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27#ifndef VIXL_UTILS_H
28#define VIXL_UTILS_H
29
30#include <cmath>
31#include <cstring>
32#include "vixl/globals.h"
33#include "vixl/compiler-intrinsics.h"
34
35namespace vixl {
36
37
38#if GCC_VERSION_OR_NEWER(4, 4, 0)
39#define PRINTF_CHECK(format_index, varargs_index) \
40 __attribute__((format(gnu_printf, format_index, varargs_index)))
41#else
42#define PRINTF_CHECK(format_index, varargs_index)
43#endif
44
45
46inline bool is_intn(unsigned n, int64_t x) {
47 VIXL_ASSERT((0 < n) && (n < 64));
48 int64_t limit = INT64_C(1) << (n - 1);
49 return (-limit <= x) && (x < limit);
50}
51
52inline bool is_uintn(unsigned n, int64_t x) {
53 VIXL_ASSERT((0 < n) && (n < 64));
54 return !(x >> n);
55}
56
57inline uint32_t truncate_to_intn(unsigned n, int64_t x) {
58 VIXL_ASSERT((0 < n) && (n < 64));
59 return static_cast<uint32_t>(x & ((INT64_C(1) << n) - 1));
60}
61
62#define INT_1_TO_63_LIST(V) \
63V(1) V(2) V(3) V(4) V(5) V(6) V(7) V(8) \
64V(9) V(10) V(11) V(12) V(13) V(14) V(15) V(16) \
65V(17) V(18) V(19) V(20) V(21) V(22) V(23) V(24) \
66V(25) V(26) V(27) V(28) V(29) V(30) V(31) V(32) \
67V(33) V(34) V(35) V(36) V(37) V(38) V(39) V(40) \
68V(41) V(42) V(43) V(44) V(45) V(46) V(47) V(48) \
69V(49) V(50) V(51) V(52) V(53) V(54) V(55) V(56) \
70V(57) V(58) V(59) V(60) V(61) V(62) V(63)
71
72#define DECLARE_IS_INT_N(N) \
73inline bool is_int##N(int64_t x) { return is_intn(N, x); }
74#define DECLARE_IS_UINT_N(N) \
75inline bool is_uint##N(int64_t x) { return is_uintn(N, x); }
76#define DECLARE_TRUNCATE_TO_INT_N(N) \
77inline uint32_t truncate_to_int##N(int x) { return truncate_to_intn(N, x); }
78INT_1_TO_63_LIST(DECLARE_IS_INT_N)
79INT_1_TO_63_LIST(DECLARE_IS_UINT_N)
80INT_1_TO_63_LIST(DECLARE_TRUNCATE_TO_INT_N)
81#undef DECLARE_IS_INT_N
82#undef DECLARE_IS_UINT_N
83#undef DECLARE_TRUNCATE_TO_INT_N
84
85
86inline uint32_t unsigned_bitextract_32(int msb, int lsb, uint32_t x) {
87 return (x >> lsb) & ((1 << (1 + msb - lsb)) - 1);
88}
89
90inline uint64_t unsigned_bitextract_64(int msb, int lsb, uint64_t x) {
91 return (x >> lsb) & ((static_cast<uint64_t>(1) << (1 + msb - lsb)) - 1);
92}
93
94inline int32_t signed_bitextract_32(int msb, int lsb, int32_t x) {
95 return (x << (31 - msb)) >> (lsb + 31 - msb);
96}
97
98inline int64_t signed_bitextract_64(int msb, int lsb, int64_t x) {
99 return (x << (63 - msb)) >> (lsb + 63 - msb);
100}
101
102
103uint32_t float_to_rawbits(float value);
104uint64_t double_to_rawbits(double value);
105float rawbits_to_float(uint32_t bits);
106double rawbits_to_double(uint64_t bits);
107
108uint32_t float_sign(float val);
109uint32_t float_exp(float val);
110uint32_t float_mantissa(float val);
111uint32_t double_sign(double val);
112uint32_t double_exp(double val);
113uint64_t double_mantissa(double val);
114
115float float_pack(uint32_t sign, uint32_t exp, uint32_t mantissa);
116double double_pack(uint64_t sign, uint64_t exp, uint64_t mantissa);
117
118
119int float16classify(float16 value);
120
121
122inline bool IsSignallingNaN(double num) {
123 const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
124 uint64_t raw = double_to_rawbits(num);
125 if (std::isnan(num) && ((raw & kFP64QuietNaNMask) == 0)) {
126 return true;
127 }
128 return false;
129}
130
131
132inline bool IsSignallingNaN(float num) {
133 const uint32_t kFP32QuietNaNMask = 0x00400000;
134 uint32_t raw = float_to_rawbits(num);
135 if (std::isnan(num) && ((raw & kFP32QuietNaNMask) == 0)) {
136 return true;
137 }
138 return false;
139}
140
141
142inline bool IsSignallingNaN(float16 num) {
143 const uint16_t kFP16QuietNaNMask = 0x0200;
144 return (float16classify(num) == FP_NAN) &&
145 ((num & kFP16QuietNaNMask) == 0);
146}
147
148
149template <typename T>
150inline bool IsQuietNaN(T num) {
151 return std::isnan(num) && !IsSignallingNaN(num);
152}
153
154
155
156inline double ToQuietNaN(double num) {
157 const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
158 VIXL_ASSERT(std::isnan(num));
159 return rawbits_to_double(double_to_rawbits(num) | kFP64QuietNaNMask);
160}
161
162
163inline float ToQuietNaN(float num) {
164 const uint32_t kFP32QuietNaNMask = 0x00400000;
165 VIXL_ASSERT(std::isnan(num));
166 return rawbits_to_float(float_to_rawbits(num) | kFP32QuietNaNMask);
167}
168
169
170
171inline double FusedMultiplyAdd(double op1, double op2, double a) {
172 return fma(op1, op2, a);
173}
174
175
176inline float FusedMultiplyAdd(float op1, float op2, float a) {
177 return fmaf(op1, op2, a);
178}
179
180
181inline uint64_t LowestSetBit(uint64_t value) {
182 return value & -value;
183}
184
185
186template<typename T>
187inline int HighestSetBitPosition(T value) {
188 VIXL_ASSERT(value != 0);
189 return (sizeof(value) * 8 - 1) - CountLeadingZeros(value);
190}
191
192
193template<typename V>
194inline int WhichPowerOf2(V value) {
195 VIXL_ASSERT(IsPowerOf2(value));
196 return CountTrailingZeros(value);
197}
198
199
200unsigned CountClearHalfWords(uint64_t imm, unsigned reg_size);
201
202
203template <typename T>
204T ReverseBits(T value) {
205 VIXL_ASSERT((sizeof(value) == 1) || (sizeof(value) == 2) ||
206 (sizeof(value) == 4) || (sizeof(value) == 8));
207 T result = 0;
208 for (unsigned i = 0; i < (sizeof(value) * 8); i++) {
209 result = (result << 1) | (value & 1);
210 value >>= 1;
211 }
212 return result;
213}
214
215
216template <typename T>
217T ReverseBytes(T value, int block_bytes_log2) {
218 VIXL_ASSERT((sizeof(value) == 4) || (sizeof(value) == 8));
219 VIXL_ASSERT((1U << block_bytes_log2) <= sizeof(value));
220
221
222 uint8_t bytes[8];
223 uint64_t mask = UINT64_C(0xff00000000000000);
224 for (int i = 7; i >= 0; i--) {
225 bytes[i] = (static_cast<uint64_t>(value) & mask) >> (i * 8);
226 mask >>= 8;
227 }
228
229
230
231
232
233 VIXL_ASSERT((0 < block_bytes_log2) && (block_bytes_log2 < 4));
234 static const uint8_t permute_table[3][8] = { {6, 7, 4, 5, 2, 3, 0, 1},
235 {4, 5, 6, 7, 0, 1, 2, 3},
236 {0, 1, 2, 3, 4, 5, 6, 7} };
237 T result = 0;
238 for (int i = 0; i < 8; i++) {
239 result <<= 8;
240 result |= bytes[permute_table[block_bytes_log2 - 1][i]];
241 }
242 return result;
243}
244
245
246
247
248template<typename T>
249bool IsWordAligned(T pointer) {
250 VIXL_ASSERT(sizeof(pointer) == sizeof(intptr_t));
251 return ((intptr_t)(pointer) & 3) == 0;
252}
253
254
255template<class T>
256T AlignUp(T pointer, size_t alignment) {
257
258
259
260 uint64_t pointer_raw = (uint64_t)pointer;
261 VIXL_STATIC_ASSERT(sizeof(pointer) <= sizeof(pointer_raw));
262
263 size_t align_step = (alignment - pointer_raw) % alignment;
264 VIXL_ASSERT((pointer_raw + align_step) % alignment == 0);
265
266 return (T)(pointer_raw + align_step);
267}
268
269
270template<class T>
271T AlignDown(T pointer, size_t alignment) {
272
273
274
275 uint64_t pointer_raw = (uint64_t)pointer;
276 VIXL_STATIC_ASSERT(sizeof(pointer) <= sizeof(pointer_raw));
277
278 size_t align_step = pointer_raw % alignment;
279 VIXL_ASSERT((pointer_raw - align_step) % alignment == 0);
280
281 return (T)(pointer_raw - align_step);
282}
283
284}
285
286#endif
287
