Line data Source code
1 : /* Definitions for simple data type for real numbers.
2 : Copyright (C) 2002-2026 Free Software Foundation, Inc.
3 :
4 : This file is part of GCC.
5 :
6 : GCC is free software; you can redistribute it and/or modify it under
7 : the terms of the GNU General Public License as published by the Free
8 : Software Foundation; either version 3, or (at your option) any later
9 : version.
10 :
11 : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 : WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 : for more details.
15 :
16 : You should have received a copy of the GNU General Public License
17 : along with GCC; see the file COPYING3. If not see
18 : <http://www.gnu.org/licenses/>. */
19 :
20 : #ifndef GCC_SREAL_H
21 : #define GCC_SREAL_H
22 :
23 : #define SREAL_PART_BITS 31
24 :
25 : #define UINT64_BITS 64
26 :
27 : #define SREAL_MIN_SIG ((int64_t) 1 << (SREAL_PART_BITS - 2))
28 : #define SREAL_MAX_SIG (((int64_t) 1 << (SREAL_PART_BITS - 1)) - 1)
29 : #define SREAL_MAX_EXP (INT_MAX / 4)
30 :
31 : #define SREAL_BITS SREAL_PART_BITS
32 :
33 : #define SREAL_SIGN(v) (v < 0 ? -1 : 1)
34 : #define SREAL_ABS(v) (v < 0 ? -v : v)
35 :
36 : struct output_block;
37 : class lto_input_block;
38 :
39 : /* Structure for holding a simple real number. */
40 : class sreal
41 : {
42 : public:
43 : /* Construct an uninitialized sreal. */
44 1813380511 : sreal () : m_sig (-1), m_exp (-1) {}
45 :
46 : /* Construct a sreal. */
47 3401836472 : sreal (int64_t sig, int exp = 0)
48 : {
49 2920825006 : normalize (sig, exp);
50 : }
51 :
52 : void dump (FILE *) const;
53 : int64_t to_int () const;
54 : int64_t to_nearest_int () const;
55 : double to_double () const;
56 : void stream_out (struct output_block *);
57 : static sreal stream_in (class lto_input_block *);
58 : sreal operator+ (const sreal &other) const;
59 : sreal operator- (const sreal &other) const;
60 : sreal operator* (const sreal &other) const;
61 : sreal operator/ (const sreal &other) const;
62 :
63 643964538 : bool operator< (const sreal &other) const
64 : {
65 643964538 : if (m_exp == other.m_exp)
66 38834641 : return m_sig < other.m_sig;
67 : else
68 : {
69 605129897 : bool negative = m_sig < 0;
70 605129897 : bool other_negative = other.m_sig < 0;
71 :
72 605129897 : if (negative != other_negative)
73 41822874 : return negative > other_negative;
74 :
75 563307023 : bool r = m_exp < other.m_exp;
76 563307023 : return negative ? !r : r;
77 : }
78 : }
79 :
80 1172661137 : bool operator== (const sreal &other) const
81 : {
82 273785328 : return m_exp == other.m_exp && m_sig == other.m_sig;
83 : }
84 :
85 11587366 : sreal operator- () const
86 : {
87 11587366 : sreal tmp = *this;
88 11587366 : tmp.m_sig *= -1;
89 :
90 11587366 : return tmp;
91 : }
92 :
93 67476710 : sreal shift (int s) const
94 : {
95 : /* Zero needs no shifting. */
96 67476710 : if (!m_sig)
97 7253929 : return *this;
98 60222781 : gcc_checking_assert (s <= SREAL_MAX_EXP);
99 60222781 : gcc_checking_assert (s >= -SREAL_MAX_EXP);
100 :
101 : /* Overflows/drop to 0 could be handled gracefully, but hopefully we do not
102 : need to do so. */
103 60222781 : gcc_checking_assert (m_exp + s <= SREAL_MAX_EXP);
104 60222781 : gcc_checking_assert (m_exp + s >= -SREAL_MAX_EXP);
105 :
106 60222781 : sreal tmp = *this;
107 60222781 : tmp.m_exp += s;
108 :
109 60222781 : return tmp;
110 : }
111 :
112 : /* Global minimum sreal can hold. */
113 1305776 : inline static sreal min ()
114 : {
115 1305776 : sreal min;
116 : /* This never needs normalization. */
117 1305776 : min.m_sig = -SREAL_MAX_SIG;
118 1305776 : min.m_exp = SREAL_MAX_EXP;
119 1305776 : return min;
120 : }
121 :
122 : /* Global minimum sreal can hold. */
123 3276625 : inline static sreal max ()
124 : {
125 3276625 : sreal max;
126 : /* This never needs normalization. */
127 3276625 : max.m_sig = SREAL_MAX_SIG;
128 3276625 : max.m_exp = SREAL_MAX_EXP;
129 581893 : return max;
130 : }
131 :
132 : private:
133 : inline void normalize (int64_t new_sig, signed int new_exp);
134 : inline void normalize_up (int64_t new_sig, signed int new_exp);
135 : inline void normalize_down (int64_t new_sig, signed int new_exp);
136 : void shift_right (int amount);
137 : static sreal signedless_plus (const sreal &a, const sreal &b, bool negative);
138 : static sreal signedless_minus (const sreal &a, const sreal &b, bool negative);
139 :
140 : int32_t m_sig; /* Significant. */
141 : signed int m_exp; /* Exponent. */
142 : };
143 :
144 : extern void debug (const sreal &ref);
145 : extern void debug (const sreal *ptr);
146 :
147 709117038 : inline sreal &operator+= (sreal &a, const sreal &b)
148 : {
149 707541999 : return a = a + b;
150 : }
151 :
152 615573 : inline sreal &operator-= (sreal &a, const sreal &b)
153 : {
154 615573 : return a = a - b;
155 : }
156 :
157 602141 : inline sreal &operator/= (sreal &a, const sreal &b)
158 : {
159 602141 : return a = a / b;
160 : }
161 :
162 21128399 : inline sreal &operator*= (sreal &a, const sreal &b)
163 : {
164 21128399 : return a = a * b;
165 : }
166 :
167 74632133 : inline bool operator!= (const sreal &a, const sreal &b)
168 : {
169 130363047 : return !(a == b);
170 : }
171 :
172 477707223 : inline bool operator> (const sreal &a, const sreal &b)
173 : {
174 492275637 : return !(a == b || a < b);
175 : }
176 :
177 14104384 : inline bool operator<= (const sreal &a, const sreal &b)
178 : {
179 14104384 : return a < b || a == b;
180 : }
181 :
182 523624238 : inline bool operator>= (const sreal &a, const sreal &b)
183 : {
184 525495309 : return a == b || a > b;
185 : }
186 :
187 3157040 : inline sreal operator<< (const sreal &a, int exp)
188 : {
189 3157040 : return a.shift (exp);
190 : }
191 :
192 51696541 : inline sreal operator>> (const sreal &a, int exp)
193 : {
194 51696541 : return a.shift (-exp);
195 : }
196 :
197 : /* Make significant to be >= SREAL_MIN_SIG.
198 :
199 : Make this separate method so inliner can handle hot path better. */
200 :
201 : inline void
202 1244868036 : sreal::normalize_up (int64_t new_sig, signed int new_exp)
203 : {
204 1244868036 : unsigned HOST_WIDE_INT sig = absu_hwi (new_sig);
205 1244868036 : int shift = SREAL_PART_BITS - 2 - floor_log2 (sig);
206 :
207 1244868036 : gcc_checking_assert (shift > 0);
208 1244868036 : sig <<= shift;
209 1244868036 : new_exp -= shift;
210 1244868036 : gcc_checking_assert (sig <= SREAL_MAX_SIG && sig >= SREAL_MIN_SIG);
211 :
212 : /* Check underflow. */
213 1244868036 : if (new_exp < -SREAL_MAX_EXP)
214 : {
215 0 : new_exp = -SREAL_MAX_EXP;
216 0 : sig = 0;
217 : }
218 1244868036 : m_exp = new_exp;
219 1244868036 : if (SREAL_SIGN (new_sig) == -1)
220 47840474 : m_sig = -sig;
221 : else
222 1197027562 : m_sig = sig;
223 1244868036 : }
224 :
225 : /* Make significant to be <= SREAL_MAX_SIG.
226 :
227 : Make this separate method so inliner can handle hot path better. */
228 :
229 : inline void
230 1039555662 : sreal::normalize_down (int64_t new_sig, signed int new_exp)
231 : {
232 1039555662 : int last_bit;
233 1039555662 : unsigned HOST_WIDE_INT sig = absu_hwi (new_sig);
234 1039555662 : int shift = floor_log2 (sig) - SREAL_PART_BITS + 2;
235 :
236 1039555662 : gcc_checking_assert (shift > 0);
237 1039555662 : last_bit = (sig >> (shift-1)) & 1;
238 1039555662 : sig >>= shift;
239 1039555662 : new_exp += shift;
240 1039555662 : gcc_checking_assert (sig <= SREAL_MAX_SIG && sig >= SREAL_MIN_SIG);
241 :
242 : /* Round the number. */
243 1039555662 : sig += last_bit;
244 1039555662 : if (sig > SREAL_MAX_SIG)
245 : {
246 3922754 : sig >>= 1;
247 3922754 : new_exp++;
248 : }
249 :
250 : /* Check overflow. */
251 1039555662 : if (new_exp > SREAL_MAX_EXP)
252 : {
253 0 : new_exp = SREAL_MAX_EXP;
254 0 : sig = SREAL_MAX_SIG;
255 : }
256 1039555662 : m_exp = new_exp;
257 1039555662 : if (SREAL_SIGN (new_sig) == -1)
258 18084774 : m_sig = -sig;
259 : else
260 1021470888 : m_sig = sig;
261 1039555662 : }
262 :
263 : /* Normalize *this; the hot path. */
264 :
265 : inline void
266 3931802757 : sreal::normalize (int64_t new_sig, signed int new_exp)
267 : {
268 3931802757 : unsigned HOST_WIDE_INT sig = absu_hwi (new_sig);
269 :
270 3931802757 : if (sig == 0)
271 : {
272 1202393687 : m_sig = 0;
273 1202393687 : m_exp = -SREAL_MAX_EXP;
274 : }
275 2729409070 : else if (sig > SREAL_MAX_SIG)
276 1039555662 : normalize_down (new_sig, new_exp);
277 1689853408 : else if (sig < SREAL_MIN_SIG)
278 1244868036 : normalize_up (new_sig, new_exp);
279 : else
280 : {
281 444985372 : m_sig = new_sig;
282 444985372 : m_exp = new_exp;
283 : }
284 3931802757 : }
285 :
286 : #endif
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