blob: 034d18199cc6d86cee34665b3c86892e28878264 [file] [log] [blame]
Andreas Färber8d725fa2011-03-07 01:34:04 +01001/*
2 * QEMU float support
3 *
Peter Maydell16017c42015-01-12 14:38:28 +00004 * The code in this source file is derived from release 2a of the SoftFloat
5 * IEC/IEEE Floating-point Arithmetic Package. Those parts of the code (and
6 * some later contributions) are provided under that license, as detailed below.
7 * It has subsequently been modified by contributors to the QEMU Project,
8 * so some portions are provided under:
9 * the SoftFloat-2a license
10 * the BSD license
11 * GPL-v2-or-later
12 *
13 * Any future contributions to this file after December 1st 2014 will be
14 * taken to be licensed under the Softfloat-2a license unless specifically
15 * indicated otherwise.
Andreas Färber8d725fa2011-03-07 01:34:04 +010016 */
bellard158142c2005-03-13 16:54:06 +000017
Peter Maydella7d1ac72015-01-12 14:38:25 +000018/*
19===============================================================================
bellard158142c2005-03-13 16:54:06 +000020This C source fragment is part of the SoftFloat IEC/IEEE Floating-point
Peter Maydella7d1ac72015-01-12 14:38:25 +000021Arithmetic Package, Release 2a.
bellard158142c2005-03-13 16:54:06 +000022
23Written by John R. Hauser. This work was made possible in part by the
24International Computer Science Institute, located at Suite 600, 1947 Center
25Street, Berkeley, California 94704. Funding was partially provided by the
26National Science Foundation under grant MIP-9311980. The original version
27of this code was written as part of a project to build a fixed-point vector
28processor in collaboration with the University of California at Berkeley,
29overseen by Profs. Nelson Morgan and John Wawrzynek. More information
Peter Maydella7d1ac72015-01-12 14:38:25 +000030is available through the Web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
bellard158142c2005-03-13 16:54:06 +000031arithmetic/SoftFloat.html'.
32
Peter Maydella7d1ac72015-01-12 14:38:25 +000033THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
34has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
35TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
36PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
37AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
bellard158142c2005-03-13 16:54:06 +000038
39Derivative works are acceptable, even for commercial purposes, so long as
Peter Maydella7d1ac72015-01-12 14:38:25 +000040(1) they include prominent notice that the work is derivative, and (2) they
41include prominent notice akin to these four paragraphs for those parts of
42this code that are retained.
bellard158142c2005-03-13 16:54:06 +000043
Peter Maydella7d1ac72015-01-12 14:38:25 +000044===============================================================================
45*/
bellard158142c2005-03-13 16:54:06 +000046
Peter Maydell16017c42015-01-12 14:38:28 +000047/* BSD licensing:
48 * Copyright (c) 2006, Fabrice Bellard
49 * All rights reserved.
50 *
51 * Redistribution and use in source and binary forms, with or without
52 * modification, are permitted provided that the following conditions are met:
53 *
54 * 1. Redistributions of source code must retain the above copyright notice,
55 * this list of conditions and the following disclaimer.
56 *
57 * 2. Redistributions in binary form must reproduce the above copyright notice,
58 * this list of conditions and the following disclaimer in the documentation
59 * and/or other materials provided with the distribution.
60 *
61 * 3. Neither the name of the copyright holder nor the names of its contributors
62 * may be used to endorse or promote products derived from this software without
63 * specific prior written permission.
64 *
65 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
66 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
67 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
68 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
69 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
70 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
71 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
72 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
73 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
74 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
75 * THE POSSIBILITY OF SUCH DAMAGE.
76 */
77
78/* Portions of this work are licensed under the terms of the GNU GPL,
79 * version 2 or later. See the COPYING file in the top-level directory.
80 */
81
Max Filippov213ff4e2012-09-19 04:23:51 +040082/* Define for architectures which deviate from IEEE in not supporting
83 * signaling NaNs (so all NaNs are treated as quiet).
84 */
Richard Henderson03385df2018-05-10 14:48:17 -070085#if defined(TARGET_XTENSA)
Max Filippov213ff4e2012-09-19 04:23:51 +040086#define NO_SIGNALING_NANS 1
87#endif
88
Richard Henderson03385df2018-05-10 14:48:17 -070089/* Define how the architecture discriminates signaling NaNs.
90 * This done with the most significant bit of the fraction.
91 * In IEEE 754-1985 this was implementation defined, but in IEEE 754-2008
92 * the msb must be zero. MIPS is (so far) unique in supporting both the
93 * 2008 revision and backward compatibility with their original choice.
94 * Thus for MIPS we must make the choice at runtime.
95 */
Richard Hendersonc1203912020-05-04 19:54:57 -070096static inline bool snan_bit_is_one(float_status *status)
Richard Henderson03385df2018-05-10 14:48:17 -070097{
98#if defined(TARGET_MIPS)
99 return status->snan_bit_is_one;
100#elif defined(TARGET_HPPA) || defined(TARGET_UNICORE32) || defined(TARGET_SH4)
101 return 1;
102#else
103 return 0;
104#endif
105}
106
Paolo Bonzini789ec7c2011-07-28 12:10:29 +0200107/*----------------------------------------------------------------------------
Richard Henderson298b4682018-05-10 12:45:29 -0700108| For the deconstructed floating-point with fraction FRAC, return true
109| if the fraction represents a signalling NaN; otherwise false.
110*----------------------------------------------------------------------------*/
111
112static bool parts_is_snan_frac(uint64_t frac, float_status *status)
113{
114#ifdef NO_SIGNALING_NANS
115 return false;
116#else
Richard Hendersonc1203912020-05-04 19:54:57 -0700117 bool msb = extract64(frac, DECOMPOSED_BINARY_POINT - 1, 1);
Richard Henderson03385df2018-05-10 14:48:17 -0700118 return msb == snan_bit_is_one(status);
Richard Henderson298b4682018-05-10 12:45:29 -0700119#endif
120}
121
122/*----------------------------------------------------------------------------
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700123| The pattern for a default generated deconstructed floating-point NaN.
124*----------------------------------------------------------------------------*/
125
126static FloatParts parts_default_nan(float_status *status)
127{
128 bool sign = 0;
129 uint64_t frac;
130
131#if defined(TARGET_SPARC) || defined(TARGET_M68K)
Richard Henderson8fb3d902018-05-14 13:12:14 -0700132 /* !snan_bit_is_one, set all bits */
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700133 frac = (1ULL << DECOMPOSED_BINARY_POINT) - 1;
Richard Henderson8fb3d902018-05-14 13:12:14 -0700134#elif defined(TARGET_I386) || defined(TARGET_X86_64) \
135 || defined(TARGET_MICROBLAZE)
136 /* !snan_bit_is_one, set sign and msb */
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700137 frac = 1ULL << (DECOMPOSED_BINARY_POINT - 1);
Richard Henderson8fb3d902018-05-14 13:12:14 -0700138 sign = 1;
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700139#elif defined(TARGET_HPPA)
Richard Henderson8fb3d902018-05-14 13:12:14 -0700140 /* snan_bit_is_one, set msb-1. */
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700141 frac = 1ULL << (DECOMPOSED_BINARY_POINT - 2);
142#else
Richard Henderson8fb3d902018-05-14 13:12:14 -0700143 /* This case is true for Alpha, ARM, MIPS, OpenRISC, PPC, RISC-V,
144 * S390, SH4, TriCore, and Xtensa. I cannot find documentation
145 * for Unicore32; the choice from the original commit is unchanged.
146 * Our other supported targets, CRIS, LM32, Moxie, Nios2, and Tile,
147 * do not have floating-point.
148 */
Richard Henderson03385df2018-05-10 14:48:17 -0700149 if (snan_bit_is_one(status)) {
Richard Henderson8fb3d902018-05-14 13:12:14 -0700150 /* set all bits other than msb */
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700151 frac = (1ULL << (DECOMPOSED_BINARY_POINT - 1)) - 1;
152 } else {
Richard Henderson8fb3d902018-05-14 13:12:14 -0700153 /* set msb */
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700154 frac = 1ULL << (DECOMPOSED_BINARY_POINT - 1);
Richard Hendersonf7e598e2018-05-10 13:09:49 -0700155 }
156#endif
157
158 return (FloatParts) {
159 .cls = float_class_qnan,
160 .sign = sign,
161 .exp = INT_MAX,
162 .frac = frac
163 };
164}
165
166/*----------------------------------------------------------------------------
Richard Henderson0bcfbcb2018-05-10 13:32:53 -0700167| Returns a quiet NaN from a signalling NaN for the deconstructed
168| floating-point parts.
169*----------------------------------------------------------------------------*/
170
171static FloatParts parts_silence_nan(FloatParts a, float_status *status)
172{
173#ifdef NO_SIGNALING_NANS
174 g_assert_not_reached();
175#elif defined(TARGET_HPPA)
176 a.frac &= ~(1ULL << (DECOMPOSED_BINARY_POINT - 1));
177 a.frac |= 1ULL << (DECOMPOSED_BINARY_POINT - 2);
178#else
Richard Henderson03385df2018-05-10 14:48:17 -0700179 if (snan_bit_is_one(status)) {
Richard Henderson0bcfbcb2018-05-10 13:32:53 -0700180 return parts_default_nan(status);
181 } else {
182 a.frac |= 1ULL << (DECOMPOSED_BINARY_POINT - 1);
183 }
184#endif
185 a.cls = float_class_qnan;
186 return a;
187}
188
189/*----------------------------------------------------------------------------
Paolo Bonzini789ec7c2011-07-28 12:10:29 +0200190| The pattern for a default generated extended double-precision NaN.
191*----------------------------------------------------------------------------*/
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200192floatx80 floatx80_default_nan(float_status *status)
193{
194 floatx80 r;
Richard Henderson0218a162018-05-14 13:56:44 -0700195
196 /* None of the targets that have snan_bit_is_one use floatx80. */
197 assert(!snan_bit_is_one(status));
Laurent Viviere5b0cbe2017-06-12 01:16:27 +0200198#if defined(TARGET_M68K)
Alex Bennéef7e81a92019-08-12 16:04:02 +0100199 r.low = UINT64_C(0xFFFFFFFFFFFFFFFF);
Laurent Viviere5b0cbe2017-06-12 01:16:27 +0200200 r.high = 0x7FFF;
201#else
Richard Henderson0218a162018-05-14 13:56:44 -0700202 /* X86 */
Alex Bennéef7e81a92019-08-12 16:04:02 +0100203 r.low = UINT64_C(0xC000000000000000);
Richard Henderson0218a162018-05-14 13:56:44 -0700204 r.high = 0xFFFF;
Laurent Viviere5b0cbe2017-06-12 01:16:27 +0200205#endif
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200206 return r;
207}
Paolo Bonzini789ec7c2011-07-28 12:10:29 +0200208
209/*----------------------------------------------------------------------------
Laurent Vivier0f605c82018-02-24 21:18:01 +0100210| The pattern for a default generated extended double-precision inf.
211*----------------------------------------------------------------------------*/
212
213#define floatx80_infinity_high 0x7FFF
214#if defined(TARGET_M68K)
Alex Bennéef7e81a92019-08-12 16:04:02 +0100215#define floatx80_infinity_low UINT64_C(0x0000000000000000)
Laurent Vivier0f605c82018-02-24 21:18:01 +0100216#else
Alex Bennéef7e81a92019-08-12 16:04:02 +0100217#define floatx80_infinity_low UINT64_C(0x8000000000000000)
Laurent Vivier0f605c82018-02-24 21:18:01 +0100218#endif
219
220const floatx80 floatx80_infinity
221 = make_floatx80_init(floatx80_infinity_high, floatx80_infinity_low);
222
223/*----------------------------------------------------------------------------
bellard158142c2005-03-13 16:54:06 +0000224| Raises the exceptions specified by `flags'. Floating-point traps can be
225| defined here if desired. It is currently not possible for such a trap
226| to substitute a result value. If traps are not implemented, this routine
227| should be simply `float_exception_flags |= flags;'.
228*----------------------------------------------------------------------------*/
229
Pranith Kumardfd60762016-08-10 14:55:02 -0400230void float_raise(uint8_t flags, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000231{
Peter Maydella2f2d282015-02-02 18:57:35 +0000232 status->float_exception_flags |= flags;
bellard158142c2005-03-13 16:54:06 +0000233}
234
235/*----------------------------------------------------------------------------
236| Internal canonical NaN format.
237*----------------------------------------------------------------------------*/
238typedef struct {
Richard Hendersonc1203912020-05-04 19:54:57 -0700239 bool sign;
Andreas Färberbb98fe42011-03-07 01:34:06 +0100240 uint64_t high, low;
bellard158142c2005-03-13 16:54:06 +0000241} commonNaNT;
242
243/*----------------------------------------------------------------------------
Peter Maydellbb4d4bb2011-02-10 11:28:56 +0000244| Returns 1 if the half-precision floating-point value `a' is a quiet
245| NaN; otherwise returns 0.
246*----------------------------------------------------------------------------*/
247
Richard Henderson150c7a92020-05-05 12:16:24 -0700248bool float16_is_quiet_nan(float16 a_, float_status *status)
Peter Maydellbb4d4bb2011-02-10 11:28:56 +0000249{
Richard Hendersonbca52232018-05-10 11:24:13 -0700250#ifdef NO_SIGNALING_NANS
251 return float16_is_any_nan(a_);
252#else
Peter Maydellbb4d4bb2011-02-10 11:28:56 +0000253 uint16_t a = float16_val(a_);
Richard Henderson03385df2018-05-10 14:48:17 -0700254 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200255 return (((a >> 9) & 0x3F) == 0x3E) && (a & 0x1FF);
256 } else {
LIU Zhiwei8cdf9122020-07-13 21:04:08 +0100257 return ((a >> 9) & 0x3F) == 0x3F;
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200258 }
Richard Hendersonbca52232018-05-10 11:24:13 -0700259#endif
Peter Maydellbb4d4bb2011-02-10 11:28:56 +0000260}
261
262/*----------------------------------------------------------------------------
263| Returns 1 if the half-precision floating-point value `a' is a signaling
264| NaN; otherwise returns 0.
265*----------------------------------------------------------------------------*/
266
Richard Henderson150c7a92020-05-05 12:16:24 -0700267bool float16_is_signaling_nan(float16 a_, float_status *status)
Peter Maydellbb4d4bb2011-02-10 11:28:56 +0000268{
Richard Hendersonbca52232018-05-10 11:24:13 -0700269#ifdef NO_SIGNALING_NANS
270 return 0;
271#else
Peter Maydellbb4d4bb2011-02-10 11:28:56 +0000272 uint16_t a = float16_val(a_);
Richard Henderson03385df2018-05-10 14:48:17 -0700273 if (snan_bit_is_one(status)) {
LIU Zhiwei8cdf9122020-07-13 21:04:08 +0100274 return ((a >> 9) & 0x3F) == 0x3F;
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200275 } else {
276 return (((a >> 9) & 0x3F) == 0x3E) && (a & 0x1FF);
277 }
Max Filippov213ff4e2012-09-19 04:23:51 +0400278#endif
Richard Hendersonbca52232018-05-10 11:24:13 -0700279}
Peter Maydellbb4d4bb2011-02-10 11:28:56 +0000280
281/*----------------------------------------------------------------------------
ths5a6932d2007-11-16 14:57:36 +0000282| Returns 1 if the single-precision floating-point value `a' is a quiet
283| NaN; otherwise returns 0.
bellard158142c2005-03-13 16:54:06 +0000284*----------------------------------------------------------------------------*/
285
Richard Henderson150c7a92020-05-05 12:16:24 -0700286bool float32_is_quiet_nan(float32 a_, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000287{
Richard Hendersonbca52232018-05-10 11:24:13 -0700288#ifdef NO_SIGNALING_NANS
289 return float32_is_any_nan(a_);
290#else
pbrookf090c9d2007-11-18 14:33:24 +0000291 uint32_t a = float32_val(a_);
Richard Henderson03385df2018-05-10 14:48:17 -0700292 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200293 return (((a >> 22) & 0x1FF) == 0x1FE) && (a & 0x003FFFFF);
294 } else {
295 return ((uint32_t)(a << 1) >= 0xFF800000);
296 }
Richard Hendersonbca52232018-05-10 11:24:13 -0700297#endif
bellard158142c2005-03-13 16:54:06 +0000298}
299
300/*----------------------------------------------------------------------------
301| Returns 1 if the single-precision floating-point value `a' is a signaling
302| NaN; otherwise returns 0.
303*----------------------------------------------------------------------------*/
304
Richard Henderson150c7a92020-05-05 12:16:24 -0700305bool float32_is_signaling_nan(float32 a_, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000306{
Richard Hendersonbca52232018-05-10 11:24:13 -0700307#ifdef NO_SIGNALING_NANS
308 return 0;
309#else
pbrookf090c9d2007-11-18 14:33:24 +0000310 uint32_t a = float32_val(a_);
Richard Henderson03385df2018-05-10 14:48:17 -0700311 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200312 return ((uint32_t)(a << 1) >= 0xFF800000);
313 } else {
314 return (((a >> 22) & 0x1FF) == 0x1FE) && (a & 0x003FFFFF);
315 }
Max Filippov213ff4e2012-09-19 04:23:51 +0400316#endif
Richard Hendersonbca52232018-05-10 11:24:13 -0700317}
bellard158142c2005-03-13 16:54:06 +0000318
319/*----------------------------------------------------------------------------
320| Returns the result of converting the single-precision floating-point NaN
321| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid
322| exception is raised.
323*----------------------------------------------------------------------------*/
324
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000325static commonNaNT float32ToCommonNaN(float32 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000326{
327 commonNaNT z;
328
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200329 if (float32_is_signaling_nan(a, status)) {
Peter Maydellff32e162015-02-02 18:47:16 +0000330 float_raise(float_flag_invalid, status);
331 }
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200332 z.sign = float32_val(a) >> 31;
bellard158142c2005-03-13 16:54:06 +0000333 z.low = 0;
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200334 z.high = ((uint64_t)float32_val(a)) << 41;
bellard158142c2005-03-13 16:54:06 +0000335 return z;
bellard158142c2005-03-13 16:54:06 +0000336}
337
338/*----------------------------------------------------------------------------
339| Returns the result of converting the canonical NaN `a' to the single-
340| precision floating-point format.
341*----------------------------------------------------------------------------*/
342
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000343static float32 commonNaNToFloat32(commonNaNT a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000344{
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200345 uint32_t mantissa = a.high >> 41;
Christophe Lyonbcd4d9a2011-02-10 11:28:57 +0000346
Peter Maydella2f2d282015-02-02 18:57:35 +0000347 if (status->default_nan_mode) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200348 return float32_default_nan(status);
Christophe Lyonbcd4d9a2011-02-10 11:28:57 +0000349 }
350
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200351 if (mantissa) {
ths85016c92007-12-25 23:59:51 +0000352 return make_float32(
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200353 (((uint32_t)a.sign) << 31) | 0x7F800000 | (a.high >> 41));
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200354 } else {
355 return float32_default_nan(status);
356 }
bellard158142c2005-03-13 16:54:06 +0000357}
358
359/*----------------------------------------------------------------------------
Peter Maydell354f2112010-12-16 11:51:17 +0000360| Select which NaN to propagate for a two-input operation.
361| IEEE754 doesn't specify all the details of this, so the
362| algorithm is target-specific.
363| The routine is passed various bits of information about the
364| two NaNs and should return 0 to select NaN a and 1 for NaN b.
365| Note that signalling NaNs are always squashed to quiet NaNs
Richard Henderson48853122018-05-10 14:11:15 -0700366| by the caller, by calling floatXX_silence_nan() before
Aurelien Jarno1f398e02011-01-06 15:38:19 +0100367| returning them.
Peter Maydell354f2112010-12-16 11:51:17 +0000368|
369| aIsLargerSignificand is only valid if both a and b are NaNs
370| of some kind, and is true if a has the larger significand,
371| or if both a and b have the same significand but a is
372| positive but b is negative. It is only needed for the x87
373| tie-break rule.
374*----------------------------------------------------------------------------*/
375
Richard Henderson4f251cf2018-05-10 15:21:31 -0700376static int pickNaN(FloatClass a_cls, FloatClass b_cls,
Richard Hendersonc1203912020-05-04 19:54:57 -0700377 bool aIsLargerSignificand)
Peter Maydell011da612010-12-16 11:51:18 +0000378{
Richard Henderson4f251cf2018-05-10 15:21:31 -0700379#if defined(TARGET_ARM) || defined(TARGET_MIPS) || defined(TARGET_HPPA)
Alex Bennée13894522017-07-19 11:49:42 +0100380 /* ARM mandated NaN propagation rules (see FPProcessNaNs()), take
381 * the first of:
Peter Maydell011da612010-12-16 11:51:18 +0000382 * 1. A if it is signaling
383 * 2. B if it is signaling
384 * 3. A (quiet)
385 * 4. B (quiet)
386 * A signaling NaN is always quietened before returning it.
387 */
Aurelien Jarno084d19b2011-01-06 15:38:19 +0100388 /* According to MIPS specifications, if one of the two operands is
389 * a sNaN, a new qNaN has to be generated. This is done in
Richard Henderson48853122018-05-10 14:11:15 -0700390 * floatXX_silence_nan(). For qNaN inputs the specifications
Aurelien Jarno084d19b2011-01-06 15:38:19 +0100391 * says: "When possible, this QNaN result is one of the operand QNaN
392 * values." In practice it seems that most implementations choose
393 * the first operand if both operands are qNaN. In short this gives
394 * the following rules:
395 * 1. A if it is signaling
396 * 2. B if it is signaling
397 * 3. A (quiet)
398 * 4. B (quiet)
399 * A signaling NaN is always silenced before returning it.
400 */
Richard Henderson4f251cf2018-05-10 15:21:31 -0700401 if (is_snan(a_cls)) {
Aurelien Jarno084d19b2011-01-06 15:38:19 +0100402 return 0;
Richard Henderson4f251cf2018-05-10 15:21:31 -0700403 } else if (is_snan(b_cls)) {
Aurelien Jarno084d19b2011-01-06 15:38:19 +0100404 return 1;
Richard Henderson4f251cf2018-05-10 15:21:31 -0700405 } else if (is_qnan(a_cls)) {
Aurelien Jarno084d19b2011-01-06 15:38:19 +0100406 return 0;
407 } else {
408 return 1;
409 }
Richard Henderson4f251cf2018-05-10 15:21:31 -0700410#elif defined(TARGET_PPC) || defined(TARGET_XTENSA) || defined(TARGET_M68K)
Aurelien Jarnoe024e882011-01-06 15:38:19 +0100411 /* PowerPC propagation rules:
412 * 1. A if it sNaN or qNaN
413 * 2. B if it sNaN or qNaN
414 * A signaling NaN is always silenced before returning it.
415 */
Laurent Viviere5b0cbe2017-06-12 01:16:27 +0200416 /* M68000 FAMILY PROGRAMMER'S REFERENCE MANUAL
417 * 3.4 FLOATING-POINT INSTRUCTION DETAILS
418 * If either operand, but not both operands, of an operation is a
419 * nonsignaling NaN, then that NaN is returned as the result. If both
420 * operands are nonsignaling NaNs, then the destination operand
421 * nonsignaling NaN is returned as the result.
422 * If either operand to an operation is a signaling NaN (SNaN), then the
423 * SNaN bit is set in the FPSR EXC byte. If the SNaN exception enable bit
424 * is set in the FPCR ENABLE byte, then the exception is taken and the
425 * destination is not modified. If the SNaN exception enable bit is not
426 * set, setting the SNaN bit in the operand to a one converts the SNaN to
427 * a nonsignaling NaN. The operation then continues as described in the
428 * preceding paragraph for nonsignaling NaNs.
429 */
Richard Henderson4f251cf2018-05-10 15:21:31 -0700430 if (is_nan(a_cls)) {
431 return 0;
Laurent Viviere5b0cbe2017-06-12 01:16:27 +0200432 } else {
Richard Henderson4f251cf2018-05-10 15:21:31 -0700433 return 1;
Laurent Viviere5b0cbe2017-06-12 01:16:27 +0200434 }
Peter Maydell011da612010-12-16 11:51:18 +0000435#else
Peter Maydell354f2112010-12-16 11:51:17 +0000436 /* This implements x87 NaN propagation rules:
437 * SNaN + QNaN => return the QNaN
438 * two SNaNs => return the one with the larger significand, silenced
439 * two QNaNs => return the one with the larger significand
440 * SNaN and a non-NaN => return the SNaN, silenced
441 * QNaN and a non-NaN => return the QNaN
442 *
443 * If we get down to comparing significands and they are the same,
444 * return the NaN with the positive sign bit (if any).
445 */
Richard Henderson4f251cf2018-05-10 15:21:31 -0700446 if (is_snan(a_cls)) {
447 if (is_snan(b_cls)) {
Peter Maydell354f2112010-12-16 11:51:17 +0000448 return aIsLargerSignificand ? 0 : 1;
449 }
Richard Henderson4f251cf2018-05-10 15:21:31 -0700450 return is_qnan(b_cls) ? 1 : 0;
451 } else if (is_qnan(a_cls)) {
452 if (is_snan(b_cls) || !is_qnan(b_cls)) {
Peter Maydell354f2112010-12-16 11:51:17 +0000453 return 0;
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200454 } else {
Peter Maydell354f2112010-12-16 11:51:17 +0000455 return aIsLargerSignificand ? 0 : 1;
456 }
457 } else {
458 return 1;
459 }
Peter Maydell011da612010-12-16 11:51:18 +0000460#endif
Richard Henderson4f251cf2018-05-10 15:21:31 -0700461}
Peter Maydell354f2112010-12-16 11:51:17 +0000462
463/*----------------------------------------------------------------------------
Peter Maydell369be8f2011-10-19 16:14:06 +0000464| Select which NaN to propagate for a three-input operation.
465| For the moment we assume that no CPU needs the 'larger significand'
466| information.
467| Return values : 0 : a; 1 : b; 2 : c; 3 : default-NaN
468*----------------------------------------------------------------------------*/
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700469static int pickNaNMulAdd(FloatClass a_cls, FloatClass b_cls, FloatClass c_cls,
470 bool infzero, float_status *status)
Peter Maydell369be8f2011-10-19 16:14:06 +0000471{
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700472#if defined(TARGET_ARM)
Peter Maydell369be8f2011-10-19 16:14:06 +0000473 /* For ARM, the (inf,zero,qnan) case sets InvalidOp and returns
474 * the default NaN
475 */
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700476 if (infzero && is_qnan(c_cls)) {
Peter Maydellff32e162015-02-02 18:47:16 +0000477 float_raise(float_flag_invalid, status);
Peter Maydell369be8f2011-10-19 16:14:06 +0000478 return 3;
479 }
480
481 /* This looks different from the ARM ARM pseudocode, because the ARM ARM
482 * puts the operands to a fused mac operation (a*b)+c in the order c,a,b.
483 */
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700484 if (is_snan(c_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000485 return 2;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700486 } else if (is_snan(a_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000487 return 0;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700488 } else if (is_snan(b_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000489 return 1;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700490 } else if (is_qnan(c_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000491 return 2;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700492 } else if (is_qnan(a_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000493 return 0;
494 } else {
495 return 1;
496 }
Aurelien Jarnobbc1ded2012-10-09 21:53:20 +0200497#elif defined(TARGET_MIPS)
Richard Henderson03385df2018-05-10 14:48:17 -0700498 if (snan_bit_is_one(status)) {
Mateja Marjanovic7ca96e12019-03-19 16:21:56 +0100499 /*
500 * For MIPS systems that conform to IEEE754-1985, the (inf,zero,nan)
501 * case sets InvalidOp and returns the default NaN
502 */
503 if (infzero) {
504 float_raise(float_flag_invalid, status);
505 return 3;
506 }
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200507 /* Prefer sNaN over qNaN, in the a, b, c order. */
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700508 if (is_snan(a_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200509 return 0;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700510 } else if (is_snan(b_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200511 return 1;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700512 } else if (is_snan(c_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200513 return 2;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700514 } else if (is_qnan(a_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200515 return 0;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700516 } else if (is_qnan(b_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200517 return 1;
518 } else {
519 return 2;
520 }
Aurelien Jarnobbc1ded2012-10-09 21:53:20 +0200521 } else {
Mateja Marjanovic7ca96e12019-03-19 16:21:56 +0100522 /*
523 * For MIPS systems that conform to IEEE754-2008, the (inf,zero,nan)
524 * case sets InvalidOp and returns the input value 'c'
525 */
526 if (infzero) {
527 float_raise(float_flag_invalid, status);
528 return 2;
529 }
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200530 /* Prefer sNaN over qNaN, in the c, a, b order. */
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700531 if (is_snan(c_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200532 return 2;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700533 } else if (is_snan(a_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200534 return 0;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700535 } else if (is_snan(b_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200536 return 1;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700537 } else if (is_qnan(c_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200538 return 2;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700539 } else if (is_qnan(a_cls)) {
Aleksandar Markovicc27644f2016-06-10 11:57:31 +0200540 return 0;
541 } else {
542 return 1;
543 }
Aurelien Jarnobbc1ded2012-10-09 21:53:20 +0200544 }
Peter Maydell369be8f2011-10-19 16:14:06 +0000545#elif defined(TARGET_PPC)
Peter Maydell369be8f2011-10-19 16:14:06 +0000546 /* For PPC, the (inf,zero,qnan) case sets InvalidOp, but we prefer
547 * to return an input NaN if we have one (ie c) rather than generating
548 * a default NaN
549 */
550 if (infzero) {
Peter Maydellff32e162015-02-02 18:47:16 +0000551 float_raise(float_flag_invalid, status);
Peter Maydell369be8f2011-10-19 16:14:06 +0000552 return 2;
553 }
554
555 /* If fRA is a NaN return it; otherwise if fRB is a NaN return it;
556 * otherwise return fRC. Note that muladd on PPC is (fRA * fRC) + frB
557 */
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700558 if (is_nan(a_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000559 return 0;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700560 } else if (is_nan(c_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000561 return 2;
562 } else {
563 return 1;
564 }
Peter Maydell369be8f2011-10-19 16:14:06 +0000565#else
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700566 /* A default implementation: prefer a to b to c.
567 * This is unlikely to actually match any real implementation.
568 */
569 if (is_nan(a_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000570 return 0;
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700571 } else if (is_nan(b_cls)) {
Peter Maydell369be8f2011-10-19 16:14:06 +0000572 return 1;
573 } else {
574 return 2;
575 }
Peter Maydell369be8f2011-10-19 16:14:06 +0000576#endif
Richard Henderson3bd2dec2018-05-10 15:38:08 -0700577}
Peter Maydell369be8f2011-10-19 16:14:06 +0000578
579/*----------------------------------------------------------------------------
bellard158142c2005-03-13 16:54:06 +0000580| Takes two single-precision floating-point values `a' and `b', one of which
581| is a NaN, and returns the appropriate NaN result. If either `a' or `b' is a
582| signaling NaN, the invalid exception is raised.
583*----------------------------------------------------------------------------*/
584
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000585static float32 propagateFloat32NaN(float32 a, float32 b, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000586{
Richard Hendersonc1203912020-05-04 19:54:57 -0700587 bool aIsLargerSignificand;
Andreas Färberbb98fe42011-03-07 01:34:06 +0100588 uint32_t av, bv;
Richard Henderson4f251cf2018-05-10 15:21:31 -0700589 FloatClass a_cls, b_cls;
bellard158142c2005-03-13 16:54:06 +0000590
Richard Henderson4f251cf2018-05-10 15:21:31 -0700591 /* This is not complete, but is good enough for pickNaN. */
592 a_cls = (!float32_is_any_nan(a)
593 ? float_class_normal
594 : float32_is_signaling_nan(a, status)
595 ? float_class_snan
596 : float_class_qnan);
597 b_cls = (!float32_is_any_nan(b)
598 ? float_class_normal
599 : float32_is_signaling_nan(b, status)
600 ? float_class_snan
601 : float_class_qnan);
602
pbrookf090c9d2007-11-18 14:33:24 +0000603 av = float32_val(a);
604 bv = float32_val(b);
Aurelien Jarno1f398e02011-01-06 15:38:19 +0100605
Richard Henderson4f251cf2018-05-10 15:21:31 -0700606 if (is_snan(a_cls) || is_snan(b_cls)) {
Peter Maydellff32e162015-02-02 18:47:16 +0000607 float_raise(float_flag_invalid, status);
608 }
Peter Maydell354f2112010-12-16 11:51:17 +0000609
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200610 if (status->default_nan_mode) {
611 return float32_default_nan(status);
612 }
Aurelien Jarno10201602011-01-14 20:39:17 +0100613
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200614 if ((uint32_t)(av << 1) < (uint32_t)(bv << 1)) {
Peter Maydell354f2112010-12-16 11:51:17 +0000615 aIsLargerSignificand = 0;
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200616 } else if ((uint32_t)(bv << 1) < (uint32_t)(av << 1)) {
Peter Maydell354f2112010-12-16 11:51:17 +0000617 aIsLargerSignificand = 1;
618 } else {
619 aIsLargerSignificand = (av < bv) ? 1 : 0;
bellard158142c2005-03-13 16:54:06 +0000620 }
Peter Maydell354f2112010-12-16 11:51:17 +0000621
Richard Henderson4f251cf2018-05-10 15:21:31 -0700622 if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
623 if (is_snan(b_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -0700624 return float32_silence_nan(b, status);
625 }
626 return b;
Peter Maydell354f2112010-12-16 11:51:17 +0000627 } else {
Richard Henderson4f251cf2018-05-10 15:21:31 -0700628 if (is_snan(a_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -0700629 return float32_silence_nan(a, status);
630 }
631 return a;
bellard158142c2005-03-13 16:54:06 +0000632 }
bellard158142c2005-03-13 16:54:06 +0000633}
634
Peter Maydell369be8f2011-10-19 16:14:06 +0000635/*----------------------------------------------------------------------------
ths5a6932d2007-11-16 14:57:36 +0000636| Returns 1 if the double-precision floating-point value `a' is a quiet
637| NaN; otherwise returns 0.
bellard158142c2005-03-13 16:54:06 +0000638*----------------------------------------------------------------------------*/
639
Richard Henderson150c7a92020-05-05 12:16:24 -0700640bool float64_is_quiet_nan(float64 a_, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000641{
Richard Hendersonbca52232018-05-10 11:24:13 -0700642#ifdef NO_SIGNALING_NANS
643 return float64_is_any_nan(a_);
644#else
Andreas Färberbb98fe42011-03-07 01:34:06 +0100645 uint64_t a = float64_val(a_);
Richard Henderson03385df2018-05-10 14:48:17 -0700646 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200647 return (((a >> 51) & 0xFFF) == 0xFFE)
648 && (a & 0x0007FFFFFFFFFFFFULL);
649 } else {
650 return ((a << 1) >= 0xFFF0000000000000ULL);
651 }
Richard Hendersonbca52232018-05-10 11:24:13 -0700652#endif
bellard158142c2005-03-13 16:54:06 +0000653}
654
655/*----------------------------------------------------------------------------
656| Returns 1 if the double-precision floating-point value `a' is a signaling
657| NaN; otherwise returns 0.
658*----------------------------------------------------------------------------*/
659
Richard Henderson150c7a92020-05-05 12:16:24 -0700660bool float64_is_signaling_nan(float64 a_, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000661{
Richard Hendersonbca52232018-05-10 11:24:13 -0700662#ifdef NO_SIGNALING_NANS
663 return 0;
664#else
Andreas Färberbb98fe42011-03-07 01:34:06 +0100665 uint64_t a = float64_val(a_);
Richard Henderson03385df2018-05-10 14:48:17 -0700666 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200667 return ((a << 1) >= 0xFFF0000000000000ULL);
668 } else {
669 return (((a >> 51) & 0xFFF) == 0xFFE)
Alex Bennéef7e81a92019-08-12 16:04:02 +0100670 && (a & UINT64_C(0x0007FFFFFFFFFFFF));
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200671 }
Max Filippov213ff4e2012-09-19 04:23:51 +0400672#endif
Richard Hendersonbca52232018-05-10 11:24:13 -0700673}
bellard158142c2005-03-13 16:54:06 +0000674
675/*----------------------------------------------------------------------------
676| Returns the result of converting the double-precision floating-point NaN
677| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid
678| exception is raised.
679*----------------------------------------------------------------------------*/
680
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000681static commonNaNT float64ToCommonNaN(float64 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000682{
683 commonNaNT z;
684
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200685 if (float64_is_signaling_nan(a, status)) {
Peter Maydellff32e162015-02-02 18:47:16 +0000686 float_raise(float_flag_invalid, status);
687 }
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200688 z.sign = float64_val(a) >> 63;
bellard158142c2005-03-13 16:54:06 +0000689 z.low = 0;
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200690 z.high = float64_val(a) << 12;
bellard158142c2005-03-13 16:54:06 +0000691 return z;
bellard158142c2005-03-13 16:54:06 +0000692}
693
694/*----------------------------------------------------------------------------
695| Returns the result of converting the canonical NaN `a' to the double-
696| precision floating-point format.
697*----------------------------------------------------------------------------*/
698
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000699static float64 commonNaNToFloat64(commonNaNT a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000700{
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200701 uint64_t mantissa = a.high >> 12;
ths85016c92007-12-25 23:59:51 +0000702
Peter Maydella2f2d282015-02-02 18:57:35 +0000703 if (status->default_nan_mode) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200704 return float64_default_nan(status);
Christophe Lyonbcd4d9a2011-02-10 11:28:57 +0000705 }
706
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200707 if (mantissa) {
ths85016c92007-12-25 23:59:51 +0000708 return make_float64(
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200709 (((uint64_t) a.sign) << 63)
Alex Bennéef7e81a92019-08-12 16:04:02 +0100710 | UINT64_C(0x7FF0000000000000)
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200711 | (a.high >> 12));
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200712 } else {
713 return float64_default_nan(status);
714 }
bellard158142c2005-03-13 16:54:06 +0000715}
716
717/*----------------------------------------------------------------------------
718| Takes two double-precision floating-point values `a' and `b', one of which
719| is a NaN, and returns the appropriate NaN result. If either `a' or `b' is a
720| signaling NaN, the invalid exception is raised.
721*----------------------------------------------------------------------------*/
722
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000723static float64 propagateFloat64NaN(float64 a, float64 b, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000724{
Richard Hendersonc1203912020-05-04 19:54:57 -0700725 bool aIsLargerSignificand;
Andreas Färberbb98fe42011-03-07 01:34:06 +0100726 uint64_t av, bv;
Richard Henderson4f251cf2018-05-10 15:21:31 -0700727 FloatClass a_cls, b_cls;
bellard158142c2005-03-13 16:54:06 +0000728
Richard Henderson4f251cf2018-05-10 15:21:31 -0700729 /* This is not complete, but is good enough for pickNaN. */
730 a_cls = (!float64_is_any_nan(a)
731 ? float_class_normal
732 : float64_is_signaling_nan(a, status)
733 ? float_class_snan
734 : float_class_qnan);
735 b_cls = (!float64_is_any_nan(b)
736 ? float_class_normal
737 : float64_is_signaling_nan(b, status)
738 ? float_class_snan
739 : float_class_qnan);
740
pbrookf090c9d2007-11-18 14:33:24 +0000741 av = float64_val(a);
742 bv = float64_val(b);
Aurelien Jarno1f398e02011-01-06 15:38:19 +0100743
Richard Henderson4f251cf2018-05-10 15:21:31 -0700744 if (is_snan(a_cls) || is_snan(b_cls)) {
Peter Maydellff32e162015-02-02 18:47:16 +0000745 float_raise(float_flag_invalid, status);
746 }
Peter Maydell354f2112010-12-16 11:51:17 +0000747
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200748 if (status->default_nan_mode) {
749 return float64_default_nan(status);
750 }
Aurelien Jarno10201602011-01-14 20:39:17 +0100751
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200752 if ((uint64_t)(av << 1) < (uint64_t)(bv << 1)) {
Peter Maydell354f2112010-12-16 11:51:17 +0000753 aIsLargerSignificand = 0;
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200754 } else if ((uint64_t)(bv << 1) < (uint64_t)(av << 1)) {
Peter Maydell354f2112010-12-16 11:51:17 +0000755 aIsLargerSignificand = 1;
756 } else {
757 aIsLargerSignificand = (av < bv) ? 1 : 0;
bellard158142c2005-03-13 16:54:06 +0000758 }
Peter Maydell354f2112010-12-16 11:51:17 +0000759
Richard Henderson4f251cf2018-05-10 15:21:31 -0700760 if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
761 if (is_snan(b_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -0700762 return float64_silence_nan(b, status);
763 }
764 return b;
Peter Maydell354f2112010-12-16 11:51:17 +0000765 } else {
Richard Henderson4f251cf2018-05-10 15:21:31 -0700766 if (is_snan(a_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -0700767 return float64_silence_nan(a, status);
768 }
769 return a;
bellard158142c2005-03-13 16:54:06 +0000770 }
bellard158142c2005-03-13 16:54:06 +0000771}
772
Peter Maydell369be8f2011-10-19 16:14:06 +0000773/*----------------------------------------------------------------------------
bellard158142c2005-03-13 16:54:06 +0000774| Returns 1 if the extended double-precision floating-point value `a' is a
Aurelien Jarnode4af5f2011-01-17 19:29:33 +0100775| quiet NaN; otherwise returns 0. This slightly differs from the same
776| function for other types as floatx80 has an explicit bit.
bellard158142c2005-03-13 16:54:06 +0000777*----------------------------------------------------------------------------*/
778
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200779int floatx80_is_quiet_nan(floatx80 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000780{
Richard Hendersonbca52232018-05-10 11:24:13 -0700781#ifdef NO_SIGNALING_NANS
782 return floatx80_is_any_nan(a);
783#else
Richard Henderson03385df2018-05-10 14:48:17 -0700784 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200785 uint64_t aLow;
bellard158142c2005-03-13 16:54:06 +0000786
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200787 aLow = a.low & ~0x4000000000000000ULL;
788 return ((a.high & 0x7FFF) == 0x7FFF)
789 && (aLow << 1)
790 && (a.low == aLow);
791 } else {
792 return ((a.high & 0x7FFF) == 0x7FFF)
Alex Bennéef7e81a92019-08-12 16:04:02 +0100793 && (UINT64_C(0x8000000000000000) <= ((uint64_t)(a.low << 1)));
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200794 }
Richard Hendersonbca52232018-05-10 11:24:13 -0700795#endif
bellard158142c2005-03-13 16:54:06 +0000796}
797
798/*----------------------------------------------------------------------------
799| Returns 1 if the extended double-precision floating-point value `a' is a
Aurelien Jarnode4af5f2011-01-17 19:29:33 +0100800| signaling NaN; otherwise returns 0. This slightly differs from the same
801| function for other types as floatx80 has an explicit bit.
bellard158142c2005-03-13 16:54:06 +0000802*----------------------------------------------------------------------------*/
803
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200804int floatx80_is_signaling_nan(floatx80 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000805{
Richard Hendersonbca52232018-05-10 11:24:13 -0700806#ifdef NO_SIGNALING_NANS
807 return 0;
808#else
Richard Henderson03385df2018-05-10 14:48:17 -0700809 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200810 return ((a.high & 0x7FFF) == 0x7FFF)
811 && ((a.low << 1) >= 0x8000000000000000ULL);
812 } else {
813 uint64_t aLow;
bellard158142c2005-03-13 16:54:06 +0000814
Alex Bennéef7e81a92019-08-12 16:04:02 +0100815 aLow = a.low & ~UINT64_C(0x4000000000000000);
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200816 return ((a.high & 0x7FFF) == 0x7FFF)
817 && (uint64_t)(aLow << 1)
818 && (a.low == aLow);
819 }
Max Filippov213ff4e2012-09-19 04:23:51 +0400820#endif
Richard Hendersonbca52232018-05-10 11:24:13 -0700821}
bellard158142c2005-03-13 16:54:06 +0000822
823/*----------------------------------------------------------------------------
Richard Hendersond619bb92018-05-10 11:39:48 -0700824| Returns a quiet NaN from a signalling NaN for the extended double-precision
825| floating point value `a'.
826*----------------------------------------------------------------------------*/
827
828floatx80 floatx80_silence_nan(floatx80 a, float_status *status)
829{
Richard Henderson377ed922018-05-14 14:26:38 -0700830 /* None of the targets that have snan_bit_is_one use floatx80. */
831 assert(!snan_bit_is_one(status));
Alex Bennéef7e81a92019-08-12 16:04:02 +0100832 a.low |= UINT64_C(0xC000000000000000);
Richard Henderson377ed922018-05-14 14:26:38 -0700833 return a;
Richard Hendersond619bb92018-05-10 11:39:48 -0700834}
835
836/*----------------------------------------------------------------------------
bellard158142c2005-03-13 16:54:06 +0000837| Returns the result of converting the extended double-precision floating-
838| point NaN `a' to the canonical NaN format. If `a' is a signaling NaN, the
839| invalid exception is raised.
840*----------------------------------------------------------------------------*/
841
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000842static commonNaNT floatx80ToCommonNaN(floatx80 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000843{
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200844 floatx80 dflt;
bellard158142c2005-03-13 16:54:06 +0000845 commonNaNT z;
846
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200847 if (floatx80_is_signaling_nan(a, status)) {
Peter Maydellff32e162015-02-02 18:47:16 +0000848 float_raise(float_flag_invalid, status);
849 }
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200850 if (a.low >> 63) {
Aurelien Jarnoe2f42202011-04-20 13:04:22 +0200851 z.sign = a.high >> 15;
852 z.low = 0;
853 z.high = a.low << 1;
854 } else {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200855 dflt = floatx80_default_nan(status);
856 z.sign = dflt.high >> 15;
Aurelien Jarnoe2f42202011-04-20 13:04:22 +0200857 z.low = 0;
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200858 z.high = dflt.low << 1;
Aurelien Jarnoe2f42202011-04-20 13:04:22 +0200859 }
bellard158142c2005-03-13 16:54:06 +0000860 return z;
bellard158142c2005-03-13 16:54:06 +0000861}
862
863/*----------------------------------------------------------------------------
864| Returns the result of converting the canonical NaN `a' to the extended
865| double-precision floating-point format.
866*----------------------------------------------------------------------------*/
867
Peter Maydelle5a41ff2015-01-30 12:04:16 +0000868static floatx80 commonNaNToFloatx80(commonNaNT a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000869{
870 floatx80 z;
871
Peter Maydella2f2d282015-02-02 18:57:35 +0000872 if (status->default_nan_mode) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200873 return floatx80_default_nan(status);
Christophe Lyonbcd4d9a2011-02-10 11:28:57 +0000874 }
875
Aurelien Jarnoe2f42202011-04-20 13:04:22 +0200876 if (a.high >> 1) {
Alex Bennéef7e81a92019-08-12 16:04:02 +0100877 z.low = UINT64_C(0x8000000000000000) | a.high >> 1;
Aleksandar Markovica59eaea2016-06-10 11:57:29 +0200878 z.high = (((uint16_t)a.sign) << 15) | 0x7FFF;
Aurelien Jarnoe2f42202011-04-20 13:04:22 +0200879 } else {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200880 z = floatx80_default_nan(status);
Aurelien Jarnoe2f42202011-04-20 13:04:22 +0200881 }
bellard158142c2005-03-13 16:54:06 +0000882 return z;
bellard158142c2005-03-13 16:54:06 +0000883}
884
885/*----------------------------------------------------------------------------
886| Takes two extended double-precision floating-point values `a' and `b', one
887| of which is a NaN, and returns the appropriate NaN result. If either `a' or
888| `b' is a signaling NaN, the invalid exception is raised.
889*----------------------------------------------------------------------------*/
890
Laurent Vivier88857ac2018-02-24 21:17:59 +0100891floatx80 propagateFloatx80NaN(floatx80 a, floatx80 b, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000892{
Richard Hendersonc1203912020-05-04 19:54:57 -0700893 bool aIsLargerSignificand;
Richard Henderson4f251cf2018-05-10 15:21:31 -0700894 FloatClass a_cls, b_cls;
bellard158142c2005-03-13 16:54:06 +0000895
Richard Henderson4f251cf2018-05-10 15:21:31 -0700896 /* This is not complete, but is good enough for pickNaN. */
897 a_cls = (!floatx80_is_any_nan(a)
898 ? float_class_normal
899 : floatx80_is_signaling_nan(a, status)
900 ? float_class_snan
901 : float_class_qnan);
902 b_cls = (!floatx80_is_any_nan(b)
903 ? float_class_normal
904 : floatx80_is_signaling_nan(b, status)
905 ? float_class_snan
906 : float_class_qnan);
Aurelien Jarno1f398e02011-01-06 15:38:19 +0100907
Richard Henderson4f251cf2018-05-10 15:21:31 -0700908 if (is_snan(a_cls) || is_snan(b_cls)) {
Peter Maydellff32e162015-02-02 18:47:16 +0000909 float_raise(float_flag_invalid, status);
910 }
Peter Maydell354f2112010-12-16 11:51:17 +0000911
Peter Maydella2f2d282015-02-02 18:57:35 +0000912 if (status->default_nan_mode) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200913 return floatx80_default_nan(status);
Aurelien Jarno10201602011-01-14 20:39:17 +0100914 }
915
Peter Maydell354f2112010-12-16 11:51:17 +0000916 if (a.low < b.low) {
917 aIsLargerSignificand = 0;
918 } else if (b.low < a.low) {
919 aIsLargerSignificand = 1;
920 } else {
921 aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
bellard158142c2005-03-13 16:54:06 +0000922 }
Peter Maydell354f2112010-12-16 11:51:17 +0000923
Richard Henderson4f251cf2018-05-10 15:21:31 -0700924 if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
925 if (is_snan(b_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -0700926 return floatx80_silence_nan(b, status);
927 }
928 return b;
Peter Maydell354f2112010-12-16 11:51:17 +0000929 } else {
Richard Henderson4f251cf2018-05-10 15:21:31 -0700930 if (is_snan(a_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -0700931 return floatx80_silence_nan(a, status);
932 }
933 return a;
bellard158142c2005-03-13 16:54:06 +0000934 }
bellard158142c2005-03-13 16:54:06 +0000935}
936
bellard158142c2005-03-13 16:54:06 +0000937/*----------------------------------------------------------------------------
ths5a6932d2007-11-16 14:57:36 +0000938| Returns 1 if the quadruple-precision floating-point value `a' is a quiet
939| NaN; otherwise returns 0.
bellard158142c2005-03-13 16:54:06 +0000940*----------------------------------------------------------------------------*/
941
Richard Henderson150c7a92020-05-05 12:16:24 -0700942bool float128_is_quiet_nan(float128 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000943{
Richard Hendersonbca52232018-05-10 11:24:13 -0700944#ifdef NO_SIGNALING_NANS
945 return float128_is_any_nan(a);
946#else
Richard Henderson03385df2018-05-10 14:48:17 -0700947 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200948 return (((a.high >> 47) & 0xFFFF) == 0xFFFE)
949 && (a.low || (a.high & 0x00007FFFFFFFFFFFULL));
950 } else {
951 return ((a.high << 1) >= 0xFFFF000000000000ULL)
952 && (a.low || (a.high & 0x0000FFFFFFFFFFFFULL));
953 }
Richard Hendersonbca52232018-05-10 11:24:13 -0700954#endif
bellard158142c2005-03-13 16:54:06 +0000955}
956
957/*----------------------------------------------------------------------------
958| Returns 1 if the quadruple-precision floating-point value `a' is a
959| signaling NaN; otherwise returns 0.
960*----------------------------------------------------------------------------*/
961
Richard Henderson150c7a92020-05-05 12:16:24 -0700962bool float128_is_signaling_nan(float128 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +0000963{
Richard Hendersonbca52232018-05-10 11:24:13 -0700964#ifdef NO_SIGNALING_NANS
965 return 0;
966#else
Richard Henderson03385df2018-05-10 14:48:17 -0700967 if (snan_bit_is_one(status)) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200968 return ((a.high << 1) >= 0xFFFF000000000000ULL)
969 && (a.low || (a.high & 0x0000FFFFFFFFFFFFULL));
970 } else {
971 return (((a.high >> 47) & 0xFFFF) == 0xFFFE)
Alex Bennéef7e81a92019-08-12 16:04:02 +0100972 && (a.low || (a.high & UINT64_C(0x00007FFFFFFFFFFF)));
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +0200973 }
Max Filippov213ff4e2012-09-19 04:23:51 +0400974#endif
Richard Hendersonbca52232018-05-10 11:24:13 -0700975}
bellard158142c2005-03-13 16:54:06 +0000976
977/*----------------------------------------------------------------------------
Richard Hendersond619bb92018-05-10 11:39:48 -0700978| Returns a quiet NaN from a signalling NaN for the quadruple-precision
979| floating point value `a'.
980*----------------------------------------------------------------------------*/
981
982float128 float128_silence_nan(float128 a, float_status *status)
983{
984#ifdef NO_SIGNALING_NANS
985 g_assert_not_reached();
986#else
Richard Henderson03385df2018-05-10 14:48:17 -0700987 if (snan_bit_is_one(status)) {
Richard Hendersond619bb92018-05-10 11:39:48 -0700988 return float128_default_nan(status);
989 } else {
Alex Bennéef7e81a92019-08-12 16:04:02 +0100990 a.high |= UINT64_C(0x0000800000000000);
Richard Hendersond619bb92018-05-10 11:39:48 -0700991 return a;
992 }
993#endif
994}
995
996/*----------------------------------------------------------------------------
bellard158142c2005-03-13 16:54:06 +0000997| Returns the result of converting the quadruple-precision floating-point NaN
998| `a' to the canonical NaN format. If `a' is a signaling NaN, the invalid
999| exception is raised.
1000*----------------------------------------------------------------------------*/
1001
Peter Maydelle5a41ff2015-01-30 12:04:16 +00001002static commonNaNT float128ToCommonNaN(float128 a, float_status *status)
bellard158142c2005-03-13 16:54:06 +00001003{
1004 commonNaNT z;
1005
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +02001006 if (float128_is_signaling_nan(a, status)) {
Peter Maydellff32e162015-02-02 18:47:16 +00001007 float_raise(float_flag_invalid, status);
1008 }
Aleksandar Markovica59eaea2016-06-10 11:57:29 +02001009 z.sign = a.high >> 63;
1010 shortShift128Left(a.high, a.low, 16, &z.high, &z.low);
bellard158142c2005-03-13 16:54:06 +00001011 return z;
bellard158142c2005-03-13 16:54:06 +00001012}
1013
1014/*----------------------------------------------------------------------------
1015| Returns the result of converting the canonical NaN `a' to the quadruple-
1016| precision floating-point format.
1017*----------------------------------------------------------------------------*/
1018
Peter Maydelle5a41ff2015-01-30 12:04:16 +00001019static float128 commonNaNToFloat128(commonNaNT a, float_status *status)
bellard158142c2005-03-13 16:54:06 +00001020{
1021 float128 z;
1022
Peter Maydella2f2d282015-02-02 18:57:35 +00001023 if (status->default_nan_mode) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +02001024 return float128_default_nan(status);
Christophe Lyonbcd4d9a2011-02-10 11:28:57 +00001025 }
1026
Aleksandar Markovica59eaea2016-06-10 11:57:29 +02001027 shift128Right(a.high, a.low, 16, &z.high, &z.low);
Alex Bennéef7e81a92019-08-12 16:04:02 +01001028 z.high |= (((uint64_t)a.sign) << 63) | UINT64_C(0x7FFF000000000000);
bellard158142c2005-03-13 16:54:06 +00001029 return z;
bellard158142c2005-03-13 16:54:06 +00001030}
1031
1032/*----------------------------------------------------------------------------
1033| Takes two quadruple-precision floating-point values `a' and `b', one of
1034| which is a NaN, and returns the appropriate NaN result. If either `a' or
1035| `b' is a signaling NaN, the invalid exception is raised.
1036*----------------------------------------------------------------------------*/
1037
Peter Maydelle5a41ff2015-01-30 12:04:16 +00001038static float128 propagateFloat128NaN(float128 a, float128 b,
1039 float_status *status)
bellard158142c2005-03-13 16:54:06 +00001040{
Richard Hendersonc1203912020-05-04 19:54:57 -07001041 bool aIsLargerSignificand;
Richard Henderson4f251cf2018-05-10 15:21:31 -07001042 FloatClass a_cls, b_cls;
bellard158142c2005-03-13 16:54:06 +00001043
Richard Henderson4f251cf2018-05-10 15:21:31 -07001044 /* This is not complete, but is good enough for pickNaN. */
1045 a_cls = (!float128_is_any_nan(a)
1046 ? float_class_normal
1047 : float128_is_signaling_nan(a, status)
1048 ? float_class_snan
1049 : float_class_qnan);
1050 b_cls = (!float128_is_any_nan(b)
1051 ? float_class_normal
1052 : float128_is_signaling_nan(b, status)
1053 ? float_class_snan
1054 : float_class_qnan);
Aurelien Jarno1f398e02011-01-06 15:38:19 +01001055
Richard Henderson4f251cf2018-05-10 15:21:31 -07001056 if (is_snan(a_cls) || is_snan(b_cls)) {
Peter Maydellff32e162015-02-02 18:47:16 +00001057 float_raise(float_flag_invalid, status);
1058 }
Peter Maydell354f2112010-12-16 11:51:17 +00001059
Peter Maydella2f2d282015-02-02 18:57:35 +00001060 if (status->default_nan_mode) {
Aleksandar Markovicaf39bc82016-06-10 11:57:28 +02001061 return float128_default_nan(status);
Aurelien Jarno10201602011-01-14 20:39:17 +01001062 }
1063
Aleksandar Markovica59eaea2016-06-10 11:57:29 +02001064 if (lt128(a.high << 1, a.low, b.high << 1, b.low)) {
Peter Maydell354f2112010-12-16 11:51:17 +00001065 aIsLargerSignificand = 0;
Aleksandar Markovica59eaea2016-06-10 11:57:29 +02001066 } else if (lt128(b.high << 1, b.low, a.high << 1, a.low)) {
Peter Maydell354f2112010-12-16 11:51:17 +00001067 aIsLargerSignificand = 1;
1068 } else {
1069 aIsLargerSignificand = (a.high < b.high) ? 1 : 0;
bellard158142c2005-03-13 16:54:06 +00001070 }
Peter Maydell354f2112010-12-16 11:51:17 +00001071
Richard Henderson4f251cf2018-05-10 15:21:31 -07001072 if (pickNaN(a_cls, b_cls, aIsLargerSignificand)) {
1073 if (is_snan(b_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -07001074 return float128_silence_nan(b, status);
1075 }
1076 return b;
Peter Maydell354f2112010-12-16 11:51:17 +00001077 } else {
Richard Henderson4f251cf2018-05-10 15:21:31 -07001078 if (is_snan(a_cls)) {
Richard Henderson48853122018-05-10 14:11:15 -07001079 return float128_silence_nan(a, status);
1080 }
1081 return a;
bellard158142c2005-03-13 16:54:06 +00001082 }
bellard158142c2005-03-13 16:54:06 +00001083}