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target/ppc: introduce dfp_finalize_decimal{64,128}() helper functions
[qemu/ar7.git] / target / ppc / dfp_helper.c
blob8e1ea2971a34be4f21778c90433c3bed2aedd8f8
1 /*
2 * PowerPC Decimal Floating Point (DPF) emulation helpers for QEMU.
3 *
4 * Copyright (c) 2014 IBM Corporation.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/helper-proto.h"
23
24 #define DECNUMDIGITS 34
25 #include "libdecnumber/decContext.h"
26 #include "libdecnumber/decNumber.h"
27 #include "libdecnumber/dpd/decimal32.h"
28 #include "libdecnumber/dpd/decimal64.h"
29 #include "libdecnumber/dpd/decimal128.h"
30
31 #if defined(HOST_WORDS_BIGENDIAN)
32 #define HI_IDX 0
33 #define LO_IDX 1
34 #else
35 #define HI_IDX 1
36 #define LO_IDX 0
37 #endif
38
39 static void get_dfp64(uint64_t *dst, ppc_fprp_t *dfp)
40 {
41 dst[0] = dfp->VsrD(0);
42 }
43
44 static void get_dfp128(uint64_t *dst, ppc_fprp_t *dfp)
45 {
46 dst[HI_IDX] = dfp[0].VsrD(0);
47 dst[LO_IDX] = dfp[1].VsrD(0);
48 }
49
50 static void set_dfp64(ppc_fprp_t *dfp, uint64_t *src)
51 {
52 dfp->VsrD(0) = src[0];
53 }
54
55 static void set_dfp128(ppc_fprp_t *dfp, uint64_t *src)
56 {
57 dfp[0].VsrD(0) = src[HI_IDX];
58 dfp[1].VsrD(0) = src[LO_IDX];
59 }
60
61 struct PPC_DFP {
62 CPUPPCState *env;
63 uint64_t t64[2], a64[2], b64[2];
64 decNumber t, a, b;
65 decContext context;
66 uint8_t crbf;
67 };
68
69 static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
70 {
71 enum rounding rnd;
72
73 switch ((fpscr & FP_DRN) >> FPSCR_DRN0) {
74 case 0:
75 rnd = DEC_ROUND_HALF_EVEN;
76 break;
77 case 1:
78 rnd = DEC_ROUND_DOWN;
79 break;
80 case 2:
81 rnd = DEC_ROUND_CEILING;
82 break;
83 case 3:
84 rnd = DEC_ROUND_FLOOR;
85 break;
86 case 4:
87 rnd = DEC_ROUND_HALF_UP;
88 break;
89 case 5:
90 rnd = DEC_ROUND_HALF_DOWN;
91 break;
92 case 6:
93 rnd = DEC_ROUND_UP;
94 break;
95 case 7:
96 rnd = DEC_ROUND_05UP;
97 break;
98 default:
99 g_assert_not_reached();
100 }
101
102 decContextSetRounding(context, rnd);
103 }
104
105 static void dfp_set_round_mode_from_immediate(uint8_t r, uint8_t rmc,
106 struct PPC_DFP *dfp)
107 {
108 enum rounding rnd;
109 if (r == 0) {
110 switch (rmc & 3) {
111 case 0:
112 rnd = DEC_ROUND_HALF_EVEN;
113 break;
114 case 1:
115 rnd = DEC_ROUND_DOWN;
116 break;
117 case 2:
118 rnd = DEC_ROUND_HALF_UP;
119 break;
120 case 3: /* use FPSCR rounding mode */
121 return;
122 default:
123 assert(0); /* cannot get here */
124 }
125 } else { /* r == 1 */
126 switch (rmc & 3) {
127 case 0:
128 rnd = DEC_ROUND_CEILING;
129 break;
130 case 1:
131 rnd = DEC_ROUND_FLOOR;
132 break;
133 case 2:
134 rnd = DEC_ROUND_UP;
135 break;
136 case 3:
137 rnd = DEC_ROUND_HALF_DOWN;
138 break;
139 default:
140 assert(0); /* cannot get here */
141 }
142 }
143 decContextSetRounding(&dfp->context, rnd);
144 }
145
146 static void dfp_prepare_decimal64(struct PPC_DFP *dfp, ppc_fprp_t *a,
147 ppc_fprp_t *b, CPUPPCState *env)
148 {
149 decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
150 dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
151 dfp->env = env;
152
153 if (a) {
154 get_dfp64(dfp->a64, a);
155 decimal64ToNumber((decimal64 *)dfp->a64, &dfp->a);
156 } else {
157 dfp->a64[0] = 0;
158 decNumberZero(&dfp->a);
159 }
160
161 if (b) {
162 get_dfp64(dfp->b64, b);
163 decimal64ToNumber((decimal64 *)dfp->b64, &dfp->b);
164 } else {
165 dfp->b64[0] = 0;
166 decNumberZero(&dfp->b);
167 }
168 }
169
170 static void dfp_prepare_decimal128(struct PPC_DFP *dfp, ppc_fprp_t *a,
171 ppc_fprp_t *b, CPUPPCState *env)
172 {
173 decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
174 dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
175 dfp->env = env;
176
177 if (a) {
178 get_dfp128(dfp->a64, a);
179 decimal128ToNumber((decimal128 *)dfp->a64, &dfp->a);
180 } else {
181 dfp->a64[0] = dfp->a64[1] = 0;
182 decNumberZero(&dfp->a);
183 }
184
185 if (b) {
186 get_dfp128(dfp->b64, b);
187 decimal128ToNumber((decimal128 *)dfp->b64, &dfp->b);
188 } else {
189 dfp->b64[0] = dfp->b64[1] = 0;
190 decNumberZero(&dfp->b);
191 }
192 }
193
194 static void dfp_finalize_decimal64(struct PPC_DFP *dfp)
195 {
196 decimal64FromNumber((decimal64 *)&dfp->t64, &dfp->t, &dfp->context);
197 }
198
199 static void dfp_finalize_decimal128(struct PPC_DFP *dfp)
200 {
201 decimal128FromNumber((decimal128 *)&dfp->t64, &dfp->t, &dfp->context);
202 }
203
204 static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
205 uint64_t enabled)
206 {
207 dfp->env->fpscr |= (flag | FP_FX);
208 if (dfp->env->fpscr & enabled) {
209 dfp->env->fpscr |= FP_FEX;
210 }
211 }
212
213 static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
214 decContext *context)
215 {
216 uint64_t fprf = 0;
217
218 /* construct FPRF */
219 switch (decNumberClass(&dfp->t, context)) {
220 case DEC_CLASS_SNAN:
221 fprf = 0x01;
222 break;
223 case DEC_CLASS_QNAN:
224 fprf = 0x11;
225 break;
226 case DEC_CLASS_NEG_INF:
227 fprf = 0x09;
228 break;
229 case DEC_CLASS_NEG_NORMAL:
230 fprf = 0x08;
231 break;
232 case DEC_CLASS_NEG_SUBNORMAL:
233 fprf = 0x18;
234 break;
235 case DEC_CLASS_NEG_ZERO:
236 fprf = 0x12;
237 break;
238 case DEC_CLASS_POS_ZERO:
239 fprf = 0x02;
240 break;
241 case DEC_CLASS_POS_SUBNORMAL:
242 fprf = 0x14;
243 break;
244 case DEC_CLASS_POS_NORMAL:
245 fprf = 0x04;
246 break;
247 case DEC_CLASS_POS_INF:
248 fprf = 0x05;
249 break;
250 default:
251 assert(0); /* should never get here */
252 }
253 dfp->env->fpscr &= ~FP_FPRF;
254 dfp->env->fpscr |= (fprf << FPSCR_FPRF);
255 }
256
257 static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
258 {
259 dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
260 }
261
262 static void dfp_set_FPRF_from_FRT_short(struct PPC_DFP *dfp)
263 {
264 decContext shortContext;
265 decContextDefault(&shortContext, DEC_INIT_DECIMAL32);
266 dfp_set_FPRF_from_FRT_with_context(dfp, &shortContext);
267 }
268
269 static void dfp_set_FPRF_from_FRT_long(struct PPC_DFP *dfp)
270 {
271 decContext longContext;
272 decContextDefault(&longContext, DEC_INIT_DECIMAL64);
273 dfp_set_FPRF_from_FRT_with_context(dfp, &longContext);
274 }
275
276 static void dfp_check_for_OX(struct PPC_DFP *dfp)
277 {
278 if (dfp->context.status & DEC_Overflow) {
279 dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
280 }
281 }
282
283 static void dfp_check_for_UX(struct PPC_DFP *dfp)
284 {
285 if (dfp->context.status & DEC_Underflow) {
286 dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
287 }
288 }
289
290 static void dfp_check_for_XX(struct PPC_DFP *dfp)
291 {
292 if (dfp->context.status & DEC_Inexact) {
293 dfp_set_FPSCR_flag(dfp, FP_XX | FP_FI, FP_XE);
294 }
295 }
296
297 static void dfp_check_for_ZX(struct PPC_DFP *dfp)
298 {
299 if (dfp->context.status & DEC_Division_by_zero) {
300 dfp_set_FPSCR_flag(dfp, FP_ZX, FP_ZE);
301 }
302 }
303
304 static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
305 {
306 if (dfp->context.status & DEC_Invalid_operation) {
307 if (decNumberIsSNaN(&dfp->a) || decNumberIsSNaN(&dfp->b)) {
308 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
309 }
310 }
311 }
312
313 static void dfp_check_for_VXSNAN_and_convert_to_QNaN(struct PPC_DFP *dfp)
314 {
315 if (decNumberIsSNaN(&dfp->t)) {
316 dfp->t.bits &= ~DECSNAN;
317 dfp->t.bits |= DECNAN;
318 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
319 }
320 }
321
322 static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
323 {
324 if (dfp->context.status & DEC_Invalid_operation) {
325 if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
326 int same = decNumberClass(&dfp->a, &dfp->context) ==
327 decNumberClass(&dfp->b, &dfp->context);
328 if ((same && testForSameSign) || (!same && !testForSameSign)) {
329 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXISI, FP_VE);
330 }
331 }
332 }
333 }
334
335 static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
336 {
337 dfp_check_for_VXISI(dfp, 0);
338 }
339
340 static void dfp_check_for_VXISI_subtract(struct PPC_DFP *dfp)
341 {
342 dfp_check_for_VXISI(dfp, 1);
343 }
344
345 static void dfp_check_for_VXIMZ(struct PPC_DFP *dfp)
346 {
347 if (dfp->context.status & DEC_Invalid_operation) {
348 if ((decNumberIsInfinite(&dfp->a) && decNumberIsZero(&dfp->b)) ||
349 (decNumberIsInfinite(&dfp->b) && decNumberIsZero(&dfp->a))) {
350 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIMZ, FP_VE);
351 }
352 }
353 }
354
355 static void dfp_check_for_VXZDZ(struct PPC_DFP *dfp)
356 {
357 if (dfp->context.status & DEC_Division_undefined) {
358 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXZDZ, FP_VE);
359 }
360 }
361
362 static void dfp_check_for_VXIDI(struct PPC_DFP *dfp)
363 {
364 if (dfp->context.status & DEC_Invalid_operation) {
365 if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
366 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIDI, FP_VE);
367 }
368 }
369 }
370
371 static void dfp_check_for_VXVC(struct PPC_DFP *dfp)
372 {
373 if (decNumberIsNaN(&dfp->a) || decNumberIsNaN(&dfp->b)) {
374 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXVC, FP_VE);
375 }
376 }
377
378 static void dfp_check_for_VXCVI(struct PPC_DFP *dfp)
379 {
380 if ((dfp->context.status & DEC_Invalid_operation) &&
381 (!decNumberIsSNaN(&dfp->a)) &&
382 (!decNumberIsSNaN(&dfp->b))) {
383 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
384 }
385 }
386
387 static void dfp_set_CRBF_from_T(struct PPC_DFP *dfp)
388 {
389 if (decNumberIsNaN(&dfp->t)) {
390 dfp->crbf = 1;
391 } else if (decNumberIsZero(&dfp->t)) {
392 dfp->crbf = 2;
393 } else if (decNumberIsNegative(&dfp->t)) {
394 dfp->crbf = 8;
395 } else {
396 dfp->crbf = 4;
397 }
398 }
399
400 static void dfp_set_FPCC_from_CRBF(struct PPC_DFP *dfp)
401 {
402 dfp->env->fpscr &= ~FP_FPCC;
403 dfp->env->fpscr |= (dfp->crbf << FPSCR_FPCC);
404 }
405
406 static inline void dfp_makeQNaN(decNumber *dn)
407 {
408 dn->bits &= ~DECSPECIAL;
409 dn->bits |= DECNAN;
410 }
411
412 static inline int dfp_get_digit(decNumber *dn, int n)
413 {
414 assert(DECDPUN == 3);
415 int unit = n / DECDPUN;
416 int dig = n % DECDPUN;
417 switch (dig) {
418 case 0:
419 return dn->lsu[unit] % 10;
420 case 1:
421 return (dn->lsu[unit] / 10) % 10;
422 case 2:
423 return dn->lsu[unit] / 100;
424 }
425 g_assert_not_reached();
426 }
427
428 #define DFP_HELPER_TAB(op, dnop, postprocs, size) \
429 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a, \
430 ppc_fprp_t *b) \
431 { \
432 struct PPC_DFP dfp; \
433 dfp_prepare_decimal##size(&dfp, a, b, env); \
434 dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context); \
435 dfp_finalize_decimal##size(&dfp); \
436 postprocs(&dfp); \
437 if (size == 64) { \
438 set_dfp64(t, dfp.t64); \
439 } else if (size == 128) { \
440 set_dfp128(t, dfp.t64); \
441 } \
442 }
443
444 static void ADD_PPs(struct PPC_DFP *dfp)
445 {
446 dfp_set_FPRF_from_FRT(dfp);
447 dfp_check_for_OX(dfp);
448 dfp_check_for_UX(dfp);
449 dfp_check_for_XX(dfp);
450 dfp_check_for_VXSNAN(dfp);
451 dfp_check_for_VXISI_add(dfp);
452 }
453
454 DFP_HELPER_TAB(dadd, decNumberAdd, ADD_PPs, 64)
455 DFP_HELPER_TAB(daddq, decNumberAdd, ADD_PPs, 128)
456
457 static void SUB_PPs(struct PPC_DFP *dfp)
458 {
459 dfp_set_FPRF_from_FRT(dfp);
460 dfp_check_for_OX(dfp);
461 dfp_check_for_UX(dfp);
462 dfp_check_for_XX(dfp);
463 dfp_check_for_VXSNAN(dfp);
464 dfp_check_for_VXISI_subtract(dfp);
465 }
466
467 DFP_HELPER_TAB(dsub, decNumberSubtract, SUB_PPs, 64)
468 DFP_HELPER_TAB(dsubq, decNumberSubtract, SUB_PPs, 128)
469
470 static void MUL_PPs(struct PPC_DFP *dfp)
471 {
472 dfp_set_FPRF_from_FRT(dfp);
473 dfp_check_for_OX(dfp);
474 dfp_check_for_UX(dfp);
475 dfp_check_for_XX(dfp);
476 dfp_check_for_VXSNAN(dfp);
477 dfp_check_for_VXIMZ(dfp);
478 }
479
480 DFP_HELPER_TAB(dmul, decNumberMultiply, MUL_PPs, 64)
481 DFP_HELPER_TAB(dmulq, decNumberMultiply, MUL_PPs, 128)
482
483 static void DIV_PPs(struct PPC_DFP *dfp)
484 {
485 dfp_set_FPRF_from_FRT(dfp);
486 dfp_check_for_OX(dfp);
487 dfp_check_for_UX(dfp);
488 dfp_check_for_ZX(dfp);
489 dfp_check_for_XX(dfp);
490 dfp_check_for_VXSNAN(dfp);
491 dfp_check_for_VXZDZ(dfp);
492 dfp_check_for_VXIDI(dfp);
493 }
494
495 DFP_HELPER_TAB(ddiv, decNumberDivide, DIV_PPs, 64)
496 DFP_HELPER_TAB(ddivq, decNumberDivide, DIV_PPs, 128)
497
498 #define DFP_HELPER_BF_AB(op, dnop, postprocs, size) \
499 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, ppc_fprp_t *b) \
500 { \
501 struct PPC_DFP dfp; \
502 dfp_prepare_decimal##size(&dfp, a, b, env); \
503 dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context); \
504 dfp_finalize_decimal##size(&dfp); \
505 postprocs(&dfp); \
506 return dfp.crbf; \
507 }
508
509 static void CMPU_PPs(struct PPC_DFP *dfp)
510 {
511 dfp_set_CRBF_from_T(dfp);
512 dfp_set_FPCC_from_CRBF(dfp);
513 dfp_check_for_VXSNAN(dfp);
514 }
515
516 DFP_HELPER_BF_AB(dcmpu, decNumberCompare, CMPU_PPs, 64)
517 DFP_HELPER_BF_AB(dcmpuq, decNumberCompare, CMPU_PPs, 128)
518
519 static void CMPO_PPs(struct PPC_DFP *dfp)
520 {
521 dfp_set_CRBF_from_T(dfp);
522 dfp_set_FPCC_from_CRBF(dfp);
523 dfp_check_for_VXSNAN(dfp);
524 dfp_check_for_VXVC(dfp);
525 }
526
527 DFP_HELPER_BF_AB(dcmpo, decNumberCompare, CMPO_PPs, 64)
528 DFP_HELPER_BF_AB(dcmpoq, decNumberCompare, CMPO_PPs, 128)
529
530 #define DFP_HELPER_TSTDC(op, size) \
531 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, uint32_t dcm) \
532 { \
533 struct PPC_DFP dfp; \
534 int match = 0; \
535 \
536 dfp_prepare_decimal##size(&dfp, a, 0, env); \
537 \
538 match |= (dcm & 0x20) && decNumberIsZero(&dfp.a); \
539 match |= (dcm & 0x10) && decNumberIsSubnormal(&dfp.a, &dfp.context); \
540 match |= (dcm & 0x08) && decNumberIsNormal(&dfp.a, &dfp.context); \
541 match |= (dcm & 0x04) && decNumberIsInfinite(&dfp.a); \
542 match |= (dcm & 0x02) && decNumberIsQNaN(&dfp.a); \
543 match |= (dcm & 0x01) && decNumberIsSNaN(&dfp.a); \
544 \
545 if (decNumberIsNegative(&dfp.a)) { \
546 dfp.crbf = match ? 0xA : 0x8; \
547 } else { \
548 dfp.crbf = match ? 0x2 : 0x0; \
549 } \
550 \
551 dfp_set_FPCC_from_CRBF(&dfp); \
552 return dfp.crbf; \
553 }
554
555 DFP_HELPER_TSTDC(dtstdc, 64)
556 DFP_HELPER_TSTDC(dtstdcq, 128)
557
558 #define DFP_HELPER_TSTDG(op, size) \
559 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, uint32_t dcm) \
560 { \
561 struct PPC_DFP dfp; \
562 int minexp, maxexp, nzero_digits, nzero_idx, is_negative, is_zero, \
563 is_extreme_exp, is_subnormal, is_normal, leftmost_is_nonzero, \
564 match; \
565 \
566 dfp_prepare_decimal##size(&dfp, a, 0, env); \
567 \
568 if ((size) == 64) { \
569 minexp = -398; \
570 maxexp = 369; \
571 nzero_digits = 16; \
572 nzero_idx = 5; \
573 } else if ((size) == 128) { \
574 minexp = -6176; \
575 maxexp = 6111; \
576 nzero_digits = 34; \
577 nzero_idx = 11; \
578 } \
579 \
580 is_negative = decNumberIsNegative(&dfp.a); \
581 is_zero = decNumberIsZero(&dfp.a); \
582 is_extreme_exp = (dfp.a.exponent == maxexp) || \
583 (dfp.a.exponent == minexp); \
584 is_subnormal = decNumberIsSubnormal(&dfp.a, &dfp.context); \
585 is_normal = decNumberIsNormal(&dfp.a, &dfp.context); \
586 leftmost_is_nonzero = (dfp.a.digits == nzero_digits) && \
587 (dfp.a.lsu[nzero_idx] != 0); \
588 match = 0; \
589 \
590 match |= (dcm & 0x20) && is_zero && !is_extreme_exp; \
591 match |= (dcm & 0x10) && is_zero && is_extreme_exp; \
592 match |= (dcm & 0x08) && \
593 (is_subnormal || (is_normal && is_extreme_exp)); \
594 match |= (dcm & 0x04) && is_normal && !is_extreme_exp && \
595 !leftmost_is_nonzero; \
596 match |= (dcm & 0x02) && is_normal && !is_extreme_exp && \
597 leftmost_is_nonzero; \
598 match |= (dcm & 0x01) && decNumberIsSpecial(&dfp.a); \
599 \
600 if (is_negative) { \
601 dfp.crbf = match ? 0xA : 0x8; \
602 } else { \
603 dfp.crbf = match ? 0x2 : 0x0; \
604 } \
605 \
606 dfp_set_FPCC_from_CRBF(&dfp); \
607 return dfp.crbf; \
608 }
609
610 DFP_HELPER_TSTDG(dtstdg, 64)
611 DFP_HELPER_TSTDG(dtstdgq, 128)
612
613 #define DFP_HELPER_TSTEX(op, size) \
614 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, ppc_fprp_t *b) \
615 { \
616 struct PPC_DFP dfp; \
617 int expa, expb, a_is_special, b_is_special; \
618 \
619 dfp_prepare_decimal##size(&dfp, a, b, env); \
620 \
621 expa = dfp.a.exponent; \
622 expb = dfp.b.exponent; \
623 a_is_special = decNumberIsSpecial(&dfp.a); \
624 b_is_special = decNumberIsSpecial(&dfp.b); \
625 \
626 if (a_is_special || b_is_special) { \
627 int atype = a_is_special ? (decNumberIsNaN(&dfp.a) ? 4 : 2) : 1; \
628 int btype = b_is_special ? (decNumberIsNaN(&dfp.b) ? 4 : 2) : 1; \
629 dfp.crbf = (atype ^ btype) ? 0x1 : 0x2; \
630 } else if (expa < expb) { \
631 dfp.crbf = 0x8; \
632 } else if (expa > expb) { \
633 dfp.crbf = 0x4; \
634 } else { \
635 dfp.crbf = 0x2; \
636 } \
637 \
638 dfp_set_FPCC_from_CRBF(&dfp); \
639 return dfp.crbf; \
640 }
641
642 DFP_HELPER_TSTEX(dtstex, 64)
643 DFP_HELPER_TSTEX(dtstexq, 128)
644
645 #define DFP_HELPER_TSTSF(op, size) \
646 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, ppc_fprp_t *b) \
647 { \
648 struct PPC_DFP dfp; \
649 unsigned k; \
650 uint64_t a64; \
651 \
652 dfp_prepare_decimal##size(&dfp, 0, b, env); \
653 \
654 get_dfp64(&a64, a); \
655 k = a64 & 0x3F; \
656 \
657 if (unlikely(decNumberIsSpecial(&dfp.b))) { \
658 dfp.crbf = 1; \
659 } else if (k == 0) { \
660 dfp.crbf = 4; \
661 } else if (unlikely(decNumberIsZero(&dfp.b))) { \
662 /* Zero has no sig digits */ \
663 dfp.crbf = 4; \
664 } else { \
665 unsigned nsd = dfp.b.digits; \
666 if (k < nsd) { \
667 dfp.crbf = 8; \
668 } else if (k > nsd) { \
669 dfp.crbf = 4; \
670 } else { \
671 dfp.crbf = 2; \
672 } \
673 } \
674 \
675 dfp_set_FPCC_from_CRBF(&dfp); \
676 return dfp.crbf; \
677 }
678
679 DFP_HELPER_TSTSF(dtstsf, 64)
680 DFP_HELPER_TSTSF(dtstsfq, 128)
681
682 #define DFP_HELPER_TSTSFI(op, size) \
683 uint32_t helper_##op(CPUPPCState *env, uint32_t a, ppc_fprp_t *b) \
684 { \
685 struct PPC_DFP dfp; \
686 unsigned uim; \
687 \
688 dfp_prepare_decimal##size(&dfp, 0, b, env); \
689 \
690 uim = a & 0x3F; \
691 \
692 if (unlikely(decNumberIsSpecial(&dfp.b))) { \
693 dfp.crbf = 1; \
694 } else if (uim == 0) { \
695 dfp.crbf = 4; \
696 } else if (unlikely(decNumberIsZero(&dfp.b))) { \
697 /* Zero has no sig digits */ \
698 dfp.crbf = 4; \
699 } else { \
700 unsigned nsd = dfp.b.digits; \
701 if (uim < nsd) { \
702 dfp.crbf = 8; \
703 } else if (uim > nsd) { \
704 dfp.crbf = 4; \
705 } else { \
706 dfp.crbf = 2; \
707 } \
708 } \
709 \
710 dfp_set_FPCC_from_CRBF(&dfp); \
711 return dfp.crbf; \
712 }
713
714 DFP_HELPER_TSTSFI(dtstsfi, 64)
715 DFP_HELPER_TSTSFI(dtstsfiq, 128)
716
717 static void QUA_PPs(struct PPC_DFP *dfp)
718 {
719 dfp_set_FPRF_from_FRT(dfp);
720 dfp_check_for_XX(dfp);
721 dfp_check_for_VXSNAN(dfp);
722 dfp_check_for_VXCVI(dfp);
723 }
724
725 static void dfp_quantize(uint8_t rmc, struct PPC_DFP *dfp)
726 {
727 dfp_set_round_mode_from_immediate(0, rmc, dfp);
728 decNumberQuantize(&dfp->t, &dfp->b, &dfp->a, &dfp->context);
729 if (decNumberIsSNaN(&dfp->a)) {
730 dfp->t = dfp->a;
731 dfp_makeQNaN(&dfp->t);
732 } else if (decNumberIsSNaN(&dfp->b)) {
733 dfp->t = dfp->b;
734 dfp_makeQNaN(&dfp->t);
735 } else if (decNumberIsQNaN(&dfp->a)) {
736 dfp->t = dfp->a;
737 } else if (decNumberIsQNaN(&dfp->b)) {
738 dfp->t = dfp->b;
739 }
740 }
741
742 #define DFP_HELPER_QUAI(op, size) \
743 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b, \
744 uint32_t te, uint32_t rmc) \
745 { \
746 struct PPC_DFP dfp; \
747 \
748 dfp_prepare_decimal##size(&dfp, 0, b, env); \
749 \
750 decNumberFromUInt32(&dfp.a, 1); \
751 dfp.a.exponent = (int32_t)((int8_t)(te << 3) >> 3); \
752 \
753 dfp_quantize(rmc, &dfp); \
754 dfp_finalize_decimal##size(&dfp); \
755 QUA_PPs(&dfp); \
756 \
757 if (size == 64) { \
758 set_dfp64(t, dfp.t64); \
759 } else if (size == 128) { \
760 set_dfp128(t, dfp.t64); \
761 } \
762 }
763
764 DFP_HELPER_QUAI(dquai, 64)
765 DFP_HELPER_QUAI(dquaiq, 128)
766
767 #define DFP_HELPER_QUA(op, size) \
768 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a, \
769 ppc_fprp_t *b, uint32_t rmc) \
770 { \
771 struct PPC_DFP dfp; \
772 \
773 dfp_prepare_decimal##size(&dfp, a, b, env); \
774 \
775 dfp_quantize(rmc, &dfp); \
776 dfp_finalize_decimal##size(&dfp); \
777 QUA_PPs(&dfp); \
778 \
779 if (size == 64) { \
780 set_dfp64(t, dfp.t64); \
781 } else if (size == 128) { \
782 set_dfp128(t, dfp.t64); \
783 } \
784 }
785
786 DFP_HELPER_QUA(dqua, 64)
787 DFP_HELPER_QUA(dquaq, 128)
788
789 static void _dfp_reround(uint8_t rmc, int32_t ref_sig, int32_t xmax,
790 struct PPC_DFP *dfp)
791 {
792 int msd_orig, msd_rslt;
793
794 if (unlikely((ref_sig == 0) || (dfp->b.digits <= ref_sig))) {
795 dfp->t = dfp->b;
796 if (decNumberIsSNaN(&dfp->b)) {
797 dfp_makeQNaN(&dfp->t);
798 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FPSCR_VE);
799 }
800 return;
801 }
802
803 /* Reround is equivalent to quantizing b with 1**E(n) where */
804 /* n = exp(b) + numDigits(b) - reference_significance. */
805
806 decNumberFromUInt32(&dfp->a, 1);
807 dfp->a.exponent = dfp->b.exponent + dfp->b.digits - ref_sig;
808
809 if (unlikely(dfp->a.exponent > xmax)) {
810 dfp->t.digits = 0;
811 dfp->t.bits &= ~DECNEG;
812 dfp_makeQNaN(&dfp->t);
813 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FPSCR_VE);
814 return;
815 }
816
817 dfp_quantize(rmc, dfp);
818
819 msd_orig = dfp_get_digit(&dfp->b, dfp->b.digits-1);
820 msd_rslt = dfp_get_digit(&dfp->t, dfp->t.digits-1);
821
822 /* If the quantization resulted in rounding up to the next magnitude, */
823 /* then we need to shift the significand and adjust the exponent. */
824
825 if (unlikely((msd_orig == 9) && (msd_rslt == 1))) {
826
827 decNumber negone;
828
829 decNumberFromInt32(&negone, -1);
830 decNumberShift(&dfp->t, &dfp->t, &negone, &dfp->context);
831 dfp->t.exponent++;
832
833 if (unlikely(dfp->t.exponent > xmax)) {
834 dfp_makeQNaN(&dfp->t);
835 dfp->t.digits = 0;
836 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
837 /* Inhibit XX in this case */
838 decContextClearStatus(&dfp->context, DEC_Inexact);
839 }
840 }
841 }
842
843 #define DFP_HELPER_RRND(op, size) \
844 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a, \
845 ppc_fprp_t *b, uint32_t rmc) \
846 { \
847 struct PPC_DFP dfp; \
848 uint64_t a64; \
849 int32_t ref_sig; \
850 int32_t xmax = ((size) == 64) ? 369 : 6111; \
851 \
852 dfp_prepare_decimal##size(&dfp, 0, b, env); \
853 \
854 get_dfp64(&a64, a); \
855 ref_sig = a64 & 0x3f; \
856 \
857 _dfp_reround(rmc, ref_sig, xmax, &dfp); \
858 dfp_finalize_decimal##size(&dfp); \
859 QUA_PPs(&dfp); \
860 \
861 if (size == 64) { \
862 set_dfp64(t, dfp.t64); \
863 } else if (size == 128) { \
864 set_dfp128(t, dfp.t64); \
865 } \
866 }
867
868 DFP_HELPER_RRND(drrnd, 64)
869 DFP_HELPER_RRND(drrndq, 128)
870
871 #define DFP_HELPER_RINT(op, postprocs, size) \
872 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b, \
873 uint32_t r, uint32_t rmc) \
874 { \
875 struct PPC_DFP dfp; \
876 \
877 dfp_prepare_decimal##size(&dfp, 0, b, env); \
878 \
879 dfp_set_round_mode_from_immediate(r, rmc, &dfp); \
880 decNumberToIntegralExact(&dfp.t, &dfp.b, &dfp.context); \
881 dfp_finalize_decimal##size(&dfp); \
882 postprocs(&dfp); \
883 \
884 if (size == 64) { \
885 set_dfp64(t, dfp.t64); \
886 } else if (size == 128) { \
887 set_dfp128(t, dfp.t64); \
888 } \
889 }
890
891 static void RINTX_PPs(struct PPC_DFP *dfp)
892 {
893 dfp_set_FPRF_from_FRT(dfp);
894 dfp_check_for_XX(dfp);
895 dfp_check_for_VXSNAN(dfp);
896 }
897
898 DFP_HELPER_RINT(drintx, RINTX_PPs, 64)
899 DFP_HELPER_RINT(drintxq, RINTX_PPs, 128)
900
901 static void RINTN_PPs(struct PPC_DFP *dfp)
902 {
903 dfp_set_FPRF_from_FRT(dfp);
904 dfp_check_for_VXSNAN(dfp);
905 }
906
907 DFP_HELPER_RINT(drintn, RINTN_PPs, 64)
908 DFP_HELPER_RINT(drintnq, RINTN_PPs, 128)
909
910 void helper_dctdp(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
911 {
912 struct PPC_DFP dfp;
913 uint64_t b64;
914 uint32_t b_short;
915
916 get_dfp64(&b64, b);
917 b_short = (uint32_t)b64;
918
919 dfp_prepare_decimal64(&dfp, 0, 0, env);
920 decimal32ToNumber((decimal32 *)&b_short, &dfp.t);
921 dfp_finalize_decimal64(&dfp);
922 set_dfp64(t, dfp.t64);
923 dfp_set_FPRF_from_FRT(&dfp);
924 }
925
926 void helper_dctqpq(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
927 {
928 struct PPC_DFP dfp;
929 uint64_t b64;
930 dfp_prepare_decimal128(&dfp, 0, 0, env);
931 get_dfp64(&b64, b);
932 decimal64ToNumber((decimal64 *)&b64, &dfp.t);
933
934 dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
935 dfp_set_FPRF_from_FRT(&dfp);
936
937 dfp_finalize_decimal128(&dfp);
938 set_dfp128(t, dfp.t64);
939 }
940
941 void helper_drsp(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
942 {
943 struct PPC_DFP dfp;
944 uint32_t t_short = 0;
945 uint64_t t64;
946 dfp_prepare_decimal64(&dfp, 0, b, env);
947 decimal32FromNumber((decimal32 *)&t_short, &dfp.b, &dfp.context);
948 decimal32ToNumber((decimal32 *)&t_short, &dfp.t);
949
950 dfp_set_FPRF_from_FRT_short(&dfp);
951 dfp_check_for_OX(&dfp);
952 dfp_check_for_UX(&dfp);
953 dfp_check_for_XX(&dfp);
954
955 t64 = (uint64_t)t_short;
956 set_dfp64(t, &t64);
957 }
958
959 void helper_drdpq(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
960 {
961 struct PPC_DFP dfp;
962 dfp_prepare_decimal128(&dfp, 0, b, env);
963 decimal64FromNumber((decimal64 *)&dfp.t64, &dfp.b, &dfp.context);
964 decimal64ToNumber((decimal64 *)&dfp.t64, &dfp.t);
965
966 dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
967 dfp_set_FPRF_from_FRT_long(&dfp);
968 dfp_check_for_OX(&dfp);
969 dfp_check_for_UX(&dfp);
970 dfp_check_for_XX(&dfp);
971
972 dfp.t64[0] = dfp.t64[1] = 0;
973 dfp_finalize_decimal64(&dfp);
974 set_dfp128(t, dfp.t64);
975 }
976
977 #define DFP_HELPER_CFFIX(op, size) \
978 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b) \
979 { \
980 struct PPC_DFP dfp; \
981 uint64_t b64; \
982 dfp_prepare_decimal##size(&dfp, 0, b, env); \
983 get_dfp64(&b64, b); \
984 decNumberFromInt64(&dfp.t, (int64_t)b64); \
985 dfp_finalize_decimal##size(&dfp); \
986 CFFIX_PPs(&dfp); \
987 \
988 if (size == 64) { \
989 set_dfp64(t, dfp.t64); \
990 } else if (size == 128) { \
991 set_dfp128(t, dfp.t64); \
992 } \
993 }
994
995 static void CFFIX_PPs(struct PPC_DFP *dfp)
996 {
997 dfp_set_FPRF_from_FRT(dfp);
998 dfp_check_for_XX(dfp);
999 }
1000
1001 DFP_HELPER_CFFIX(dcffix, 64)
1002 DFP_HELPER_CFFIX(dcffixq, 128)
1003
1004 #define DFP_HELPER_CTFIX(op, size) \
1005 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b) \
1006 { \
1007 struct PPC_DFP dfp; \
1008 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1009 \
1010 if (unlikely(decNumberIsSpecial(&dfp.b))) { \
1011 uint64_t invalid_flags = FP_VX | FP_VXCVI; \
1012 if (decNumberIsInfinite(&dfp.b)) { \
1013 dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
1014 } else { /* NaN */ \
1015 dfp.t64[0] = INT64_MIN; \
1016 if (decNumberIsSNaN(&dfp.b)) { \
1017 invalid_flags |= FP_VXSNAN; \
1018 } \
1019 } \
1020 dfp_set_FPSCR_flag(&dfp, invalid_flags, FP_VE); \
1021 } else if (unlikely(decNumberIsZero(&dfp.b))) { \
1022 dfp.t64[0] = 0; \
1023 } else { \
1024 decNumberToIntegralExact(&dfp.b, &dfp.b, &dfp.context); \
1025 dfp.t64[0] = decNumberIntegralToInt64(&dfp.b, &dfp.context); \
1026 if (decContextTestStatus(&dfp.context, DEC_Invalid_operation)) { \
1027 dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
1028 dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FP_VE); \
1029 } else { \
1030 dfp_check_for_XX(&dfp); \
1031 } \
1032 } \
1033 \
1034 set_dfp64(t, dfp.t64); \
1035 }
1036
1037 DFP_HELPER_CTFIX(dctfix, 64)
1038 DFP_HELPER_CTFIX(dctfixq, 128)
1039
1040 static inline void dfp_set_bcd_digit_64(uint64_t *t, uint8_t digit,
1041 unsigned n)
1042 {
1043 *t |= ((uint64_t)(digit & 0xF) << (n << 2));
1044 }
1045
1046 static inline void dfp_set_bcd_digit_128(uint64_t *t, uint8_t digit,
1047 unsigned n)
1048 {
1049 t[(n & 0x10) ? HI_IDX : LO_IDX] |=
1050 ((uint64_t)(digit & 0xF) << ((n & 15) << 2));
1051 }
1052
1053 static inline void dfp_set_sign_64(uint64_t *t, uint8_t sgn)
1054 {
1055 *t <<= 4;
1056 *t |= (sgn & 0xF);
1057 }
1058
1059 static inline void dfp_set_sign_128(uint64_t *t, uint8_t sgn)
1060 {
1061 t[HI_IDX] <<= 4;
1062 t[HI_IDX] |= (t[LO_IDX] >> 60);
1063 t[LO_IDX] <<= 4;
1064 t[LO_IDX] |= (sgn & 0xF);
1065 }
1066
1067 #define DFP_HELPER_DEDPD(op, size) \
1068 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b, \
1069 uint32_t sp) \
1070 { \
1071 struct PPC_DFP dfp; \
1072 uint8_t digits[34]; \
1073 int i, N; \
1074 \
1075 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1076 \
1077 decNumberGetBCD(&dfp.b, digits); \
1078 dfp.t64[0] = dfp.t64[1] = 0; \
1079 N = dfp.b.digits; \
1080 \
1081 for (i = 0; (i < N) && (i < (size)/4); i++) { \
1082 dfp_set_bcd_digit_##size(dfp.t64, digits[N-i-1], i); \
1083 } \
1084 \
1085 if (sp & 2) { \
1086 uint8_t sgn; \
1087 \
1088 if (decNumberIsNegative(&dfp.b)) { \
1089 sgn = 0xD; \
1090 } else { \
1091 sgn = ((sp & 1) ? 0xF : 0xC); \
1092 } \
1093 dfp_set_sign_##size(dfp.t64, sgn); \
1094 } \
1095 \
1096 if (size == 64) { \
1097 set_dfp64(t, dfp.t64); \
1098 } else if (size == 128) { \
1099 set_dfp128(t, dfp.t64); \
1100 } \
1101 }
1102
1103 DFP_HELPER_DEDPD(ddedpd, 64)
1104 DFP_HELPER_DEDPD(ddedpdq, 128)
1105
1106 static inline uint8_t dfp_get_bcd_digit_64(uint64_t *t, unsigned n)
1107 {
1108 return *t >> ((n << 2) & 63) & 15;
1109 }
1110
1111 static inline uint8_t dfp_get_bcd_digit_128(uint64_t *t, unsigned n)
1112 {
1113 return t[(n & 0x10) ? HI_IDX : LO_IDX] >> ((n << 2) & 63) & 15;
1114 }
1115
1116 #define DFP_HELPER_ENBCD(op, size) \
1117 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b, \
1118 uint32_t s) \
1119 { \
1120 struct PPC_DFP dfp; \
1121 uint8_t digits[32]; \
1122 int n = 0, offset = 0, sgn = 0, nonzero = 0; \
1123 \
1124 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1125 \
1126 decNumberZero(&dfp.t); \
1127 \
1128 if (s) { \
1129 uint8_t sgnNibble = dfp_get_bcd_digit_##size(dfp.b64, offset++); \
1130 switch (sgnNibble) { \
1131 case 0xD: \
1132 case 0xB: \
1133 sgn = 1; \
1134 break; \
1135 case 0xC: \
1136 case 0xF: \
1137 case 0xA: \
1138 case 0xE: \
1139 sgn = 0; \
1140 break; \
1141 default: \
1142 dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE); \
1143 return; \
1144 } \
1145 } \
1146 \
1147 while (offset < (size) / 4) { \
1148 n++; \
1149 digits[(size) / 4 - n] = dfp_get_bcd_digit_##size(dfp.b64, offset++); \
1150 if (digits[(size) / 4 - n] > 10) { \
1151 dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE); \
1152 return; \
1153 } else { \
1154 nonzero |= (digits[(size) / 4 - n] > 0); \
1155 } \
1156 } \
1157 \
1158 if (nonzero) { \
1159 decNumberSetBCD(&dfp.t, digits + ((size) / 4) - n, n); \
1160 } \
1161 \
1162 if (s && sgn) { \
1163 dfp.t.bits |= DECNEG; \
1164 } \
1165 dfp_finalize_decimal##size(&dfp); \
1166 dfp_set_FPRF_from_FRT(&dfp); \
1167 if ((size) == 64) { \
1168 set_dfp64(t, dfp.t64); \
1169 } else if ((size) == 128) { \
1170 set_dfp128(t, dfp.t64); \
1171 } \
1172 }
1173
1174 DFP_HELPER_ENBCD(denbcd, 64)
1175 DFP_HELPER_ENBCD(denbcdq, 128)
1176
1177 #define DFP_HELPER_XEX(op, size) \
1178 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b) \
1179 { \
1180 struct PPC_DFP dfp; \
1181 uint64_t t64; \
1182 \
1183 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1184 \
1185 if (unlikely(decNumberIsSpecial(&dfp.b))) { \
1186 if (decNumberIsInfinite(&dfp.b)) { \
1187 t64 = -1; \
1188 } else if (decNumberIsSNaN(&dfp.b)) { \
1189 t64 = -3; \
1190 } else if (decNumberIsQNaN(&dfp.b)) { \
1191 t64 = -2; \
1192 } else { \
1193 assert(0); \
1194 } \
1195 set_dfp64(t, &t64); \
1196 } else { \
1197 if ((size) == 64) { \
1198 t64 = dfp.b.exponent + 398; \
1199 } else if ((size) == 128) { \
1200 t64 = dfp.b.exponent + 6176; \
1201 } else { \
1202 assert(0); \
1203 } \
1204 set_dfp64(t, &t64); \
1205 } \
1206 }
1207
1208 DFP_HELPER_XEX(dxex, 64)
1209 DFP_HELPER_XEX(dxexq, 128)
1210
1211 static void dfp_set_raw_exp_64(uint64_t *t, uint64_t raw)
1212 {
1213 *t &= 0x8003ffffffffffffULL;
1214 *t |= (raw << (63 - 13));
1215 }
1216
1217 static void dfp_set_raw_exp_128(uint64_t *t, uint64_t raw)
1218 {
1219 t[HI_IDX] &= 0x80003fffffffffffULL;
1220 t[HI_IDX] |= (raw << (63 - 17));
1221 }
1222
1223 #define DFP_HELPER_IEX(op, size) \
1224 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a, \
1225 ppc_fprp_t *b) \
1226 { \
1227 struct PPC_DFP dfp; \
1228 uint64_t raw_qnan, raw_snan, raw_inf, max_exp, a64; \
1229 int bias; \
1230 int64_t exp; \
1231 \
1232 get_dfp64(&a64, a); \
1233 exp = (int64_t)a64; \
1234 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1235 \
1236 if ((size) == 64) { \
1237 max_exp = 767; \
1238 raw_qnan = 0x1F00; \
1239 raw_snan = 0x1F80; \
1240 raw_inf = 0x1E00; \
1241 bias = 398; \
1242 } else if ((size) == 128) { \
1243 max_exp = 12287; \
1244 raw_qnan = 0x1f000; \
1245 raw_snan = 0x1f800; \
1246 raw_inf = 0x1e000; \
1247 bias = 6176; \
1248 } else { \
1249 assert(0); \
1250 } \
1251 \
1252 if (unlikely((exp < 0) || (exp > max_exp))) { \
1253 dfp.t64[0] = dfp.b64[0]; \
1254 dfp.t64[1] = dfp.b64[1]; \
1255 if (exp == -1) { \
1256 dfp_set_raw_exp_##size(dfp.t64, raw_inf); \
1257 } else if (exp == -3) { \
1258 dfp_set_raw_exp_##size(dfp.t64, raw_snan); \
1259 } else { \
1260 dfp_set_raw_exp_##size(dfp.t64, raw_qnan); \
1261 } \
1262 } else { \
1263 dfp.t = dfp.b; \
1264 if (unlikely(decNumberIsSpecial(&dfp.t))) { \
1265 dfp.t.bits &= ~DECSPECIAL; \
1266 } \
1267 dfp.t.exponent = exp - bias; \
1268 dfp_finalize_decimal##size(&dfp); \
1269 } \
1270 if (size == 64) { \
1271 set_dfp64(t, dfp.t64); \
1272 } else if (size == 128) { \
1273 set_dfp128(t, dfp.t64); \
1274 } \
1275 }
1276
1277 DFP_HELPER_IEX(diex, 64)
1278 DFP_HELPER_IEX(diexq, 128)
1279
1280 static void dfp_clear_lmd_from_g5msb(uint64_t *t)
1281 {
1282
1283 /* The most significant 5 bits of the PowerPC DFP format combine bits */
1284 /* from the left-most decimal digit (LMD) and the biased exponent. */
1285 /* This routine clears the LMD bits while preserving the exponent */
1286 /* bits. See "Figure 80: Encoding of bits 0:4 of the G field for */
1287 /* Finite Numbers" in the Power ISA for additional details. */
1288
1289 uint64_t g5msb = (*t >> 58) & 0x1F;
1290
1291 if ((g5msb >> 3) < 3) { /* LMD in [0-7] ? */
1292 *t &= ~(7ULL << 58);
1293 } else {
1294 switch (g5msb & 7) {
1295 case 0:
1296 case 1:
1297 g5msb = 0;
1298 break;
1299 case 2:
1300 case 3:
1301 g5msb = 0x8;
1302 break;
1303 case 4:
1304 case 5:
1305 g5msb = 0x10;
1306 break;
1307 case 6:
1308 g5msb = 0x1E;
1309 break;
1310 case 7:
1311 g5msb = 0x1F;
1312 break;
1313 }
1314
1315 *t &= ~(0x1fULL << 58);
1316 *t |= (g5msb << 58);
1317 }
1318 }
1319
1320 #define DFP_HELPER_SHIFT(op, size, shift_left) \
1321 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a, \
1322 uint32_t sh) \
1323 { \
1324 struct PPC_DFP dfp; \
1325 unsigned max_digits = ((size) == 64) ? 16 : 34; \
1326 \
1327 dfp_prepare_decimal##size(&dfp, a, 0, env); \
1328 \
1329 if (sh <= max_digits) { \
1330 \
1331 decNumber shd; \
1332 unsigned special = dfp.a.bits & DECSPECIAL; \
1333 \
1334 if (shift_left) { \
1335 decNumberFromUInt32(&shd, sh); \
1336 } else { \
1337 decNumberFromInt32(&shd, -((int32_t)sh)); \
1338 } \
1339 \
1340 dfp.a.bits &= ~DECSPECIAL; \
1341 decNumberShift(&dfp.t, &dfp.a, &shd, &dfp.context); \
1342 \
1343 dfp.t.bits |= special; \
1344 if (special && (dfp.t.digits >= max_digits)) { \
1345 dfp.t.digits = max_digits - 1; \
1346 } \
1347 \
1348 dfp_finalize_decimal##size(&dfp); \
1349 } else { \
1350 if ((size) == 64) { \
1351 dfp.t64[0] = dfp.a64[0] & 0xFFFC000000000000ULL; \
1352 dfp_clear_lmd_from_g5msb(dfp.t64); \
1353 } else { \
1354 dfp.t64[HI_IDX] = dfp.a64[HI_IDX] & \
1355 0xFFFFC00000000000ULL; \
1356 dfp_clear_lmd_from_g5msb(dfp.t64 + HI_IDX); \
1357 dfp.t64[LO_IDX] = 0; \
1358 } \
1359 } \
1360 \
1361 if ((size) == 64) { \
1362 set_dfp64(t, dfp.t64); \
1363 } else { \
1364 set_dfp128(t, dfp.t64); \
1365 } \
1366 }
1367
1368 DFP_HELPER_SHIFT(dscli, 64, 1)
1369 DFP_HELPER_SHIFT(dscliq, 128, 1)
1370 DFP_HELPER_SHIFT(dscri, 64, 0)
1371 DFP_HELPER_SHIFT(dscriq, 128, 0)
AR7 emulation for QEMU