llvm-6502/lib/CodeGen/MachineFunction.cpp
2002-12-25 05:03:22 +00:00

341 lines
11 KiB
C++

//===-- MachineFunction.cpp -----------------------------------------------===//
//
// Collect native machine code information for a function. This allows
// target-specific information about the generated code to be stored with each
// function.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineCodeForInstruction.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/MachineFrameInfo.h"
#include "llvm/Target/MachineCacheInfo.h"
#include "llvm/Function.h"
#include "llvm/iOther.h"
#include "llvm/Pass.h"
#include <limits.h>
const int INVALID_FRAME_OFFSET = INT_MAX; // std::numeric_limits<int>::max();
static AnnotationID MF_AID(
AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
//===---------------------------------------------------------------------===//
// Code generation/destruction passes
//===---------------------------------------------------------------------===//
namespace {
class ConstructMachineFunction : public FunctionPass {
TargetMachine &Target;
public:
ConstructMachineFunction(TargetMachine &T) : Target(T) {}
const char *getPassName() const {
return "ConstructMachineFunction";
}
bool runOnFunction(Function &F) {
MachineFunction::construct(&F, Target).CalculateArgSize();
return false;
}
};
struct DestroyMachineFunction : public FunctionPass {
const char *getPassName() const { return "FreeMachineFunction"; }
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;
}
};
struct Printer : public FunctionPass {
const char *getPassName() const { return "MachineFunction Printer"; }
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
bool runOnFunction(Function &F) {
MachineFunction::get(&F).dump();
return false;
}
};
}
Pass *createMachineCodeConstructionPass(TargetMachine &Target) {
return new ConstructMachineFunction(Target);
}
Pass *createMachineCodeDestructionPass() {
return new DestroyMachineFunction();
}
Pass *createMachineFunctionPrinterPass() {
return new Printer();
}
//===---------------------------------------------------------------------===//
// MachineFunction implementation
//===---------------------------------------------------------------------===//
MachineFunction::MachineFunction(const Function *F,
const TargetMachine& target)
: Annotation(MF_AID), Fn(F), Target(target) {
SSARegMapping = new SSARegMap();
// FIXME: move state into another class
staticStackSize = automaticVarsSize = regSpillsSize = 0;
maxOptionalArgsSize = maxOptionalNumArgs = currentTmpValuesSize = 0;
maxTmpValuesSize = 0;
compiledAsLeaf = spillsAreaFrozen = automaticVarsAreaFrozen = false;
}
MachineFunction::~MachineFunction() {
delete SSARegMapping;
}
void MachineFunction::dump() const { print(std::cerr); }
void MachineFunction::print(std::ostream &OS) const {
OS << "\n" << *(Value*)Fn->getReturnType() << " \"" << Fn->getName()<< "\"\n";
for (const_iterator BB = begin(); BB != end(); ++BB) {
BasicBlock *LBB = BB->getBasicBlock();
OS << "\n" << LBB->getName() << " (" << (const void*)LBB << "):\n";
for (MachineBasicBlock::const_iterator I = BB->begin(); I != BB->end();++I){
OS << "\t";
(*I)->print(OS, Target);
}
}
OS << "\nEnd function \"" << Fn->getName() << "\"\n\n";
}
// The next two methods are used to construct and to retrieve
// the MachineCodeForFunction object for the given function.
// construct() -- Allocates and initializes for a given function and target
// get() -- Returns a handle to the object.
// This should not be called before "construct()"
// for a given Function.
//
MachineFunction&
MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
{
assert(Fn->getAnnotation(MF_AID) == 0 &&
"Object already exists for this function!");
MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
Fn->addAnnotation(mcInfo);
return *mcInfo;
}
void
MachineFunction::destruct(const Function *Fn)
{
bool Deleted = Fn->deleteAnnotation(MF_AID);
assert(Deleted && "Machine code did not exist for function!");
}
MachineFunction& MachineFunction::get(const Function *F)
{
MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
assert(mc && "Call construct() method first to allocate the object");
return *mc;
}
void MachineFunction::clearSSARegMap() {
delete SSARegMapping;
SSARegMapping = 0;
}
static unsigned
ComputeMaxOptionalArgsSize(const TargetMachine& target, const Function *F,
unsigned &maxOptionalNumArgs)
{
const MachineFrameInfo& frameInfo = target.getFrameInfo();
unsigned maxSize = 0;
for (Function::const_iterator BB = F->begin(), BBE = F->end(); BB !=BBE; ++BB)
for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
if (const CallInst *callInst = dyn_cast<CallInst>(&*I))
{
unsigned numOperands = callInst->getNumOperands() - 1;
int numExtra = (int)numOperands-frameInfo.getNumFixedOutgoingArgs();
if (numExtra <= 0)
continue;
unsigned int sizeForThisCall;
if (frameInfo.argsOnStackHaveFixedSize())
{
int argSize = frameInfo.getSizeOfEachArgOnStack();
sizeForThisCall = numExtra * (unsigned) argSize;
}
else
{
assert(0 && "UNTESTED CODE: Size per stack argument is not "
"fixed on this architecture: use actual arg sizes to "
"compute MaxOptionalArgsSize");
sizeForThisCall = 0;
for (unsigned i = 0; i < numOperands; ++i)
sizeForThisCall += target.DataLayout.getTypeSize(callInst->
getOperand(i)->getType());
}
if (maxSize < sizeForThisCall)
maxSize = sizeForThisCall;
if ((int)maxOptionalNumArgs < numExtra)
maxOptionalNumArgs = (unsigned) numExtra;
}
return maxSize;
}
// Align data larger than one L1 cache line on L1 cache line boundaries.
// Align all smaller data on the next higher 2^x boundary (4, 8, ...),
// but not higher than the alignment of the largest type we support
// (currently a double word). -- see class TargetData).
//
// This function is similar to the corresponding function in EmitAssembly.cpp
// but they are unrelated. This one does not align at more than a
// double-word boundary whereas that one might.
//
inline unsigned int
SizeToAlignment(unsigned int size, const TargetMachine& target)
{
unsigned short cacheLineSize = target.getCacheInfo().getCacheLineSize(1);
if (size > (unsigned) cacheLineSize / 2)
return cacheLineSize;
else
for (unsigned sz=1; /*no condition*/; sz *= 2)
if (sz >= size || sz >= target.DataLayout.getDoubleAlignment())
return sz;
}
void MachineFunction::CalculateArgSize() {
maxOptionalArgsSize = ComputeMaxOptionalArgsSize(Target, Fn,
maxOptionalNumArgs);
staticStackSize = maxOptionalArgsSize
+ Target.getFrameInfo().getMinStackFrameSize();
}
int
MachineFunction::computeOffsetforLocalVar(const TargetMachine& target,
const Value* val,
unsigned int& getPaddedSize,
unsigned int sizeToUse)
{
if (sizeToUse == 0)
sizeToUse = target.findOptimalStorageSize(val->getType());
unsigned int align = SizeToAlignment(sizeToUse, target);
bool growUp;
int firstOffset = target.getFrameInfo().getFirstAutomaticVarOffset(*this,
growUp);
int offset = growUp? firstOffset + getAutomaticVarsSize()
: firstOffset - (getAutomaticVarsSize() + sizeToUse);
int aligned = target.getFrameInfo().adjustAlignment(offset, growUp, align);
getPaddedSize = sizeToUse + abs(aligned - offset);
return aligned;
}
int
MachineFunction::allocateLocalVar(const TargetMachine& target,
const Value* val,
unsigned int sizeToUse)
{
assert(! automaticVarsAreaFrozen &&
"Size of auto vars area has been used to compute an offset so "
"no more automatic vars should be allocated!");
// Check if we've allocated a stack slot for this value already
//
int offset = getOffset(val);
if (offset == INVALID_FRAME_OFFSET)
{
unsigned int getPaddedSize;
offset = computeOffsetforLocalVar(target, val, getPaddedSize, sizeToUse);
offsets[val] = offset;
incrementAutomaticVarsSize(getPaddedSize);
}
return offset;
}
int
MachineFunction::allocateSpilledValue(const TargetMachine& target,
const Type* type)
{
assert(! spillsAreaFrozen &&
"Size of reg spills area has been used to compute an offset so "
"no more register spill slots should be allocated!");
unsigned int size = target.DataLayout.getTypeSize(type);
unsigned char align = target.DataLayout.getTypeAlignment(type);
bool growUp;
int firstOffset = target.getFrameInfo().getRegSpillAreaOffset(*this, growUp);
int offset = growUp? firstOffset + getRegSpillsSize()
: firstOffset - (getRegSpillsSize() + size);
int aligned = target.getFrameInfo().adjustAlignment(offset, growUp, align);
size += abs(aligned - offset); // include alignment padding in size
incrementRegSpillsSize(size); // update size of reg. spills area
return aligned;
}
int
MachineFunction::pushTempValue(const TargetMachine& target,
unsigned int size)
{
unsigned int align = SizeToAlignment(size, target);
bool growUp;
int firstOffset = target.getFrameInfo().getTmpAreaOffset(*this, growUp);
int offset = growUp? firstOffset + currentTmpValuesSize
: firstOffset - (currentTmpValuesSize + size);
int aligned = target.getFrameInfo().adjustAlignment(offset, growUp, align);
size += abs(aligned - offset); // include alignment padding in size
incrementTmpAreaSize(size); // update "current" size of tmp area
return aligned;
}
void
MachineFunction::popAllTempValues(const TargetMachine& target)
{
resetTmpAreaSize(); // clear tmp area to reuse
}
int
MachineFunction::getOffset(const Value* val) const
{
hash_map<const Value*, int>::const_iterator pair = offsets.find(val);
return (pair == offsets.end()) ? INVALID_FRAME_OFFSET : pair->second;
}