1 //===----------------------------------------------------------------------===//
2 // LLVM 'GCCAS' UTILITY
4 // This utility is designed to be used by the GCC frontend for creating
5 // bytecode files from it's intermediate llvm assembly. The requirements for
6 // this utility 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/Assembly/Parser.h"
13 #include "llvm/Transforms/RaisePointerReferences.h"
14 #include "llvm/Transforms/IPO.h"
15 #include "llvm/Transforms/Scalar.h"
16 #include "llvm/Analysis/LoadValueNumbering.h"
17 #include "llvm/Analysis/Verifier.h"
18 #include "llvm/Bytecode/WriteBytecodePass.h"
19 #include "llvm/Target/TargetData.h"
20 #include "Support/CommandLine.h"
21 #include "Support/Signals.h"
26 // FIXME: This should eventually be parameterized...
27 TargetData TD("gccas target");
30 InputFilename(cl::Positional,cl::desc("<input llvm assembly>"),cl::init("-"));
33 OutputFilename("o", cl::desc("Override output filename"),
34 cl::value_desc("filename"));
37 RunNPasses("stopAfterNPasses",
38 cl::desc("Only run the first N passes of gccas"), cl::Hidden,
39 cl::value_desc("# passes"));
42 Verify("verify", cl::desc("Verify each pass result"));
46 static inline void addPass(PassManager &PM, Pass *P) {
47 static int NumPassesCreated = 0;
49 // If we haven't already created the number of passes that was requested...
50 if (RunNPasses == 0 || RunNPasses > NumPassesCreated) {
51 // Add the pass to the pass manager...
54 // If we are verifying all of the intermediate steps, add the verifier...
55 if (Verify) PM.add(createVerifierPass());
57 // Keep track of how many passes we made for -stopAfterNPasses
60 delete P; // We don't want this pass to run, just delete it now
65 void AddConfiguredTransformationPasses(PassManager &PM) {
66 if (Verify) PM.add(createVerifierPass());
68 addPass(PM, createFunctionResolvingPass()); // Resolve (...) functions
69 addPass(PM, createGlobalDCEPass()); // Kill unused uinit g-vars
70 addPass(PM, createDeadTypeEliminationPass()); // Eliminate dead types
71 addPass(PM, createConstantMergePass()); // Merge dup global constants
72 addPass(PM, createVerifierPass()); // Verify that input is correct
73 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
74 addPass(PM, createDeadInstEliminationPass()); // Remove Dead code/vars
75 addPass(PM, createRaiseAllocationsPass()); // call %malloc -> malloc inst
76 addPass(PM, createIndVarSimplifyPass()); // Simplify indvars
77 addPass(PM, createRaisePointerReferencesPass(TD));// Recover type information
78 addPass(PM, createInstructionCombiningPass()); // Combine silly seq's
79 addPass(PM, createPromoteMemoryToRegister()); // Promote alloca's to regs
80 addPass(PM, createReassociatePass()); // Reassociate expressions
81 //addPass(PM, createCorrelatedExpressionEliminationPass());// Kill corr branches
82 addPass(PM, createInstructionCombiningPass()); // Combine silly seq's
83 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
84 addPass(PM, createLICMPass()); // Hoist loop invariants
85 addPass(PM, createLoadValueNumberingPass()); // GVN for load instructions
86 addPass(PM, createGCSEPass()); // Remove common subexprs
87 addPass(PM, createSCCPPass()); // Constant prop with SCCP
89 // Run instcombine after redundancy elimination to exploit opportunities
91 addPass(PM, createInstructionCombiningPass());
92 addPass(PM, createAggressiveDCEPass()); // SSA based 'Agressive DCE'
93 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
97 int main(int argc, char **argv) {
98 cl::ParseCommandLineOptions(argc, argv, " llvm .s -> .o assembler for GCC\n");
100 std::auto_ptr<Module> M;
102 // Parse the file now...
103 M.reset(ParseAssemblyFile(InputFilename));
104 } catch (const ParseException &E) {
105 std::cerr << argv[0] << ": " << E.getMessage() << "\n";
110 std::cerr << argv[0] << ": assembly didn't read correctly.\n";
114 std::ostream *Out = 0;
115 if (OutputFilename == "") { // Didn't specify an output filename?
116 if (InputFilename == "-") {
117 OutputFilename = "-";
119 std::string IFN = InputFilename;
120 int Len = IFN.length();
121 if (IFN[Len-2] == '.' && IFN[Len-1] == 's') { // Source ends in .s?
122 OutputFilename = std::string(IFN.begin(), IFN.end()-2);
124 OutputFilename = IFN; // Append a .o to it
126 OutputFilename += ".o";
130 if (OutputFilename == "-")
133 Out = new std::ofstream(OutputFilename.c_str(), std::ios::out);
135 // Make sure that the Out file gets unlink'd from the disk if we get a
137 RemoveFileOnSignal(OutputFilename);
142 std::cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
146 // In addition to just parsing the input from GCC, we also want to spiff it up
147 // a little bit. Do this now.
151 // Add all of the transformation passes to the pass manager to do the cleanup
152 // and optimization of the GCC output.
154 AddConfiguredTransformationPasses(Passes);
156 // Write bytecode to file...
157 Passes.add(new WriteBytecodePass(Out));
159 // Run our queue of passes all at once now, efficiently.
160 Passes.run(*M.get());
162 if (Out != &std::cout) delete Out;