1 //===-- gccas.cpp - The "optimizing assembler" used by the GCC frontend ---===//
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 utility is designed to be used by the GCC frontend for creating bytecode
11 // files from its intermediate LLVM assembly. The requirements for this utility
12 // are thus slightly different than that of the standard `as' util.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Module.h"
17 #include "llvm/PassManager.h"
18 #include "llvm/Analysis/LoadValueNumbering.h"
19 #include "llvm/Analysis/Verifier.h"
20 #include "llvm/Assembly/Parser.h"
21 #include "llvm/Bytecode/WriteBytecodePass.h"
22 #include "llvm/Target/TargetData.h"
23 #include "llvm/Transforms/IPO.h"
24 #include "llvm/Transforms/Scalar.h"
25 #include "llvm/Support/CommandLine.h"
26 #include "llvm/Support/Streams.h"
27 #include "llvm/Support/ManagedStatic.h"
28 #include "llvm/System/Signals.h"
36 InputFilename(cl::Positional,cl::desc("<input llvm assembly>"),cl::init("-"));
39 OutputFilename("o", cl::desc("Override output filename"),
40 cl::value_desc("filename"));
43 Verify("verify", cl::desc("Verify each pass result"));
46 DisableInline("disable-inlining", cl::desc("Do not run the inliner pass"));
49 DisableOptimizations("disable-opt",
50 cl::desc("Do not run any optimization passes"));
53 StripDebug("strip-debug",
54 cl::desc("Strip debugger symbol info from translation unit"));
57 NoCompress("disable-compression", cl::init(true),
58 cl::desc("Don't compress the generated bytecode"));
60 cl::opt<bool> TF("traditional-format", cl::Hidden,
61 cl::desc("Compatibility option: ignored"));
65 static inline void addPass(PassManager &PM, Pass *P) {
66 // Add the pass to the pass manager...
69 // If we are verifying all of the intermediate steps, add the verifier...
70 if (Verify) PM.add(createVerifierPass());
74 void AddConfiguredTransformationPasses(PassManager &PM) {
75 PM.add(createVerifierPass()); // Verify that input is correct
77 addPass(PM, createLowerSetJmpPass()); // Lower llvm.setjmp/.longjmp
78 addPass(PM, createFunctionResolvingPass()); // Resolve (...) functions
80 // If the -strip-debug command line option was specified, do it.
82 addPass(PM, createStripSymbolsPass(true));
84 if (DisableOptimizations) return;
86 addPass(PM, createRaiseAllocationsPass()); // call %malloc -> malloc inst
87 addPass(PM, createCFGSimplificationPass()); // Clean up disgusting code
88 addPass(PM, createPromoteMemoryToRegisterPass());// Kill useless allocas
89 addPass(PM, createGlobalOptimizerPass()); // Optimize out global vars
90 addPass(PM, createGlobalDCEPass()); // Remove unused fns and globs
91 addPass(PM, createIPConstantPropagationPass());// IP Constant Propagation
92 addPass(PM, createDeadArgEliminationPass()); // Dead argument elimination
93 addPass(PM, createInstructionCombiningPass()); // Clean up after IPCP & DAE
94 addPass(PM, createCFGSimplificationPass()); // Clean up after IPCP & DAE
96 addPass(PM, createPruneEHPass()); // Remove dead EH info
99 addPass(PM, createFunctionInliningPass()); // Inline small functions
100 addPass(PM, createArgumentPromotionPass()); // Scalarize uninlined fn args
102 addPass(PM, createRaisePointerReferencesPass());// Recover type information
103 addPass(PM, createTailDuplicationPass()); // Simplify cfg by copying code
104 addPass(PM, createInstructionCombiningPass()); // Cleanup for scalarrepl.
105 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
106 addPass(PM, createScalarReplAggregatesPass()); // Break up aggregate allocas
107 addPass(PM, createInstructionCombiningPass()); // Combine silly seq's
108 addPass(PM, createCondPropagationPass()); // Propagate conditionals
110 addPass(PM, createTailCallEliminationPass()); // Eliminate tail calls
111 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
112 addPass(PM, createReassociatePass()); // Reassociate expressions
113 addPass(PM, createLICMPass()); // Hoist loop invariants
114 addPass(PM, createLoopUnswitchPass()); // Unswitch loops.
115 addPass(PM, createInstructionCombiningPass()); // Clean up after LICM/reassoc
116 addPass(PM, createIndVarSimplifyPass()); // Canonicalize indvars
117 addPass(PM, createLoopUnrollPass()); // Unroll small loops
118 addPass(PM, createInstructionCombiningPass()); // Clean up after the unroller
119 addPass(PM, createLoadValueNumberingPass()); // GVN for load instructions
120 addPass(PM, createGCSEPass()); // Remove common subexprs
121 addPass(PM, createSCCPPass()); // Constant prop with SCCP
123 // Run instcombine after redundancy elimination to exploit opportunities
124 // opened up by them.
125 addPass(PM, createInstructionCombiningPass());
126 addPass(PM, createCondPropagationPass()); // Propagate conditionals
128 addPass(PM, createDeadStoreEliminationPass()); // Delete dead stores
129 addPass(PM, createAggressiveDCEPass()); // SSA based 'Aggressive DCE'
130 addPass(PM, createCFGSimplificationPass()); // Merge & remove BBs
131 addPass(PM, createSimplifyLibCallsPass()); // Library Call Optimizations
132 addPass(PM, createDeadTypeEliminationPass()); // Eliminate dead types
133 addPass(PM, createConstantMergePass()); // Merge dup global constants
137 int main(int argc, char **argv) {
138 llvm_shutdown_obj X; // Call llvm_shutdown() on exit.
140 cl::ParseCommandLineOptions(argc, argv,
141 " llvm .s -> .o assembler for GCC\n");
142 sys::PrintStackTraceOnErrorSignal();
145 std::auto_ptr<Module> M(ParseAssemblyFile(InputFilename,&Err));
147 cerr << argv[0] << ": " << Err.getMessage() << "\n";
151 std::ostream *Out = 0;
152 if (OutputFilename == "") { // Didn't specify an output filename?
153 if (InputFilename == "-") {
154 OutputFilename = "-";
156 std::string IFN = InputFilename;
157 int Len = IFN.length();
158 if (IFN[Len-2] == '.' && IFN[Len-1] == 's') { // Source ends in .s?
159 OutputFilename = std::string(IFN.begin(), IFN.end()-2);
161 OutputFilename = IFN; // Append a .o to it
163 OutputFilename += ".o";
167 if (OutputFilename == "-")
168 // FIXME: cout is not binary!
171 std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
173 Out = new std::ofstream(OutputFilename.c_str(), io_mode);
175 // Make sure that the Out file gets unlinked from the disk if we get a
177 sys::RemoveFileOnSignal(sys::Path(OutputFilename));
182 cerr << argv[0] << ": error opening " << OutputFilename << "!\n";
186 // In addition to just parsing the input from GCC, we also want to spiff
187 // it up a little bit. Do this now.
190 // Add an appropriate TargetData instance for this module...
191 Passes.add(new TargetData(M.get()));
193 // Add all of the transformation passes to the pass manager to do the
194 // cleanup and optimization of the GCC output.
195 AddConfiguredTransformationPasses(Passes);
197 // Make sure everything is still good.
198 Passes.add(createVerifierPass());
200 // Write bytecode to file...
202 Passes.add(new WriteBytecodePass(&L,false,!NoCompress));
204 // Run our queue of passes all at once now, efficiently.
205 Passes.run(*M.get());
207 if (Out != &std::cout) delete Out;
209 } catch (const std::string& msg) {
210 cerr << argv[0] << ": " << msg << "\n";
212 cerr << argv[0] << ": Unexpected unknown exception occurred.\n";