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"
36 class TargetData : public ImmutablePass {
37 bool LittleEndian; // Defaults to false
40 unsigned char BoolABIAlignment; // Defaults to 1 byte
41 unsigned char ByteABIAlignment; // Defaults to 1 byte
42 unsigned char ShortABIAlignment; // Defaults to 2 bytes
43 unsigned char IntABIAlignment; // Defaults to 4 bytes
44 unsigned char LongABIAlignment; // Defaults to 8 bytes
45 unsigned char FloatABIAlignment; // Defaults to 4 bytes
46 unsigned char DoubleABIAlignment; // Defaults to 8 bytes
47 unsigned char PointerMemSize; // Defaults to 8 bytes
48 unsigned char PointerABIAlignment; // Defaults to 8 bytes
50 // Preferred stack/global type alignments
51 unsigned char BoolPrefAlignment; // Defaults to BoolABIAlignment
52 unsigned char BytePrefAlignment; // Defaults to ByteABIAlignment
53 unsigned char ShortPrefAlignment; // Defaults to ShortABIAlignment
54 unsigned char IntPrefAlignment; // Defaults to IntABIAlignment
55 unsigned char LongPrefAlignment; // Defaults to LongABIAlignment
56 unsigned char FloatPrefAlignment; // Defaults to FloatABIAlignment
57 unsigned char DoublePrefAlignment; // Defaults to DoubleABIAlignment
58 unsigned char PointerPrefAlignment; // Defaults to PointerABIAlignment
59 unsigned char AggMinPrefAlignment; // Defaults to 0 bytes
62 /// Default ctor - This has to exist, because this is a pass, but it should
65 assert(0 && "ERROR: Bad TargetData ctor used. "
66 "Tool did not specify a TargetData to use?");
70 /// Constructs a TargetData from a string of the following format:
71 /// "E-p:64:64-d:64-f:32-l:64-i:32-s:16-b:8-B:8"
72 /// The above string is considered the default, and any values not specified
73 /// in the string will be assumed to be as above.
74 TargetData(const std::string &TargetDescription) {
75 init(TargetDescription);
78 /// Initialize target data from properties stored in the module.
79 TargetData(const Module *M);
81 TargetData(const TargetData &TD) :
83 LittleEndian(TD.isLittleEndian()),
84 BoolABIAlignment(TD.getBoolABIAlignment()),
85 ByteABIAlignment(TD.getByteABIAlignment()),
86 ShortABIAlignment(TD.getShortABIAlignment()),
87 IntABIAlignment(TD.getIntABIAlignment()),
88 LongABIAlignment(TD.getLongABIAlignment()),
89 FloatABIAlignment(TD.getFloatABIAlignment()),
90 DoubleABIAlignment(TD.getDoubleABIAlignment()),
91 PointerMemSize(TD.getPointerSize()),
92 PointerABIAlignment(TD.getPointerABIAlignment()),
93 BoolPrefAlignment(TD.getBoolPrefAlignment()),
94 BytePrefAlignment(TD.getBytePrefAlignment()),
95 ShortPrefAlignment(TD.getShortPrefAlignment()),
96 IntPrefAlignment(TD.getIntPrefAlignment()),
97 LongPrefAlignment(TD.getLongPrefAlignment()),
98 FloatPrefAlignment(TD.getFloatPrefAlignment()),
99 DoublePrefAlignment(TD.getDoublePrefAlignment()),
100 PointerPrefAlignment(TD.getPointerPrefAlignment()),
101 AggMinPrefAlignment(TD.getAggMinPrefAlignment()) {
104 ~TargetData(); // Not virtual, do not subclass this class
106 /// Parse a target data layout string and initialize TargetData members.
108 /// Parse a target data layout string, initializing the various TargetData
109 /// members along the way. A TargetData specification string looks like
110 /// "E-p:64:64-d:64-f:32-l:64-i:32-s:16-b:8-B:8" and specifies the
111 /// target's endianess, the ABI alignments of various data types and
112 /// the size of pointers.
114 /// "-" is used as a separator and ":" separates a token from its argument.
116 /// Alignment is indicated in bits and internally converted to the
117 /// appropriate number of bytes.
119 /// The preferred stack/global alignment specifications (":[prefalign]") are
120 /// optional and default to the ABI alignment.
124 /// <em>E</em> specifies big endian architecture (1234) [default]<br>
125 /// <em>e</em> specifies little endian architecture (4321) <br>
126 /// <em>p:[ptr size]:[ptr align]</em> specifies pointer size and alignment
127 /// [default = 64:64] <br>
128 /// <em>d:[align]:[prefalign]</em> specifies double floating
129 /// point alignment [default = 64] <br>
130 /// <em>f:[align]:[prefalign]</em> specifies single floating
131 /// point alignment [default = 32] <br>
132 /// <em>l:[align]:[prefalign]:[globalign[</em> specifies long integer
133 /// alignment [default = 64] <br>
134 /// <em>i:[align]:[prefalign]</em> specifies integer alignment
135 /// [default = 32] <br>
136 /// <em>s:[align]:[prefalign]</em> specifies short integer
137 /// alignment [default = 16] <br>
138 /// <em>b:[align]:[prefalign]</em> specifies byte data type
139 /// alignment [default = 8] <br>
140 /// <em>B:[align]:[prefalign]</em> specifies boolean data type
141 /// alignment [default = 8] <br>
142 /// <em>A:[prefalign]</em> specifies an aggregates' minimum alignment
143 /// on the stack and when emitted as a global. The default minimum aggregate
144 /// alignment defaults to 0, which causes the aggregate's "natural" internal
145 /// alignment calculated by llvm to be preferred.
147 /// All other token types are silently ignored.
148 void init(const std::string &TargetDescription);
151 /// Target endianness...
152 bool isLittleEndian() const { return LittleEndian; }
153 bool isBigEndian() const { return !LittleEndian; }
155 /// Target boolean alignment
156 unsigned char getBoolABIAlignment() const { return BoolABIAlignment; }
157 /// Target byte alignment
158 unsigned char getByteABIAlignment() const { return ByteABIAlignment; }
159 /// Target short alignment
160 unsigned char getShortABIAlignment() const { return ShortABIAlignment; }
161 /// Target integer alignment
162 unsigned char getIntABIAlignment() const { return IntABIAlignment; }
163 /// Target long alignment
164 unsigned char getLongABIAlignment() const { return LongABIAlignment; }
165 /// Target single precision float alignment
166 unsigned char getFloatABIAlignment() const { return FloatABIAlignment; }
167 /// Target double precision float alignment
168 unsigned char getDoubleABIAlignment() const { return DoubleABIAlignment; }
169 /// Target pointer alignment
170 unsigned char getPointerABIAlignment() const { return PointerABIAlignment; }
171 /// Target pointer size
172 unsigned char getPointerSize() const { return PointerMemSize; }
173 /// Target pointer size, in bits
174 unsigned char getPointerSizeInBits() const { return 8*PointerMemSize; }
176 /// Return target's alignment for booleans on stack
177 unsigned char getBoolPrefAlignment() const {
178 return BoolPrefAlignment;
180 /// Return target's alignment for integers on stack
181 unsigned char getBytePrefAlignment() const {
182 return BytePrefAlignment;
184 /// Return target's alignment for shorts on stack
185 unsigned char getShortPrefAlignment() const {
186 return ShortPrefAlignment;
188 /// Return target's alignment for integers on stack
189 unsigned char getIntPrefAlignment() const {
190 return IntPrefAlignment;
192 /// Return target's alignment for longs on stack
193 unsigned char getLongPrefAlignment() const {
194 return LongPrefAlignment;
196 /// Return target's alignment for single precision floats on stack
197 unsigned char getFloatPrefAlignment() const {
198 return FloatPrefAlignment;
200 /// Return target's alignment for double preceision floats on stack
201 unsigned char getDoublePrefAlignment() const {
202 return DoublePrefAlignment;
204 /// Return target's alignment for stack-based pointers
205 unsigned char getPointerPrefAlignment() const {
206 return PointerPrefAlignment;
208 /// Return target's alignment for stack-based structures
209 unsigned char getAggMinPrefAlignment() const {
210 return AggMinPrefAlignment;
213 /// getStringRepresentation - Return the string representation of the
214 /// TargetData. This representation is in the same format accepted by the
215 /// string constructor above.
216 std::string getStringRepresentation() const;
218 /// getTypeSize - Return the number of bytes necessary to hold the specified
221 uint64_t getTypeSize(const Type *Ty) const;
223 /// getTypeAlignmentABI - Return the minimum ABI-required alignment for the
225 unsigned char getTypeAlignmentABI(const Type *Ty) const;
227 /// getTypeAlignmentPref - Return the preferred stack/global alignment for
228 /// the specified type.
229 unsigned char getTypeAlignmentPref(const Type *Ty) const;
231 /// getTypeAlignmentShift - Return the minimum required alignment for the
232 /// specified type, returned as log2 of the value (a shift amount).
234 unsigned char getTypeAlignmentShift(const Type *Ty) const;
236 /// getIntPtrType - Return an unsigned integer type that is the same size or
237 /// greater to the host pointer size.
239 const Type *getIntPtrType() const;
241 /// getIndexOffset - return the offset from the beginning of the type for the
242 /// specified indices. This is used to implement getelementptr.
244 uint64_t getIndexedOffset(const Type *Ty,
245 const std::vector<Value*> &Indices) const;
247 /// getStructLayout - Return a StructLayout object, indicating the alignment
248 /// of the struct, its size, and the offsets of its fields. Note that this
249 /// information is lazily cached.
250 const StructLayout *getStructLayout(const StructType *Ty) const;
252 /// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout
253 /// objects. If a TargetData object is alive when types are being refined and
254 /// removed, this method must be called whenever a StructType is removed to
255 /// avoid a dangling pointer in this cache.
256 void InvalidateStructLayoutInfo(const StructType *Ty) const;
258 /// getPreferredAlignmentLog - Return the preferred alignment of the
259 /// specified global, returned in log form. This includes an explicitly
260 /// requested alignment (if the global has one).
261 unsigned getPreferredAlignmentLog(const GlobalVariable *GV) const;
264 /// StructLayout - used to lazily calculate structure layout information for a
265 /// target machine, based on the TargetData structure.
269 std::vector<uint64_t> MemberOffsets;
271 unsigned StructAlignment;
273 /// getElementContainingOffset - Given a valid offset into the structure,
274 /// return the structure index that contains it.
276 unsigned getElementContainingOffset(uint64_t Offset) const;
279 friend class TargetData; // Only TargetData can create this class
280 StructLayout(const StructType *ST, const TargetData &TD);
283 } // End llvm namespace