llvm-6502/include/llvm/Target/TargetData.h
Evan Cheng 9b631a58ef Update comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33450 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-22 23:14:52 +00:00

291 lines
12 KiB
C++

//===-- llvm/Target/TargetData.h - Data size & alignment info ---*- C++ -*-===//
//
// 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.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_TARGETDATA_H
#define LLVM_TARGET_TARGETDATA_H
#include "llvm/Pass.h"
#include "llvm/Support/DataTypes.h"
#include <vector>
#include <string>
namespace llvm {
class Value;
class Type;
class StructType;
class StructLayout;
class GlobalVariable;
class TargetData : public ImmutablePass {
bool LittleEndian; // Defaults to false
// ABI alignments
unsigned char BoolABIAlignment; // Defaults to 1 byte
unsigned char ByteABIAlignment; // Defaults to 1 byte
unsigned char ShortABIAlignment; // Defaults to 2 bytes
unsigned char IntABIAlignment; // Defaults to 4 bytes
unsigned char LongABIAlignment; // Defaults to 8 bytes
unsigned char FloatABIAlignment; // Defaults to 4 bytes
unsigned char DoubleABIAlignment; // Defaults to 8 bytes
unsigned char PointerMemSize; // Defaults to 8 bytes
unsigned char PointerABIAlignment; // Defaults to 8 bytes
// Preferred stack/global type alignments
unsigned char BoolPrefAlignment; // Defaults to BoolABIAlignment
unsigned char BytePrefAlignment; // Defaults to ByteABIAlignment
unsigned char ShortPrefAlignment; // Defaults to ShortABIAlignment
unsigned char IntPrefAlignment; // Defaults to IntABIAlignment
unsigned char LongPrefAlignment; // Defaults to LongABIAlignment
unsigned char FloatPrefAlignment; // Defaults to FloatABIAlignment
unsigned char DoublePrefAlignment; // Defaults to DoubleABIAlignment
unsigned char PointerPrefAlignment; // Defaults to PointerABIAlignment
unsigned char AggMinPrefAlignment; // Defaults to 0 bytes
public:
/// Default ctor - This has to exist, because this is a pass, but it should
/// never be used.
TargetData() {
assert(0 && "ERROR: Bad TargetData ctor used. "
"Tool did not specify a TargetData to use?");
abort();
}
/// Constructs a TargetData from a string of the following format:
/// "E-p:64:64-d:64-f:32-l:64-i:32-s:16-b:8-B:8"
/// The above string is considered the default, and any values not specified
/// in the string will be assumed to be as above, with the caveat that unspecified
/// values are always assumed to be smaller than the size of a pointer.
TargetData(const std::string &TargetDescription) {
init(TargetDescription);
}
/// Initialize target data from properties stored in the module.
TargetData(const Module *M);
TargetData(const TargetData &TD) :
ImmutablePass(),
LittleEndian(TD.isLittleEndian()),
BoolABIAlignment(TD.getBoolABIAlignment()),
ByteABIAlignment(TD.getByteABIAlignment()),
ShortABIAlignment(TD.getShortABIAlignment()),
IntABIAlignment(TD.getIntABIAlignment()),
LongABIAlignment(TD.getLongABIAlignment()),
FloatABIAlignment(TD.getFloatABIAlignment()),
DoubleABIAlignment(TD.getDoubleABIAlignment()),
PointerMemSize(TD.getPointerSize()),
PointerABIAlignment(TD.getPointerABIAlignment()),
BoolPrefAlignment(TD.getBoolPrefAlignment()),
BytePrefAlignment(TD.getBytePrefAlignment()),
ShortPrefAlignment(TD.getShortPrefAlignment()),
IntPrefAlignment(TD.getIntPrefAlignment()),
LongPrefAlignment(TD.getLongPrefAlignment()),
FloatPrefAlignment(TD.getFloatPrefAlignment()),
DoublePrefAlignment(TD.getDoublePrefAlignment()),
PointerPrefAlignment(TD.getPointerPrefAlignment()),
AggMinPrefAlignment(TD.getAggMinPrefAlignment()) {
}
~TargetData(); // Not virtual, do not subclass this class
/// Parse a target data layout string and initialize TargetData members.
///
/// Parse a target data layout string, initializing the various TargetData
/// members along the way. A TargetData specification string looks like
/// "E-p:64:64-d:64-f:32-l:64-i:32-s:16-b:8-B:8" and specifies the
/// target's endianess, the ABI alignments of various data types and
/// the size of pointers.
///
/// "-" is used as a separator and ":" separates a token from its argument.
///
/// Alignment is indicated in bits and internally converted to the
/// appropriate number of bytes.
///
/// The preferred stack/global alignment specifications (":[prefalign]") are
/// optional and default to the ABI alignment.
///
/// Valid tokens:
/// <br>
/// <em>E</em> specifies big endian architecture (1234) [default]<br>
/// <em>e</em> specifies little endian architecture (4321) <br>
/// <em>p:[ptr size]:[ptr align]</em> specifies pointer size and alignment
/// [default = 64:64] <br>
/// <em>d:[align]:[prefalign]</em> specifies double floating
/// point alignment [default = 64] <br>
/// <em>f:[align]:[prefalign]</em> specifies single floating
/// point alignment [default = 32] <br>
/// <em>l:[align]:[prefalign]:[globalign[</em> specifies long integer
/// alignment [default = 64] <br>
/// <em>i:[align]:[prefalign]</em> specifies integer alignment
/// [default = 32] <br>
/// <em>s:[align]:[prefalign]</em> specifies short integer
/// alignment [default = 16] <br>
/// <em>b:[align]:[prefalign]</em> specifies byte data type
/// alignment [default = 8] <br>
/// <em>B:[align]:[prefalign]</em> specifies boolean data type
/// alignment [default = 8] <br>
/// <em>A:[prefalign]</em> specifies an aggregates' minimum alignment
/// on the stack and when emitted as a global. The default minimum aggregate
/// alignment defaults to 0, which causes the aggregate's "natural" internal
/// alignment calculated by llvm to be preferred.
///
/// All other token types are silently ignored.
void init(const std::string &TargetDescription);
/// Target endianness...
bool isLittleEndian() const { return LittleEndian; }
bool isBigEndian() const { return !LittleEndian; }
/// Target boolean alignment
unsigned char getBoolABIAlignment() const { return BoolABIAlignment; }
/// Target byte alignment
unsigned char getByteABIAlignment() const { return ByteABIAlignment; }
/// Target short alignment
unsigned char getShortABIAlignment() const { return ShortABIAlignment; }
/// Target integer alignment
unsigned char getIntABIAlignment() const { return IntABIAlignment; }
/// Target long alignment
unsigned char getLongABIAlignment() const { return LongABIAlignment; }
/// Target single precision float alignment
unsigned char getFloatABIAlignment() const { return FloatABIAlignment; }
/// Target double precision float alignment
unsigned char getDoubleABIAlignment() const { return DoubleABIAlignment; }
/// Target pointer alignment
unsigned char getPointerABIAlignment() const { return PointerABIAlignment; }
/// Target pointer size
unsigned char getPointerSize() const { return PointerMemSize; }
/// Target pointer size, in bits
unsigned char getPointerSizeInBits() const { return 8*PointerMemSize; }
/// Return target's alignment for booleans on stack
unsigned char getBoolPrefAlignment() const {
return BoolPrefAlignment;
}
/// Return target's alignment for integers on stack
unsigned char getBytePrefAlignment() const {
return BytePrefAlignment;
}
/// Return target's alignment for shorts on stack
unsigned char getShortPrefAlignment() const {
return ShortPrefAlignment;
}
/// Return target's alignment for integers on stack
unsigned char getIntPrefAlignment() const {
return IntPrefAlignment;
}
/// Return target's alignment for longs on stack
unsigned char getLongPrefAlignment() const {
return LongPrefAlignment;
}
/// Return target's alignment for single precision floats on stack
unsigned char getFloatPrefAlignment() const {
return FloatPrefAlignment;
}
/// Return target's alignment for double preceision floats on stack
unsigned char getDoublePrefAlignment() const {
return DoublePrefAlignment;
}
/// Return target's alignment for stack-based pointers
unsigned char getPointerPrefAlignment() const {
return PointerPrefAlignment;
}
/// Return target's alignment for stack-based structures
unsigned char getAggMinPrefAlignment() const {
return AggMinPrefAlignment;
}
/// getStringRepresentation - Return the string representation of the
/// TargetData. This representation is in the same format accepted by the
/// string constructor above.
std::string getStringRepresentation() const;
/// getTypeSize - Return the number of bytes necessary to hold the specified
/// type.
///
uint64_t getTypeSize(const Type *Ty) const;
/// getTypeSizeInBits - Return the number of bytes necessary to hold the
/// specified type.
uint64_t getTypeSizeInBits(const Type* Ty) const;
/// getTypeAlignmentABI - Return the minimum ABI-required alignment for the
/// specified type.
unsigned char getTypeAlignmentABI(const Type *Ty) const;
/// getTypeAlignmentPref - Return the preferred stack/global alignment for
/// the specified type.
unsigned char getTypeAlignmentPref(const Type *Ty) const;
/// getTypeAlignmentShift - Return the preferred alignment for the
/// specified type, returned as log2 of the value (a shift amount).
///
unsigned char getTypeAlignmentShift(const Type *Ty) const;
/// getIntPtrType - Return an unsigned integer type that is the same size or
/// greater to the host pointer size.
///
const Type *getIntPtrType() const;
/// getIndexOffset - return the offset from the beginning of the type for the
/// specified indices. This is used to implement getelementptr.
///
uint64_t getIndexedOffset(const Type *Ty,
const std::vector<Value*> &Indices) const;
/// getStructLayout - Return a StructLayout object, indicating the alignment
/// of the struct, its size, and the offsets of its fields. Note that this
/// information is lazily cached.
const StructLayout *getStructLayout(const StructType *Ty) const;
/// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout
/// objects. If a TargetData object is alive when types are being refined and
/// removed, this method must be called whenever a StructType is removed to
/// avoid a dangling pointer in this cache.
void InvalidateStructLayoutInfo(const StructType *Ty) const;
/// getPreferredAlignmentLog - Return the preferred alignment of the
/// specified global, returned in log form. This includes an explicitly
/// requested alignment (if the global has one).
unsigned getPreferredAlignmentLog(const GlobalVariable *GV) const;
};
/// StructLayout - used to lazily calculate structure layout information for a
/// target machine, based on the TargetData structure.
///
class StructLayout {
public:
std::vector<uint64_t> MemberOffsets;
uint64_t StructSize;
unsigned StructAlignment;
/// getElementContainingOffset - Given a valid offset into the structure,
/// return the structure index that contains it.
///
unsigned getElementContainingOffset(uint64_t Offset) const;
private:
friend class TargetData; // Only TargetData can create this class
StructLayout(const StructType *ST, const TargetData &TD);
};
} // End llvm namespace
#endif