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_LIBARTBASE_ARCH_INSTRUCTION_SET_H_
18 #define ART_LIBARTBASE_ARCH_INSTRUCTION_SET_H_
19
20 #include <iosfwd>
21 #include <string>
22
23 #include "base/enums.h"
24 #include "base/macros.h"
25
26 namespace art {
27
28 enum class InstructionSet {
29 kNone,
30 kArm,
31 kArm64,
32 kThumb2,
33 kX86,
34 kX86_64,
35 kLast = kX86_64
36 };
37 std::ostream& operator<<(std::ostream& os, InstructionSet rhs);
38
39 #if defined(__arm__)
40 static constexpr InstructionSet kRuntimeISA = InstructionSet::kArm;
41 #elif defined(__aarch64__)
42 static constexpr InstructionSet kRuntimeISA = InstructionSet::kArm64;
43 #elif defined(__i386__)
44 static constexpr InstructionSet kRuntimeISA = InstructionSet::kX86;
45 #elif defined(__x86_64__)
46 static constexpr InstructionSet kRuntimeISA = InstructionSet::kX86_64;
47 #else
48 static constexpr InstructionSet kRuntimeISA = InstructionSet::kNone;
49 #endif
50
51 // Architecture-specific pointer sizes
52 static constexpr PointerSize kArmPointerSize = PointerSize::k32;
53 static constexpr PointerSize kArm64PointerSize = PointerSize::k64;
54 static constexpr PointerSize kX86PointerSize = PointerSize::k32;
55 static constexpr PointerSize kX86_64PointerSize = PointerSize::k64;
56
57 // ARM instruction alignment. ARM processors require code to be 4-byte aligned,
58 // but ARM ELF requires 8..
59 static constexpr size_t kArmAlignment = 8;
60
61 // ARM64 instruction alignment. This is the recommended alignment for maximum performance.
62 static constexpr size_t kArm64Alignment = 16;
63
64 // ARM64 default SVE vector length.
65 static constexpr size_t kArm64DefaultSVEVectorLength = 256;
66
67 // X86 instruction alignment. This is the recommended alignment for maximum performance.
68 static constexpr size_t kX86Alignment = 16;
69
70 // Different than code alignment since code alignment is only first instruction of method.
71 static constexpr size_t kThumb2InstructionAlignment = 2;
72 static constexpr size_t kArm64InstructionAlignment = 4;
73 static constexpr size_t kX86InstructionAlignment = 1;
74 static constexpr size_t kX86_64InstructionAlignment = 1;
75
76 const char* GetInstructionSetString(InstructionSet isa);
77
78 // Note: Returns kNone when the string cannot be parsed to a known value.
79 InstructionSet GetInstructionSetFromString(const char* instruction_set);
80
81 // Fatal logging out of line to keep the header clean of logging.h.
82 NO_RETURN void InstructionSetAbort(InstructionSet isa);
83
GetInstructionSetPointerSize(InstructionSet isa)84 constexpr PointerSize GetInstructionSetPointerSize(InstructionSet isa) {
85 switch (isa) {
86 case InstructionSet::kArm:
87 // Fall-through.
88 case InstructionSet::kThumb2:
89 return kArmPointerSize;
90 case InstructionSet::kArm64:
91 return kArm64PointerSize;
92 case InstructionSet::kX86:
93 return kX86PointerSize;
94 case InstructionSet::kX86_64:
95 return kX86_64PointerSize;
96
97 case InstructionSet::kNone:
98 break;
99 }
100 InstructionSetAbort(isa);
101 }
102
GetInstructionSetInstructionAlignment(InstructionSet isa)103 constexpr size_t GetInstructionSetInstructionAlignment(InstructionSet isa) {
104 switch (isa) {
105 case InstructionSet::kArm:
106 // Fall-through.
107 case InstructionSet::kThumb2:
108 return kThumb2InstructionAlignment;
109 case InstructionSet::kArm64:
110 return kArm64InstructionAlignment;
111 case InstructionSet::kX86:
112 return kX86InstructionAlignment;
113 case InstructionSet::kX86_64:
114 return kX86_64InstructionAlignment;
115
116 case InstructionSet::kNone:
117 break;
118 }
119 InstructionSetAbort(isa);
120 }
121
IsValidInstructionSet(InstructionSet isa)122 constexpr bool IsValidInstructionSet(InstructionSet isa) {
123 switch (isa) {
124 case InstructionSet::kArm:
125 case InstructionSet::kThumb2:
126 case InstructionSet::kArm64:
127 case InstructionSet::kX86:
128 case InstructionSet::kX86_64:
129 return true;
130
131 case InstructionSet::kNone:
132 return false;
133 }
134 return false;
135 }
136
137 size_t GetInstructionSetAlignment(InstructionSet isa);
138
Is64BitInstructionSet(InstructionSet isa)139 constexpr bool Is64BitInstructionSet(InstructionSet isa) {
140 switch (isa) {
141 case InstructionSet::kArm:
142 case InstructionSet::kThumb2:
143 case InstructionSet::kX86:
144 return false;
145
146 case InstructionSet::kArm64:
147 case InstructionSet::kX86_64:
148 return true;
149
150 case InstructionSet::kNone:
151 break;
152 }
153 InstructionSetAbort(isa);
154 }
155
InstructionSetPointerSize(InstructionSet isa)156 constexpr PointerSize InstructionSetPointerSize(InstructionSet isa) {
157 return Is64BitInstructionSet(isa) ? PointerSize::k64 : PointerSize::k32;
158 }
159
GetBytesPerGprSpillLocation(InstructionSet isa)160 constexpr size_t GetBytesPerGprSpillLocation(InstructionSet isa) {
161 switch (isa) {
162 case InstructionSet::kArm:
163 // Fall-through.
164 case InstructionSet::kThumb2:
165 return 4;
166 case InstructionSet::kArm64:
167 return 8;
168 case InstructionSet::kX86:
169 return 4;
170 case InstructionSet::kX86_64:
171 return 8;
172
173 case InstructionSet::kNone:
174 break;
175 }
176 InstructionSetAbort(isa);
177 }
178
GetBytesPerFprSpillLocation(InstructionSet isa)179 constexpr size_t GetBytesPerFprSpillLocation(InstructionSet isa) {
180 switch (isa) {
181 case InstructionSet::kArm:
182 // Fall-through.
183 case InstructionSet::kThumb2:
184 return 4;
185 case InstructionSet::kArm64:
186 return 8;
187 case InstructionSet::kX86:
188 return 8;
189 case InstructionSet::kX86_64:
190 return 8;
191
192 case InstructionSet::kNone:
193 break;
194 }
195 InstructionSetAbort(isa);
196 }
197
198 namespace instruction_set_details {
199
200 #if !defined(ART_STACK_OVERFLOW_GAP_arm) || !defined(ART_STACK_OVERFLOW_GAP_arm64) || \
201 !defined(ART_STACK_OVERFLOW_GAP_x86) || !defined(ART_STACK_OVERFLOW_GAP_x86_64)
202 #error "Missing defines for stack overflow gap"
203 #endif
204
205 static constexpr size_t kArmStackOverflowReservedBytes = ART_STACK_OVERFLOW_GAP_arm;
206 static constexpr size_t kArm64StackOverflowReservedBytes = ART_STACK_OVERFLOW_GAP_arm64;
207 static constexpr size_t kX86StackOverflowReservedBytes = ART_STACK_OVERFLOW_GAP_x86;
208 static constexpr size_t kX86_64StackOverflowReservedBytes = ART_STACK_OVERFLOW_GAP_x86_64;
209
210 NO_RETURN void GetStackOverflowReservedBytesFailure(const char* error_msg);
211
212 } // namespace instruction_set_details
213
214 ALWAYS_INLINE
GetStackOverflowReservedBytes(InstructionSet isa)215 constexpr size_t GetStackOverflowReservedBytes(InstructionSet isa) {
216 switch (isa) {
217 case InstructionSet::kArm: // Intentional fall-through.
218 case InstructionSet::kThumb2:
219 return instruction_set_details::kArmStackOverflowReservedBytes;
220
221 case InstructionSet::kArm64:
222 return instruction_set_details::kArm64StackOverflowReservedBytes;
223
224 case InstructionSet::kX86:
225 return instruction_set_details::kX86StackOverflowReservedBytes;
226
227 case InstructionSet::kX86_64:
228 return instruction_set_details::kX86_64StackOverflowReservedBytes;
229
230 case InstructionSet::kNone:
231 instruction_set_details::GetStackOverflowReservedBytesFailure(
232 "kNone has no stack overflow size");
233 }
234 instruction_set_details::GetStackOverflowReservedBytesFailure("Unknown instruction set");
235 }
236
237 // The following definitions create return types for two word-sized entities that will be passed
238 // in registers so that memory operations for the interface trampolines can be avoided. The entities
239 // are the resolved method and the pointer to the code to be invoked.
240 //
241 // On x86 and ARM32, this is given for a *scalar* 64bit value. The definition thus *must* be
242 // uint64_t or long long int.
243 //
244 // On x86_64 and ARM64, structs are decomposed for allocation, so we can create a structs of
245 // two size_t-sized values.
246 //
247 // We need two operations:
248 //
249 // 1) A flag value that signals failure. The assembly stubs expect the lower part to be "0".
250 // GetTwoWordFailureValue() will return a value that has lower part == 0.
251 //
252 // 2) A value that combines two word-sized values.
253 // GetTwoWordSuccessValue() constructs this.
254 //
255 // IMPORTANT: If you use this to transfer object pointers, it is your responsibility to ensure
256 // that the object does not move or the value is updated. Simple use of this is NOT SAFE
257 // when the garbage collector can move objects concurrently. Ensure that required locks
258 // are held when using!
259
260 #if defined(__i386__) || defined(__arm__)
261 typedef uint64_t TwoWordReturn;
262
263 // Encodes method_ptr==nullptr and code_ptr==nullptr
GetTwoWordFailureValue()264 static inline constexpr TwoWordReturn GetTwoWordFailureValue() {
265 return 0;
266 }
267
268 // Use the lower 32b for the method pointer and the upper 32b for the code pointer.
GetTwoWordSuccessValue(uintptr_t hi,uintptr_t lo)269 static inline constexpr TwoWordReturn GetTwoWordSuccessValue(uintptr_t hi, uintptr_t lo) {
270 static_assert(sizeof(uint32_t) == sizeof(uintptr_t), "Unexpected size difference");
271 uint32_t lo32 = lo;
272 uint64_t hi64 = static_cast<uint64_t>(hi);
273 return ((hi64 << 32) | lo32);
274 }
275
276 #elif defined(__x86_64__) || defined(__aarch64__)
277
278 // Note: TwoWordReturn can't be constexpr for 64-bit targets. We'd need a constexpr constructor,
279 // which would violate C-linkage in the entrypoint functions.
280
281 struct TwoWordReturn {
282 uintptr_t lo;
283 uintptr_t hi;
284 };
285
286 // Encodes method_ptr==nullptr. Leaves random value in code pointer.
GetTwoWordFailureValue()287 static inline TwoWordReturn GetTwoWordFailureValue() {
288 TwoWordReturn ret;
289 ret.lo = 0;
290 return ret;
291 }
292
293 // Write values into their respective members.
GetTwoWordSuccessValue(uintptr_t hi,uintptr_t lo)294 static inline TwoWordReturn GetTwoWordSuccessValue(uintptr_t hi, uintptr_t lo) {
295 TwoWordReturn ret;
296 ret.lo = lo;
297 ret.hi = hi;
298 return ret;
299 }
300 #else
301 #error "Unsupported architecture"
302 #endif
303
304 } // namespace art
305
306 #endif // ART_LIBARTBASE_ARCH_INSTRUCTION_SET_H_
307