| //===-- gccas.cpp - The "optimizing assembler" used by the GCC frontend ---===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This utility is designed to be used by the GCC frontend for creating bytecode |
| // files from its 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/Analysis/LoadValueNumbering.h" |
| #include "llvm/Analysis/Verifier.h" |
| #include "llvm/Assembly/Parser.h" |
| #include "llvm/Bytecode/WriteBytecodePass.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/Transforms/Scalar.h" |
| #include "Support/CommandLine.h" |
| #include "Support/Signals.h" |
| #include <memory> |
| #include <fstream> |
| |
| using namespace llvm; |
| |
| namespace { |
| cl::opt<std::string> |
| InputFilename(cl::Positional,cl::desc("<input llvm assembly>"),cl::init("-")); |
| |
| cl::opt<std::string> |
| OutputFilename("o", cl::desc("Override output filename"), |
| cl::value_desc("filename")); |
| |
| cl::opt<bool> |
| Verify("verify", cl::desc("Verify each pass result")); |
| |
| cl::opt<bool> |
| DisableInline("disable-inlining", cl::desc("Do not run the inliner pass")); |
| } |
| |
| |
| static inline void addPass(PassManager &PM, Pass *P) { |
| // Add the pass to the pass manager... |
| PM.add(P); |
| |
| // If we are verifying all of the intermediate steps, add the verifier... |
| if (Verify) PM.add(createVerifierPass()); |
| } |
| |
| |
| void AddConfiguredTransformationPasses(PassManager &PM) { |
| PM.add(createVerifierPass()); // Verify that input is correct |
| addPass(PM, createLowerSetJmpPass()); // Lower llvm.setjmp/.longjmp |
| addPass(PM, createFunctionResolvingPass()); // Resolve (...) functions |
| addPass(PM, createCFGSimplificationPass()); // Clean up disgusting code |
| addPass(PM, createRaiseAllocationsPass()); // call %malloc -> malloc inst |
| addPass(PM, createGlobalDCEPass()); // Remove unused globals |
| addPass(PM, createIPConstantPropagationPass());// IP Constant Propagation |
| addPass(PM, createDeadArgEliminationPass()); // Dead argument elimination |
| |
| addPass(PM, createPruneEHPass()); // Remove dead EH info |
| |
| if (!DisableInline) |
| addPass(PM, createFunctionInliningPass()); // Inline small functions |
| |
| addPass(PM, createInstructionCombiningPass()); // Cleanup code for raise |
| addPass(PM, createRaisePointerReferencesPass());// Recover type information |
| addPass(PM, createTailDuplicationPass()); // Simplify cfg by copying code |
| addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs |
| addPass(PM, createScalarReplAggregatesPass()); // Break up aggregate allocas |
| addPass(PM, createTailCallEliminationPass()); // Eliminate tail calls |
| addPass(PM, createInstructionCombiningPass()); // Combine silly seq's |
| |
| addPass(PM, createReassociatePass()); // Reassociate expressions |
| addPass(PM, createInstructionCombiningPass()); // Combine silly seq's |
| addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs |
| addPass(PM, createLICMPass()); // Hoist loop invariants |
| addPass(PM, createLoadValueNumberingPass()); // GVN for load instructions |
| addPass(PM, createGCSEPass()); // Remove common subexprs |
| addPass(PM, createSCCPPass()); // Constant prop with SCCP |
| |
| // Run instcombine after redundancy elimination to exploit opportunities |
| // opened up by them. |
| addPass(PM, createInstructionCombiningPass()); |
| addPass(PM, createIndVarSimplifyPass()); // Canonicalize indvars |
| addPass(PM, createAggressiveDCEPass()); // SSA based 'Aggressive DCE' |
| addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs |
| addPass(PM, createDeadTypeEliminationPass()); // Eliminate dead types |
| addPass(PM, createConstantMergePass()); // Merge dup global constants |
| } |
| |
| |
| 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) { |
| std::cerr << argv[0] << ": " << E.getMessage() << "\n"; |
| return 1; |
| } |
| |
| if (M.get() == 0) { |
| std::cerr << argv[0] << ": assembly didn't read correctly.\n"; |
| return 1; |
| } |
| |
| std::ostream *Out = 0; |
| if (OutputFilename == "") { // Didn't specify an output filename? |
| if (InputFilename == "-") { |
| OutputFilename = "-"; |
| } else { |
| 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"; |
| } |
| } |
| |
| if (OutputFilename == "-") |
| Out = &std::cout; |
| else { |
| Out = new std::ofstream(OutputFilename.c_str(), std::ios::out); |
| |
| // Make sure that the Out file gets unlinked from the disk if we get a |
| // signal |
| RemoveFileOnSignal(OutputFilename); |
| } |
| |
| |
| if (!Out->good()) { |
| std::cerr << argv[0] << ": error opening " << OutputFilename << "!\n"; |
| return 1; |
| } |
| |
| // In addition to just parsing the input from GCC, we also want to spiff it up |
| // a little bit. Do this now. |
| // |
| PassManager Passes; |
| |
| // Add an appropriate TargetData instance for this module... |
| Passes.add(new TargetData("gccas", M.get())); |
| |
| // Add all of the transformation passes to the pass manager to do the cleanup |
| // and optimization of the GCC output. |
| // |
| AddConfiguredTransformationPasses(Passes); |
| |
| // Write bytecode to file... |
| Passes.add(new WriteBytecodePass(Out)); |
| |
| // Run our queue of passes all at once now, efficiently. |
| Passes.run(*M.get()); |
| |
| if (Out != &std::cout) delete Out; |
| return 0; |
| } |