llvm-6502/lib/CodeGen/LLVMTargetMachine.cpp
Dan Gohman 6f65d79750 Add a new pass for doing late hoisting of floating-point and vector
constants out of loops. These aren't covered by the regular LICM
pass, because in LLVM IR constants don't require separate
instructions. They're not always covered by the MachineLICM pass
either, because it doesn't know how to unfold folded constant-pool
loads. This is somewhat experimental at this point, and off by
default.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82076 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-16 20:25:11 +00:00

346 lines
12 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/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/Target/TargetRegistry.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FormattedStream.h"
using namespace llvm;
namespace llvm {
bool EnableFastISel;
}
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> PrintEmittedAsm("print-emitted-asm", cl::Hidden,
cl::desc("Dump emitter generated instructions as assembly"));
static cl::opt<bool> PrintGCInfo("print-gc", cl::Hidden,
cl::desc("Dump garbage collector data"));
static cl::opt<bool> HoistConstants("hoist-constants", cl::Hidden,
cl::desc("Hoist constants out of loops"));
static cl::opt<bool> VerifyMachineCode("verify-machineinstrs", cl::Hidden,
cl::desc("Verify generated machine code"),
cl::init(getenv("LLVM_VERIFY_MACHINEINSTRS")!=NULL));
// When this works it will be on by default.
static cl::opt<bool>
DisablePostRAScheduler("disable-post-RA-scheduler",
cl::desc("Disable scheduling after register allocation"),
cl::init(true));
// 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"));
LLVMTargetMachine::LLVMTargetMachine(const Target &T,
const std::string &TargetTriple)
: TargetMachine(T) {
AsmInfo = T.createAsmInfo(TargetTriple);
}
FileModel::Model
LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
formatted_raw_ostream &Out,
CodeGenFileType FileType,
CodeGenOpt::Level OptLevel) {
// Add common CodeGen passes.
if (addCommonCodeGenPasses(PM, OptLevel))
return FileModel::Error;
// Fold redundant debug labels.
PM.add(createDebugLabelFoldingPass());
if (PrintMachineCode)
PM.add(createMachineFunctionPrinterPass(errs()));
if (addPreEmitPass(PM, OptLevel) && PrintMachineCode)
PM.add(createMachineFunctionPrinterPass(errs()));
if (OptLevel != CodeGenOpt::None)
PM.add(createCodePlacementOptPass());
switch (FileType) {
default:
break;
case TargetMachine::AssemblyFile:
if (addAssemblyEmitter(PM, OptLevel, getAsmVerbosityDefault(), Out))
return FileModel::Error;
return FileModel::AsmFile;
case TargetMachine::ObjectFile:
if (getMachOWriterInfo())
return FileModel::MachOFile;
else if (getELFWriterInfo())
return FileModel::ElfFile;
}
return FileModel::Error;
}
bool LLVMTargetMachine::addAssemblyEmitter(PassManagerBase &PM,
CodeGenOpt::Level OptLevel,
bool Verbose,
formatted_raw_ostream &Out) {
FunctionPass *Printer =
getTarget().createAsmPrinter(Out, *this, getMCAsmInfo(), Verbose);
if (!Printer)
return true;
PM.add(Printer);
return false;
}
/// addPassesToEmitFileFinish - If the passes to emit the specified file had to
/// be split up (e.g., to add an object writer pass), this method can be used to
/// finish up adding passes to emit the file, if necessary.
bool LLVMTargetMachine::addPassesToEmitFileFinish(PassManagerBase &PM,
MachineCodeEmitter *MCE,
CodeGenOpt::Level OptLevel) {
if (MCE)
addSimpleCodeEmitter(PM, OptLevel, *MCE);
if (PrintEmittedAsm)
addAssemblyEmitter(PM, OptLevel, true, ferrs());
PM.add(createGCInfoDeleter());
return false; // success!
}
/// addPassesToEmitFileFinish - If the passes to emit the specified file had to
/// be split up (e.g., to add an object writer pass), this method can be used to
/// finish up adding passes to emit the file, if necessary.
bool LLVMTargetMachine::addPassesToEmitFileFinish(PassManagerBase &PM,
JITCodeEmitter *JCE,
CodeGenOpt::Level OptLevel) {
if (JCE)
addSimpleCodeEmitter(PM, OptLevel, *JCE);
if (PrintEmittedAsm)
addAssemblyEmitter(PM, OptLevel, true, ferrs());
PM.add(createGCInfoDeleter());
return false; // success!
}
/// addPassesToEmitFileFinish - If the passes to emit the specified file had to
/// be split up (e.g., to add an object writer pass), this method can be used to
/// finish up adding passes to emit the file, if necessary.
bool LLVMTargetMachine::addPassesToEmitFileFinish(PassManagerBase &PM,
ObjectCodeEmitter *OCE,
CodeGenOpt::Level OptLevel) {
if (OCE)
addSimpleCodeEmitter(PM, OptLevel, *OCE);
if (PrintEmittedAsm)
addAssemblyEmitter(PM, OptLevel, true, ferrs());
PM.add(createGCInfoDeleter());
return false; // success!
}
/// addPassesToEmitMachineCode - Add passes to the specified pass manager to
/// get machine code emitted. This uses a MachineCodeEmitter 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,
MachineCodeEmitter &MCE,
CodeGenOpt::Level OptLevel) {
// Add common CodeGen passes.
if (addCommonCodeGenPasses(PM, OptLevel))
return true;
if (addPreEmitPass(PM, OptLevel) && PrintMachineCode)
PM.add(createMachineFunctionPrinterPass(errs()));
addCodeEmitter(PM, OptLevel, MCE);
if (PrintEmittedAsm)
addAssemblyEmitter(PM, OptLevel, true, ferrs());
PM.add(createGCInfoDeleter());
return false; // success!
}
/// addPassesToEmitMachineCode - Add passes to the specified pass manager to
/// get machine code emitted. This uses a MachineCodeEmitter 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) {
// Add common CodeGen passes.
if (addCommonCodeGenPasses(PM, OptLevel))
return true;
if (addPreEmitPass(PM, OptLevel) && PrintMachineCode)
PM.add(createMachineFunctionPrinterPass(errs()));
addCodeEmitter(PM, OptLevel, JCE);
if (PrintEmittedAsm)
addAssemblyEmitter(PM, OptLevel, true, ferrs());
PM.add(createGCInfoDeleter());
return false; // success!
}
static void printAndVerify(PassManagerBase &PM,
bool allowDoubleDefs = false) {
if (PrintMachineCode)
PM.add(createMachineFunctionPrinterPass(errs()));
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.
// Run loop strength reduction before anything else.
if (OptLevel != CodeGenOpt::None) {
PM.add(createLoopStrengthReducePass(getTargetLowering()));
if (PrintLSR)
PM.add(createPrintFunctionPass("\n\n*** Code after LSR ***\n", &errs()));
}
// 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
PM.add(createDwarfEHPass(getTargetLowering(), OptLevel==CodeGenOpt::None));
PM.add(createSjLjEHPass(getTargetLowering()));
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) {
if (HoistConstants)
PM.add(createCodeGenLICMPass());
PM.add(createCodeGenPreparePass(getTargetLowering()));
}
PM.add(createStackProtectorPass(getTargetLowering()));
if (PrintISelInput)
PM.add(createPrintFunctionPass("\n\n"
"*** Final LLVM Code input to ISel ***\n",
&errs()));
// 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, /* allowDoubleDefs= */ true);
if (OptLevel != CodeGenOpt::None) {
PM.add(createMachineLICMPass());
PM.add(createMachineSinkingPass());
printAndVerify(PM, /* allowDoubleDefs= */ true);
}
// Run pre-ra passes.
if (addPreRegAlloc(PM, OptLevel))
printAndVerify(PM, /* allowDoubleDefs= */ true);
// Perform register allocation.
PM.add(createRegisterAllocator());
// Perform stack slot coloring.
if (OptLevel != CodeGenOpt::None)
// FIXME: Re-enable coloring with register when it's capable of adding
// kill markers.
PM.add(createStackSlotColoringPass(false));
printAndVerify(PM); // Print the register-allocated code
// Run post-ra passes.
if (addPostRegAlloc(PM, OptLevel))
printAndVerify(PM);
PM.add(createLowerSubregsPass());
printAndVerify(PM);
// Insert prolog/epilog code. Eliminate abstract frame index references...
PM.add(createPrologEpilogCodeInserter());
printAndVerify(PM);
// Second pass scheduler.
if (OptLevel != CodeGenOpt::None && !DisablePostRAScheduler) {
PM.add(createPostRAScheduler());
printAndVerify(PM);
}
// Branch folding must be run after regalloc and prolog/epilog insertion.
if (OptLevel != CodeGenOpt::None) {
PM.add(createBranchFoldingPass(getEnableTailMergeDefault()));
printAndVerify(PM);
}
PM.add(createGCMachineCodeAnalysisPass());
printAndVerify(PM);
if (PrintGCInfo)
PM.add(createGCInfoPrinter(errs()));
return false;
}