llvm/lib/Target/TargetData.cpp
2003-11-11 22:41:34 +00:00

227 lines
8.3 KiB
C++

//===-- TargetData.cpp - Data size & alignment routines --------------------==//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines target properties related to datatype size/offset/alignment
// information. It uses lazy annotations to cache information about how
// structure types are laid out and used.
//
// This structure should be created once, filled in if the defaults are not
// correct and then passed around by const&. None of the members functions
// require modification to the object.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetData.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
namespace llvm {
// Handle the Pass registration stuff necessary to use TargetData's.
namespace {
// Register the default SparcV9 implementation...
RegisterPass<TargetData> X("targetdata", "Target Data Layout");
}
static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
uint64_t &Size, unsigned char &Alignment);
//===----------------------------------------------------------------------===//
// Support for StructLayout Annotation
//===----------------------------------------------------------------------===//
StructLayout::StructLayout(const StructType *ST, const TargetData &TD)
: Annotation(TD.getStructLayoutAID()) {
StructAlignment = 0;
StructSize = 0;
// Loop over each of the elements, placing them in memory...
for (StructType::ElementTypes::const_iterator
TI = ST->getElementTypes().begin(),
TE = ST->getElementTypes().end(); TI != TE; ++TI) {
const Type *Ty = *TI;
unsigned char A;
unsigned TyAlign;
uint64_t TySize;
getTypeInfo(Ty, &TD, TySize, A);
TyAlign = A;
// Add padding if necessary to make the data element aligned properly...
if (StructSize % TyAlign != 0)
StructSize = (StructSize/TyAlign + 1) * TyAlign; // Add padding...
// Keep track of maximum alignment constraint
StructAlignment = std::max(TyAlign, StructAlignment);
MemberOffsets.push_back(StructSize);
StructSize += TySize; // Consume space for this data item
}
// Empty structures have alignment of 1 byte.
if (StructAlignment == 0) StructAlignment = 1;
// Add padding to the end of the struct so that it could be put in an array
// and all array elements would be aligned correctly.
if (StructSize % StructAlignment != 0)
StructSize = (StructSize/StructAlignment + 1) * StructAlignment;
}
Annotation *TargetData::TypeAnFactory(AnnotationID AID, const Annotable *T,
void *D) {
const TargetData &TD = *(const TargetData*)D;
assert(AID == TD.AID && "Target data annotation ID mismatch!");
const Type *Ty = cast<Type>((const Value *)T);
assert(isa<StructType>(Ty) &&
"Can only create StructLayout annotation on structs!");
return new StructLayout(cast<StructType>(Ty), TD);
}
//===----------------------------------------------------------------------===//
// TargetData Class Implementation
//===----------------------------------------------------------------------===//
TargetData::TargetData(const std::string &TargetName,
bool isLittleEndian, unsigned char PtrSize,
unsigned char PtrAl, unsigned char DoubleAl,
unsigned char FloatAl, unsigned char LongAl,
unsigned char IntAl, unsigned char ShortAl,
unsigned char ByteAl)
: AID(AnnotationManager::getID("TargetData::" + TargetName)) {
AnnotationManager::registerAnnotationFactory(AID, TypeAnFactory, this);
// If this assert triggers, a pass "required" TargetData information, but the
// top level tool did not provide once for it. We do not want to default
// construct, or else we might end up using a bad endianness or pointer size!
//
assert(!TargetName.empty() &&
"ERROR: Tool did not specify a target data to use!");
LittleEndian = isLittleEndian;
PointerSize = PtrSize;
PointerAlignment = PtrAl;
DoubleAlignment = DoubleAl;
assert(DoubleAlignment == PtrAl &&
"Double alignment and pointer alignment agree for now!");
FloatAlignment = FloatAl;
LongAlignment = LongAl;
IntAlignment = IntAl;
ShortAlignment = ShortAl;
ByteAlignment = ByteAl;
}
TargetData::TargetData(const std::string &ToolName, const Module *M)
: AID(AnnotationManager::getID("TargetData::" + ToolName)) {
AnnotationManager::registerAnnotationFactory(AID, TypeAnFactory, this);
LittleEndian = M->getEndianness() != Module::BigEndian;
PointerSize = M->getPointerSize() != Module::Pointer64 ? 4 : 8;
PointerAlignment = PointerSize;
DoubleAlignment = PointerSize;
FloatAlignment = 4;
LongAlignment = 8;
IntAlignment = 4;
ShortAlignment = 2;
ByteAlignment = 1;
}
TargetData::~TargetData() {
AnnotationManager::registerAnnotationFactory(AID, 0); // Deregister factory
}
static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
uint64_t &Size, unsigned char &Alignment) {
assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
switch (Ty->getPrimitiveID()) {
case Type::VoidTyID:
case Type::BoolTyID:
case Type::UByteTyID:
case Type::SByteTyID: Size = 1; Alignment = TD->getByteAlignment(); return;
case Type::UShortTyID:
case Type::ShortTyID: Size = 2; Alignment = TD->getShortAlignment(); return;
case Type::UIntTyID:
case Type::IntTyID: Size = 4; Alignment = TD->getIntAlignment(); return;
case Type::ULongTyID:
case Type::LongTyID: Size = 8; Alignment = TD->getLongAlignment(); return;
case Type::FloatTyID: Size = 4; Alignment = TD->getFloatAlignment(); return;
case Type::DoubleTyID: Size = 8; Alignment = TD->getDoubleAlignment(); return;
case Type::LabelTyID:
case Type::PointerTyID:
Size = TD->getPointerSize(); Alignment = TD->getPointerAlignment();
return;
case Type::ArrayTyID: {
const ArrayType *ATy = (const ArrayType *)Ty;
getTypeInfo(ATy->getElementType(), TD, Size, Alignment);
Size *= ATy->getNumElements();
return;
}
case Type::StructTyID: {
// Get the layout annotation... which is lazily created on demand.
const StructLayout *Layout = TD->getStructLayout((const StructType*)Ty);
Size = Layout->StructSize; Alignment = Layout->StructAlignment;
return;
}
case Type::TypeTyID:
default:
assert(0 && "Bad type for getTypeInfo!!!");
return;
}
}
uint64_t TargetData::getTypeSize(const Type *Ty) const {
uint64_t Size;
unsigned char Align;
getTypeInfo(Ty, this, Size, Align);
return Size;
}
unsigned char TargetData::getTypeAlignment(const Type *Ty) const {
uint64_t Size;
unsigned char Align;
getTypeInfo(Ty, this, Size, Align);
return Align;
}
uint64_t TargetData::getIndexedOffset(const Type *ptrTy,
const std::vector<Value*> &Idx) const {
const Type *Ty = ptrTy;
assert(isa<PointerType>(Ty) && "Illegal argument for getIndexedOffset()");
uint64_t Result = 0;
for (unsigned CurIDX = 0; CurIDX != Idx.size(); ++CurIDX) {
if (Idx[CurIDX]->getType() == Type::LongTy) {
// Update Ty to refer to current element
Ty = cast<SequentialType>(Ty)->getElementType();
// Get the array index and the size of each array element.
int64_t arrayIdx = cast<ConstantSInt>(Idx[CurIDX])->getValue();
Result += arrayIdx * (int64_t)getTypeSize(Ty);
} else {
const StructType *STy = cast<StructType>(Ty);
assert(Idx[CurIDX]->getType() == Type::UByteTy && "Illegal struct idx");
unsigned FieldNo = cast<ConstantUInt>(Idx[CurIDX])->getValue();
// Get structure layout information...
const StructLayout *Layout = getStructLayout(STy);
// Add in the offset, as calculated by the structure layout info...
assert(FieldNo < Layout->MemberOffsets.size() &&"FieldNo out of range!");
Result += Layout->MemberOffsets[FieldNo];
// Update Ty to refer to current element
Ty = STy->getElementTypes()[FieldNo];
}
}
return Result;
}
} // End llvm namespace