1 //===----------------------------------------------------------------------===//
2 // LLVM 'GCCAS' UTILITY
4 // This utility is designed to be used by the GCC frontend for creating bytecode
5 // files from its intermediate LLVM assembly. The requirements for this utility
6 // are thus slightly different than that of the standard `as' util.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/Module.h"
11 #include "llvm/PassManager.h"
12 #include "llvm/Analysis/LoadValueNumbering.h"
13 #include "llvm/Analysis/Verifier.h"
14 #include "llvm/Assembly/Parser.h"
15 #include "llvm/Bytecode/WriteBytecodePass.h"
16 #include "llvm/Target/TargetData.h"
17 #include "llvm/Transforms/IPO.h"
18 #include "llvm/Transforms/Scalar.h"
19 #include "Support/CommandLine.h"
20 #include "Support/Signals.h"
26 InputFilename(cl::Positional,cl::desc("<input llvm assembly>"),cl::init("-"));
29 OutputFilename("o", cl::desc("Override output filename"),
30 cl::value_desc("filename"));
33 Verify("verify", cl::desc("Verify each pass result"));
36 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
40 static inline void addPass(PassManager &PM, Pass *P) {
41 // Add the pass to the pass manager...
44 // If we are verifying all of the intermediate steps, add the verifier...
45 if (Verify) PM.add(createVerifierPass());
49 void AddConfiguredTransformationPasses(PassManager &PM) {
50 PM.add(createVerifierPass()); // Verify that input is correct
51 addPass(PM, createLowerSetJmpPass()); // Lower llvm.setjmp/.longjmp
52 addPass(PM, createFunctionResolvingPass()); // Resolve (...) functions
53 addPass(PM, createRaiseAllocationsPass()); // call %malloc -> malloc inst
54 addPass(PM, createGlobalDCEPass()); // Remove unused globals
55 addPass(PM, createPruneEHPass()); // Remove dead EH info
58 addPass(PM, createFunctionInliningPass()); // Inline small functions
60 addPass(PM, createInstructionCombiningPass()); // Cleanup code for raise
61 // FIXME: levelraise pass disabled until it can be rewritten at a later date.
62 //addPass(PM, createRaisePointerReferencesPass());// Recover type information
63 addPass(PM, createTailDuplicationPass()); // Simplify cfg by copying code
64 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
65 addPass(PM, createScalarReplAggregatesPass()); // Break up aggregate allocas
66 addPass(PM, createTailCallEliminationPass()); // Eliminate tail calls
67 addPass(PM, createInstructionCombiningPass()); // Combine silly seq's
69 addPass(PM, createReassociatePass()); // Reassociate expressions
70 addPass(PM, createInstructionCombiningPass()); // Combine silly seq's
71 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
72 addPass(PM, createLICMPass()); // Hoist loop invariants
73 addPass(PM, createLoadValueNumberingPass()); // GVN for load instructions
74 addPass(PM, createGCSEPass()); // Remove common subexprs
75 addPass(PM, createSCCPPass()); // Constant prop with SCCP
77 // Run instcombine after redundancy elimination to exploit opportunities
79 addPass(PM, createInstructionCombiningPass());
80 addPass(PM, createIndVarSimplifyPass()); // Canonicalize indvars
81 addPass(PM, createAggressiveDCEPass()); // SSA based 'Aggressive DCE'
82 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
83 addPass(PM, createDeadTypeEliminationPass()); // Eliminate dead types
84 addPass(PM, createConstantMergePass()); // Merge dup global constants
88 int main(int argc, char **argv) {
89 cl::ParseCommandLineOptions(argc, argv, " llvm .s -> .o assembler for GCC\n");
91 std::auto_ptr<Module> M;
93 // Parse the file now...
94 M.reset(ParseAssemblyFile(InputFilename));
95 } catch (const ParseException &E) {
96 std::cerr << argv[0] << ": " << E.getMessage() << "\n";
101 std::cerr << argv[0] << ": assembly didn't read correctly.\n";
105 std::ostream *Out = 0;
106 if (OutputFilename == "") { // Didn't specify an output filename?
107 if (InputFilename == "-") {
108 OutputFilename = "-";
110 std::string IFN = InputFilename;
111 int Len = IFN.length();
112 if (IFN[Len-2] == '.' && IFN[Len-1] == 's') { // Source ends in .s?
113 OutputFilename = std::string(IFN.begin(), IFN.end()-2);
115 OutputFilename = IFN; // Append a .o to it
117 OutputFilename += ".o";
121 if (OutputFilename == "-")
124 Out = new std::ofstream(OutputFilename.c_str(), std::ios::out);
126 // Make sure that the Out file gets unlinked from the disk if we get a
128 RemoveFileOnSignal(OutputFilename);
133 std::cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
137 // In addition to just parsing the input from GCC, we also want to spiff it up
138 // a little bit. Do this now.
142 // Add an appropriate TargetData instance for this module...
143 Passes.add(new TargetData("gccas", M.get()));
145 // Add all of the transformation passes to the pass manager to do the cleanup
146 // and optimization of the GCC output.
148 AddConfiguredTransformationPasses(Passes);
150 // Write bytecode to file...
151 Passes.add(new WriteBytecodePass(Out));
153 // Run our queue of passes all at once now, efficiently.
154 Passes.run(*M.get());
156 if (Out != &std::cout) delete Out;