llvm/lib/Target/TargetMachine.cpp
2002-09-23 12:55:50 +00:00

240 lines
7.5 KiB
C++

//===-- TargetMachine.cpp - General Target Information ---------------------==//
//
// This file describes the general parts of a Target machine.
// This file also implements MachineInstrInfo and MachineCacheInfo.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/MachineInstrInfo.h"
#include "llvm/Target/MachineCacheInfo.h"
#include "llvm/CodeGen/PreSelection.h"
#include "llvm/CodeGen/StackSlots.h"
#include "llvm/CodeGen/InstrSelection.h"
#include "llvm/CodeGen/InstrScheduling.h"
#include "llvm/CodeGen/RegisterAllocation.h"
#include "llvm/CodeGen/PeepholeOpts.h"
#include "llvm/CodeGen/MachineCodeForMethod.h"
#include "llvm/CodeGen/MachineCodeForInstruction.h"
#include "llvm/Reoptimizer/Mapping/MappingInfo.h"
#include "llvm/Reoptimizer/Mapping/FInfo.h"
#include "llvm/Transforms/Scalar.h"
#include "Support/CommandLine.h"
#include "llvm/PassManager.h"
#include "llvm/Function.h"
#include "llvm/DerivedTypes.h"
//---------------------------------------------------------------------------
// Command line options to control choice of code generation passes.
//---------------------------------------------------------------------------
static cl::opt<bool> DisablePreSelect("nopreselect",
cl::desc("Disable preselection pass"));
static cl::opt<bool> DisableSched("nosched",
cl::desc("Disable local scheduling pass"));
static cl::opt<bool> DisablePeephole("nopeephole",
cl::desc("Disable peephole optimization pass"));
//---------------------------------------------------------------------------
// class TargetMachine
//
// Purpose:
// Machine description.
//
//---------------------------------------------------------------------------
// function TargetMachine::findOptimalStorageSize
//
// Purpose:
// This default implementation assumes that all sub-word data items use
// space equal to optSizeForSubWordData, and all other primitive data
// items use space according to the type.
//
unsigned int
TargetMachine::findOptimalStorageSize(const Type* ty) const
{
switch(ty->getPrimitiveID())
{
case Type::BoolTyID:
case Type::UByteTyID:
case Type::SByteTyID:
case Type::UShortTyID:
case Type::ShortTyID:
return optSizeForSubWordData;
default:
return DataLayout.getTypeSize(ty);
}
}
//===---------------------------------------------------------------------===//
// Default code generation passes.
//
// Native code generation for a specified target.
//===---------------------------------------------------------------------===//
class ConstructMachineCodeForFunction : public FunctionPass {
TargetMachine &Target;
public:
inline ConstructMachineCodeForFunction(TargetMachine &T) : Target(T) {}
const char *getPassName() const {
return "ConstructMachineCodeForFunction";
}
bool runOnFunction(Function &F) {
MachineCodeForMethod::construct(&F, Target);
return false;
}
};
struct FreeMachineCodeForFunction : public FunctionPass {
const char *getPassName() const { return "FreeMachineCodeForFunction"; }
static void freeMachineCode(Instruction &I) {
MachineCodeForInstruction::destroy(&I);
}
bool runOnFunction(Function &F) {
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
for (BasicBlock::iterator I = FI->begin(), E = FI->end(); I != E; ++I)
MachineCodeForInstruction::get(I).dropAllReferences();
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
for_each(FI->begin(), FI->end(), freeMachineCode);
return false;
}
};
// addPassesToEmitAssembly - This method controls the entire code generation
// process for the ultra sparc.
//
void
TargetMachine::addPassesToEmitAssembly(PassManager &PM, std::ostream &Out)
{
// Construct and initialize the MachineCodeForMethod object for this fn.
PM.add(new ConstructMachineCodeForFunction(*this));
//Insert empty stackslots in the stack frame of each function
//so %fp+offset-8 and %fp+offset-16 are empty slots now!
PM.add(createStackSlotsPass(*this));
// Specialize LLVM code for this target machine and then
// run basic dataflow optimizations on LLVM code.
if (!DisablePreSelect)
{
PM.add(createPreSelectionPass(*this));
/* PM.add(createReassociatePass()); */
PM.add(createGCSEPass());
PM.add(createLICMPass());
}
PM.add(createInstructionSelectionPass(*this));
if (!DisableSched)
PM.add(createInstructionSchedulingWithSSAPass(*this));
PM.add(getRegisterAllocator(*this));
PM.add(getPrologEpilogInsertionPass());
if (!DisablePeephole)
PM.add(createPeepholeOptsPass(*this));
PM.add(MappingInfoForFunction(Out));
// Output assembly language to the .s file. Assembly emission is split into
// two parts: Function output and Global value output. This is because
// function output is pipelined with all of the rest of code generation stuff,
// allowing machine code representations for functions to be free'd after the
// function has been emitted.
//
PM.add(getFunctionAsmPrinterPass(Out));
PM.add(new FreeMachineCodeForFunction()); // Free stuff no longer needed
// Emit Module level assembly after all of the functions have been processed.
PM.add(getModuleAsmPrinterPass(Out));
// Emit bytecode to the assembly file into its special section next
PM.add(getEmitBytecodeToAsmPass(Out));
PM.add(getFunctionInfo(Out));
}
//---------------------------------------------------------------------------
// class MachineInstructionInfo
// Interface to description of machine instructions
//---------------------------------------------------------------------------
/*ctor*/
MachineInstrInfo::MachineInstrInfo(const TargetMachine& tgt,
const MachineInstrDescriptor* _desc,
unsigned int _descSize,
unsigned int _numRealOpCodes)
: target(tgt),
desc(_desc), descSize(_descSize), numRealOpCodes(_numRealOpCodes)
{
// FIXME: TargetInstrDescriptors should not be global
assert(TargetInstrDescriptors == NULL && desc != NULL);
TargetInstrDescriptors = desc; // initialize global variable
}
MachineInstrInfo::~MachineInstrInfo()
{
TargetInstrDescriptors = NULL; // reset global variable
}
bool
MachineInstrInfo::constantFitsInImmedField(MachineOpCode opCode,
int64_t intValue) const
{
// First, check if opCode has an immed field.
bool isSignExtended;
uint64_t maxImmedValue = maxImmedConstant(opCode, isSignExtended);
if (maxImmedValue != 0)
{
// NEED TO HANDLE UNSIGNED VALUES SINCE THEY MAY BECOME MUCH
// SMALLER AFTER CASTING TO SIGN-EXTENDED int, short, or char.
// See CreateUIntSetInstruction in SparcInstrInfo.cpp.
// Now check if the constant fits
if (intValue <= (int64_t) maxImmedValue &&
intValue >= -((int64_t) maxImmedValue+1))
return true;
}
return false;
}
//---------------------------------------------------------------------------
// class MachineCacheInfo
//
// Purpose:
// Describes properties of the target cache architecture.
//---------------------------------------------------------------------------
/*ctor*/
MachineCacheInfo::MachineCacheInfo(const TargetMachine& tgt)
: target(tgt)
{
Initialize();
}
void
MachineCacheInfo::Initialize()
{
numLevels = 2;
cacheLineSizes.push_back(16); cacheLineSizes.push_back(32);
cacheSizes.push_back(1 << 15); cacheSizes.push_back(1 << 20);
cacheAssoc.push_back(1); cacheAssoc.push_back(4);
}