1 //===-- llvm/Target/TargetData.h - Data size & alignment routines-*- C++ -*-==//
3 // This file defines target properties related to datatype size/offset/alignment
4 // information. It uses lazy annotations to cache information about how
5 // structure types are laid out and used.
7 // This structure should be created once, filled in if the defaults are not
8 // correct and then passed around by const&. None of the members functions
9 // require modification to the object.
11 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_TARGET_TARGETDATA_H
14 #define LLVM_TARGET_TARGETDATA_H
16 #include "llvm/Pass.h"
17 #include "Support/Annotation.h"
18 #include "Support/DataTypes.h"
25 class TargetData : public ImmutablePass {
26 bool LittleEndian; // Defaults to false
27 unsigned char ByteAlignment; // Defaults to 1 bytes
28 unsigned char ShortAlignment; // Defaults to 2 bytes
29 unsigned char IntAlignment; // Defaults to 4 bytes
30 unsigned char LongAlignment; // Defaults to 8 bytes
31 unsigned char FloatAlignment; // Defaults to 4 bytes
32 unsigned char DoubleAlignment; // Defaults to 8 bytes
33 unsigned char PointerSize; // Defaults to 8 bytes
34 unsigned char PointerAlignment; // Defaults to 8 bytes
35 AnnotationID AID; // AID for structure layout annotation
37 static Annotation *TypeAnFactory(AnnotationID, const Annotable *, void *);
39 TargetData(const std::string &TargetName = "",
40 bool LittleEndian = false,
41 unsigned char PtrSize = 8,
42 unsigned char PtrAl = 8, unsigned char DoubleAl = 8,
43 unsigned char FloatAl = 4, unsigned char LongAl = 8,
44 unsigned char IntAl = 4, unsigned char ShortAl = 2,
45 unsigned char ByteAl = 1);
46 TargetData(const std::string &ToolName, const Module *M);
47 ~TargetData(); // Not virtual, do not subclass this class
49 /// Target endianness...
50 bool isLittleEndian() const { return LittleEndian; }
51 bool isBigEndian() const { return !LittleEndian; }
53 /// Target alignment constraints
54 unsigned char getByteAlignment() const { return ByteAlignment; }
55 unsigned char getShortAlignment() const { return ShortAlignment; }
56 unsigned char getIntAlignment() const { return IntAlignment; }
57 unsigned char getLongAlignment() const { return LongAlignment; }
58 unsigned char getFloatAlignment() const { return FloatAlignment; }
59 unsigned char getDoubleAlignment() const { return DoubleAlignment; }
60 unsigned char getPointerAlignment() const { return PointerAlignment; }
61 unsigned char getPointerSize() const { return PointerSize; }
62 AnnotationID getStructLayoutAID() const { return AID; }
64 // getTypeSize - Return the number of bytes necessary to hold the specified
66 uint64_t getTypeSize (const Type *Ty) const;
68 // getTypeAlignment - Return the minimum required alignment for the specified
70 unsigned char getTypeAlignment(const Type *Ty) const;
72 // getIndexOffset - return the offset from the beginning of the type for the
73 // specified indices. This is used to implement getelementptr.
75 uint64_t getIndexedOffset(const Type *Ty,
76 const std::vector<Value*> &Indices) const;
78 inline const StructLayout *getStructLayout(const StructType *Ty) const {
79 return (const StructLayout*)
80 ((const Annotable*)Ty)->getOrCreateAnnotation(AID);
84 // This annotation (attached ONLY to StructType classes) is used to lazily
85 // calculate structure layout information for a target machine, based on the
86 // TargetData structure.
88 struct StructLayout : public Annotation {
89 std::vector<uint64_t> MemberOffsets;
91 unsigned StructAlignment;
93 friend class TargetData; // Only TargetData can create this class
94 inline StructLayout(const StructType *ST, const TargetData &TD);