llc.cpp revision 2fbfdcffd3e0cf41422aaa6c526c37cb02b81341 
1//===-- llc.cpp - Implement the LLVM Compiler -----------------------------===//
2//
3// This is the llc compiler driver.
4//
5//===----------------------------------------------------------------------===//
6
7#include "llvm/Bytecode/Reader.h"
8#include "llvm/Target/Sparc.h"
9#include "llvm/Target/TargetMachine.h"
10#include "llvm/Transforms/Instrumentation/TraceValues.h"
11#include "llvm/Transforms/ChangeAllocations.h"
12#include "llvm/Transforms/HoistPHIConstants.h"
13#include "llvm/Transforms/Scalar/DecomposeMultiDimRefs.h"
14#include "llvm/Assembly/PrintModulePass.h"
15#include "llvm/Bytecode/WriteBytecodePass.h"
16#include "llvm/Transforms/ConstantMerge.h"
17#include "llvm/Module.h"
18#include "llvm/Function.h"
19#include "llvm/PassManager.h"
20#include "Support/CommandLine.h"
21#include <memory>
22#include <string>
23#include <fstream>
24using std::string;
25
26static cl::String InputFilename ("", "Input filename", cl::NoFlags, "-");
27static cl::String OutputFilename("o", "Output filename", cl::NoFlags, "");
28static cl::Flag   Force         ("f", "Overwrite output files");
29static cl::Flag   DumpAsm       ("d", "Print bytecode before native code generation", cl::Hidden);
30
31enum TraceLevel {
32  TraceOff, TraceFunctions, TraceBasicBlocks
33};
34
35static cl::Enum<enum TraceLevel> TraceValues("trace", cl::NoFlags,
36  "Trace values through functions or basic blocks",
37  clEnumValN(TraceOff        , "off",        "Disable trace code"),
38  clEnumValN(TraceFunctions  , "function",   "Trace each function"),
39  clEnumValN(TraceBasicBlocks, "basicblock", "Trace each basic block"), 0);
40
41
42// GetFileNameRoot - Helper function to get the basename of a filename...
43static inline string GetFileNameRoot(const string &InputFilename) {
44  string IFN = InputFilename;
45  string outputFilename;
46  int Len = IFN.length();
47  if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
48    outputFilename = string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
49  } else {
50    outputFilename = IFN;
51  }
52  return outputFilename;
53}
54
55
56//===---------------------------------------------------------------------===//
57// Function main()
58//
59// Entry point for the llc compiler.
60//===---------------------------------------------------------------------===//
61
62int main(int argc, char **argv) {
63  cl::ParseCommandLineOptions(argc, argv, " llvm system compiler\n");
64
65  // Allocate a target... in the future this will be controllable on the
66  // command line.
67  std::auto_ptr<TargetMachine> target(allocateSparcTargetMachine());
68  assert(target.get() && "Could not allocate target machine!");
69
70  TargetMachine &Target = *target.get();
71
72  // Load the module to be compiled...
73  std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
74  if (M.get() == 0) {
75    cerr << "bytecode didn't read correctly.\n";
76    return 1;
77  }
78
79  // Build up all of the passes that we want to do to the module...
80  PassManager Passes;
81
82  // Hoist constants out of PHI nodes into predecessor BB's
83  Passes.add(createHoistPHIConstantsPass());
84
85  if (TraceValues != TraceOff) {   // If tracing enabled...
86    // Insert trace code in all functions in the module
87    if (TraceValues == TraceBasicBlocks)
88      Passes.add(createTraceValuesPassForBasicBlocks());
89    else if (TraceValues == TraceFunctions)
90      Passes.add(createTraceValuesPassForMethod());
91    else
92      assert(0 && "Bad value for TraceValues!");
93
94    // Eliminate duplication in constant pool
95    Passes.add(createDynamicConstantMergePass());
96  }
97
98  // Decompose multi-dimensional refs into a sequence of 1D refs
99  Passes.add(createDecomposeMultiDimRefsPass());
100
101  // Write out the module with tracing code just before code generation
102  if (TraceValues != TraceOff) {   // If tracing enabled...
103    assert(InputFilename != "-" &&
104           "files on stdin not supported with tracing");
105    string traceFileName = GetFileNameRoot(InputFilename) + ".trace.bc";
106
107    if (!Force && std::ifstream(OutputFilename.c_str())) {
108      // If force is not specified, make sure not to overwrite a file!
109      cerr << "Error opening '" << OutputFilename << "': File exists!\n"
110           << "Use -f command line argument to force output\n";
111      return 1;
112    }
113
114    std::ostream *os = new std::ofstream(traceFileName.c_str());
115    if (!os->good()) {
116      cerr << "Error opening " << traceFileName
117           << "! SKIPPING OUTPUT OF TRACE CODE\n";
118      delete os;
119      return 1;
120    }
121
122    Passes.add(new WriteBytecodePass(os, true));
123  }
124
125  // Replace malloc and free instructions with library calls.
126  // Do this after tracing until lli implements these lib calls.
127  // For now, it will emulate malloc and free internally.
128  Passes.add(createLowerAllocationsPass(Target.DataLayout));
129
130  // If LLVM dumping after transformations is requested, add it to the pipeline
131  if (DumpAsm)
132    Passes.add(new PrintMethodPass("Code after xformations: \n", &cerr));
133
134  // Figure out where we are going to send the output...
135  std::ostream *Out = 0;
136  if (OutputFilename != "") {   // Specified an output filename?
137    if (!Force && std::ifstream(OutputFilename.c_str())) {
138      // If force is not specified, make sure not to overwrite a file!
139      cerr << "Error opening '" << OutputFilename << "': File exists!\n"
140           << "Use -f command line argument to force output\n";
141      return 1;
142    }
143    Out = new std::ofstream(OutputFilename.c_str());
144  } else {
145    if (InputFilename == "-") {
146      OutputFilename = "-";
147      Out = &std::cout;
148    } else {
149      string OutputFilename = GetFileNameRoot(InputFilename);
150      OutputFilename += ".s";
151
152      if (!Force && std::ifstream(OutputFilename.c_str())) {
153        // If force is not specified, make sure not to overwrite a file!
154        cerr << "Error opening '" << OutputFilename << "': File exists!\n"
155             << "Use -f command line argument to force output\n";
156        return 1;
157      }
158
159      Out = new std::ofstream(OutputFilename.c_str());
160      if (!Out->good()) {
161        cerr << "Error opening " << OutputFilename << "!\n";
162        delete Out;
163        return 1;
164      }
165    }
166  }
167
168  Target.addPassesToEmitAssembly(Passes, *Out);
169
170  // Run our queue of passes all at once now, efficiently.
171  Passes.run(M.get());
172
173  if (Out != &std::cout) delete Out;
174
175  return 0;
176}
177