llvm-6502/lib/Target/TargetData.cpp
Vikram S. Adve 0e7c737f6e Fix cute little bug that was causing the last
structure offset to be ignored in computing an offset!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1310 91177308-0d34-0410-b5e6-96231b3b80d8
2001-11-14 21:24:44 +00:00

181 lines
6.6 KiB
C++

//===-- TargetData.cpp - Data size & alignment routines --------------------==//
//
// 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/DerivedTypes.h"
#include "llvm/ConstPoolVals.h"
static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
unsigned &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 TySize, TyAlign;
getTypeInfo(Ty, &TD, TySize, A); TyAlign = A;
// Add padding if neccesary 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 = max(TyAlign, StructAlignment);
MemberOffsets.push_back(StructSize);
StructSize += TySize; // Consume space for this data item...
}
// 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;
if (StructSize == 0) {
StructSize = 1; // Empty struct is 1 byte
StructAlignment = 1;
}
}
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<const Type>((const Value *)T);
assert(Ty->isStructType() &&
"Can only create StructLayout annotation on structs!");
return new StructLayout((const StructType *)Ty, TD);
}
//===----------------------------------------------------------------------===//
// TargetData Class Implementation
//===----------------------------------------------------------------------===//
TargetData::TargetData(const string &TargetName, unsigned char PtrSize = 8,
unsigned char PtrAl = 8, unsigned char DoubleAl = 8,
unsigned char FloatAl = 4, unsigned char LongAl = 8,
unsigned char IntAl = 4, unsigned char ShortAl = 2,
unsigned char ByteAl = 1)
: AID(AnnotationManager::getID("TargetData::" + TargetName)) {
AnnotationManager::registerAnnotationFactory(AID, TypeAnFactory, this);
PointerSize = PtrSize;
PointerAlignment = PtrAl;
DoubleAlignment = DoubleAl;
FloatAlignment = FloatAl;
LongAlignment = LongAl;
IntAlignment = IntAl;
ShortAlignment = ShortAl;
ByteAlignment = ByteAl;
}
TargetData::~TargetData() {
AnnotationManager::registerAnnotationFactory(AID, 0); // Deregister factory
}
static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
unsigned &Size, unsigned char &Alignment) {
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;
assert(ATy->isSized() && "Can't get TypeInfo of an unsized array!");
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;
}
}
unsigned TargetData::getTypeSize(const Type *Ty) const {
unsigned Size; unsigned char Align;
getTypeInfo(Ty, this, Size, Align);
return Size;
}
unsigned char TargetData::getTypeAlignment(const Type *Ty) const {
unsigned Size; unsigned char Align;
getTypeInfo(Ty, this, Size, Align);
return Align;
}
unsigned TargetData::getIndexedOffset(const Type *ptrTy,
const vector<ConstPoolVal*> &Idx) const {
const PointerType *PtrTy = cast<const PointerType>(ptrTy);
unsigned Result = 0;
// Get the type pointed to...
const Type *Ty = PtrTy->getValueType();
for (unsigned CurIDX = 0; CurIDX < Idx.size(); ++CurIDX) {
if (const StructType *STy = dyn_cast<const StructType>(Ty)) {
assert(Idx[CurIDX]->getType() == Type::UByteTy && "Illegal struct idx");
unsigned FieldNo = ((ConstPoolUInt*)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];
} else if (const ArrayType *ATy = dyn_cast<const ArrayType>(Ty)) {
assert(0 && "Loading from arrays not implemented yet!");
} else {
assert(0 && "Indexing type that is not struct or array?");
return 0; // Load directly through ptr
}
}
return Result;
}