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 "llvm/Support/DataTypes.h"
35 class TargetData : public ImmutablePass {
36 bool LittleEndian; // Defaults to false
37 unsigned char BoolAlignment; // Defaults to 1 byte
38 unsigned char ByteAlignment; // Defaults to 1 byte
39 unsigned char ShortAlignment; // Defaults to 2 bytes
40 unsigned char IntAlignment; // Defaults to 4 bytes
41 unsigned char LongAlignment; // Defaults to 8 bytes
42 unsigned char FloatAlignment; // Defaults to 4 bytes
43 unsigned char DoubleAlignment; // Defaults to 8 bytes
44 unsigned char PointerSize; // Defaults to 8 bytes
45 unsigned char PointerAlignment; // Defaults to 8 bytes
48 TargetData(const std::string &TargetName = "",
49 bool LittleEndian = false,
50 unsigned char PtrSize = 8,
51 unsigned char PtrAl = 8, unsigned char DoubleAl = 8,
52 unsigned char FloatAl = 4, unsigned char LongAl = 8,
53 unsigned char IntAl = 4, unsigned char ShortAl = 2,
54 unsigned char ByteAl = 1, unsigned char BoolAl = 1);
57 TargetData (const TargetData &TD) :
59 LittleEndian(TD.isLittleEndian()),
60 BoolAlignment(TD.getBoolAlignment()),
61 ByteAlignment(TD.getByteAlignment()),
62 ShortAlignment(TD.getShortAlignment()),
63 IntAlignment(TD.getIntAlignment()),
64 LongAlignment(TD.getLongAlignment()),
65 FloatAlignment(TD.getFloatAlignment()),
66 DoubleAlignment(TD.getDoubleAlignment()),
67 PointerSize(TD.getPointerSize()),
68 PointerAlignment(TD.getPointerAlignment()) {
71 TargetData(const std::string &ToolName, const Module *M);
72 ~TargetData(); // Not virtual, do not subclass this class
74 /// Target endianness...
75 bool isLittleEndian() const { return LittleEndian; }
76 bool isBigEndian() const { return !LittleEndian; }
78 /// Target alignment constraints
79 unsigned char getBoolAlignment() const { return BoolAlignment; }
80 unsigned char getByteAlignment() const { return ByteAlignment; }
81 unsigned char getShortAlignment() const { return ShortAlignment; }
82 unsigned char getIntAlignment() const { return IntAlignment; }
83 unsigned char getLongAlignment() const { return LongAlignment; }
84 unsigned char getFloatAlignment() const { return FloatAlignment; }
85 unsigned char getDoubleAlignment() const { return DoubleAlignment; }
86 unsigned char getPointerAlignment() const { return PointerAlignment; }
87 unsigned char getPointerSize() const { return PointerSize; }
89 /// getTypeSize - Return the number of bytes necessary to hold the specified
91 uint64_t getTypeSize(const Type *Ty) const;
93 /// getTypeAlignment - Return the minimum required alignment for the specified
95 unsigned char getTypeAlignment(const Type *Ty) const;
97 /// getTypeAlignmentShift - Return the minimum required alignment for the
98 /// specified type, returned as log2 of the value (a shift amount).
99 unsigned char getTypeAlignmentShift(const Type *Ty) const;
101 /// getIntPtrType - Return an unsigned integer type that is the same size or
102 /// greater to the host pointer size.
103 const Type *getIntPtrType() const;
105 /// getIndexOffset - return the offset from the beginning of the type for the
106 /// specified indices. This is used to implement getelementptr.
108 uint64_t getIndexedOffset(const Type *Ty,
109 const std::vector<Value*> &Indices) const;
111 const StructLayout *getStructLayout(const StructType *Ty) const;
114 // This object is used to lazily calculate structure layout information for a
115 // target machine, based on the TargetData structure.
119 std::vector<uint64_t> MemberOffsets;
121 unsigned StructAlignment;
123 friend class TargetData; // Only TargetData can create this class
124 StructLayout(const StructType *ST, const TargetData &TD);
127 } // End llvm namespace