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1 : /* Operations with long integers.
2 : Copyright (C) 2006-2026 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
7 : under the terms of the GNU General Public License as published by the
8 : Free Software Foundation; either version 3, or (at your option) any
9 : later version.
10 :
11 : GCC is distributed in the hope that it will be useful, but WITHOUT
12 : ANY 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 DOUBLE_INT_H
21 : #define DOUBLE_INT_H
22 :
23 : /* A large integer is currently represented as a pair of HOST_WIDE_INTs.
24 : It therefore represents a number with precision of
25 : 2 * HOST_BITS_PER_WIDE_INT bits (it is however possible that the
26 : internal representation will change, if numbers with greater precision
27 : are needed, so the users should not rely on it). The representation does
28 : not contain any information about signedness of the represented value, so
29 : it can be used to represent both signed and unsigned numbers. For
30 : operations where the results depend on signedness (division, comparisons),
31 : it must be specified separately. For each such operation, there are three
32 : versions of the function -- double_int_op, that takes an extra UNS argument
33 : giving the signedness of the values, and double_int_sop and double_int_uop
34 : that stand for its specializations for signed and unsigned values.
35 :
36 : You may also represent with numbers in smaller precision using double_int.
37 : You however need to use double_int_ext (that fills in the bits of the
38 : number over the prescribed precision with zeros or with the sign bit) before
39 : operations that do not perform arithmetics modulo 2^precision (comparisons,
40 : division), and possibly before storing the results, if you want to keep
41 : them in some canonical form). In general, the signedness of double_int_ext
42 : should match the signedness of the operation.
43 :
44 : ??? The components of double_int differ in signedness mostly for
45 : historical reasons (they replace an older structure used to represent
46 : numbers with precision higher than HOST_WIDE_INT). It might be less
47 : confusing to have them both signed or both unsigned. */
48 :
49 : struct double_int
50 : {
51 : /* Normally, we would define constructors to create instances.
52 : Two things prevent us from doing so.
53 : First, defining a constructor makes the class non-POD in C++03,
54 : and we certainly want double_int to be a POD.
55 : Second, the GCC conding conventions prefer explicit conversion,
56 : and explicit conversion operators are not available until C++11. */
57 :
58 : static double_int from_uhwi (unsigned HOST_WIDE_INT cst);
59 : static double_int from_shwi (HOST_WIDE_INT cst);
60 : static double_int from_pair (HOST_WIDE_INT high, unsigned HOST_WIDE_INT low);
61 :
62 : /* Construct from a fuffer of length LEN. BUFFER will be read according
63 : to byte endianness and word endianness. */
64 : static double_int from_buffer (const unsigned char *buffer, int len);
65 :
66 : /* No copy assignment operator or destructor to keep the type a POD. */
67 :
68 : /* There are some special value-creation static member functions. */
69 :
70 : static double_int mask (unsigned prec);
71 : static double_int max_value (unsigned int prec, bool uns);
72 : static double_int min_value (unsigned int prec, bool uns);
73 :
74 : /* The following functions are mutating operations. */
75 :
76 : double_int &operator ++ (); // prefix
77 : double_int &operator -- (); // prefix
78 : double_int &operator *= (double_int);
79 : double_int &operator += (double_int);
80 : double_int &operator -= (double_int);
81 : double_int &operator &= (double_int);
82 : double_int &operator ^= (double_int);
83 : double_int &operator |= (double_int);
84 :
85 : /* The following functions are non-mutating operations. */
86 :
87 : /* Conversion functions. */
88 :
89 : HOST_WIDE_INT to_shwi () const;
90 : unsigned HOST_WIDE_INT to_uhwi () const;
91 :
92 : /* Conversion query functions. */
93 :
94 : bool fits_uhwi () const;
95 : bool fits_shwi () const;
96 : bool fits_hwi (bool uns) const;
97 :
98 : /* Attribute query functions. */
99 :
100 : int trailing_zeros () const;
101 : int popcount () const;
102 :
103 : /* Arithmetic query operations. */
104 :
105 : bool multiple_of (double_int, bool, double_int *) const;
106 :
107 : /* Arithmetic operation functions. */
108 :
109 : /* The following operations perform arithmetics modulo 2^precision, so you
110 : do not need to call .ext between them, even if you are representing
111 : numbers with precision less than HOST_BITS_PER_DOUBLE_INT bits. */
112 :
113 : double_int set_bit (unsigned) const;
114 : double_int mul_with_sign (double_int, bool unsigned_p, bool *overflow) const;
115 : double_int wide_mul_with_sign (double_int, bool unsigned_p,
116 : double_int *higher, bool *overflow) const;
117 : double_int add_with_sign (double_int, bool unsigned_p, bool *overflow) const;
118 : double_int sub_with_overflow (double_int, bool *overflow) const;
119 : double_int neg_with_overflow (bool *overflow) const;
120 :
121 : double_int operator * (double_int) const;
122 : double_int operator + (double_int) const;
123 : double_int operator - (double_int) const;
124 : double_int operator - () const;
125 : double_int operator ~ () const;
126 : double_int operator & (double_int) const;
127 : double_int operator | (double_int) const;
128 : double_int operator ^ (double_int) const;
129 : double_int and_not (double_int) const;
130 :
131 : double_int lshift (HOST_WIDE_INT count) const;
132 : double_int lshift (HOST_WIDE_INT count, unsigned int prec, bool arith) const;
133 : double_int rshift (HOST_WIDE_INT count) const;
134 : double_int rshift (HOST_WIDE_INT count, unsigned int prec, bool arith) const;
135 : double_int alshift (HOST_WIDE_INT count, unsigned int prec) const;
136 : double_int arshift (HOST_WIDE_INT count, unsigned int prec) const;
137 : double_int llshift (HOST_WIDE_INT count, unsigned int prec) const;
138 : double_int lrshift (HOST_WIDE_INT count, unsigned int prec) const;
139 : double_int lrotate (HOST_WIDE_INT count, unsigned int prec) const;
140 : double_int rrotate (HOST_WIDE_INT count, unsigned int prec) const;
141 :
142 : /* You must ensure that double_int::ext is called on the operands
143 : of the following operations, if the precision of the numbers
144 : is less than HOST_BITS_PER_DOUBLE_INT bits. */
145 :
146 : double_int div (double_int, bool, unsigned) const;
147 : double_int sdiv (double_int, unsigned) const;
148 : double_int udiv (double_int, unsigned) const;
149 : double_int mod (double_int, bool, unsigned) const;
150 : double_int smod (double_int, unsigned) const;
151 : double_int umod (double_int, unsigned) const;
152 : double_int divmod_with_overflow (double_int, bool, unsigned,
153 : double_int *, bool *) const;
154 : double_int divmod (double_int, bool, unsigned, double_int *) const;
155 : double_int sdivmod (double_int, unsigned, double_int *) const;
156 : double_int udivmod (double_int, unsigned, double_int *) const;
157 :
158 : /* Precision control functions. */
159 :
160 : double_int ext (unsigned prec, bool uns) const;
161 : double_int zext (unsigned prec) const;
162 : double_int sext (unsigned prec) const;
163 :
164 : /* Comparative functions. */
165 :
166 : bool is_zero () const;
167 : bool is_one () const;
168 : bool is_minus_one () const;
169 : bool is_negative () const;
170 :
171 : int cmp (double_int b, bool uns) const;
172 : int ucmp (double_int b) const;
173 : int scmp (double_int b) const;
174 :
175 : bool ult (double_int b) const;
176 : bool ule (double_int b) const;
177 : bool ugt (double_int b) const;
178 : bool slt (double_int b) const;
179 : bool sle (double_int b) const;
180 : bool sgt (double_int b) const;
181 :
182 : double_int max (double_int b, bool uns);
183 : double_int smax (double_int b);
184 : double_int umax (double_int b);
185 :
186 : double_int min (double_int b, bool uns);
187 : double_int smin (double_int b);
188 : double_int umin (double_int b);
189 :
190 : bool operator == (double_int cst2) const;
191 : bool operator != (double_int cst2) const;
192 :
193 : /* Please migrate away from using these member variables publicly. */
194 :
195 : unsigned HOST_WIDE_INT low;
196 : HOST_WIDE_INT high;
197 :
198 : };
199 :
200 : #define HOST_BITS_PER_DOUBLE_INT (2 * HOST_BITS_PER_WIDE_INT)
201 :
202 : /* Constructors and conversions. */
203 :
204 : /* Constructs double_int from integer CST. The bits over the precision of
205 : HOST_WIDE_INT are filled with the sign bit. */
206 :
207 : inline double_int
208 157 : double_int::from_shwi (HOST_WIDE_INT cst)
209 : {
210 157 : double_int r;
211 157 : r.low = (unsigned HOST_WIDE_INT) cst;
212 157 : r.high = cst < 0 ? -1 : 0;
213 157 : return r;
214 : }
215 :
216 : /* Some useful constants. */
217 : /* FIXME(crowl): Maybe remove after converting callers?
218 : The problem is that a named constant would not be as optimizable,
219 : while the functional syntax is more verbose. */
220 :
221 : #define double_int_minus_one (double_int::from_shwi (-1))
222 : #define double_int_zero (double_int::from_shwi (0))
223 : #define double_int_one (double_int::from_shwi (1))
224 : #define double_int_two (double_int::from_shwi (2))
225 : #define double_int_ten (double_int::from_shwi (10))
226 :
227 : /* Constructs double_int from unsigned integer CST. The bits over the
228 : precision of HOST_WIDE_INT are filled with zeros. */
229 :
230 : inline double_int
231 : double_int::from_uhwi (unsigned HOST_WIDE_INT cst)
232 : {
233 : double_int r;
234 : r.low = cst;
235 : r.high = 0;
236 : return r;
237 : }
238 :
239 : inline double_int
240 : double_int::from_pair (HOST_WIDE_INT high, unsigned HOST_WIDE_INT low)
241 : {
242 : double_int r;
243 : r.low = low;
244 : r.high = high;
245 : return r;
246 : }
247 :
248 : inline double_int &
249 : double_int::operator ++ ()
250 : {
251 : *this += double_int_one;
252 : return *this;
253 : }
254 :
255 : inline double_int &
256 0 : double_int::operator -- ()
257 : {
258 0 : *this -= double_int_one;
259 0 : return *this;
260 : }
261 :
262 : inline double_int &
263 : double_int::operator &= (double_int b)
264 : {
265 : *this = *this & b;
266 : return *this;
267 : }
268 :
269 : inline double_int &
270 : double_int::operator ^= (double_int b)
271 : {
272 : *this = *this ^ b;
273 : return *this;
274 : }
275 :
276 : inline double_int &
277 : double_int::operator |= (double_int b)
278 : {
279 : *this = *this | b;
280 : return *this;
281 : }
282 :
283 : /* Returns value of CST as a signed number. CST must satisfy
284 : double_int::fits_signed. */
285 :
286 : inline HOST_WIDE_INT
287 : double_int::to_shwi () const
288 : {
289 : return (HOST_WIDE_INT) low;
290 : }
291 :
292 : /* Returns value of CST as an unsigned number. CST must satisfy
293 : double_int::fits_unsigned. */
294 :
295 : inline unsigned HOST_WIDE_INT
296 : double_int::to_uhwi () const
297 : {
298 : return low;
299 : }
300 :
301 : /* Returns true if CST fits in unsigned HOST_WIDE_INT. */
302 :
303 : inline bool
304 0 : double_int::fits_uhwi () const
305 : {
306 0 : return high == 0;
307 : }
308 :
309 : /* Logical operations. */
310 :
311 : /* Returns ~A. */
312 :
313 : inline double_int
314 : double_int::operator ~ () const
315 : {
316 : double_int result;
317 : result.low = ~low;
318 : result.high = ~high;
319 : return result;
320 : }
321 :
322 : /* Returns A | B. */
323 :
324 : inline double_int
325 0 : double_int::operator | (double_int b) const
326 : {
327 0 : double_int result;
328 0 : result.low = low | b.low;
329 0 : result.high = high | b.high;
330 0 : return result;
331 : }
332 :
333 : /* Returns A & B. */
334 :
335 : inline double_int
336 : double_int::operator & (double_int b) const
337 : {
338 : double_int result;
339 : result.low = low & b.low;
340 : result.high = high & b.high;
341 : return result;
342 : }
343 :
344 : /* Returns A & ~B. */
345 :
346 : inline double_int
347 : double_int::and_not (double_int b) const
348 : {
349 : double_int result;
350 : result.low = low & ~b.low;
351 : result.high = high & ~b.high;
352 : return result;
353 : }
354 :
355 : /* Returns A ^ B. */
356 :
357 : inline double_int
358 : double_int::operator ^ (double_int b) const
359 : {
360 : double_int result;
361 : result.low = low ^ b.low;
362 : result.high = high ^ b.high;
363 : return result;
364 : }
365 :
366 : void dump_double_int (FILE *, double_int, bool);
367 :
368 : #define ALL_ONES HOST_WIDE_INT_M1U
369 :
370 : /* The operands of the following comparison functions must be processed
371 : with double_int_ext, if their precision is less than
372 : HOST_BITS_PER_DOUBLE_INT bits. */
373 :
374 : /* Returns true if CST is zero. */
375 :
376 : inline bool
377 0 : double_int::is_zero () const
378 : {
379 0 : return low == 0 && high == 0;
380 : }
381 :
382 : /* Returns true if CST is one. */
383 :
384 : inline bool
385 : double_int::is_one () const
386 : {
387 : return low == 1 && high == 0;
388 : }
389 :
390 : /* Returns true if CST is minus one. */
391 :
392 : inline bool
393 : double_int::is_minus_one () const
394 : {
395 : return low == ALL_ONES && high == -1;
396 : }
397 :
398 : /* Returns true if CST is negative. */
399 :
400 : inline bool
401 0 : double_int::is_negative () const
402 : {
403 0 : return high < 0;
404 : }
405 :
406 : /* Returns true if CST1 == CST2. */
407 :
408 : inline bool
409 0 : double_int::operator == (double_int cst2) const
410 : {
411 0 : return low == cst2.low && high == cst2.high;
412 : }
413 :
414 : /* Returns true if CST1 != CST2. */
415 :
416 : inline bool
417 0 : double_int::operator != (double_int cst2) const
418 : {
419 0 : return low != cst2.low || high != cst2.high;
420 : }
421 :
422 : /* Return number of set bits of CST. */
423 :
424 : inline int
425 : double_int::popcount () const
426 : {
427 : return popcount_hwi (high) + popcount_hwi (low);
428 : }
429 :
430 :
431 : #ifndef GENERATOR_FILE
432 : /* Conversion to and from GMP integer representations. */
433 :
434 : void mpz_set_double_int (mpz_t, double_int, bool);
435 : double_int mpz_get_double_int (const_tree, mpz_t, bool);
436 : #endif
437 :
438 : namespace wi
439 : {
440 : template <>
441 : struct int_traits <double_int>
442 : {
443 : static const enum precision_type precision_type = INL_CONST_PRECISION;
444 : static const bool host_dependent_precision = true;
445 : static const bool needs_write_val_arg = false;
446 : static const unsigned int precision = HOST_BITS_PER_DOUBLE_INT;
447 : static unsigned int get_precision (const double_int &);
448 : static wi::storage_ref decompose (HOST_WIDE_INT *, unsigned int,
449 : const double_int &);
450 : };
451 : }
452 :
453 : inline unsigned int
454 : wi::int_traits <double_int>::get_precision (const double_int &)
455 : {
456 : return precision;
457 : }
458 :
459 : inline wi::storage_ref
460 7287762 : wi::int_traits <double_int>::decompose (HOST_WIDE_INT *scratch, unsigned int p,
461 : const double_int &x)
462 : {
463 7287762 : gcc_checking_assert (precision == p);
464 7287762 : scratch[0] = x.low;
465 7287762 : if ((x.high == 0 && scratch[0] >= 0) || (x.high == -1 && scratch[0] < 0))
466 7270523 : return wi::storage_ref (scratch, 1, precision);
467 17239 : scratch[1] = x.high;
468 17239 : return wi::storage_ref (scratch, 2, precision);
469 : }
470 :
471 : #endif /* DOUBLE_INT_H */
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