence in various ways. A simple example of using it would be:
29 ///
30 ///  PassManagerBuilder Builder;
31 ///  Builder.OptLevel = 2;
32 ///  Builder.populateFunctionPassManager(FPM);
33 ///  Builder.populateModulePassManager(MPM);
34 ///
35 /// In addition to setting up the basic passes, PassManagerBuilder allows
36 /// frontends to vend a plugin API, where plugins are allowed to add extensions
37 /// to the default pass manager.  They do this by specifying where in the pass
38 /// pipeline they want to be added, along with a callback function that adds
39 /// the pass(es).  For example, a plugin that wanted to add a loop optimization
40 /// could do something like this:
41 ///
42 /// static void addMyLoopPass(const PMBuilder &Builder, PassManagerBase &PM) {
43 ///   if (Builder.getOptLevel() > 2 && Builder.getOptSizeLevel() == 0)
44 ///     PM.add(createMyAwesomePass());
45 /// }
46 ///   ...
47 ///   Builder.addExtension(PassManagerBuilder::EP_LoopOptimizerEnd,
48 ///                        addMyLoopPass);
49 ///   ...
50 class PassManagerBuilder {
51 public:
52 
53   /// Extensions are passed the builder itself (so they can see how it is
54   /// configured) as well as the pass manager to add stuff to.
55   typedef void (*ExtensionFn)(const PassManagerBuilder &Builder,
56                               PassManagerBase &PM);
57   enum ExtensionPointTy {
58     /// EP_EarlyAsPossible - This extension point allows adding passes before
59     /// any other transformations, allowing them to see the code as it is coming
60     /// out of the frontend.
61     EP_EarlyAsPossible,
62 
63     /// EP_ModuleOptimizerEarly - This extension point allows adding passes
64     /// just before the main module-level optimization passes.
65     EP_ModuleOptimizerEarly,
66 
67     /// EP_LoopOptimizerEnd - This extension point allows adding loop passes to
68     /// the end of the loop optimizer.
69     EP_LoopOptimizerEnd,
70 
71     /// EP_ScalarOptimizerLate - This extension point allows adding optimization
72     /// passes after most of the main optimizations, but before the last
73     /// cleanup-ish optimizations.
74     EP_ScalarOptimizerLate,
75 
76     /// EP_OptimizerLast -- This extension point allows adding passes that
77     /// run after everything else.
78     EP_OptimizerLast,
79 
80     /// EP_EnabledOnOptLevel0 - This extension point allows adding passes that
81     /// should not be disabled by O0 optimization level. The passes will be
82     /// inserted after the inlining pass.
83     EP_EnabledOnOptLevel0
84   };
85 
86   /// The Optimization Level - Specify the basic optimization level.
87   ///    0 = -O0, 1 = -O1, 2 = -O2, 3 = -O3
88   unsigned OptLevel;
89 
90   /// SizeLevel - How much we're optimizing for size.
91   ///    0 = none, 1 = -Os, 2 = -Oz
92   unsigned SizeLevel;
93 
94   /// LibraryInfo - Specifies information about the runtime library for the
95   /// optimizer.  If this is non-null, it is added to both the function and
96   /// per-module pass pipeline.
97   TargetLibraryInfo *LibraryInfo;
98 
99   /// Inliner - Specifies the inliner to use.  If this is non-null, it is
100   /// added to the per-module passes.
101   Pass *Inliner;
102 
103   bool DisableSimplifyLibCalls;
104   bool DisableUnitAtATime;
105   bool DisableUnrollLoops;
106   bool Vectorize;
107 
108 private:
109   /// ExtensionList - This is list of all of the extensions that are registered.
110   std::vector<std::pair<ExtensionPointTy, ExtensionFn> > Extensions;
111 
112 public:
113   PassManagerBuilder();
114   ~PassManagerBuilder();
115   /// Adds an extension that will be used by all PassManagerBuilder instances.
116   /// This is intended to be used by plugins, to register a set of
117   /// optimisations to run automatically.
118   static void addGlobalExtension(ExtensionPointTy Ty, ExtensionFn Fn);
119   void addExtension(ExtensionPointTy Ty, ExtensionFn Fn);
120 
121 private:
122   void addExtensionsToPM(ExtensionPointTy ETy, PassManagerBase &PM) const;
123   void addInitialAliasAnalysisPasses(PassManagerBase &PM) const;
124 public:
125 
126   /// populateFunctionPassManager - This fills in the function pass manager,
127   /// which is expected to be run on each function immediately as it is
128   /// generated.  The idea is to reduce the size of the IR in memory.
129   void populateFunctionPassManager(FunctionPassManager &FPM);
130 
131   /// populateModulePassManager - This sets up the primary pass manager.
132   void populateModulePassManager(PassManagerBase &MPM);
133   void populateLTOPassManager(PassManagerBase &PM, bool Internalize,
134                               bool RunInliner, bool DisableGVNLoadPRE = false);
135 };
136 
137 /// Registers a function for adding a standard set of passes.  This should be
138 /// used by optimizer plugins to allow all front ends to transparently use
139 /// them.  Create a static instance of this class in your plugin, providing a
140 /// private function that the PassManagerBuilder can use to add your passes.
141 struct RegisterStandardPasses {
RegisterStandardPassesRegisterStandardPasses142   RegisterStandardPasses(PassManagerBuilder::ExtensionPointTy Ty,
143                          PassManagerBuilder::ExtensionFn Fn) {
144     PassManagerBuilder::addGlobalExtension(Ty, Fn);
145   }
146 };
147 
148 } // end namespace llvm
149 #endif
150