1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ART_RUNTIME_INSTRUCTION_SET_H_
18 #define ART_RUNTIME_INSTRUCTION_SET_H_
19
20 #include <iosfwd>
21 #include <string>
22
23 #include "base/logging.h" // Logging is required for FATAL in the helper functions.
24 #include "base/macros.h"
25 #include "globals.h" // For KB.
26
27 namespace art {
28
29 enum InstructionSet {
30 kNone,
31 kArm,
32 kArm64,
33 kThumb2,
34 kX86,
35 kX86_64,
36 kMips,
37 kMips64
38 };
39 std::ostream& operator<<(std::ostream& os, const InstructionSet& rhs);
40
41 #if defined(__arm__)
42 static constexpr InstructionSet kRuntimeISA = kArm;
43 #elif defined(__aarch64__)
44 static constexpr InstructionSet kRuntimeISA = kArm64;
45 #elif defined(__mips__)
46 static constexpr InstructionSet kRuntimeISA = kMips;
47 #elif defined(__i386__)
48 static constexpr InstructionSet kRuntimeISA = kX86;
49 #elif defined(__x86_64__)
50 static constexpr InstructionSet kRuntimeISA = kX86_64;
51 #else
52 static constexpr InstructionSet kRuntimeISA = kNone;
53 #endif
54
55 // Architecture-specific pointer sizes
56 static constexpr size_t kArmPointerSize = 4;
57 static constexpr size_t kArm64PointerSize = 8;
58 static constexpr size_t kMipsPointerSize = 4;
59 static constexpr size_t kX86PointerSize = 4;
60 static constexpr size_t kX86_64PointerSize = 8;
61
62 // ARM instruction alignment. ARM processors require code to be 4-byte aligned,
63 // but ARM ELF requires 8..
64 static constexpr size_t kArmAlignment = 8;
65
66 // ARM64 instruction alignment. This is the recommended alignment for maximum performance.
67 static constexpr size_t kArm64Alignment = 16;
68
69 // MIPS instruction alignment. MIPS processors require code to be 4-byte aligned.
70 // TODO: Can this be 4?
71 static constexpr size_t kMipsAlignment = 8;
72
73 // X86 instruction alignment. This is the recommended alignment for maximum performance.
74 static constexpr size_t kX86Alignment = 16;
75
76
77 const char* GetInstructionSetString(InstructionSet isa);
78
79 // Note: Returns kNone when the string cannot be parsed to a known value.
80 InstructionSet GetInstructionSetFromString(const char* instruction_set);
81
GetInstructionSetPointerSize(InstructionSet isa)82 static inline size_t GetInstructionSetPointerSize(InstructionSet isa) {
83 switch (isa) {
84 case kArm:
85 // Fall-through.
86 case kThumb2:
87 return kArmPointerSize;
88 case kArm64:
89 return kArm64PointerSize;
90 case kX86:
91 return kX86PointerSize;
92 case kX86_64:
93 return kX86_64PointerSize;
94 case kMips:
95 return kMipsPointerSize;
96 case kNone:
97 LOG(FATAL) << "ISA kNone does not have pointer size.";
98 return 0;
99 default:
100 LOG(FATAL) << "Unknown ISA " << isa;
101 return 0;
102 }
103 }
104
105 size_t GetInstructionSetAlignment(InstructionSet isa);
106
Is64BitInstructionSet(InstructionSet isa)107 static inline bool Is64BitInstructionSet(InstructionSet isa) {
108 switch (isa) {
109 case kArm:
110 case kThumb2:
111 case kX86:
112 case kMips:
113 return false;
114
115 case kArm64:
116 case kX86_64:
117 return true;
118
119 case kNone:
120 LOG(FATAL) << "ISA kNone does not have bit width.";
121 return 0;
122 default:
123 LOG(FATAL) << "Unknown ISA " << isa;
124 return 0;
125 }
126 }
127
InstructionSetPointerSize(InstructionSet isa)128 static inline size_t InstructionSetPointerSize(InstructionSet isa) {
129 return Is64BitInstructionSet(isa) ? 8U : 4U;
130 }
131
GetBytesPerGprSpillLocation(InstructionSet isa)132 static inline size_t GetBytesPerGprSpillLocation(InstructionSet isa) {
133 switch (isa) {
134 case kArm:
135 // Fall-through.
136 case kThumb2:
137 return 4;
138 case kArm64:
139 return 8;
140 case kX86:
141 return 4;
142 case kX86_64:
143 return 8;
144 case kMips:
145 return 4;
146 case kNone:
147 LOG(FATAL) << "ISA kNone does not have spills.";
148 return 0;
149 default:
150 LOG(FATAL) << "Unknown ISA " << isa;
151 return 0;
152 }
153 }
154
GetBytesPerFprSpillLocation(InstructionSet isa)155 static inline size_t GetBytesPerFprSpillLocation(InstructionSet isa) {
156 switch (isa) {
157 case kArm:
158 // Fall-through.
159 case kThumb2:
160 return 4;
161 case kArm64:
162 return 8;
163 case kX86:
164 return 8;
165 case kX86_64:
166 return 8;
167 case kMips:
168 return 4;
169 case kNone:
170 LOG(FATAL) << "ISA kNone does not have spills.";
171 return 0;
172 default:
173 LOG(FATAL) << "Unknown ISA " << isa;
174 return 0;
175 }
176 }
177
178 size_t GetStackOverflowReservedBytes(InstructionSet isa);
179
180 enum InstructionFeatures {
181 kHwDiv = 0x1, // Supports hardware divide.
182 kHwLpae = 0x2, // Supports Large Physical Address Extension.
183 };
184
185 // This is a bitmask of supported features per architecture.
186 class PACKED(4) InstructionSetFeatures {
187 public:
InstructionSetFeatures()188 InstructionSetFeatures() : mask_(0) {}
InstructionSetFeatures(uint32_t mask)189 explicit InstructionSetFeatures(uint32_t mask) : mask_(mask) {}
190
191 static InstructionSetFeatures GuessInstructionSetFeatures();
192
HasDivideInstruction()193 bool HasDivideInstruction() const {
194 return (mask_ & kHwDiv) != 0;
195 }
196
SetHasDivideInstruction(bool v)197 void SetHasDivideInstruction(bool v) {
198 mask_ = (mask_ & ~kHwDiv) | (v ? kHwDiv : 0);
199 }
200
HasLpae()201 bool HasLpae() const {
202 return (mask_ & kHwLpae) != 0;
203 }
204
SetHasLpae(bool v)205 void SetHasLpae(bool v) {
206 mask_ = (mask_ & ~kHwLpae) | (v ? kHwLpae : 0);
207 }
208
209 std::string GetFeatureString() const;
210
211 // Other features in here.
212
213 bool operator==(const InstructionSetFeatures &peer) const {
214 return mask_ == peer.mask_;
215 }
216
217 bool operator!=(const InstructionSetFeatures &peer) const {
218 return mask_ != peer.mask_;
219 }
220
221 bool operator<=(const InstructionSetFeatures &peer) const {
222 return (mask_ & peer.mask_) == mask_;
223 }
224
225 private:
226 uint32_t mask_;
227 };
228
229 // The following definitions create return types for two word-sized entities that will be passed
230 // in registers so that memory operations for the interface trampolines can be avoided. The entities
231 // are the resolved method and the pointer to the code to be invoked.
232 //
233 // On x86, ARM32 and MIPS, this is given for a *scalar* 64bit value. The definition thus *must* be
234 // uint64_t or long long int.
235 //
236 // On x86_64 and ARM64, structs are decomposed for allocation, so we can create a structs of two
237 // size_t-sized values.
238 //
239 // We need two operations:
240 //
241 // 1) A flag value that signals failure. The assembly stubs expect the lower part to be "0".
242 // GetTwoWordFailureValue() will return a value that has lower part == 0.
243 //
244 // 2) A value that combines two word-sized values.
245 // GetTwoWordSuccessValue() constructs this.
246 //
247 // IMPORTANT: If you use this to transfer object pointers, it is your responsibility to ensure
248 // that the object does not move or the value is updated. Simple use of this is NOT SAFE
249 // when the garbage collector can move objects concurrently. Ensure that required locks
250 // are held when using!
251
252 #if defined(__i386__) || defined(__arm__) || defined(__mips__)
253 typedef uint64_t TwoWordReturn;
254
255 // Encodes method_ptr==nullptr and code_ptr==nullptr
GetTwoWordFailureValue()256 static inline constexpr TwoWordReturn GetTwoWordFailureValue() {
257 return 0;
258 }
259
260 // Use the lower 32b for the method pointer and the upper 32b for the code pointer.
GetTwoWordSuccessValue(uintptr_t hi,uintptr_t lo)261 static inline TwoWordReturn GetTwoWordSuccessValue(uintptr_t hi, uintptr_t lo) {
262 uint32_t lo32 = static_cast<uint32_t>(lo);
263 uint64_t hi64 = static_cast<uint64_t>(hi);
264 return ((hi64 << 32) | lo32);
265 }
266
267 #elif defined(__x86_64__) || defined(__aarch64__)
268 struct TwoWordReturn {
269 uintptr_t lo;
270 uintptr_t hi;
271 };
272
273 // Encodes method_ptr==nullptr. Leaves random value in code pointer.
GetTwoWordFailureValue()274 static inline TwoWordReturn GetTwoWordFailureValue() {
275 TwoWordReturn ret;
276 ret.lo = 0;
277 return ret;
278 }
279
280 // Write values into their respective members.
GetTwoWordSuccessValue(uintptr_t hi,uintptr_t lo)281 static inline TwoWordReturn GetTwoWordSuccessValue(uintptr_t hi, uintptr_t lo) {
282 TwoWordReturn ret;
283 ret.lo = lo;
284 ret.hi = hi;
285 return ret;
286 }
287 #else
288 #error "Unsupported architecture"
289 #endif
290
291 } // namespace art
292
293 #endif // ART_RUNTIME_INSTRUCTION_SET_H_
294