1 //===-- llvm/Target/TargetData.h - Data size & alignment info ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines target properties related to datatype size/offset/alignment
11 // information. It uses lazy annotations to cache information about how
12 // structure types are laid out and used.
14 // This structure should be created once, filled in if the defaults are not
15 // correct and then passed around by const&. None of the members functions
16 // require modification to the object.
18 //===----------------------------------------------------------------------===//
20 #ifndef LLVM_TARGET_TARGETDATA_H
21 #define LLVM_TARGET_TARGETDATA_H
23 #include "llvm/Pass.h"
24 #include "Support/DataTypes.h"
35 class TargetData : public ImmutablePass {
36 bool LittleEndian; // Defaults to false
37 unsigned char ByteAlignment; // Defaults to 1 bytes
38 unsigned char ShortAlignment; // Defaults to 2 bytes
39 unsigned char IntAlignment; // Defaults to 4 bytes
40 unsigned char LongAlignment; // Defaults to 8 bytes
41 unsigned char FloatAlignment; // Defaults to 4 bytes
42 unsigned char DoubleAlignment; // Defaults to 8 bytes
43 unsigned char PointerSize; // Defaults to 8 bytes
44 unsigned char PointerAlignment; // Defaults to 8 bytes
46 TargetData(const std::string &TargetName = "",
47 bool LittleEndian = false,
48 unsigned char PtrSize = 8,
49 unsigned char PtrAl = 8, unsigned char DoubleAl = 8,
50 unsigned char FloatAl = 4, unsigned char LongAl = 8,
51 unsigned char IntAl = 4, unsigned char ShortAl = 2,
52 unsigned char ByteAl = 1);
53 TargetData(const std::string &ToolName, const Module *M);
54 ~TargetData(); // Not virtual, do not subclass this class
56 /// Target endianness...
57 bool isLittleEndian() const { return LittleEndian; }
58 bool isBigEndian() const { return !LittleEndian; }
60 /// Target alignment constraints
61 unsigned char getByteAlignment() const { return ByteAlignment; }
62 unsigned char getShortAlignment() const { return ShortAlignment; }
63 unsigned char getIntAlignment() const { return IntAlignment; }
64 unsigned char getLongAlignment() const { return LongAlignment; }
65 unsigned char getFloatAlignment() const { return FloatAlignment; }
66 unsigned char getDoubleAlignment() const { return DoubleAlignment; }
67 unsigned char getPointerAlignment() const { return PointerAlignment; }
68 unsigned char getPointerSize() const { return PointerSize; }
70 /// getTypeSize - Return the number of bytes necessary to hold the specified
72 uint64_t getTypeSize(const Type *Ty) const;
74 /// getTypeAlignment - Return the minimum required alignment for the specified
76 unsigned char getTypeAlignment(const Type *Ty) const;
78 /// getIntPtrType - Return an unsigned integer type that is the same size or
79 /// greater to the host pointer size.
80 const Type *getIntPtrType() const;
82 /// getIndexOffset - return the offset from the beginning of the type for the
83 /// specified indices. This is used to implement getelementptr.
85 uint64_t getIndexedOffset(const Type *Ty,
86 const std::vector<Value*> &Indices) const;
88 const StructLayout *getStructLayout(const StructType *Ty) const;
91 // This object is used to lazily calculate structure layout information for a
92 // target machine, based on the TargetData structure.
95 std::vector<uint64_t> MemberOffsets;
97 unsigned StructAlignment;
99 friend class TargetData; // Only TargetData can create this class
100 StructLayout(const StructType *ST, const TargetData &TD);
103 } // End llvm namespace