opt.cpp revision 22d26d7c7d7c9666d0da0e51250586da5a0744da 
1//===----------------------------------------------------------------------===//
2// LLVM 'OPT' UTILITY
3//
4// Optimizations may be specified an arbitrary number of times on the command
5// line, they are run in the order specified.
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/Module.h"
10#include "llvm/PassManager.h"
11#include "llvm/Bytecode/Reader.h"
12#include "llvm/Bytecode/WriteBytecodePass.h"
13#include "llvm/Assembly/PrintModulePass.h"
14#include "llvm/Analysis/Verifier.h"
15#include "llvm/Transforms/UnifyMethodExitNodes.h"
16#include "llvm/Transforms/ConstantMerge.h"
17#include "llvm/Transforms/CleanupGCCOutput.h"
18#include "llvm/Transforms/LevelChange.h"
19#include "llvm/Transforms/MethodInlining.h"
20#include "llvm/Transforms/SymbolStripping.h"
21#include "llvm/Transforms/ChangeAllocations.h"
22#include "llvm/Transforms/IPO/SimpleStructMutation.h"
23#include "llvm/Transforms/IPO/GlobalDCE.h"
24#include "llvm/Transforms/Scalar/DCE.h"
25#include "llvm/Transforms/Scalar/ConstantProp.h"
26#include "llvm/Transforms/Scalar/IndVarSimplify.h"
27#include "llvm/Transforms/Scalar/InstructionCombining.h"
28#include "llvm/Transforms/Scalar/PromoteMemoryToRegister.h"
29#include "llvm/Transforms/Instrumentation/TraceValues.h"
30#include "Support/CommandLine.h"
31#include <fstream>
32#include <memory>
33
34// Opts enum - All of the transformations we can do...
35enum Opts {
36  // Basic optimizations
37  dce, constprop, inlining, constmerge, strip, mstrip, mergereturn,
38
39  // Miscellaneous Transformations
40  trace, tracem, raiseallocs, cleangcc,
41
42  // Printing and verifying...
43  print, verify,
44
45  // More powerful optimizations
46  indvars, instcombine, sccp, adce, raise, mem2reg,
47
48  // Interprocedural optimizations...
49  globaldce, swapstructs, sortstructs,
50};
51
52
53// New template functions - Provide functions that return passes of specified
54// types, with specified arguments...
55//
56template<class PassClass>
57Pass *New() {
58  return new PassClass();
59}
60
61template<class PassClass, typename ArgTy1, ArgTy1 Arg1>
62Pass *New() {
63  return new PassClass(Arg1);
64}
65
66template<class PassClass, typename ArgTy1, ArgTy1 Arg1,
67                          typename ArgTy2, ArgTy1 Arg2>
68Pass *New() {
69  return new PassClass(Arg1, Arg2);
70}
71
72static Pass *NewPrintMethodPass() {
73  return new PrintMethodPass("Current Method: \n", &cerr);
74}
75
76// OptTable - Correlate enum Opts to Pass constructors...
77//
78struct {
79  enum Opts OptID;
80  Pass * (*PassCtor)();
81} OptTable[] = {
82  { dce        , New<DeadCodeElimination> },
83  { constprop  , New<ConstantPropogation> },
84  { inlining   , New<MethodInlining> },
85  { constmerge , New<ConstantMerge> },
86  { strip      , New<SymbolStripping> },
87  { mstrip     , New<FullSymbolStripping> },
88  { mergereturn, New<UnifyMethodExitNodes> },
89
90  { indvars    , New<InductionVariableSimplify> },
91  { instcombine, New<InstructionCombining> },
92  { sccp       , New<SCCPPass> },
93  { adce       , New<AgressiveDCE> },
94  { raise      , New<RaisePointerReferences> },
95  { mem2reg    , newPromoteMemoryToRegister },
96
97  { trace      , New<InsertTraceCode, bool, true, bool, true> },
98  { tracem     , New<InsertTraceCode, bool, false, bool, true> },
99  { print      , NewPrintMethodPass },
100  { verify     , createVerifierPass },
101  { raiseallocs, New<RaiseAllocations> },
102  { cleangcc   , New<CleanupGCCOutput> },
103  { globaldce  , New<GlobalDCE> },
104  { swapstructs, New<SimpleStructMutation, SimpleStructMutation::Transform,
105                     SimpleStructMutation::SwapElements>},
106  { sortstructs, New<SimpleStructMutation, SimpleStructMutation::Transform,
107                     SimpleStructMutation::SortElements>},
108};
109
110// Command line option handling code...
111//
112cl::String InputFilename ("", "Load <arg> file to optimize", cl::NoFlags, "-");
113cl::String OutputFilename("o", "Override output filename", cl::NoFlags, "");
114cl::Flag   Force         ("f", "Overwrite output files", cl::NoFlags, false);
115cl::Flag   PrintEachXForm("p", "Print module after each transformation");
116cl::Flag   Quiet         ("q", "Don't print modifying pass names", 0, false);
117cl::Alias  QuietA        ("quiet", "Alias for -q", cl::NoFlags, Quiet);
118cl::EnumList<enum Opts> OptimizationList(cl::NoFlags,
119  clEnumVal(dce        , "Dead Code Elimination"),
120  clEnumVal(constprop  , "Simple constant propogation"),
121 clEnumValN(inlining   , "inline", "Method integration"),
122  clEnumVal(constmerge , "Merge identical global constants"),
123  clEnumVal(strip      , "Strip symbols"),
124  clEnumVal(mstrip     , "Strip module symbols"),
125  clEnumVal(mergereturn, "Unify method exit nodes"),
126
127  clEnumVal(indvars    , "Simplify Induction Variables"),
128  clEnumVal(instcombine, "Combine redundant instructions"),
129  clEnumVal(sccp       , "Sparse Conditional Constant Propogation"),
130  clEnumVal(adce       , "Agressive DCE"),
131  clEnumVal(mem2reg    , "Promote alloca locations to registers"),
132
133  clEnumVal(globaldce  , "Remove unreachable globals"),
134  clEnumVal(swapstructs, "Swap structure types around"),
135  clEnumVal(sortstructs, "Sort structure elements"),
136
137  clEnumVal(raiseallocs, "Raise allocations from calls to instructions"),
138  clEnumVal(cleangcc   , "Cleanup GCC Output"),
139  clEnumVal(raise      , "Raise to Higher Level"),
140  clEnumVal(trace      , "Insert BB & Method trace code"),
141  clEnumVal(tracem     , "Insert Method trace code only"),
142
143  clEnumVal(print      , "Print working method to stderr"),
144  clEnumVal(verify     , "Verify module is well formed"),
1450);
146
147
148
149int main(int argc, char **argv) {
150  cl::ParseCommandLineOptions(argc, argv,
151			      " llvm .bc -> .bc modular optimizer\n");
152
153  // Load the input module...
154  std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
155  if (M.get() == 0) {
156    cerr << "bytecode didn't read correctly.\n";
157    return 1;
158  }
159
160  // Figure out what stream we are supposed to write to...
161  std::ostream *Out = &std::cout;  // Default to printing to stdout...
162  if (OutputFilename != "") {
163    if (!Force && std::ifstream(OutputFilename.c_str())) {
164      // If force is not specified, make sure not to overwrite a file!
165      cerr << "Error opening '" << OutputFilename << "': File exists!\n"
166           << "Use -f command line argument to force output\n";
167      return 1;
168    }
169    Out = new std::ofstream(OutputFilename.c_str());
170
171    if (!Out->good()) {
172      cerr << "Error opening " << OutputFilename << "!\n";
173      return 1;
174    }
175  }
176
177  // Create a PassManager to hold and optimize the collection of passes we are
178  // about to build...
179  //
180  PassManager Passes;
181
182  // Create a new optimization pass for each one specified on the command line
183  for (unsigned i = 0; i < OptimizationList.size(); ++i) {
184    enum Opts Opt = OptimizationList[i];
185    for (unsigned j = 0; j < sizeof(OptTable)/sizeof(OptTable[0]); ++j)
186      if (Opt == OptTable[j].OptID) {
187        Passes.add(OptTable[j].PassCtor());
188        break;
189      }
190
191    if (PrintEachXForm)
192      Passes.add(new PrintModulePass(&std::cerr));
193  }
194
195  // Check that the module is well formed on completion of optimization
196  Passes.add(createVerifierPass());
197
198  // Write bytecode out to disk or cout as the last step...
199  Passes.add(new WriteBytecodePass(Out, Out != &std::cout));
200
201  // Now that we have all of the passes ready, run them.
202  if (Passes.run(M.get()) && !Quiet)
203    cerr << "Program modified.\n";
204
205  return 0;
206}
207