llvm-project/llvm/lib/CodeGen/MachineFunction.cpp

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//===-- MachineCodeForMethod.cpp -------------------------------------------=//
//
// Purpose:
// 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/MachineCodeForMethod.h"
#include "llvm/CodeGen/MachineInstr.h" // For debug output
#include "llvm/CodeGen/MachineCodeForBasicBlock.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/MachineFrameInfo.h"
#include "llvm/Target/MachineCacheInfo.h"
#include "llvm/Function.h"
#include "llvm/BasicBlock.h"
#include "llvm/iOther.h"
#include <limits.h>
#include <iostream>
const int INVALID_FRAME_OFFSET = INT_MAX; // std::numeric_limits<int>::max();
static AnnotationID MCFM_AID(
AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
// 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.
//
MachineCodeForMethod&
MachineCodeForMethod::construct(const Function *M, const TargetMachine &Tar)
{
assert(M->getAnnotation(MCFM_AID) == 0 &&
"Object already exists for this function!");
MachineCodeForMethod* mcInfo = new MachineCodeForMethod(M, Tar);
M->addAnnotation(mcInfo);
return *mcInfo;
}
void
MachineCodeForMethod::destruct(const Function *M)
{
bool Deleted = M->deleteAnnotation(MCFM_AID);
assert(Deleted && "Machine code did not exist for function!");
}
MachineCodeForMethod&
MachineCodeForMethod::get(const Function *F)
{
MachineCodeForMethod *mc = (MachineCodeForMethod*)F->getAnnotation(MCFM_AID);
assert(mc && "Call construct() method first to allocate the object");
return *mc;
}
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.findOptimalStorageSize(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, ...).
//
// THIS FUNCTION HAS BEEN COPIED FROM EMITASSEMBLY.CPP AND
// SHOULD BE USED DIRECTLY THERE
//
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)
return sz;
}
/*ctor*/
MachineCodeForMethod::MachineCodeForMethod(const Function *F,
const TargetMachine& target)
: Annotation(MCFM_AID),
method(F), staticStackSize(0),
automaticVarsSize(0), regSpillsSize(0),
maxOptionalArgsSize(0), maxOptionalNumArgs(0),
currentTmpValuesSize(0), maxTmpValuesSize(0), compiledAsLeaf(false),
spillsAreaFrozen(false), automaticVarsAreaFrozen(false)
{
maxOptionalArgsSize = ComputeMaxOptionalArgsSize(target, method,
maxOptionalNumArgs);
staticStackSize = maxOptionalArgsSize
+ target.getFrameInfo().getMinStackFrameSize();
}
int
MachineCodeForMethod::computeOffsetforLocalVar(const TargetMachine& target,
const Value* val,
unsigned int& getPaddedSize,
unsigned int sizeToUse = 0)
{
bool growUp;
int firstOffset =target.getFrameInfo().getFirstAutomaticVarOffset(*this,
growUp);
unsigned char align;
if (sizeToUse == 0)
{
sizeToUse = target.findOptimalStorageSize(val->getType());
// align = target.DataLayout.getTypeAlignment(val->getType());
}
align = SizeToAlignment(sizeToUse, target);
int offset = getAutomaticVarsSize();
if (! growUp)
offset += sizeToUse;
if (unsigned int mod = offset % align)
{
offset += align - mod;
getPaddedSize = sizeToUse + align - mod;
}
else
getPaddedSize = sizeToUse;
offset = growUp? firstOffset + offset
: firstOffset - offset;
return offset;
}
int
MachineCodeForMethod::allocateLocalVar(const TargetMachine& target,
const Value* val,
unsigned int sizeToUse = 0)
{
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 = this->computeOffsetforLocalVar(target, val, getPaddedSize,
sizeToUse);
offsets[val] = offset;
incrementAutomaticVarsSize(getPaddedSize);
}
return offset;
}
int
MachineCodeForMethod::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.findOptimalStorageSize(type);
unsigned char align = target.DataLayout.getTypeAlignment(type);
bool growUp;
int firstOffset = target.getFrameInfo().getRegSpillAreaOffset(*this, growUp);
int offset = getRegSpillsSize();
if (! growUp)
offset += size;
if (unsigned int mod = offset % align)
{
offset += align - mod;
size += align - mod;
}
offset = growUp? firstOffset + offset
: firstOffset - offset;
incrementRegSpillsSize(size);
return offset;
}
int
MachineCodeForMethod::pushTempValue(const TargetMachine& target,
unsigned int size)
{
// Compute a power-of-2 alignment according to the possible sizes,
// but not greater than the alignment of the largest type we support
// (currently a double word -- see class TargetData).
unsigned char align = 1;
for (; align < size && align < target.DataLayout.getDoubleAlignment();
align = 2*align)
;
bool growUp;
int firstTmpOffset = target.getFrameInfo().getTmpAreaOffset(*this, growUp);
int offset = currentTmpValuesSize;
if (! growUp)
offset += size;
if (unsigned int mod = offset % align)
{
offset += align - mod;
size += align - mod;
}
offset = growUp ? firstTmpOffset + offset : firstTmpOffset - offset;
incrementTmpAreaSize(size);
return offset;
}
void
MachineCodeForMethod::popAllTempValues(const TargetMachine& target)
{
resetTmpAreaSize();
}
int
MachineCodeForMethod::getOffset(const Value* val) const
{
std::hash_map<const Value*, int>::const_iterator pair = offsets.find(val);
return (pair == offsets.end())? INVALID_FRAME_OFFSET : pair->second;
}
void
MachineCodeForMethod::dump() const
{
std::cerr << "\n" << method->getReturnType()
<< " \"" << method->getName() << "\"\n";
for (Function::const_iterator BB = method->begin(); BB != method->end(); ++BB)
{
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std::cerr << std::endl << (*BB).getName() << " (" << (const void*) BB << ")" << ":" << std::endl;
MachineCodeForBasicBlock& mvec = MachineCodeForBasicBlock::get(BB);
for (unsigned i=0; i < mvec.size(); i++)
std::cerr << "\t" << *mvec[i];
}
std::cerr << "\nEnd function \"" << method->getName() << "\"\n\n";
}