1 //===-- llc.cpp - Implement the LLVM Native Code Generator ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the llc code generator.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Bytecode/Reader.h"
15 #include "llvm/Target/TargetMachineImpls.h"
16 #include "llvm/Target/TargetMachine.h"
17 #include "llvm/Transforms/Scalar.h"
18 #include "llvm/Module.h"
19 #include "llvm/PassManager.h"
20 #include "llvm/Pass.h"
21 #include "Support/CommandLine.h"
22 #include "Support/Signals.h"
28 // General options for llc. Other pass-specific options are specified
29 // within the corresponding llc passes, and target-specific options
30 // and back-end code generation options are specified with the target machine.
32 static cl::opt<std::string>
33 InputFilename(cl::Positional, cl::desc("<input bytecode>"), cl::init("-"));
35 static cl::opt<std::string>
36 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
38 static cl::opt<bool> Force("f", cl::desc("Overwrite output files"));
40 enum ArchName { noarch, X86, SparcV9, PowerPC, CBackend };
42 static cl::opt<ArchName>
43 Arch("march", cl::desc("Architecture to generate assembly for:"), cl::Prefix,
44 cl::values(clEnumValN(X86, "x86", " IA-32 (Pentium and above)"),
45 clEnumValN(SparcV9, "sparcv9", " SPARC V9"),
46 clEnumValN(PowerPC, "powerpc", " PowerPC (experimental)"),
47 clEnumValN(CBackend, "c", " C backend"),
51 // GetFileNameRoot - Helper function to get the basename of a filename...
52 static inline std::string
53 GetFileNameRoot(const std::string &InputFilename)
55 std::string IFN = InputFilename;
56 std::string outputFilename;
57 int Len = IFN.length();
59 IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
60 outputFilename = std::string(IFN.begin(), IFN.end()-3); // s/.bc/.s/
64 return outputFilename;
68 // main - Entry point for the llc compiler.
70 int main(int argc, char **argv) {
71 cl::ParseCommandLineOptions(argc, argv, " llvm system compiler\n");
72 PrintStackTraceOnErrorSignal();
74 // Load the module to be compiled...
75 std::auto_ptr<Module> M(ParseBytecodeFile(InputFilename));
77 std::cerr << argv[0] << ": bytecode didn't read correctly.\n";
80 Module &mod = *M.get();
82 // Allocate target machine. First, check whether the user has
83 // explicitly specified an architecture to compile for.
84 TargetMachine* (*TargetMachineAllocator)(const Module&,
85 IntrinsicLowering *) = 0;
88 TargetMachineAllocator = allocateCTargetMachine;
91 TargetMachineAllocator = allocateX86TargetMachine;
94 TargetMachineAllocator = allocateSparcV9TargetMachine;
97 TargetMachineAllocator = allocatePowerPCTargetMachine;
100 // Decide what the default target machine should be, by looking at
101 // the module. This heuristic (ILP32, LE -> IA32; LP64, BE ->
102 // SPARCV9) is kind of gross, but it will work until we have more
103 // sophisticated target information to work from.
104 if (mod.getEndianness() == Module::LittleEndian &&
105 mod.getPointerSize() == Module::Pointer32) {
106 TargetMachineAllocator = allocateX86TargetMachine;
107 } else if (mod.getEndianness() == Module::BigEndian &&
108 mod.getPointerSize() == Module::Pointer32) {
109 TargetMachineAllocator = allocatePowerPCTargetMachine;
110 } else if (mod.getEndianness() == Module::BigEndian &&
111 mod.getPointerSize() == Module::Pointer64) {
112 TargetMachineAllocator = allocateSparcV9TargetMachine;
114 // If the module is target independent, favor a target which matches the
115 // current build system.
116 #if defined(i386) || defined(__i386__) || defined(__x86__)
117 TargetMachineAllocator = allocateX86TargetMachine;
118 #elif defined(sparc) || defined(__sparc__) || defined(__sparcv9)
119 TargetMachineAllocator = allocateSparcV9TargetMachine;
120 #elif defined(__POWERPC__) || defined(__ppc__) || defined(__APPLE__)
121 TargetMachineAllocator = allocatePowerPCTargetMachine;
123 std::cerr << argv[0] << ": module does not specify a target to use. "
124 << "You must use the -march option. If no native target is "
125 << "available, use -march=c to emit C code.\n";
131 std::auto_ptr<TargetMachine> target(TargetMachineAllocator(mod, 0));
132 assert(target.get() && "Could not allocate target machine!");
133 TargetMachine &Target = *target.get();
134 const TargetData &TD = Target.getTargetData();
136 // Build up all of the passes that we want to do to the module...
139 Passes.add(new TargetData("llc", TD.isLittleEndian(), TD.getPointerSize(),
140 TD.getPointerAlignment(), TD.getDoubleAlignment()));
142 // Figure out where we are going to send the output...
143 std::ostream *Out = 0;
144 if (OutputFilename != "") {
145 if (OutputFilename != "-") {
146 // Specified an output filename?
147 if (!Force && std::ifstream(OutputFilename.c_str())) {
148 // If force is not specified, make sure not to overwrite a file!
149 std::cerr << argv[0] << ": error opening '" << OutputFilename
150 << "': file exists!\n"
151 << "Use -f command line argument to force output\n";
154 Out = new std::ofstream(OutputFilename.c_str());
156 // Make sure that the Out file gets unlinked from the disk if we get a
158 RemoveFileOnSignal(OutputFilename);
163 if (InputFilename == "-") {
164 OutputFilename = "-";
167 OutputFilename = GetFileNameRoot(InputFilename);
169 if (Arch != CBackend)
170 OutputFilename += ".s";
172 OutputFilename += ".cbe.c";
174 if (!Force && std::ifstream(OutputFilename.c_str())) {
175 // If force is not specified, make sure not to overwrite a file!
176 std::cerr << argv[0] << ": error opening '" << OutputFilename
177 << "': file exists!\n"
178 << "Use -f command line argument to force output\n";
182 Out = new std::ofstream(OutputFilename.c_str());
184 std::cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
189 // Make sure that the Out file gets unlinked from the disk if we get a
191 RemoveFileOnSignal(OutputFilename);
195 // Ask the target to add backend passes as necessary
196 if (Target.addPassesToEmitAssembly(Passes, *Out)) {
197 std::cerr << argv[0] << ": target '" << Target.getName()
198 << "' does not support static compilation!\n";
199 if (Out != &std::cout) delete Out;
200 // And the Out file is empty and useless, so remove it now.
201 std::remove(OutputFilename.c_str());
204 // Run our queue of passes all at once now, efficiently.
205 Passes.run(*M.get());
208 // Delete the ostream if it's not a stdout stream
209 if (Out != &std::cout) delete Out;