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source: vbox/trunk/src/libs/softfloat-3e/source/s_mulAddF64.c@ 104661

Last change on this file since 104661 was 94558, checked in by vboxsync, 3 years ago

VMM/IEM,libs/softfloat: Don't use global variables in SoftFloat, pass in a state pointer to (almost) all functions instead. Started on fsqrt instruction implementation. bugref:9898
  • Property svn:eol-style set to native
File size: 18.1 KB
Line 
1
2/*============================================================================
3
4This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
5Package, Release 3e, by John R. Hauser.
6
7Copyright 2011, 2012, 2013, 2014, 2015, 2016 The Regents of the University of
8California. All rights reserved.
9
10Redistribution and use in source and binary forms, with or without
11modification, are permitted provided that the following conditions are met:
12
13 1. Redistributions of source code must retain the above copyright notice,
14 this list of conditions, and the following disclaimer.
15
16 2. Redistributions in binary form must reproduce the above copyright notice,
17 this list of conditions, and the following disclaimer in the documentation
18 and/or other materials provided with the distribution.
19
20 3. Neither the name of the University nor the names of its contributors may
21 be used to endorse or promote products derived from this software without
22 specific prior written permission.
23
24THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
25EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
26WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
27DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
28DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
29(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34
35=============================================================================*/
36
37#include <stdbool.h>
38#include <stdint.h>
39#include "platform.h"
40#include "internals.h"
41#include "specialize.h"
42#include "softfloat.h"
43
44#ifdef SOFTFLOAT_FAST_INT64
45
46float64_t
47 softfloat_mulAddF64(
48 uint_fast64_t uiA, uint_fast64_t uiB, uint_fast64_t uiC, uint_fast8_t op SOFTFLOAT_STATE_DECL_COMMA )
49{
50 bool signA;
51 int_fast16_t expA;
52 uint_fast64_t sigA;
53 bool signB;
54 int_fast16_t expB;
55 uint_fast64_t sigB;
56 bool signC;
57 int_fast16_t expC;
58 uint_fast64_t sigC;
59 bool signZ;
60 uint_fast64_t magBits, uiZ;
61 struct exp16_sig64 normExpSig;
62 int_fast16_t expZ;
63 struct uint128 sig128Z;
64 uint_fast64_t sigZ;
65 int_fast16_t expDiff;
66 struct uint128 sig128C = { 0, 0 }; /* vbox: shut up MSC warning*/
67 int_fast8_t shiftDist;
68 union ui64_f64 uZ;
69
70 /*------------------------------------------------------------------------
71 *------------------------------------------------------------------------*/
72 signA = signF64UI( uiA );
73 expA = expF64UI( uiA );
74 sigA = fracF64UI( uiA );
75 signB = signF64UI( uiB );
76 expB = expF64UI( uiB );
77 sigB = fracF64UI( uiB );
78 signC = signF64UI( uiC ) ^ (op == softfloat_mulAdd_subC);
79 expC = expF64UI( uiC );
80 sigC = fracF64UI( uiC );
81 signZ = signA ^ signB ^ (op == softfloat_mulAdd_subProd);
82 /*------------------------------------------------------------------------
83 *------------------------------------------------------------------------*/
84 if ( expA == 0x7FF ) {
85 if ( sigA || ((expB == 0x7FF) && sigB) ) goto propagateNaN_ABC;
86 magBits = expB | sigB;
87 goto infProdArg;
88 }
89 if ( expB == 0x7FF ) {
90 if ( sigB ) goto propagateNaN_ABC;
91 magBits = expA | sigA;
92 goto infProdArg;
93 }
94 if ( expC == 0x7FF ) {
95 if ( sigC ) {
96 uiZ = 0;
97 goto propagateNaN_ZC;
98 }
99 uiZ = uiC;
100 goto uiZ;
101 }
102 /*------------------------------------------------------------------------
103 *------------------------------------------------------------------------*/
104 if ( ! expA ) {
105 if ( ! sigA ) goto zeroProd;
106 normExpSig = softfloat_normSubnormalF64Sig( sigA );
107 expA = normExpSig.exp;
108 sigA = normExpSig.sig;
109 }
110 if ( ! expB ) {
111 if ( ! sigB ) goto zeroProd;
112 normExpSig = softfloat_normSubnormalF64Sig( sigB );
113 expB = normExpSig.exp;
114 sigB = normExpSig.sig;
115 }
116 /*------------------------------------------------------------------------
117 *------------------------------------------------------------------------*/
118 expZ = expA + expB - 0x3FE;
119 sigA = (sigA | UINT64_C( 0x0010000000000000 ))<<10;
120 sigB = (sigB | UINT64_C( 0x0010000000000000 ))<<10;
121 sig128Z = softfloat_mul64To128( sigA, sigB );
122 if ( sig128Z.v64 < UINT64_C( 0x2000000000000000 ) ) {
123 --expZ;
124 sig128Z =
125 softfloat_add128(
126 sig128Z.v64, sig128Z.v0, sig128Z.v64, sig128Z.v0 );
127 }
128 if ( ! expC ) {
129 if ( ! sigC ) {
130 --expZ;
131 sigZ = sig128Z.v64<<1 | (sig128Z.v0 != 0);
132 goto roundPack;
133 }
134 normExpSig = softfloat_normSubnormalF64Sig( sigC );
135 expC = normExpSig.exp;
136 sigC = normExpSig.sig;
137 }
138 sigC = (sigC | UINT64_C( 0x0010000000000000 ))<<9;
139 /*------------------------------------------------------------------------
140 *------------------------------------------------------------------------*/
141 expDiff = expZ - expC;
142 if ( expDiff < 0 ) {
143 expZ = expC;
144 if ( (signZ == signC) || (expDiff < -1) ) {
145 sig128Z.v64 = softfloat_shiftRightJam64( sig128Z.v64, -expDiff );
146 } else {
147 sig128Z =
148 softfloat_shortShiftRightJam128( sig128Z.v64, sig128Z.v0, 1 );
149 }
150 } else if ( expDiff ) {
151 sig128C = softfloat_shiftRightJam128( sigC, 0, expDiff );
152 }
153 /*------------------------------------------------------------------------
154 *------------------------------------------------------------------------*/
155 if ( signZ == signC ) {
156 /*--------------------------------------------------------------------
157 *--------------------------------------------------------------------*/
158 if ( expDiff <= 0 ) {
159 sigZ = (sigC + sig128Z.v64) | (sig128Z.v0 != 0);
160 } else {
161 sig128Z =
162 softfloat_add128(
163 sig128Z.v64, sig128Z.v0, sig128C.v64, sig128C.v0 );
164 sigZ = sig128Z.v64 | (sig128Z.v0 != 0);
165 }
166 if ( sigZ < UINT64_C( 0x4000000000000000 ) ) {
167 --expZ;
168 sigZ <<= 1;
169 }
170 } else {
171 /*--------------------------------------------------------------------
172 *--------------------------------------------------------------------*/
173 if ( expDiff < 0 ) {
174 signZ = signC;
175 sig128Z = softfloat_sub128( sigC, 0, sig128Z.v64, sig128Z.v0 );
176 } else if ( ! expDiff ) {
177 sig128Z.v64 = sig128Z.v64 - sigC;
178 if ( ! (sig128Z.v64 | sig128Z.v0) ) goto completeCancellation;
179 if ( sig128Z.v64 & UINT64_C( 0x8000000000000000 ) ) {
180 signZ = ! signZ;
181 sig128Z = softfloat_sub128( 0, 0, sig128Z.v64, sig128Z.v0 );
182 }
183 } else {
184 sig128Z =
185 softfloat_sub128(
186 sig128Z.v64, sig128Z.v0, sig128C.v64, sig128C.v0 );
187 }
188 /*--------------------------------------------------------------------
189 *--------------------------------------------------------------------*/
190 if ( ! sig128Z.v64 ) {
191 expZ -= 64;
192 sig128Z.v64 = sig128Z.v0;
193 sig128Z.v0 = 0;
194 }
195 shiftDist = softfloat_countLeadingZeros64( sig128Z.v64 ) - 1;
196 expZ -= shiftDist;
197 if ( shiftDist < 0 ) {
198 sigZ = softfloat_shortShiftRightJam64( sig128Z.v64, -shiftDist );
199 } else {
200 sig128Z =
201 softfloat_shortShiftLeft128(
202 sig128Z.v64, sig128Z.v0, shiftDist );
203 sigZ = sig128Z.v64;
204 }
205 sigZ |= (sig128Z.v0 != 0);
206 }
207 roundPack:
208 return softfloat_roundPackToF64( signZ, expZ, sigZ SOFTFLOAT_STATE_ARG_COMMA );
209 /*------------------------------------------------------------------------
210 *------------------------------------------------------------------------*/
211 propagateNaN_ABC:
212 uiZ = softfloat_propagateNaNF64UI( uiA, uiB SOFTFLOAT_STATE_ARG_COMMA );
213 goto propagateNaN_ZC;
214 /*------------------------------------------------------------------------
215 *------------------------------------------------------------------------*/
216 infProdArg:
217 if ( magBits ) {
218 uiZ = packToF64UI( signZ, 0x7FF, 0 );
219 if ( expC != 0x7FF ) goto uiZ;
220 if ( sigC ) goto propagateNaN_ZC;
221 if ( signZ == signC ) goto uiZ;
222 }
223 softfloat_raiseFlags( softfloat_flag_invalid SOFTFLOAT_STATE_ARG_COMMA );
224 uiZ = defaultNaNF64UI;
225 propagateNaN_ZC:
226 uiZ = softfloat_propagateNaNF64UI( uiZ, uiC SOFTFLOAT_STATE_ARG_COMMA );
227 goto uiZ;
228 /*------------------------------------------------------------------------
229 *------------------------------------------------------------------------*/
230 zeroProd:
231 uiZ = uiC;
232 if ( ! (expC | sigC) && (signZ != signC) ) {
233 completeCancellation:
234 uiZ =
235 packToF64UI(
236 (softfloat_roundingMode == softfloat_round_min), 0, 0 );
237 }
238 uiZ:
239 uZ.ui = uiZ;
240 return uZ.f;
241
242}
243
244#else
245
246float64_t
247 softfloat_mulAddF64(
248 uint_fast64_t uiA, uint_fast64_t uiB, uint_fast64_t uiC, uint_fast8_t op SOFTFLOAT_STATE_DECL_COMMA )
249{
250 bool signA;
251 int_fast16_t expA;
252 uint64_t sigA;
253 bool signB;
254 int_fast16_t expB;
255 uint64_t sigB;
256 bool signC;
257 int_fast16_t expC;
258 uint64_t sigC;
259 bool signZ;
260 uint64_t magBits, uiZ;
261 struct exp16_sig64 normExpSig;
262 int_fast16_t expZ;
263 uint32_t sig128Z[4];
264 uint64_t sigZ;
265 int_fast16_t shiftDist, expDiff;
266 uint32_t sig128C[4];
267 union ui64_f64 uZ;
268
269 /*------------------------------------------------------------------------
270 *------------------------------------------------------------------------*/
271 signA = signF64UI( uiA );
272 expA = expF64UI( uiA );
273 sigA = fracF64UI( uiA );
274 signB = signF64UI( uiB );
275 expB = expF64UI( uiB );
276 sigB = fracF64UI( uiB );
277 signC = signF64UI( uiC ) ^ (op == softfloat_mulAdd_subC);
278 expC = expF64UI( uiC );
279 sigC = fracF64UI( uiC );
280 signZ = signA ^ signB ^ (op == softfloat_mulAdd_subProd);
281 /*------------------------------------------------------------------------
282 *------------------------------------------------------------------------*/
283 if ( expA == 0x7FF ) {
284 if ( sigA || ((expB == 0x7FF) && sigB) ) goto propagateNaN_ABC;
285 magBits = expB | sigB;
286 goto infProdArg;
287 }
288 if ( expB == 0x7FF ) {
289 if ( sigB ) goto propagateNaN_ABC;
290 magBits = expA | sigA;
291 goto infProdArg;
292 }
293 if ( expC == 0x7FF ) {
294 if ( sigC ) {
295 uiZ = 0;
296 goto propagateNaN_ZC;
297 }
298 uiZ = uiC;
299 goto uiZ;
300 }
301 /*------------------------------------------------------------------------
302 *------------------------------------------------------------------------*/
303 if ( ! expA ) {
304 if ( ! sigA ) goto zeroProd;
305 normExpSig = softfloat_normSubnormalF64Sig( sigA );
306 expA = normExpSig.exp;
307 sigA = normExpSig.sig;
308 }
309 if ( ! expB ) {
310 if ( ! sigB ) goto zeroProd;
311 normExpSig = softfloat_normSubnormalF64Sig( sigB );
312 expB = normExpSig.exp;
313 sigB = normExpSig.sig;
314 }
315 /*------------------------------------------------------------------------
316 *------------------------------------------------------------------------*/
317 expZ = expA + expB - 0x3FE;
318 sigA = (sigA | UINT64_C( 0x0010000000000000 ))<<10;
319 sigB = (sigB | UINT64_C( 0x0010000000000000 ))<<11;
320 softfloat_mul64To128M( sigA, sigB, sig128Z );
321 sigZ =
322 (uint64_t) sig128Z[indexWord( 4, 3 )]<<32 | sig128Z[indexWord( 4, 2 )];
323 shiftDist = 0;
324 if ( ! (sigZ & UINT64_C( 0x4000000000000000 )) ) {
325 --expZ;
326 shiftDist = -1;
327 }
328 if ( ! expC ) {
329 if ( ! sigC ) {
330 if ( shiftDist ) sigZ <<= 1;
331 goto sigZ;
332 }
333 normExpSig = softfloat_normSubnormalF64Sig( sigC );
334 expC = normExpSig.exp;
335 sigC = normExpSig.sig;
336 }
337 sigC = (sigC | UINT64_C( 0x0010000000000000 ))<<10;
338 /*------------------------------------------------------------------------
339 *------------------------------------------------------------------------*/
340 expDiff = expZ - expC;
341 if ( expDiff < 0 ) {
342 expZ = expC;
343 if ( (signZ == signC) || (expDiff < -1) ) {
344 shiftDist -= expDiff;
345 if ( shiftDist) {
346 sigZ = softfloat_shiftRightJam64( sigZ, shiftDist );
347 }
348 } else {
349 if ( ! shiftDist ) {
350 softfloat_shortShiftRight128M( sig128Z, 1, sig128Z );
351 }
352 }
353 } else {
354 if ( shiftDist ) softfloat_add128M( sig128Z, sig128Z, sig128Z );
355 if ( ! expDiff ) {
356 sigZ =
357 (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
358 | sig128Z[indexWord( 4, 2 )];
359 } else {
360 sig128C[indexWord( 4, 3 )] = sigC>>32;
361 sig128C[indexWord( 4, 2 )] = sigC;
362 sig128C[indexWord( 4, 1 )] = 0;
363 sig128C[indexWord( 4, 0 )] = 0;
364 softfloat_shiftRightJam128M( sig128C, expDiff, sig128C );
365 }
366 }
367 /*------------------------------------------------------------------------
368 *------------------------------------------------------------------------*/
369 if ( signZ == signC ) {
370 /*--------------------------------------------------------------------
371 *--------------------------------------------------------------------*/
372 if ( expDiff <= 0 ) {
373 sigZ += sigC;
374 } else {
375 softfloat_add128M( sig128Z, sig128C, sig128Z );
376 sigZ =
377 (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
378 | sig128Z[indexWord( 4, 2 )];
379 }
380 if ( sigZ & UINT64_C( 0x8000000000000000 ) ) {
381 ++expZ;
382 sigZ = softfloat_shortShiftRightJam64( sigZ, 1 );
383 }
384 } else {
385 /*--------------------------------------------------------------------
386 *--------------------------------------------------------------------*/
387 if ( expDiff < 0 ) {
388 signZ = signC;
389 if ( expDiff < -1 ) {
390 sigZ = sigC - sigZ;
391 if (
392 sig128Z[indexWord( 4, 1 )] || sig128Z[indexWord( 4, 0 )]
393 ) {
394 sigZ = (sigZ - 1) | 1;
395 }
396 if ( ! (sigZ & UINT64_C( 0x4000000000000000 )) ) {
397 --expZ;
398 sigZ <<= 1;
399 }
400 goto roundPack;
401 } else {
402 sig128C[indexWord( 4, 3 )] = sigC>>32;
403 sig128C[indexWord( 4, 2 )] = sigC;
404 sig128C[indexWord( 4, 1 )] = 0;
405 sig128C[indexWord( 4, 0 )] = 0;
406 softfloat_sub128M( sig128C, sig128Z, sig128Z );
407 }
408 } else if ( ! expDiff ) {
409 sigZ -= sigC;
410 if (
411 ! sigZ && ! sig128Z[indexWord( 4, 1 )]
412 && ! sig128Z[indexWord( 4, 0 )]
413 ) {
414 goto completeCancellation;
415 }
416 sig128Z[indexWord( 4, 3 )] = sigZ>>32;
417 sig128Z[indexWord( 4, 2 )] = sigZ;
418 if ( sigZ & UINT64_C( 0x8000000000000000 ) ) {
419 signZ = ! signZ;
420 softfloat_negX128M( sig128Z );
421 }
422 } else {
423 softfloat_sub128M( sig128Z, sig128C, sig128Z );
424 if ( 1 < expDiff ) {
425 sigZ =
426 (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
427 | sig128Z[indexWord( 4, 2 )];
428 if ( ! (sigZ & UINT64_C( 0x4000000000000000 )) ) {
429 --expZ;
430 sigZ <<= 1;
431 }
432 goto sigZ;
433 }
434 }
435 /*--------------------------------------------------------------------
436 *--------------------------------------------------------------------*/
437 shiftDist = 0;
438 sigZ =
439 (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
440 | sig128Z[indexWord( 4, 2 )];
441 if ( ! sigZ ) {
442 shiftDist = 64;
443 sigZ =
444 (uint64_t) sig128Z[indexWord( 4, 1 )]<<32
445 | sig128Z[indexWord( 4, 0 )];
446 }
447 shiftDist += softfloat_countLeadingZeros64( sigZ ) - 1;
448 if ( shiftDist ) {
449 expZ -= shiftDist;
450 softfloat_shiftLeft128M( sig128Z, shiftDist, sig128Z );
451 sigZ =
452 (uint64_t) sig128Z[indexWord( 4, 3 )]<<32
453 | sig128Z[indexWord( 4, 2 )];
454 }
455 }
456 sigZ:
457 if ( sig128Z[indexWord( 4, 1 )] || sig128Z[indexWord( 4, 0 )] ) sigZ |= 1;
458 roundPack:
459 return softfloat_roundPackToF64( signZ, expZ - 1, sigZ SOFTFLOAT_STATE_ARG_COMMA );
460 /*------------------------------------------------------------------------
461 *------------------------------------------------------------------------*/
462 propagateNaN_ABC:
463 uiZ = softfloat_propagateNaNF64UI( uiA, uiB SOFTFLOAT_STATE_ARG_COMMA );
464 goto propagateNaN_ZC;
465 /*------------------------------------------------------------------------
466 *------------------------------------------------------------------------*/
467 infProdArg:
468 if ( magBits ) {
469 uiZ = packToF64UI( signZ, 0x7FF, 0 );
470 if ( expC != 0x7FF ) goto uiZ;
471 if ( sigC ) goto propagateNaN_ZC;
472 if ( signZ == signC ) goto uiZ;
473 }
474 softfloat_raiseFlags( softfloat_flag_invalid SOFTFLOAT_STATE_ARG_COMMA );
475 uiZ = defaultNaNF64UI;
476 propagateNaN_ZC:
477 uiZ = softfloat_propagateNaNF64UI( uiZ, uiC SOFTFLOAT_STATE_ARG_COMMA );
478 goto uiZ;
479 /*------------------------------------------------------------------------
480 *------------------------------------------------------------------------*/
481 zeroProd:
482 uiZ = uiC;
483 if ( ! (expC | sigC) && (signZ != signC) ) {
484 completeCancellation:
485 uiZ =
486 packToF64UI(
487 (softfloat_roundingMode == softfloat_round_min), 0, 0 );
488 }
489 uiZ:
490 uZ.ui = uiZ;
491 return uZ.f;
492
493}
494
495#endif
496
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