YouCompleteMe/cpp/llvm/tools/llvm-ld/Optimize.cpp
2012-07-05 17:51:06 -07:00

131 lines
4.5 KiB
C++

//===- Optimize.cpp - Optimize a complete program -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements all optimization of the linked module for llvm-ld.
//
//===----------------------------------------------------------------------===//
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/PassNameParser.h"
#include "llvm/Support/PluginLoader.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
#include "llvm/Transforms/Scalar.h"
using namespace llvm;
// Pass Name Options as generated by the PassNameParser
static cl::list<const PassInfo*, bool, PassNameParser>
OptimizationList(cl::desc("Optimizations available:"));
//Don't verify at the end
static cl::opt<bool> DontVerify("disable-verify", cl::ReallyHidden);
static cl::opt<bool> DisableInline("disable-inlining",
cl::desc("Do not run the inliner pass"));
static cl::opt<bool>
DisableOptimizations("disable-opt",
cl::desc("Do not run any optimization passes"));
static cl::opt<bool> DisableInternalize("disable-internalize",
cl::desc("Do not mark all symbols as internal"));
static cl::opt<bool> VerifyEach("verify-each",
cl::desc("Verify intermediate results of all passes"));
static cl::alias ExportDynamic("export-dynamic",
cl::aliasopt(DisableInternalize),
cl::desc("Alias for -disable-internalize"));
static cl::opt<bool> Strip("strip-all",
cl::desc("Strip all symbol info from executable"));
static cl::alias A0("s", cl::desc("Alias for --strip-all"),
cl::aliasopt(Strip));
static cl::opt<bool> StripDebug("strip-debug",
cl::desc("Strip debugger symbol info from executable"));
static cl::alias A1("S", cl::desc("Alias for --strip-debug"),
cl::aliasopt(StripDebug));
// A utility function that adds a pass to the pass manager but will also add
// a verifier pass after if we're supposed to verify.
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 (VerifyEach)
PM.add(createVerifierPass());
}
namespace llvm {
/// Optimize - Perform link time optimizations. This will run the scalar
/// optimizations, any loaded plugin-optimization modules, and then the
/// inter-procedural optimizations if applicable.
void Optimize(Module *M) {
// Instantiate the pass manager to organize the passes.
PassManager Passes;
// If we're verifying, start off with a verification pass.
if (VerifyEach)
Passes.add(createVerifierPass());
// Add an appropriate TargetData instance for this module...
addPass(Passes, new TargetData(M));
if (!DisableOptimizations)
PassManagerBuilder().populateLTOPassManager(Passes, !DisableInternalize,
!DisableInline);
// If the -s or -S command line options were specified, strip the symbols out
// of the resulting program to make it smaller. -s and -S are GNU ld options
// that we are supporting; they alias -strip-all and -strip-debug.
if (Strip || StripDebug)
addPass(Passes, createStripSymbolsPass(StripDebug && !Strip));
// Create a new optimization pass for each one specified on the command line
std::auto_ptr<TargetMachine> target;
for (unsigned i = 0; i < OptimizationList.size(); ++i) {
const PassInfo *Opt = OptimizationList[i];
if (Opt->getNormalCtor())
addPass(Passes, Opt->getNormalCtor()());
else
errs() << "llvm-ld: cannot create pass: " << Opt->getPassName()
<< "\n";
}
// The user's passes may leave cruft around. Clean up after them them but
// only if we haven't got DisableOptimizations set
if (!DisableOptimizations) {
addPass(Passes, createInstructionCombiningPass());
addPass(Passes, createCFGSimplificationPass());
addPass(Passes, createAggressiveDCEPass());
addPass(Passes, createGlobalDCEPass());
}
// Make sure everything is still good.
if (!DontVerify)
Passes.add(createVerifierPass());
// Run our queue of passes all at once now, efficiently.
Passes.run(*M);
}
}