llvm-6502/lib/CodeGen/LLVMTargetMachine.cpp
2010-02-12 23:12:47 +00:00

387 lines
14 KiB
C++

//===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the LLVMTargetMachine class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetMachine.h"
#include "llvm/PassManager.h"
#include "llvm/Pass.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/MachineFunctionAnalysis.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormattedStream.h"
using namespace llvm;
namespace llvm {
bool EnableFastISel;
}
static cl::opt<bool> DisablePostRA("disable-post-ra", cl::Hidden,
cl::desc("Disable Post Regalloc"));
static cl::opt<bool> DisableBranchFold("disable-branch-fold", cl::Hidden,
cl::desc("Disable branch folding"));
static cl::opt<bool> DisableTailDuplicate("disable-tail-duplicate", cl::Hidden,
cl::desc("Disable tail duplication"));
static cl::opt<bool> DisableEarlyTailDup("disable-early-taildup", cl::Hidden,
cl::desc("Disable pre-register allocation tail duplication"));
static cl::opt<bool> DisableCodePlace("disable-code-place", cl::Hidden,
cl::desc("Disable code placement"));
static cl::opt<bool> DisableSSC("disable-ssc", cl::Hidden,
cl::desc("Disable Stack Slot Coloring"));
static cl::opt<bool> DisableMachineLICM("disable-machine-licm", cl::Hidden,
cl::desc("Disable Machine LICM"));
static cl::opt<bool> DisableMachineSink("disable-machine-sink", cl::Hidden,
cl::desc("Disable Machine Sinking"));
static cl::opt<bool> DisableLSR("disable-lsr", cl::Hidden,
cl::desc("Disable Loop Strength Reduction Pass"));
static cl::opt<bool> DisableCGP("disable-cgp", cl::Hidden,
cl::desc("Disable Codegen Prepare"));
static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden,
cl::desc("Print LLVM IR produced by the loop-reduce pass"));
static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden,
cl::desc("Print LLVM IR input to isel pass"));
static cl::opt<bool> PrintGCInfo("print-gc", cl::Hidden,
cl::desc("Dump garbage collector data"));
static cl::opt<bool> VerifyMachineCode("verify-machineinstrs", cl::Hidden,
cl::desc("Verify generated machine code"),
cl::init(getenv("LLVM_VERIFY_MACHINEINSTRS")!=NULL));
static cl::opt<cl::boolOrDefault>
AsmVerbose("asm-verbose", cl::desc("Add comments to directives."),
cl::init(cl::BOU_UNSET));
static bool getVerboseAsm() {
switch (AsmVerbose) {
default:
case cl::BOU_UNSET: return TargetMachine::getAsmVerbosityDefault();
case cl::BOU_TRUE: return true;
case cl::BOU_FALSE: return false;
}
}
// Enable or disable FastISel. Both options are needed, because
// FastISel is enabled by default with -fast, and we wish to be
// able to enable or disable fast-isel independently from -O0.
static cl::opt<cl::boolOrDefault>
EnableFastISelOption("fast-isel", cl::Hidden,
cl::desc("Enable the \"fast\" instruction selector"));
// Enable or disable an experimental optimization to split GEPs
// and run a special GVN pass which does not examine loads, in
// an effort to factor out redundancy implicit in complex GEPs.
static cl::opt<bool> EnableSplitGEPGVN("split-gep-gvn", cl::Hidden,
cl::desc("Split GEPs and run no-load GVN"));
LLVMTargetMachine::LLVMTargetMachine(const Target &T,
const std::string &TargetTriple)
: TargetMachine(T) {
AsmInfo = T.createAsmInfo(TargetTriple);
}
// Set the default code model for the JIT for a generic target.
// FIXME: Is small right here? or .is64Bit() ? Large : Small?
void
LLVMTargetMachine::setCodeModelForJIT() {
setCodeModel(CodeModel::Small);
}
// Set the default code model for static compilation for a generic target.
void
LLVMTargetMachine::setCodeModelForStatic() {
setCodeModel(CodeModel::Small);
}
bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
formatted_raw_ostream &Out,
CodeGenFileType FileType,
CodeGenOpt::Level OptLevel) {
// Add common CodeGen passes.
if (addCommonCodeGenPasses(PM, OptLevel))
return true;
OwningPtr<MCContext> Context(new MCContext());
OwningPtr<MCStreamer> AsmStreamer;
formatted_raw_ostream *LegacyOutput;
switch (FileType) {
default: return true;
case CGFT_AssemblyFile: {
const MCAsmInfo &MAI = *getMCAsmInfo();
MCInstPrinter *InstPrinter =
getTarget().createMCInstPrinter(MAI.getAssemblerDialect(), MAI, Out);
AsmStreamer.reset(createAsmStreamer(*Context, Out, MAI,
getTargetData()->isLittleEndian(),
getVerboseAsm(), InstPrinter,
/*codeemitter*/0));
// Set the AsmPrinter's "O" to the output file.
LegacyOutput = &Out;
break;
}
case CGFT_ObjectFile: {
// Create the code emitter for the target if it exists. If not, .o file
// emission fails.
MCCodeEmitter *MCE = getTarget().createCodeEmitter(*this, *Context);
if (MCE == 0)
return true;
AsmStreamer.reset(createMachOStreamer(*Context, Out, MCE));
// Any output to the asmprinter's "O" stream is bad and needs to be fixed,
// force it to come out stderr.
// FIXME: this is horrible and leaks, eventually remove the raw_ostream from
// asmprinter.
LegacyOutput = new formatted_raw_ostream(errs());
break;
}
case CGFT_Null:
// The Null output is intended for use for performance analysis and testing,
// not real users.
AsmStreamer.reset(createNullStreamer(*Context));
// Any output to the asmprinter's "O" stream is bad and needs to be fixed,
// force it to come out stderr.
// FIXME: this is horrible and leaks, eventually remove the raw_ostream from
// asmprinter.
LegacyOutput = new formatted_raw_ostream(errs());
break;
}
// Create the AsmPrinter, which takes ownership of Context and AsmStreamer
// if successful.
FunctionPass *Printer =
getTarget().createAsmPrinter(*LegacyOutput, *this, *Context, *AsmStreamer,
getMCAsmInfo());
if (Printer == 0)
return true;
// If successful, createAsmPrinter took ownership of AsmStreamer and Context.
Context.take(); AsmStreamer.take();
PM.add(Printer);
// Make sure the code model is set.
setCodeModelForStatic();
PM.add(createGCInfoDeleter());
return false;
}
/// addPassesToEmitMachineCode - Add passes to the specified pass manager to
/// get machine code emitted. This uses a JITCodeEmitter object to handle
/// actually outputting the machine code and resolving things like the address
/// of functions. This method should returns true if machine code emission is
/// not supported.
///
bool LLVMTargetMachine::addPassesToEmitMachineCode(PassManagerBase &PM,
JITCodeEmitter &JCE,
CodeGenOpt::Level OptLevel) {
// Make sure the code model is set.
setCodeModelForJIT();
// Add common CodeGen passes.
if (addCommonCodeGenPasses(PM, OptLevel))
return true;
addCodeEmitter(PM, OptLevel, JCE);
PM.add(createGCInfoDeleter());
return false; // success!
}
static void printAndVerify(PassManagerBase &PM,
const char *Banner,
bool allowDoubleDefs = false) {
if (PrintMachineCode)
PM.add(createMachineFunctionPrinterPass(dbgs(), Banner));
if (VerifyMachineCode)
PM.add(createMachineVerifierPass(allowDoubleDefs));
}
/// addCommonCodeGenPasses - Add standard LLVM codegen passes used for both
/// emitting to assembly files or machine code output.
///
bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
CodeGenOpt::Level OptLevel) {
// Standard LLVM-Level Passes.
// Optionally, tun split-GEPs and no-load GVN.
if (EnableSplitGEPGVN) {
PM.add(createGEPSplitterPass());
PM.add(createGVNPass(/*NoPRE=*/false, /*NoLoads=*/true));
}
// Run loop strength reduction before anything else.
if (OptLevel != CodeGenOpt::None && !DisableLSR) {
PM.add(createLoopStrengthReducePass(getTargetLowering()));
if (PrintLSR)
PM.add(createPrintFunctionPass("\n\n*** Code after LSR ***\n", &dbgs()));
#ifndef NDEBUG
PM.add(createVerifierPass());
#endif
}
// Turn exception handling constructs into something the code generators can
// handle.
switch (getMCAsmInfo()->getExceptionHandlingType())
{
case ExceptionHandling::SjLj:
// SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both
// Dwarf EH prepare needs to be run after SjLj prepare. Otherwise,
// catch info can get misplaced when a selector ends up more than one block
// removed from the parent invoke(s). This could happen when a landing
// pad is shared by multiple invokes and is also a target of a normal
// edge from elsewhere.
PM.add(createSjLjEHPass(getTargetLowering()));
PM.add(createDwarfEHPass(getTargetLowering(), OptLevel==CodeGenOpt::None));
break;
case ExceptionHandling::Dwarf:
PM.add(createDwarfEHPass(getTargetLowering(), OptLevel==CodeGenOpt::None));
break;
case ExceptionHandling::None:
PM.add(createLowerInvokePass(getTargetLowering()));
break;
}
PM.add(createGCLoweringPass());
// Make sure that no unreachable blocks are instruction selected.
PM.add(createUnreachableBlockEliminationPass());
if (OptLevel != CodeGenOpt::None && !DisableCGP)
PM.add(createCodeGenPreparePass(getTargetLowering()));
PM.add(createStackProtectorPass(getTargetLowering()));
if (PrintISelInput)
PM.add(createPrintFunctionPass("\n\n"
"*** Final LLVM Code input to ISel ***\n",
&dbgs()));
// Standard Lower-Level Passes.
// Set up a MachineFunction for the rest of CodeGen to work on.
PM.add(new MachineFunctionAnalysis(*this, OptLevel));
// Enable FastISel with -fast, but allow that to be overridden.
if (EnableFastISelOption == cl::BOU_TRUE ||
(OptLevel == CodeGenOpt::None && EnableFastISelOption != cl::BOU_FALSE))
EnableFastISel = true;
// Ask the target for an isel.
if (addInstSelector(PM, OptLevel))
return true;
// Print the instruction selected machine code...
printAndVerify(PM, "After Instruction Selection",
/* allowDoubleDefs= */ true);
// Delete dead machine instructions regardless of optimization level.
PM.add(createDeadMachineInstructionElimPass());
printAndVerify(PM, "After codegen DCE pass",
/* allowDoubleDefs= */ true);
if (OptLevel != CodeGenOpt::None) {
PM.add(createOptimizeExtsPass());
PM.add(createOptimizePHIsPass());
if (!DisableMachineLICM)
PM.add(createMachineLICMPass());
if (!DisableMachineSink)
PM.add(createMachineSinkingPass());
printAndVerify(PM, "After MachineLICM and MachineSinking",
/* allowDoubleDefs= */ true);
}
// Pre-ra tail duplication.
if (OptLevel != CodeGenOpt::None && !DisableEarlyTailDup) {
PM.add(createTailDuplicatePass(true));
printAndVerify(PM, "After Pre-RegAlloc TailDuplicate",
/* allowDoubleDefs= */ true);
}
// Run pre-ra passes.
if (addPreRegAlloc(PM, OptLevel))
printAndVerify(PM, "After PreRegAlloc passes",
/* allowDoubleDefs= */ true);
// Perform register allocation.
PM.add(createRegisterAllocator());
printAndVerify(PM, "After Register Allocation");
// Perform stack slot coloring.
if (OptLevel != CodeGenOpt::None && !DisableSSC) {
// FIXME: Re-enable coloring with register when it's capable of adding
// kill markers.
PM.add(createStackSlotColoringPass(false));
printAndVerify(PM, "After StackSlotColoring");
}
// Run post-ra passes.
if (addPostRegAlloc(PM, OptLevel))
printAndVerify(PM, "After PostRegAlloc passes");
PM.add(createLowerSubregsPass());
printAndVerify(PM, "After LowerSubregs");
// Insert prolog/epilog code. Eliminate abstract frame index references...
PM.add(createPrologEpilogCodeInserter());
printAndVerify(PM, "After PrologEpilogCodeInserter");
// Run pre-sched2 passes.
if (addPreSched2(PM, OptLevel))
printAndVerify(PM, "After PreSched2 passes");
// Second pass scheduler.
if (OptLevel != CodeGenOpt::None && !DisablePostRA) {
PM.add(createPostRAScheduler(OptLevel));
printAndVerify(PM, "After PostRAScheduler");
}
// Branch folding must be run after regalloc and prolog/epilog insertion.
if (OptLevel != CodeGenOpt::None && !DisableBranchFold) {
PM.add(createBranchFoldingPass(getEnableTailMergeDefault()));
printAndVerify(PM, "After BranchFolding");
}
// Tail duplication.
if (OptLevel != CodeGenOpt::None && !DisableTailDuplicate) {
PM.add(createTailDuplicatePass(false));
printAndVerify(PM, "After TailDuplicate");
}
PM.add(createGCMachineCodeAnalysisPass());
if (PrintGCInfo)
PM.add(createGCInfoPrinter(dbgs()));
if (OptLevel != CodeGenOpt::None && !DisableCodePlace) {
PM.add(createCodePlacementOptPass());
printAndVerify(PM, "After CodePlacementOpt");
}
if (addPreEmitPass(PM, OptLevel))
printAndVerify(PM, "After PreEmit passes");
return false;
}