1 //===- llvm/ADT/APFloat.h - Arbitrary Precision Floating Point ---*- C++ -*-==//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// \brief
11 /// This file declares a class to represent arbitrary precision floating point
12 /// values and provide a variety of arithmetic operations on them.
13 ///
14 //===----------------------------------------------------------------------===//
15
16 #ifndef LLVM_ADT_APFLOAT_H
17 #define LLVM_ADT_APFLOAT_H
18
19 #include "llvm/ADT/APInt.h"
20 #include "llvm/ADT/ArrayRef.h"
21 #include "llvm/ADT/FloatingPointMode.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include <memory>
24
25 #define APFLOAT_DISPATCH_ON_SEMANTICS(METHOD_CALL) \
26 do { \
27 if (usesLayout<IEEEFloat>(getSemantics())) \
28 return U.IEEE.METHOD_CALL; \
29 if (usesLayout<DoubleAPFloat>(getSemantics())) \
30 return U.Double.METHOD_CALL; \
31 llvm_unreachable("Unexpected semantics"); \
32 } while (false)
33
34 namespace llvm {
35
36 struct fltSemantics;
37 class APSInt;
38 class StringRef;
39 class APFloat;
40 class raw_ostream;
41
42 template <typename T> class Expected;
43 template <typename T> class SmallVectorImpl;
44
45 /// Enum that represents what fraction of the LSB truncated bits of an fp number
46 /// represent.
47 ///
48 /// This essentially combines the roles of guard and sticky bits.
49 enum lostFraction { // Example of truncated bits:
50 lfExactlyZero, // 000000
51 lfLessThanHalf, // 0xxxxx x's not all zero
52 lfExactlyHalf, // 100000
53 lfMoreThanHalf // 1xxxxx x's not all zero
54 };
55
56 /// A self-contained host- and target-independent arbitrary-precision
57 /// floating-point software implementation.
58 ///
59 /// APFloat uses bignum integer arithmetic as provided by static functions in
60 /// the APInt class. The library will work with bignum integers whose parts are
61 /// any unsigned type at least 16 bits wide, but 64 bits is recommended.
62 ///
63 /// Written for clarity rather than speed, in particular with a view to use in
64 /// the front-end of a cross compiler so that target arithmetic can be correctly
65 /// performed on the host. Performance should nonetheless be reasonable,
66 /// particularly for its intended use. It may be useful as a base
67 /// implementation for a run-time library during development of a faster
68 /// target-specific one.
69 ///
70 /// All 5 rounding modes in the IEEE-754R draft are handled correctly for all
71 /// implemented operations. Currently implemented operations are add, subtract,
72 /// multiply, divide, fused-multiply-add, conversion-to-float,
73 /// conversion-to-integer and conversion-from-integer. New rounding modes
74 /// (e.g. away from zero) can be added with three or four lines of code.
75 ///
76 /// Four formats are built-in: IEEE single precision, double precision,
77 /// quadruple precision, and x87 80-bit extended double (when operating with
78 /// full extended precision). Adding a new format that obeys IEEE semantics
79 /// only requires adding two lines of code: a declaration and definition of the
80 /// format.
81 ///
82 /// All operations return the status of that operation as an exception bit-mask,
83 /// so multiple operations can be done consecutively with their results or-ed
84 /// together. The returned status can be useful for compiler diagnostics; e.g.,
85 /// inexact, underflow and overflow can be easily diagnosed on constant folding,
86 /// and compiler optimizers can determine what exceptions would be raised by
87 /// folding operations and optimize, or perhaps not optimize, accordingly.
88 ///
89 /// At present, underflow tininess is detected after rounding; it should be
90 /// straight forward to add support for the before-rounding case too.
91 ///
92 /// The library reads hexadecimal floating point numbers as per C99, and
93 /// correctly rounds if necessary according to the specified rounding mode.
94 /// Syntax is required to have been validated by the caller. It also converts
95 /// floating point numbers to hexadecimal text as per the C99 %a and %A
96 /// conversions. The output precision (or alternatively the natural minimal
97 /// precision) can be specified; if the requested precision is less than the
98 /// natural precision the output is correctly rounded for the specified rounding
99 /// mode.
100 ///
101 /// It also reads decimal floating point numbers and correctly rounds according
102 /// to the specified rounding mode.
103 ///
104 /// Conversion to decimal text is not currently implemented.
105 ///
106 /// Non-zero finite numbers are represented internally as a sign bit, a 16-bit
107 /// signed exponent, and the significand as an array of integer parts. After
108 /// normalization of a number of precision P the exponent is within the range of
109 /// the format, and if the number is not denormal the P-th bit of the
110 /// significand is set as an explicit integer bit. For denormals the most
111 /// significant bit is shifted right so that the exponent is maintained at the
112 /// format's minimum, so that the smallest denormal has just the least
113 /// significant bit of the significand set. The sign of zeroes and infinities
114 /// is significant; the exponent and significand of such numbers is not stored,
115 /// but has a known implicit (deterministic) value: 0 for the significands, 0
116 /// for zero exponent, all 1 bits for infinity exponent. For NaNs the sign and
117 /// significand are deterministic, although not really meaningful, and preserved
118 /// in non-conversion operations. The exponent is implicitly all 1 bits.
119 ///
120 /// APFloat does not provide any exception handling beyond default exception
121 /// handling. We represent Signaling NaNs via IEEE-754R 2008 6.2.1 should clause
122 /// by encoding Signaling NaNs with the first bit of its trailing significand as
123 /// 0.
124 ///
125 /// TODO
126 /// ====
127 ///
128 /// Some features that may or may not be worth adding:
129 ///
130 /// Binary to decimal conversion (hard).
131 ///
132 /// Optional ability to detect underflow tininess before rounding.
133 ///
134 /// New formats: x87 in single and double precision mode (IEEE apart from
135 /// extended exponent range) (hard).
136 ///
137 /// New operations: sqrt, IEEE remainder, C90 fmod, nexttoward.
138 ///
139
140 // This is the common type definitions shared by APFloat and its internal
141 // implementation classes. This struct should not define any non-static data
142 // members.
143 struct APFloatBase {
144 typedef APInt::WordType integerPart;
145 static constexpr unsigned integerPartWidth = APInt::APINT_BITS_PER_WORD;
146
147 /// A signed type to represent a floating point numbers unbiased exponent.
148 typedef int32_t ExponentType;
149
150 /// \name Floating Point Semantics.
151 /// @{
152 enum Semantics {
153 S_IEEEhalf,
154 S_BFloat,
155 S_IEEEsingle,
156 S_IEEEdouble,
157 S_x87DoubleExtended,
158 S_IEEEquad,
159 S_PPCDoubleDouble
160 };
161
162 static const llvm::fltSemantics &EnumToSemantics(Semantics S);
163 static Semantics SemanticsToEnum(const llvm::fltSemantics &Sem);
164
165 static const fltSemantics &IEEEhalf() LLVM_READNONE;
166 static const fltSemantics &BFloat() LLVM_READNONE;
167 static const fltSemantics &IEEEsingle() LLVM_READNONE;
168 static const fltSemantics &IEEEdouble() LLVM_READNONE;
169 static const fltSemantics &IEEEquad() LLVM_READNONE;
170 static const fltSemantics &PPCDoubleDouble() LLVM_READNONE;
171 static const fltSemantics &x87DoubleExtended() LLVM_READNONE;
172
173 /// A Pseudo fltsemantic used to construct APFloats that cannot conflict with
174 /// anything real.
175 static const fltSemantics &Bogus() LLVM_READNONE;
176
177 /// @}
178
179 /// IEEE-754R 5.11: Floating Point Comparison Relations.
180 enum cmpResult {
181 cmpLessThan,
182 cmpEqual,
183 cmpGreaterThan,
184 cmpUnordered
185 };
186
187 /// IEEE-754R 4.3: Rounding-direction attributes.
188 using roundingMode = llvm::RoundingMode;
189
190 static constexpr roundingMode rmNearestTiesToEven =
191 RoundingMode::NearestTiesToEven;
192 static constexpr roundingMode rmTowardPositive = RoundingMode::TowardPositive;
193 static constexpr roundingMode rmTowardNegative = RoundingMode::TowardNegative;
194 static constexpr roundingMode rmTowardZero = RoundingMode::TowardZero;
195 static constexpr roundingMode rmNearestTiesToAway =
196 RoundingMode::NearestTiesToAway;
197
198 /// IEEE-754R 7: Default exception handling.
199 ///
200 /// opUnderflow or opOverflow are always returned or-ed with opInexact.
201 ///
202 /// APFloat models this behavior specified by IEEE-754:
203 /// "For operations producing results in floating-point format, the default
204 /// result of an operation that signals the invalid operation exception
205 /// shall be a quiet NaN."
206 enum opStatus {
207 opOK = 0x00,
208 opInvalidOp = 0x01,
209 opDivByZero = 0x02,
210 opOverflow = 0x04,
211 opUnderflow = 0x08,
212 opInexact = 0x10
213 };
214
215 /// Category of internally-represented number.
216 enum fltCategory {
217 fcInfinity,
218 fcNaN,
219 fcNormal,
220 fcZero
221 };
222
223 /// Convenience enum used to construct an uninitialized APFloat.
224 enum uninitializedTag {
225 uninitialized
226 };
227
228 /// Enumeration of \c ilogb error results.
229 enum IlogbErrorKinds {
230 IEK_Zero = INT_MIN + 1,
231 IEK_NaN = INT_MIN,
232 IEK_Inf = INT_MAX
233 };
234
235 static unsigned int semanticsPrecision(const fltSemantics &);
236 static ExponentType semanticsMinExponent(const fltSemantics &);
237 static ExponentType semanticsMaxExponent(const fltSemantics &);
238 static unsigned int semanticsSizeInBits(const fltSemantics &);
239
240 /// Returns the size of the floating point number (in bits) in the given
241 /// semantics.
242 static unsigned getSizeInBits(const fltSemantics &Sem);
243 };
244
245 namespace detail {
246
247 class IEEEFloat final : public APFloatBase {
248 public:
249 /// \name Constructors
250 /// @{
251
252 IEEEFloat(const fltSemantics &); // Default construct to 0.0
253 IEEEFloat(const fltSemantics &, integerPart);
254 IEEEFloat(const fltSemantics &, uninitializedTag);
255 IEEEFloat(const fltSemantics &, const APInt &);
256 explicit IEEEFloat(double d);
257 explicit IEEEFloat(float f);
258 IEEEFloat(const IEEEFloat &);
259 IEEEFloat(IEEEFloat &&);
260 ~IEEEFloat();
261
262 /// @}
263
264 /// Returns whether this instance allocated memory.
needsCleanup()265 bool needsCleanup() const { return partCount() > 1; }
266
267 /// \name Convenience "constructors"
268 /// @{
269
270 /// @}
271
272 /// \name Arithmetic
273 /// @{
274
275 opStatus add(const IEEEFloat &, roundingMode);
276 opStatus subtract(const IEEEFloat &, roundingMode);
277 opStatus multiply(const IEEEFloat &, roundingMode);
278 opStatus divide(const IEEEFloat &, roundingMode);
279 /// IEEE remainder.
280 opStatus remainder(const IEEEFloat &);
281 /// C fmod, or llvm frem.
282 opStatus mod(const IEEEFloat &);
283 opStatus fusedMultiplyAdd(const IEEEFloat &, const IEEEFloat &, roundingMode);
284 opStatus roundToIntegral(roundingMode);
285 /// IEEE-754R 5.3.1: nextUp/nextDown.
286 opStatus next(bool nextDown);
287
288 /// @}
289
290 /// \name Sign operations.
291 /// @{
292
293 void changeSign();
294
295 /// @}
296
297 /// \name Conversions
298 /// @{
299
300 opStatus convert(const fltSemantics &, roundingMode, bool *);
301 opStatus convertToInteger(MutableArrayRef<integerPart>, unsigned int, bool,
302 roundingMode, bool *) const;
303 opStatus convertFromAPInt(const APInt &, bool, roundingMode);
304 opStatus convertFromSignExtendedInteger(const integerPart *, unsigned int,
305 bool, roundingMode);
306 opStatus convertFromZeroExtendedInteger(const integerPart *, unsigned int,
307 bool, roundingMode);
308 Expected<opStatus> convertFromString(StringRef, roundingMode);
309 APInt bitcastToAPInt() const;
310 double convertToDouble() const;
311 float convertToFloat() const;
312
313 /// @}
314
315 /// The definition of equality is not straightforward for floating point, so
316 /// we won't use operator==. Use one of the following, or write whatever it
317 /// is you really mean.
318 bool operator==(const IEEEFloat &) const = delete;
319
320 /// IEEE comparison with another floating point number (NaNs compare
321 /// unordered, 0==-0).
322 cmpResult compare(const IEEEFloat &) const;
323
324 /// Bitwise comparison for equality (QNaNs compare equal, 0!=-0).
325 bool bitwiseIsEqual(const IEEEFloat &) const;
326
327 /// Write out a hexadecimal representation of the floating point value to DST,
328 /// which must be of sufficient size, in the C99 form [-]0xh.hhhhp[+-]d.
329 /// Return the number of characters written, excluding the terminating NUL.
330 unsigned int convertToHexString(char *dst, unsigned int hexDigits,
331 bool upperCase, roundingMode) const;
332
333 /// \name IEEE-754R 5.7.2 General operations.
334 /// @{
335
336 /// IEEE-754R isSignMinus: Returns true if and only if the current value is
337 /// negative.
338 ///
339 /// This applies to zeros and NaNs as well.
isNegative()340 bool isNegative() const { return sign; }
341
342 /// IEEE-754R isNormal: Returns true if and only if the current value is normal.
343 ///
344 /// This implies that the current value of the float is not zero, subnormal,
345 /// infinite, or NaN following the definition of normality from IEEE-754R.
isNormal()346 bool isNormal() const { return !isDenormal() && isFiniteNonZero(); }
347
348 /// Returns true if and only if the current value is zero, subnormal, or
349 /// normal.
350 ///
351 /// This means that the value is not infinite or NaN.
isFinite()352 bool isFinite() const { return !isNaN() && !isInfinity(); }
353
354 /// Returns true if and only if the float is plus or minus zero.
isZero()355 bool isZero() const { return category == fcZero; }
356
357 /// IEEE-754R isSubnormal(): Returns true if and only if the float is a
358 /// denormal.
359 bool isDenormal() const;
360
361 /// IEEE-754R isInfinite(): Returns true if and only if the float is infinity.
isInfinity()362 bool isInfinity() const { return category == fcInfinity; }
363
364 /// Returns true if and only if the float is a quiet or signaling NaN.
isNaN()365 bool isNaN() const { return category == fcNaN; }
366
367 /// Returns true if and only if the float is a signaling NaN.
368 bool isSignaling() const;
369
370 /// @}
371
372 /// \name Simple Queries
373 /// @{
374
getCategory()375 fltCategory getCategory() const { return category; }
getSemantics()376 const fltSemantics &getSemantics() const { return *semantics; }
isNonZero()377 bool isNonZero() const { return category != fcZero; }
isFiniteNonZero()378 bool isFiniteNonZero() const { return isFinite() && !isZero(); }
isPosZero()379 bool isPosZero() const { return isZero() && !isNegative(); }
isNegZero()380 bool isNegZero() const { return isZero() && isNegative(); }
381
382 /// Returns true if and only if the number has the smallest possible non-zero
383 /// magnitude in the current semantics.
384 bool isSmallest() const;
385
386 /// Returns true if and only if the number has the largest possible finite
387 /// magnitude in the current semantics.
388 bool isLargest() const;
389
390 /// Returns true if and only if the number is an exact integer.
391 bool isInteger() const;
392
393 /// @}
394
395 IEEEFloat &operator=(const IEEEFloat &);
396 IEEEFloat &operator=(IEEEFloat &&);
397
398 /// Overload to compute a hash code for an APFloat value.
399 ///
400 /// Note that the use of hash codes for floating point values is in general
401 /// frought with peril. Equality is hard to define for these values. For
402 /// example, should negative and positive zero hash to different codes? Are
403 /// they equal or not? This hash value implementation specifically
404 /// emphasizes producing different codes for different inputs in order to
405 /// be used in canonicalization and memoization. As such, equality is
406 /// bitwiseIsEqual, and 0 != -0.
407 friend hash_code hash_value(const IEEEFloat &Arg);
408
409 /// Converts this value into a decimal string.
410 ///
411 /// \param FormatPrecision The maximum number of digits of
412 /// precision to output. If there are fewer digits available,
413 /// zero padding will not be used unless the value is
414 /// integral and small enough to be expressed in
415 /// FormatPrecision digits. 0 means to use the natural
416 /// precision of the number.
417 /// \param FormatMaxPadding The maximum number of zeros to
418 /// consider inserting before falling back to scientific
419 /// notation. 0 means to always use scientific notation.
420 ///
421 /// \param TruncateZero Indicate whether to remove the trailing zero in
422 /// fraction part or not. Also setting this parameter to false forcing
423 /// producing of output more similar to default printf behavior.
424 /// Specifically the lower e is used as exponent delimiter and exponent
425 /// always contains no less than two digits.
426 ///
427 /// Number Precision MaxPadding Result
428 /// ------ --------- ---------- ------
429 /// 1.01E+4 5 2 10100
430 /// 1.01E+4 4 2 1.01E+4
431 /// 1.01E+4 5 1 1.01E+4
432 /// 1.01E-2 5 2 0.0101
433 /// 1.01E-2 4 2 0.0101
434 /// 1.01E-2 4 1 1.01E-2
435 void toString(SmallVectorImpl<char> &Str, unsigned FormatPrecision = 0,
436 unsigned FormatMaxPadding = 3, bool TruncateZero = true) const;
437
438 /// If this value has an exact multiplicative inverse, store it in inv and
439 /// return true.
440 bool getExactInverse(APFloat *inv) const;
441
442 /// Returns the exponent of the internal representation of the APFloat.
443 ///
444 /// Because the radix of APFloat is 2, this is equivalent to floor(log2(x)).
445 /// For special APFloat values, this returns special error codes:
446 ///
447 /// NaN -> \c IEK_NaN
448 /// 0 -> \c IEK_Zero
449 /// Inf -> \c IEK_Inf
450 ///
451 friend int ilogb(const IEEEFloat &Arg);
452
453 /// Returns: X * 2^Exp for integral exponents.
454 friend IEEEFloat scalbn(IEEEFloat X, int Exp, roundingMode);
455
456 friend IEEEFloat frexp(const IEEEFloat &X, int &Exp, roundingMode);
457
458 /// \name Special value setters.
459 /// @{
460
461 void makeLargest(bool Neg = false);
462 void makeSmallest(bool Neg = false);
463 void makeNaN(bool SNaN = false, bool Neg = false,
464 const APInt *fill = nullptr);
465 void makeInf(bool Neg = false);
466 void makeZero(bool Neg = false);
467 void makeQuiet();
468
469 /// Returns the smallest (by magnitude) normalized finite number in the given
470 /// semantics.
471 ///
472 /// \param Negative - True iff the number should be negative
473 void makeSmallestNormalized(bool Negative = false);
474
475 /// @}
476
477 cmpResult compareAbsoluteValue(const IEEEFloat &) const;
478
479 private:
480 /// \name Simple Queries
481 /// @{
482
483 integerPart *significandParts();
484 const integerPart *significandParts() const;
485 unsigned int partCount() const;
486
487 /// @}
488
489 /// \name Significand operations.
490 /// @{
491
492 integerPart addSignificand(const IEEEFloat &);
493 integerPart subtractSignificand(const IEEEFloat &, integerPart);
494 lostFraction addOrSubtractSignificand(const IEEEFloat &, bool subtract);
495 lostFraction multiplySignificand(const IEEEFloat &, IEEEFloat);
496 lostFraction multiplySignificand(const IEEEFloat&);
497 lostFraction divideSignificand(const IEEEFloat &);
498 void incrementSignificand();
499 void initialize(const fltSemantics *);
500 void shiftSignificandLeft(unsigned int);
501 lostFraction shiftSignificandRight(unsigned int);
502 unsigned int significandLSB() const;
503 unsigned int significandMSB() const;
504 void zeroSignificand();
505 /// Return true if the significand excluding the integral bit is all ones.
506 bool isSignificandAllOnes() const;
507 /// Return true if the significand excluding the integral bit is all zeros.
508 bool isSignificandAllZeros() const;
509
510 /// @}
511
512 /// \name Arithmetic on special values.
513 /// @{
514
515 opStatus addOrSubtractSpecials(const IEEEFloat &, bool subtract);
516 opStatus divideSpecials(const IEEEFloat &);
517 opStatus multiplySpecials(const IEEEFloat &);
518 opStatus modSpecials(const IEEEFloat &);
519 opStatus remainderSpecials(const IEEEFloat&);
520
521 /// @}
522
523 /// \name Miscellany
524 /// @{
525
526 bool convertFromStringSpecials(StringRef str);
527 opStatus normalize(roundingMode, lostFraction);
528 opStatus addOrSubtract(const IEEEFloat &, roundingMode, bool subtract);
529 opStatus handleOverflow(roundingMode);
530 bool roundAwayFromZero(roundingMode, lostFraction, unsigned int) const;
531 opStatus convertToSignExtendedInteger(MutableArrayRef<integerPart>,
532 unsigned int, bool, roundingMode,
533 bool *) const;
534 opStatus convertFromUnsignedParts(const integerPart *, unsigned int,
535 roundingMode);
536 Expected<opStatus> convertFromHexadecimalString(StringRef, roundingMode);
537 Expected<opStatus> convertFromDecimalString(StringRef, roundingMode);
538 char *convertNormalToHexString(char *, unsigned int, bool,
539 roundingMode) const;
540 opStatus roundSignificandWithExponent(const integerPart *, unsigned int, int,
541 roundingMode);
542
543 /// @}
544
545 APInt convertHalfAPFloatToAPInt() const;
546 APInt convertBFloatAPFloatToAPInt() const;
547 APInt convertFloatAPFloatToAPInt() const;
548 APInt convertDoubleAPFloatToAPInt() const;
549 APInt convertQuadrupleAPFloatToAPInt() const;
550 APInt convertF80LongDoubleAPFloatToAPInt() const;
551 APInt convertPPCDoubleDoubleAPFloatToAPInt() const;
552 void initFromAPInt(const fltSemantics *Sem, const APInt &api);
553 void initFromHalfAPInt(const APInt &api);
554 void initFromBFloatAPInt(const APInt &api);
555 void initFromFloatAPInt(const APInt &api);
556 void initFromDoubleAPInt(const APInt &api);
557 void initFromQuadrupleAPInt(const APInt &api);
558 void initFromF80LongDoubleAPInt(const APInt &api);
559 void initFromPPCDoubleDoubleAPInt(const APInt &api);
560
561 void assign(const IEEEFloat &);
562 void copySignificand(const IEEEFloat &);
563 void freeSignificand();
564
565 /// Note: this must be the first data member.
566 /// The semantics that this value obeys.
567 const fltSemantics *semantics;
568
569 /// A binary fraction with an explicit integer bit.
570 ///
571 /// The significand must be at least one bit wider than the target precision.
572 union Significand {
573 integerPart part;
574 integerPart *parts;
575 } significand;
576
577 /// The signed unbiased exponent of the value.
578 ExponentType exponent;
579
580 /// What kind of floating point number this is.
581 ///
582 /// Only 2 bits are required, but VisualStudio incorrectly sign extends it.
583 /// Using the extra bit keeps it from failing under VisualStudio.
584 fltCategory category : 3;
585
586 /// Sign bit of the number.
587 unsigned int sign : 1;
588 };
589
590 hash_code hash_value(const IEEEFloat &Arg);
591 int ilogb(const IEEEFloat &Arg);
592 IEEEFloat scalbn(IEEEFloat X, int Exp, IEEEFloat::roundingMode);
593 IEEEFloat frexp(const IEEEFloat &Val, int &Exp, IEEEFloat::roundingMode RM);
594
595 // This mode implements more precise float in terms of two APFloats.
596 // The interface and layout is designed for arbitrary underlying semantics,
597 // though currently only PPCDoubleDouble semantics are supported, whose
598 // corresponding underlying semantics are IEEEdouble.
599 class DoubleAPFloat final : public APFloatBase {
600 // Note: this must be the first data member.
601 const fltSemantics *Semantics;
602 std::unique_ptr<APFloat[]> Floats;
603
604 opStatus addImpl(const APFloat &a, const APFloat &aa, const APFloat &c,
605 const APFloat &cc, roundingMode RM);
606
607 opStatus addWithSpecial(const DoubleAPFloat &LHS, const DoubleAPFloat &RHS,
608 DoubleAPFloat &Out, roundingMode RM);
609
610 public:
611 DoubleAPFloat(const fltSemantics &S);
612 DoubleAPFloat(const fltSemantics &S, uninitializedTag);
613 DoubleAPFloat(const fltSemantics &S, integerPart);
614 DoubleAPFloat(const fltSemantics &S, const APInt &I);
615 DoubleAPFloat(const fltSemantics &S, APFloat &&First, APFloat &&Second);
616 DoubleAPFloat(const DoubleAPFloat &RHS);
617 DoubleAPFloat(DoubleAPFloat &&RHS);
618
619 DoubleAPFloat &operator=(const DoubleAPFloat &RHS);
620
621 DoubleAPFloat &operator=(DoubleAPFloat &&RHS) {
622 if (this != &RHS) {
623 this->~DoubleAPFloat();
624 new (this) DoubleAPFloat(std::move(RHS));
625 }
626 return *this;
627 }
628
needsCleanup()629 bool needsCleanup() const { return Floats != nullptr; }
630
getFirst()631 APFloat &getFirst() { return Floats[0]; }
getFirst()632 const APFloat &getFirst() const { return Floats[0]; }
getSecond()633 APFloat &getSecond() { return Floats[1]; }
getSecond()634 const APFloat &getSecond() const { return Floats[1]; }
635
636 opStatus add(const DoubleAPFloat &RHS, roundingMode RM);
637 opStatus subtract(const DoubleAPFloat &RHS, roundingMode RM);
638 opStatus multiply(const DoubleAPFloat &RHS, roundingMode RM);
639 opStatus divide(const DoubleAPFloat &RHS, roundingMode RM);
640 opStatus remainder(const DoubleAPFloat &RHS);
641 opStatus mod(const DoubleAPFloat &RHS);
642 opStatus fusedMultiplyAdd(const DoubleAPFloat &Multiplicand,
643 const DoubleAPFloat &Addend, roundingMode RM);
644 opStatus roundToIntegral(roundingMode RM);
645 void changeSign();
646 cmpResult compareAbsoluteValue(const DoubleAPFloat &RHS) const;
647
648 fltCategory getCategory() const;
649 bool isNegative() const;
650
651 void makeInf(bool Neg);
652 void makeZero(bool Neg);
653 void makeLargest(bool Neg);
654 void makeSmallest(bool Neg);
655 void makeSmallestNormalized(bool Neg);
656 void makeNaN(bool SNaN, bool Neg, const APInt *fill);
657
658 cmpResult compare(const DoubleAPFloat &RHS) const;
659 bool bitwiseIsEqual(const DoubleAPFloat &RHS) const;
660 APInt bitcastToAPInt() const;
661 Expected<opStatus> convertFromString(StringRef, roundingMode);
662 opStatus next(bool nextDown);
663
664 opStatus convertToInteger(MutableArrayRef<integerPart> Input,
665 unsigned int Width, bool IsSigned, roundingMode RM,
666 bool *IsExact) const;
667 opStatus convertFromAPInt(const APInt &Input, bool IsSigned, roundingMode RM);
668 opStatus convertFromSignExtendedInteger(const integerPart *Input,
669 unsigned int InputSize, bool IsSigned,
670 roundingMode RM);
671 opStatus convertFromZeroExtendedInteger(const integerPart *Input,
672 unsigned int InputSize, bool IsSigned,
673 roundingMode RM);
674 unsigned int convertToHexString(char *DST, unsigned int HexDigits,
675 bool UpperCase, roundingMode RM) const;
676
677 bool isDenormal() const;
678 bool isSmallest() const;
679 bool isLargest() const;
680 bool isInteger() const;
681
682 void toString(SmallVectorImpl<char> &Str, unsigned FormatPrecision,
683 unsigned FormatMaxPadding, bool TruncateZero = true) const;
684
685 bool getExactInverse(APFloat *inv) const;
686
687 friend int ilogb(const DoubleAPFloat &Arg);
688 friend DoubleAPFloat scalbn(DoubleAPFloat X, int Exp, roundingMode);
689 friend DoubleAPFloat frexp(const DoubleAPFloat &X, int &Exp, roundingMode);
690 friend hash_code hash_value(const DoubleAPFloat &Arg);
691 };
692
693 hash_code hash_value(const DoubleAPFloat &Arg);
694
695 } // End detail namespace
696
697 // This is a interface class that is currently forwarding functionalities from
698 // detail::IEEEFloat.
699 class APFloat : public APFloatBase {
700 typedef detail::IEEEFloat IEEEFloat;
701 typedef detail::DoubleAPFloat DoubleAPFloat;
702
703 static_assert(std::is_standard_layout<IEEEFloat>::value, "");
704
705 union Storage {
706 const fltSemantics *semantics;
707 IEEEFloat IEEE;
708 DoubleAPFloat Double;
709
710 explicit Storage(IEEEFloat F, const fltSemantics &S);
Storage(DoubleAPFloat F,const fltSemantics & S)711 explicit Storage(DoubleAPFloat F, const fltSemantics &S)
712 : Double(std::move(F)) {
713 assert(&S == &PPCDoubleDouble());
714 }
715
716 template <typename... ArgTypes>
Storage(const fltSemantics & Semantics,ArgTypes &&...Args)717 Storage(const fltSemantics &Semantics, ArgTypes &&... Args) {
718 if (usesLayout<IEEEFloat>(Semantics)) {
719 new (&IEEE) IEEEFloat(Semantics, std::forward<ArgTypes>(Args)...);
720 return;
721 }
722 if (usesLayout<DoubleAPFloat>(Semantics)) {
723 new (&Double) DoubleAPFloat(Semantics, std::forward<ArgTypes>(Args)...);
724 return;
725 }
726 llvm_unreachable("Unexpected semantics");
727 }
728
~Storage()729 ~Storage() {
730 if (usesLayout<IEEEFloat>(*semantics)) {
731 IEEE.~IEEEFloat();
732 return;
733 }
734 if (usesLayout<DoubleAPFloat>(*semantics)) {
735 Double.~DoubleAPFloat();
736 return;
737 }
738 llvm_unreachable("Unexpected semantics");
739 }
740
Storage(const Storage & RHS)741 Storage(const Storage &RHS) {
742 if (usesLayout<IEEEFloat>(*RHS.semantics)) {
743 new (this) IEEEFloat(RHS.IEEE);
744 return;
745 }
746 if (usesLayout<DoubleAPFloat>(*RHS.semantics)) {
747 new (this) DoubleAPFloat(RHS.Double);
748 return;
749 }
750 llvm_unreachable("Unexpected semantics");
751 }
752
Storage(Storage && RHS)753 Storage(Storage &&RHS) {
754 if (usesLayout<IEEEFloat>(*RHS.semantics)) {
755 new (this) IEEEFloat(std::move(RHS.IEEE));
756 return;
757 }
758 if (usesLayout<DoubleAPFloat>(*RHS.semantics)) {
759 new (this) DoubleAPFloat(std::move(RHS.Double));
760 return;
761 }
762 llvm_unreachable("Unexpected semantics");
763 }
764
765 Storage &operator=(const Storage &RHS) {
766 if (usesLayout<IEEEFloat>(*semantics) &&
767 usesLayout<IEEEFloat>(*RHS.semantics)) {
768 IEEE = RHS.IEEE;
769 } else if (usesLayout<DoubleAPFloat>(*semantics) &&
770 usesLayout<DoubleAPFloat>(*RHS.semantics)) {
771 Double = RHS.Double;
772 } else if (this != &RHS) {
773 this->~Storage();
774 new (this) Storage(RHS);
775 }
776 return *this;
777 }
778
779 Storage &operator=(Storage &&RHS) {
780 if (usesLayout<IEEEFloat>(*semantics) &&
781 usesLayout<IEEEFloat>(*RHS.semantics)) {
782 IEEE = std::move(RHS.IEEE);
783 } else if (usesLayout<DoubleAPFloat>(*semantics) &&
784 usesLayout<DoubleAPFloat>(*RHS.semantics)) {
785 Double = std::move(RHS.Double);
786 } else if (this != &RHS) {
787 this->~Storage();
788 new (this) Storage(std::move(RHS));
789 }
790 return *this;
791 }
792 } U;
793
usesLayout(const fltSemantics & Semantics)794 template <typename T> static bool usesLayout(const fltSemantics &Semantics) {
795 static_assert(std::is_same<T, IEEEFloat>::value ||
796 std::is_same<T, DoubleAPFloat>::value, "");
797 if (std::is_same<T, DoubleAPFloat>::value) {
798 return &Semantics == &PPCDoubleDouble();
799 }
800 return &Semantics != &PPCDoubleDouble();
801 }
802
getIEEE()803 IEEEFloat &getIEEE() {
804 if (usesLayout<IEEEFloat>(*U.semantics))
805 return U.IEEE;
806 if (usesLayout<DoubleAPFloat>(*U.semantics))
807 return U.Double.getFirst().U.IEEE;
808 llvm_unreachable("Unexpected semantics");
809 }
810
getIEEE()811 const IEEEFloat &getIEEE() const {
812 if (usesLayout<IEEEFloat>(*U.semantics))
813 return U.IEEE;
814 if (usesLayout<DoubleAPFloat>(*U.semantics))
815 return U.Double.getFirst().U.IEEE;
816 llvm_unreachable("Unexpected semantics");
817 }
818
makeZero(bool Neg)819 void makeZero(bool Neg) { APFLOAT_DISPATCH_ON_SEMANTICS(makeZero(Neg)); }
820
makeInf(bool Neg)821 void makeInf(bool Neg) { APFLOAT_DISPATCH_ON_SEMANTICS(makeInf(Neg)); }
822
makeNaN(bool SNaN,bool Neg,const APInt * fill)823 void makeNaN(bool SNaN, bool Neg, const APInt *fill) {
824 APFLOAT_DISPATCH_ON_SEMANTICS(makeNaN(SNaN, Neg, fill));
825 }
826
makeLargest(bool Neg)827 void makeLargest(bool Neg) {
828 APFLOAT_DISPATCH_ON_SEMANTICS(makeLargest(Neg));
829 }
830
makeSmallest(bool Neg)831 void makeSmallest(bool Neg) {
832 APFLOAT_DISPATCH_ON_SEMANTICS(makeSmallest(Neg));
833 }
834
makeSmallestNormalized(bool Neg)835 void makeSmallestNormalized(bool Neg) {
836 APFLOAT_DISPATCH_ON_SEMANTICS(makeSmallestNormalized(Neg));
837 }
838
839 // FIXME: This is due to clang 3.3 (or older version) always checks for the
840 // default constructor in an array aggregate initialization, even if no
841 // elements in the array is default initialized.
APFloat()842 APFloat() : U(IEEEdouble()) {
843 llvm_unreachable("This is a workaround for old clang.");
844 }
845
APFloat(IEEEFloat F,const fltSemantics & S)846 explicit APFloat(IEEEFloat F, const fltSemantics &S) : U(std::move(F), S) {}
APFloat(DoubleAPFloat F,const fltSemantics & S)847 explicit APFloat(DoubleAPFloat F, const fltSemantics &S)
848 : U(std::move(F), S) {}
849
compareAbsoluteValue(const APFloat & RHS)850 cmpResult compareAbsoluteValue(const APFloat &RHS) const {
851 assert(&getSemantics() == &RHS.getSemantics() &&
852 "Should only compare APFloats with the same semantics");
853 if (usesLayout<IEEEFloat>(getSemantics()))
854 return U.IEEE.compareAbsoluteValue(RHS.U.IEEE);
855 if (usesLayout<DoubleAPFloat>(getSemantics()))
856 return U.Double.compareAbsoluteValue(RHS.U.Double);
857 llvm_unreachable("Unexpected semantics");
858 }
859
860 public:
APFloat(const fltSemantics & Semantics)861 APFloat(const fltSemantics &Semantics) : U(Semantics) {}
862 APFloat(const fltSemantics &Semantics, StringRef S);
APFloat(const fltSemantics & Semantics,integerPart I)863 APFloat(const fltSemantics &Semantics, integerPart I) : U(Semantics, I) {}
864 template <typename T,
865 typename = std::enable_if_t<std::is_floating_point<T>::value>>
866 APFloat(const fltSemantics &Semantics, T V) = delete;
867 // TODO: Remove this constructor. This isn't faster than the first one.
APFloat(const fltSemantics & Semantics,uninitializedTag)868 APFloat(const fltSemantics &Semantics, uninitializedTag)
869 : U(Semantics, uninitialized) {}
APFloat(const fltSemantics & Semantics,const APInt & I)870 APFloat(const fltSemantics &Semantics, const APInt &I) : U(Semantics, I) {}
APFloat(double d)871 explicit APFloat(double d) : U(IEEEFloat(d), IEEEdouble()) {}
APFloat(float f)872 explicit APFloat(float f) : U(IEEEFloat(f), IEEEsingle()) {}
873 APFloat(const APFloat &RHS) = default;
874 APFloat(APFloat &&RHS) = default;
875
876 ~APFloat() = default;
877
needsCleanup()878 bool needsCleanup() const { APFLOAT_DISPATCH_ON_SEMANTICS(needsCleanup()); }
879
880 /// Factory for Positive and Negative Zero.
881 ///
882 /// \param Negative True iff the number should be negative.
883 static APFloat getZero(const fltSemantics &Sem, bool Negative = false) {
884 APFloat Val(Sem, uninitialized);
885 Val.makeZero(Negative);
886 return Val;
887 }
888
889 /// Factory for Positive and Negative Infinity.
890 ///
891 /// \param Negative True iff the number should be negative.
892 static APFloat getInf(const fltSemantics &Sem, bool Negative = false) {
893 APFloat Val(Sem, uninitialized);
894 Val.makeInf(Negative);
895 return Val;
896 }
897
898 /// Factory for NaN values.
899 ///
900 /// \param Negative - True iff the NaN generated should be negative.
901 /// \param payload - The unspecified fill bits for creating the NaN, 0 by
902 /// default. The value is truncated as necessary.
903 static APFloat getNaN(const fltSemantics &Sem, bool Negative = false,
904 uint64_t payload = 0) {
905 if (payload) {
906 APInt intPayload(64, payload);
907 return getQNaN(Sem, Negative, &intPayload);
908 } else {
909 return getQNaN(Sem, Negative, nullptr);
910 }
911 }
912
913 /// Factory for QNaN values.
914 static APFloat getQNaN(const fltSemantics &Sem, bool Negative = false,
915 const APInt *payload = nullptr) {
916 APFloat Val(Sem, uninitialized);
917 Val.makeNaN(false, Negative, payload);
918 return Val;
919 }
920
921 /// Factory for SNaN values.
922 static APFloat getSNaN(const fltSemantics &Sem, bool Negative = false,
923 const APInt *payload = nullptr) {
924 APFloat Val(Sem, uninitialized);
925 Val.makeNaN(true, Negative, payload);
926 return Val;
927 }
928
929 /// Returns the largest finite number in the given semantics.
930 ///
931 /// \param Negative - True iff the number should be negative
932 static APFloat getLargest(const fltSemantics &Sem, bool Negative = false) {
933 APFloat Val(Sem, uninitialized);
934 Val.makeLargest(Negative);
935 return Val;
936 }
937
938 /// Returns the smallest (by magnitude) finite number in the given semantics.
939 /// Might be denormalized, which implies a relative loss of precision.
940 ///
941 /// \param Negative - True iff the number should be negative
942 static APFloat getSmallest(const fltSemantics &Sem, bool Negative = false) {
943 APFloat Val(Sem, uninitialized);
944 Val.makeSmallest(Negative);
945 return Val;
946 }
947
948 /// Returns the smallest (by magnitude) normalized finite number in the given
949 /// semantics.
950 ///
951 /// \param Negative - True iff the number should be negative
952 static APFloat getSmallestNormalized(const fltSemantics &Sem,
953 bool Negative = false) {
954 APFloat Val(Sem, uninitialized);
955 Val.makeSmallestNormalized(Negative);
956 return Val;
957 }
958
959 /// Returns a float which is bitcasted from an all one value int.
960 ///
961 /// \param Semantics - type float semantics
962 /// \param BitWidth - Select float type
963 static APFloat getAllOnesValue(const fltSemantics &Semantics,
964 unsigned BitWidth);
965
966 /// Used to insert APFloat objects, or objects that contain APFloat objects,
967 /// into FoldingSets.
968 void Profile(FoldingSetNodeID &NID) const;
969
add(const APFloat & RHS,roundingMode RM)970 opStatus add(const APFloat &RHS, roundingMode RM) {
971 assert(&getSemantics() == &RHS.getSemantics() &&
972 "Should only call on two APFloats with the same semantics");
973 if (usesLayout<IEEEFloat>(getSemantics()))
974 return U.IEEE.add(RHS.U.IEEE, RM);
975 if (usesLayout<DoubleAPFloat>(getSemantics()))
976 return U.Double.add(RHS.U.Double, RM);
977 llvm_unreachable("Unexpected semantics");
978 }
subtract(const APFloat & RHS,roundingMode RM)979 opStatus subtract(const APFloat &RHS, roundingMode RM) {
980 assert(&getSemantics() == &RHS.getSemantics() &&
981 "Should only call on two APFloats with the same semantics");
982 if (usesLayout<IEEEFloat>(getSemantics()))
983 return U.IEEE.subtract(RHS.U.IEEE, RM);
984 if (usesLayout<DoubleAPFloat>(getSemantics()))
985 return U.Double.subtract(RHS.U.Double, RM);
986 llvm_unreachable("Unexpected semantics");
987 }
multiply(const APFloat & RHS,roundingMode RM)988 opStatus multiply(const APFloat &RHS, roundingMode RM) {
989 assert(&getSemantics() == &RHS.getSemantics() &&
990 "Should only call on two APFloats with the same semantics");
991 if (usesLayout<IEEEFloat>(getSemantics()))
992 return U.IEEE.multiply(RHS.U.IEEE, RM);
993 if (usesLayout<DoubleAPFloat>(getSemantics()))
994 return U.Double.multiply(RHS.U.Double, RM);
995 llvm_unreachable("Unexpected semantics");
996 }
divide(const APFloat & RHS,roundingMode RM)997 opStatus divide(const APFloat &RHS, roundingMode RM) {
998 assert(&getSemantics() == &RHS.getSemantics() &&
999 "Should only call on two APFloats with the same semantics");
1000 if (usesLayout<IEEEFloat>(getSemantics()))
1001 return U.IEEE.divide(RHS.U.IEEE, RM);
1002 if (usesLayout<DoubleAPFloat>(getSemantics()))
1003 return U.Double.divide(RHS.U.Double, RM);
1004 llvm_unreachable("Unexpected semantics");
1005 }
remainder(const APFloat & RHS)1006 opStatus remainder(const APFloat &RHS) {
1007 assert(&getSemantics() == &RHS.getSemantics() &&
1008 "Should only call on two APFloats with the same semantics");
1009 if (usesLayout<IEEEFloat>(getSemantics()))
1010 return U.IEEE.remainder(RHS.U.IEEE);
1011 if (usesLayout<DoubleAPFloat>(getSemantics()))
1012 return U.Double.remainder(RHS.U.Double);
1013 llvm_unreachable("Unexpected semantics");
1014 }
mod(const APFloat & RHS)1015 opStatus mod(const APFloat &RHS) {
1016 assert(&getSemantics() == &RHS.getSemantics() &&
1017 "Should only call on two APFloats with the same semantics");
1018 if (usesLayout<IEEEFloat>(getSemantics()))
1019 return U.IEEE.mod(RHS.U.IEEE);
1020 if (usesLayout<DoubleAPFloat>(getSemantics()))
1021 return U.Double.mod(RHS.U.Double);
1022 llvm_unreachable("Unexpected semantics");
1023 }
fusedMultiplyAdd(const APFloat & Multiplicand,const APFloat & Addend,roundingMode RM)1024 opStatus fusedMultiplyAdd(const APFloat &Multiplicand, const APFloat &Addend,
1025 roundingMode RM) {
1026 assert(&getSemantics() == &Multiplicand.getSemantics() &&
1027 "Should only call on APFloats with the same semantics");
1028 assert(&getSemantics() == &Addend.getSemantics() &&
1029 "Should only call on APFloats with the same semantics");
1030 if (usesLayout<IEEEFloat>(getSemantics()))
1031 return U.IEEE.fusedMultiplyAdd(Multiplicand.U.IEEE, Addend.U.IEEE, RM);
1032 if (usesLayout<DoubleAPFloat>(getSemantics()))
1033 return U.Double.fusedMultiplyAdd(Multiplicand.U.Double, Addend.U.Double,
1034 RM);
1035 llvm_unreachable("Unexpected semantics");
1036 }
roundToIntegral(roundingMode RM)1037 opStatus roundToIntegral(roundingMode RM) {
1038 APFLOAT_DISPATCH_ON_SEMANTICS(roundToIntegral(RM));
1039 }
1040
1041 // TODO: bool parameters are not readable and a source of bugs.
1042 // Do something.
next(bool nextDown)1043 opStatus next(bool nextDown) {
1044 APFLOAT_DISPATCH_ON_SEMANTICS(next(nextDown));
1045 }
1046
1047 /// Negate an APFloat.
1048 APFloat operator-() const {
1049 APFloat Result(*this);
1050 Result.changeSign();
1051 return Result;
1052 }
1053
1054 /// Add two APFloats, rounding ties to the nearest even.
1055 /// No error checking.
1056 APFloat operator+(const APFloat &RHS) const {
1057 APFloat Result(*this);
1058 (void)Result.add(RHS, rmNearestTiesToEven);
1059 return Result;
1060 }
1061
1062 /// Subtract two APFloats, rounding ties to the nearest even.
1063 /// No error checking.
1064 APFloat operator-(const APFloat &RHS) const {
1065 APFloat Result(*this);
1066 (void)Result.subtract(RHS, rmNearestTiesToEven);
1067 return Result;
1068 }
1069
1070 /// Multiply two APFloats, rounding ties to the nearest even.
1071 /// No error checking.
1072 APFloat operator*(const APFloat &RHS) const {
1073 APFloat Result(*this);
1074 (void)Result.multiply(RHS, rmNearestTiesToEven);
1075 return Result;
1076 }
1077
1078 /// Divide the first APFloat by the second, rounding ties to the nearest even.
1079 /// No error checking.
1080 APFloat operator/(const APFloat &RHS) const {
1081 APFloat Result(*this);
1082 (void)Result.divide(RHS, rmNearestTiesToEven);
1083 return Result;
1084 }
1085
changeSign()1086 void changeSign() { APFLOAT_DISPATCH_ON_SEMANTICS(changeSign()); }
clearSign()1087 void clearSign() {
1088 if (isNegative())
1089 changeSign();
1090 }
copySign(const APFloat & RHS)1091 void copySign(const APFloat &RHS) {
1092 if (isNegative() != RHS.isNegative())
1093 changeSign();
1094 }
1095
1096 /// A static helper to produce a copy of an APFloat value with its sign
1097 /// copied from some other APFloat.
copySign(APFloat Value,const APFloat & Sign)1098 static APFloat copySign(APFloat Value, const APFloat &Sign) {
1099 Value.copySign(Sign);
1100 return Value;
1101 }
1102
1103 opStatus convert(const fltSemantics &ToSemantics, roundingMode RM,
1104 bool *losesInfo);
convertToInteger(MutableArrayRef<integerPart> Input,unsigned int Width,bool IsSigned,roundingMode RM,bool * IsExact)1105 opStatus convertToInteger(MutableArrayRef<integerPart> Input,
1106 unsigned int Width, bool IsSigned, roundingMode RM,
1107 bool *IsExact) const {
1108 APFLOAT_DISPATCH_ON_SEMANTICS(
1109 convertToInteger(Input, Width, IsSigned, RM, IsExact));
1110 }
1111 opStatus convertToInteger(APSInt &Result, roundingMode RM,
1112 bool *IsExact) const;
convertFromAPInt(const APInt & Input,bool IsSigned,roundingMode RM)1113 opStatus convertFromAPInt(const APInt &Input, bool IsSigned,
1114 roundingMode RM) {
1115 APFLOAT_DISPATCH_ON_SEMANTICS(convertFromAPInt(Input, IsSigned, RM));
1116 }
convertFromSignExtendedInteger(const integerPart * Input,unsigned int InputSize,bool IsSigned,roundingMode RM)1117 opStatus convertFromSignExtendedInteger(const integerPart *Input,
1118 unsigned int InputSize, bool IsSigned,
1119 roundingMode RM) {
1120 APFLOAT_DISPATCH_ON_SEMANTICS(
1121 convertFromSignExtendedInteger(Input, InputSize, IsSigned, RM));
1122 }
convertFromZeroExtendedInteger(const integerPart * Input,unsigned int InputSize,bool IsSigned,roundingMode RM)1123 opStatus convertFromZeroExtendedInteger(const integerPart *Input,
1124 unsigned int InputSize, bool IsSigned,
1125 roundingMode RM) {
1126 APFLOAT_DISPATCH_ON_SEMANTICS(
1127 convertFromZeroExtendedInteger(Input, InputSize, IsSigned, RM));
1128 }
1129 Expected<opStatus> convertFromString(StringRef, roundingMode);
bitcastToAPInt()1130 APInt bitcastToAPInt() const {
1131 APFLOAT_DISPATCH_ON_SEMANTICS(bitcastToAPInt());
1132 }
convertToDouble()1133 double convertToDouble() const { return getIEEE().convertToDouble(); }
convertToFloat()1134 float convertToFloat() const { return getIEEE().convertToFloat(); }
1135
1136 bool operator==(const APFloat &RHS) const { return compare(RHS) == cmpEqual; }
1137
1138 bool operator!=(const APFloat &RHS) const { return compare(RHS) != cmpEqual; }
1139
1140 bool operator<(const APFloat &RHS) const {
1141 return compare(RHS) == cmpLessThan;
1142 }
1143
1144 bool operator>(const APFloat &RHS) const {
1145 return compare(RHS) == cmpGreaterThan;
1146 }
1147
1148 bool operator<=(const APFloat &RHS) const {
1149 cmpResult Res = compare(RHS);
1150 return Res == cmpLessThan || Res == cmpEqual;
1151 }
1152
1153 bool operator>=(const APFloat &RHS) const {
1154 cmpResult Res = compare(RHS);
1155 return Res == cmpGreaterThan || Res == cmpEqual;
1156 }
1157
compare(const APFloat & RHS)1158 cmpResult compare(const APFloat &RHS) const {
1159 assert(&getSemantics() == &RHS.getSemantics() &&
1160 "Should only compare APFloats with the same semantics");
1161 if (usesLayout<IEEEFloat>(getSemantics()))
1162 return U.IEEE.compare(RHS.U.IEEE);
1163 if (usesLayout<DoubleAPFloat>(getSemantics()))
1164 return U.Double.compare(RHS.U.Double);
1165 llvm_unreachable("Unexpected semantics");
1166 }
1167
bitwiseIsEqual(const APFloat & RHS)1168 bool bitwiseIsEqual(const APFloat &RHS) const {
1169 if (&getSemantics() != &RHS.getSemantics())
1170 return false;
1171 if (usesLayout<IEEEFloat>(getSemantics()))
1172 return U.IEEE.bitwiseIsEqual(RHS.U.IEEE);
1173 if (usesLayout<DoubleAPFloat>(getSemantics()))
1174 return U.Double.bitwiseIsEqual(RHS.U.Double);
1175 llvm_unreachable("Unexpected semantics");
1176 }
1177
1178 /// We don't rely on operator== working on double values, as
1179 /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
1180 /// As such, this method can be used to do an exact bit-for-bit comparison of
1181 /// two floating point values.
1182 ///
1183 /// We leave the version with the double argument here because it's just so
1184 /// convenient to write "2.0" and the like. Without this function we'd
1185 /// have to duplicate its logic everywhere it's called.
isExactlyValue(double V)1186 bool isExactlyValue(double V) const {
1187 bool ignored;
1188 APFloat Tmp(V);
1189 Tmp.convert(getSemantics(), APFloat::rmNearestTiesToEven, &ignored);
1190 return bitwiseIsEqual(Tmp);
1191 }
1192
convertToHexString(char * DST,unsigned int HexDigits,bool UpperCase,roundingMode RM)1193 unsigned int convertToHexString(char *DST, unsigned int HexDigits,
1194 bool UpperCase, roundingMode RM) const {
1195 APFLOAT_DISPATCH_ON_SEMANTICS(
1196 convertToHexString(DST, HexDigits, UpperCase, RM));
1197 }
1198
isZero()1199 bool isZero() const { return getCategory() == fcZero; }
isInfinity()1200 bool isInfinity() const { return getCategory() == fcInfinity; }
isNaN()1201 bool isNaN() const { return getCategory() == fcNaN; }
1202
isNegative()1203 bool isNegative() const { return getIEEE().isNegative(); }
isDenormal()1204 bool isDenormal() const { APFLOAT_DISPATCH_ON_SEMANTICS(isDenormal()); }
isSignaling()1205 bool isSignaling() const { return getIEEE().isSignaling(); }
1206
isNormal()1207 bool isNormal() const { return !isDenormal() && isFiniteNonZero(); }
isFinite()1208 bool isFinite() const { return !isNaN() && !isInfinity(); }
1209
getCategory()1210 fltCategory getCategory() const { return getIEEE().getCategory(); }
getSemantics()1211 const fltSemantics &getSemantics() const { return *U.semantics; }
isNonZero()1212 bool isNonZero() const { return !isZero(); }
isFiniteNonZero()1213 bool isFiniteNonZero() const { return isFinite() && !isZero(); }
isPosZero()1214 bool isPosZero() const { return isZero() && !isNegative(); }
isNegZero()1215 bool isNegZero() const { return isZero() && isNegative(); }
isSmallest()1216 bool isSmallest() const { APFLOAT_DISPATCH_ON_SEMANTICS(isSmallest()); }
isLargest()1217 bool isLargest() const { APFLOAT_DISPATCH_ON_SEMANTICS(isLargest()); }
isInteger()1218 bool isInteger() const { APFLOAT_DISPATCH_ON_SEMANTICS(isInteger()); }
1219
1220 APFloat &operator=(const APFloat &RHS) = default;
1221 APFloat &operator=(APFloat &&RHS) = default;
1222
1223 void toString(SmallVectorImpl<char> &Str, unsigned FormatPrecision = 0,
1224 unsigned FormatMaxPadding = 3, bool TruncateZero = true) const {
1225 APFLOAT_DISPATCH_ON_SEMANTICS(
1226 toString(Str, FormatPrecision, FormatMaxPadding, TruncateZero));
1227 }
1228
1229 void print(raw_ostream &) const;
1230 void dump() const;
1231
getExactInverse(APFloat * inv)1232 bool getExactInverse(APFloat *inv) const {
1233 APFLOAT_DISPATCH_ON_SEMANTICS(getExactInverse(inv));
1234 }
1235
1236 friend hash_code hash_value(const APFloat &Arg);
ilogb(const APFloat & Arg)1237 friend int ilogb(const APFloat &Arg) { return ilogb(Arg.getIEEE()); }
1238 friend APFloat scalbn(APFloat X, int Exp, roundingMode RM);
1239 friend APFloat frexp(const APFloat &X, int &Exp, roundingMode RM);
1240 friend IEEEFloat;
1241 friend DoubleAPFloat;
1242 };
1243
1244 /// See friend declarations above.
1245 ///
1246 /// These additional declarations are required in order to compile LLVM with IBM
1247 /// xlC compiler.
1248 hash_code hash_value(const APFloat &Arg);
scalbn(APFloat X,int Exp,APFloat::roundingMode RM)1249 inline APFloat scalbn(APFloat X, int Exp, APFloat::roundingMode RM) {
1250 if (APFloat::usesLayout<detail::IEEEFloat>(X.getSemantics()))
1251 return APFloat(scalbn(X.U.IEEE, Exp, RM), X.getSemantics());
1252 if (APFloat::usesLayout<detail::DoubleAPFloat>(X.getSemantics()))
1253 return APFloat(scalbn(X.U.Double, Exp, RM), X.getSemantics());
1254 llvm_unreachable("Unexpected semantics");
1255 }
1256
1257 /// Equivalent of C standard library function.
1258 ///
1259 /// While the C standard says Exp is an unspecified value for infinity and nan,
1260 /// this returns INT_MAX for infinities, and INT_MIN for NaNs.
frexp(const APFloat & X,int & Exp,APFloat::roundingMode RM)1261 inline APFloat frexp(const APFloat &X, int &Exp, APFloat::roundingMode RM) {
1262 if (APFloat::usesLayout<detail::IEEEFloat>(X.getSemantics()))
1263 return APFloat(frexp(X.U.IEEE, Exp, RM), X.getSemantics());
1264 if (APFloat::usesLayout<detail::DoubleAPFloat>(X.getSemantics()))
1265 return APFloat(frexp(X.U.Double, Exp, RM), X.getSemantics());
1266 llvm_unreachable("Unexpected semantics");
1267 }
1268 /// Returns the absolute value of the argument.
abs(APFloat X)1269 inline APFloat abs(APFloat X) {
1270 X.clearSign();
1271 return X;
1272 }
1273
1274 /// Returns the negated value of the argument.
neg(APFloat X)1275 inline APFloat neg(APFloat X) {
1276 X.changeSign();
1277 return X;
1278 }
1279
1280 /// Implements IEEE minNum semantics. Returns the smaller of the 2 arguments if
1281 /// both are not NaN. If either argument is a NaN, returns the other argument.
1282 LLVM_READONLY
minnum(const APFloat & A,const APFloat & B)1283 inline APFloat minnum(const APFloat &A, const APFloat &B) {
1284 if (A.isNaN())
1285 return B;
1286 if (B.isNaN())
1287 return A;
1288 return B < A ? B : A;
1289 }
1290
1291 /// Implements IEEE maxNum semantics. Returns the larger of the 2 arguments if
1292 /// both are not NaN. If either argument is a NaN, returns the other argument.
1293 LLVM_READONLY
maxnum(const APFloat & A,const APFloat & B)1294 inline APFloat maxnum(const APFloat &A, const APFloat &B) {
1295 if (A.isNaN())
1296 return B;
1297 if (B.isNaN())
1298 return A;
1299 return A < B ? B : A;
1300 }
1301
1302 /// Implements IEEE 754-2018 minimum semantics. Returns the smaller of 2
1303 /// arguments, propagating NaNs and treating -0 as less than +0.
1304 LLVM_READONLY
minimum(const APFloat & A,const APFloat & B)1305 inline APFloat minimum(const APFloat &A, const APFloat &B) {
1306 if (A.isNaN())
1307 return A;
1308 if (B.isNaN())
1309 return B;
1310 if (A.isZero() && B.isZero() && (A.isNegative() != B.isNegative()))
1311 return A.isNegative() ? A : B;
1312 return B < A ? B : A;
1313 }
1314
1315 /// Implements IEEE 754-2018 maximum semantics. Returns the larger of 2
1316 /// arguments, propagating NaNs and treating -0 as less than +0.
1317 LLVM_READONLY
maximum(const APFloat & A,const APFloat & B)1318 inline APFloat maximum(const APFloat &A, const APFloat &B) {
1319 if (A.isNaN())
1320 return A;
1321 if (B.isNaN())
1322 return B;
1323 if (A.isZero() && B.isZero() && (A.isNegative() != B.isNegative()))
1324 return A.isNegative() ? B : A;
1325 return A < B ? B : A;
1326 }
1327
1328 } // namespace llvm
1329
1330 #undef APFLOAT_DISPATCH_ON_SEMANTICS
1331 #endif // LLVM_ADT_APFLOAT_H
1332