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//===----------------------------------------------------------------------===//
// LLVM 'GCCAS' UTILITY
//
// This utility is designed to be used by the GCC frontend for creating
// bytecode files from it's intermediate llvm assembly. The requirements for
// this utility are thus slightly different than that of the standard as util.
//
//===----------------------------------------------------------------------===//
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Assembly/Parser.h"
#include "llvm/Transforms/CleanupGCCOutput.h"
#include "llvm/Transforms/LevelChange.h"
#include "llvm/Transforms/ConstantMerge.h"
#include "llvm/Transforms/ChangeAllocations.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Bytecode/WriteBytecodePass.h"
#include "Support/CommandLine.h"
#include "Support/Signals.h"
#include <memory>
#include <fstream>
cl::String InputFilename ("", "Parse <arg> file, compile to bytecode",
cl::Required, "");
cl::String OutputFilename("o", "Override output filename", cl::NoFlags, "");
cl::Flag StopAtLevelRaise("stopraise", "Stop optimization before level raise",
cl::Hidden);
int main(int argc, char **argv) {
cl::ParseCommandLineOptions(argc, argv, " llvm .s -> .o assembler for GCC\n");
std::auto_ptr<Module> M;
try {
// Parse the file now...
M.reset(ParseAssemblyFile(InputFilename));
} catch (const ParseException &E) {
cerr << E.getMessage() << endl;
return 1;
}
if (M.get() == 0) {
cerr << "assembly didn't read correctly.\n";
return 1;
}
if (OutputFilename == "") { // Didn't specify an output filename?
std::string IFN = InputFilename;
int Len = IFN.length();
if (IFN[Len-2] == '.' && IFN[Len-1] == 's') { // Source ends in .s?
OutputFilename = std::string(IFN.begin(), IFN.end()-2);
} else {
OutputFilename = IFN; // Append a .o to it
}
OutputFilename += ".o";
}
std::ofstream Out(OutputFilename.c_str(), ios::out);
if (!Out.good()) {
cerr << "Error opening " << OutputFilename << "!\n";
return 1;
}
// Make sure that the Out file gets unlink'd from the disk if we get a SIGINT
RemoveFileOnSignal(OutputFilename);
// In addition to just parsing the input from GCC, we also want to spiff it up
// a little bit. Do this now.
//
PassManager Passes;
Passes.add(createFunctionResolvingPass()); // Resolve (...) functions
Passes.add(createConstantMergePass()); // Merge dup global constants
Passes.add(createDeadInstEliminationPass()); // Remove Dead code/vars
Passes.add(createRaiseAllocationsPass()); // call %malloc -> malloc inst
Passes.add(createCleanupGCCOutputPass()); // Fix gccisms
Passes.add(createIndVarSimplifyPass()); // Simplify indvars
if (!StopAtLevelRaise) {
Passes.add(createRaisePointerReferencesPass()); // Eliminate casts
Passes.add(createPromoteMemoryToRegister()); // Promote alloca's to regs
Passes.add(createReassociatePass()); // Reassociate expressions
Passes.add(createInstructionCombiningPass()); // Combine silly seq's
Passes.add(createDeadInstEliminationPass()); // Kill InstCombine remnants
Passes.add(createLICMPass()); // Hoist loop invariants
Passes.add(createGCSEPass()); // Remove common subexprs
Passes.add(createSCCPPass()); // Constant prop with SCCP
// Run instcombine after redundancy elimination to exploit opportunities
// opened up by them.
Passes.add(createInstructionCombiningPass());
Passes.add(createAggressiveDCEPass()); // SSA based 'Agressive DCE'
Passes.add(createCFGSimplificationPass()); // Merge & remove BBs
}
Passes.add(new WriteBytecodePass(&Out)); // Write bytecode to file...
// Run our queue of passes all at once now, efficiently.
Passes.run(M.get());
return 0;
}
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