1 // Copyright 2013, ARM Limited
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are met:
6 //
7 // * Redistributions of source code must retain the above copyright notice,
8 // this list of conditions and the following disclaimer.
9 // * Redistributions in binary form must reproduce the above copyright notice,
10 // this list of conditions and the following disclaimer in the documentation
11 // and/or other materials provided with the distribution.
12 // * Neither the name of ARM Limited nor the names of its contributors may be
13 // used to endorse or promote products derived from this software without
14 // specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
17 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
20 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27 #ifndef VIXL_UTILS_H
28 #define VIXL_UTILS_H
29
30 #include <cmath>
31 #include <string.h>
32 #include "globals-vixl.h"
33
34 namespace vixl {
35
36 // Check number width.
is_intn(unsigned n,int64_t x)37 inline bool is_intn(unsigned n, int64_t x) {
38 VIXL_ASSERT((0 < n) && (n < 64));
39 int64_t limit = INT64_C(1) << (n - 1);
40 return (-limit <= x) && (x < limit);
41 }
42
is_uintn(unsigned n,int64_t x)43 inline bool is_uintn(unsigned n, int64_t x) {
44 VIXL_ASSERT((0 < n) && (n < 64));
45 return !(x >> n);
46 }
47
truncate_to_intn(unsigned n,int64_t x)48 inline unsigned truncate_to_intn(unsigned n, int64_t x) {
49 VIXL_ASSERT((0 < n) && (n < 64));
50 return (x & ((INT64_C(1) << n) - 1));
51 }
52
53 #define INT_1_TO_63_LIST(V) \
54 V(1) V(2) V(3) V(4) V(5) V(6) V(7) V(8) \
55 V(9) V(10) V(11) V(12) V(13) V(14) V(15) V(16) \
56 V(17) V(18) V(19) V(20) V(21) V(22) V(23) V(24) \
57 V(25) V(26) V(27) V(28) V(29) V(30) V(31) V(32) \
58 V(33) V(34) V(35) V(36) V(37) V(38) V(39) V(40) \
59 V(41) V(42) V(43) V(44) V(45) V(46) V(47) V(48) \
60 V(49) V(50) V(51) V(52) V(53) V(54) V(55) V(56) \
61 V(57) V(58) V(59) V(60) V(61) V(62) V(63)
62
63 #define DECLARE_IS_INT_N(N) \
64 inline bool is_int##N(int64_t x) { return is_intn(N, x); }
65 #define DECLARE_IS_UINT_N(N) \
66 inline bool is_uint##N(int64_t x) { return is_uintn(N, x); }
67 #define DECLARE_TRUNCATE_TO_INT_N(N) \
68 inline int truncate_to_int##N(int x) { return truncate_to_intn(N, x); }
69 INT_1_TO_63_LIST(DECLARE_IS_INT_N)
INT_1_TO_63_LIST(DECLARE_IS_UINT_N)70 INT_1_TO_63_LIST(DECLARE_IS_UINT_N)
71 INT_1_TO_63_LIST(DECLARE_TRUNCATE_TO_INT_N)
72 #undef DECLARE_IS_INT_N
73 #undef DECLARE_IS_UINT_N
74 #undef DECLARE_TRUNCATE_TO_INT_N
75
76 // Bit field extraction.
77 inline uint32_t unsigned_bitextract_32(int msb, int lsb, uint32_t x) {
78 return (x >> lsb) & ((1 << (1 + msb - lsb)) - 1);
79 }
80
unsigned_bitextract_64(int msb,int lsb,uint64_t x)81 inline uint64_t unsigned_bitextract_64(int msb, int lsb, uint64_t x) {
82 return (x >> lsb) & ((static_cast<uint64_t>(1) << (1 + msb - lsb)) - 1);
83 }
84
signed_bitextract_32(int msb,int lsb,int32_t x)85 inline int32_t signed_bitextract_32(int msb, int lsb, int32_t x) {
86 return (x << (31 - msb)) >> (lsb + 31 - msb);
87 }
88
signed_bitextract_64(int msb,int lsb,int64_t x)89 inline int64_t signed_bitextract_64(int msb, int lsb, int64_t x) {
90 return (x << (63 - msb)) >> (lsb + 63 - msb);
91 }
92
93 // Floating point representation.
94 uint32_t float_to_rawbits(float value);
95 uint64_t double_to_rawbits(double value);
96 float rawbits_to_float(uint32_t bits);
97 double rawbits_to_double(uint64_t bits);
98
99
100 // NaN tests.
IsSignallingNaN(double num)101 inline bool IsSignallingNaN(double num) {
102 const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
103 uint64_t raw = double_to_rawbits(num);
104 if (std::isnan(num) && ((raw & kFP64QuietNaNMask) == 0)) {
105 return true;
106 }
107 return false;
108 }
109
110
IsSignallingNaN(float num)111 inline bool IsSignallingNaN(float num) {
112 const uint32_t kFP32QuietNaNMask = 0x00400000;
113 uint32_t raw = float_to_rawbits(num);
114 if (std::isnan(num) && ((raw & kFP32QuietNaNMask) == 0)) {
115 return true;
116 }
117 return false;
118 }
119
120
121 template <typename T>
IsQuietNaN(T num)122 inline bool IsQuietNaN(T num) {
123 return std::isnan(num) && !IsSignallingNaN(num);
124 }
125
126
127 // Convert the NaN in 'num' to a quiet NaN.
ToQuietNaN(double num)128 inline double ToQuietNaN(double num) {
129 const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
130 VIXL_ASSERT(isnan(num));
131 return rawbits_to_double(double_to_rawbits(num) | kFP64QuietNaNMask);
132 }
133
134
ToQuietNaN(float num)135 inline float ToQuietNaN(float num) {
136 const uint32_t kFP32QuietNaNMask = 0x00400000;
137 VIXL_ASSERT(isnan(num));
138 return rawbits_to_float(float_to_rawbits(num) | kFP32QuietNaNMask);
139 }
140
141
142 // Fused multiply-add.
FusedMultiplyAdd(double op1,double op2,double a)143 inline double FusedMultiplyAdd(double op1, double op2, double a) {
144 return fma(op1, op2, a);
145 }
146
147
FusedMultiplyAdd(float op1,float op2,float a)148 inline float FusedMultiplyAdd(float op1, float op2, float a) {
149 return fmaf(op1, op2, a);
150 }
151
152
153 // Bit counting.
154 int CountLeadingZeros(uint64_t value, int width);
155 int CountLeadingSignBits(int64_t value, int width);
156 int CountTrailingZeros(uint64_t value, int width);
157 int CountSetBits(uint64_t value, int width);
158
159 // Pointer alignment
160 // TODO: rename/refactor to make it specific to instructions.
161 template<typename T>
IsWordAligned(T pointer)162 bool IsWordAligned(T pointer) {
163 VIXL_ASSERT(sizeof(pointer) == sizeof(intptr_t)); // NOLINT(runtime/sizeof)
164 return (reinterpret_cast<intptr_t>(pointer) & 3) == 0;
165 }
166
167 // Increment a pointer until it has the specified alignment.
168 template<class T>
AlignUp(T pointer,size_t alignment)169 T AlignUp(T pointer, size_t alignment) {
170 VIXL_STATIC_ASSERT(sizeof(pointer) == sizeof(uintptr_t));
171 uintptr_t pointer_raw = reinterpret_cast<uintptr_t>(pointer);
172 size_t align_step = (alignment - pointer_raw) % alignment;
173 VIXL_ASSERT((pointer_raw + align_step) % alignment == 0);
174 return reinterpret_cast<T>(pointer_raw + align_step);
175 }
176
177 // Decrement a pointer until it has the specified alignment.
178 template<class T>
AlignDown(T pointer,size_t alignment)179 T AlignDown(T pointer, size_t alignment) {
180 VIXL_STATIC_ASSERT(sizeof(pointer) == sizeof(uintptr_t));
181 uintptr_t pointer_raw = reinterpret_cast<uintptr_t>(pointer);
182 size_t align_step = pointer_raw % alignment;
183 VIXL_ASSERT((pointer_raw - align_step) % alignment == 0);
184 return reinterpret_cast<T>(pointer_raw - align_step);
185 }
186
187
188 } // namespace vixl
189
190 #endif // VIXL_UTILS_H
191