xref: /openbmc/qemu/target/ppc/dfp_helper.c (revision 927f93e0)
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 2.1 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 
32 static void get_dfp64(ppc_vsr_t *dst, ppc_fprp_t *dfp)
33 {
34     dst->VsrD(1) = dfp->VsrD(0);
35 }
36 
37 static void get_dfp128(ppc_vsr_t *dst, ppc_fprp_t *dfp)
38 {
39     dst->VsrD(0) = dfp[0].VsrD(0);
40     dst->VsrD(1) = dfp[1].VsrD(0);
41 }
42 
43 static void set_dfp64(ppc_fprp_t *dfp, ppc_vsr_t *src)
44 {
45     dfp->VsrD(0) = src->VsrD(1);
46 }
47 
48 static void set_dfp128(ppc_fprp_t *dfp, ppc_vsr_t *src)
49 {
50     dfp[0].VsrD(0) = src->VsrD(0);
51     dfp[1].VsrD(0) = src->VsrD(1);
52 }
53 
54 static void set_dfp128_to_avr(ppc_avr_t *dst, ppc_vsr_t *src)
55 {
56     *dst = *src;
57 }
58 
59 struct PPC_DFP {
60     CPUPPCState *env;
61     ppc_vsr_t vt, va, vb;
62     decNumber t, a, b;
63     decContext context;
64     uint8_t crbf;
65 };
66 
67 static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
68 {
69     enum rounding rnd;
70 
71     switch ((fpscr & FP_DRN) >> FPSCR_DRN0) {
72     case 0:
73         rnd = DEC_ROUND_HALF_EVEN;
74         break;
75     case 1:
76         rnd = DEC_ROUND_DOWN;
77         break;
78     case 2:
79          rnd = DEC_ROUND_CEILING;
80          break;
81     case 3:
82          rnd = DEC_ROUND_FLOOR;
83          break;
84     case 4:
85          rnd = DEC_ROUND_HALF_UP;
86          break;
87     case 5:
88          rnd = DEC_ROUND_HALF_DOWN;
89          break;
90     case 6:
91          rnd = DEC_ROUND_UP;
92          break;
93     case 7:
94          rnd = DEC_ROUND_05UP;
95          break;
96     default:
97         g_assert_not_reached();
98     }
99 
100     decContextSetRounding(context, rnd);
101 }
102 
103 static void dfp_set_round_mode_from_immediate(uint8_t r, uint8_t rmc,
104                                                   struct PPC_DFP *dfp)
105 {
106     enum rounding rnd;
107     if (r == 0) {
108         switch (rmc & 3) {
109         case 0:
110             rnd = DEC_ROUND_HALF_EVEN;
111             break;
112         case 1:
113             rnd = DEC_ROUND_DOWN;
114             break;
115         case 2:
116             rnd = DEC_ROUND_HALF_UP;
117             break;
118         case 3: /* use FPSCR rounding mode */
119             return;
120         default:
121             assert(0); /* cannot get here */
122         }
123     } else { /* r == 1 */
124         switch (rmc & 3) {
125         case 0:
126             rnd = DEC_ROUND_CEILING;
127             break;
128         case 1:
129             rnd = DEC_ROUND_FLOOR;
130             break;
131         case 2:
132             rnd = DEC_ROUND_UP;
133             break;
134         case 3:
135             rnd = DEC_ROUND_HALF_DOWN;
136             break;
137         default:
138             assert(0); /* cannot get here */
139         }
140     }
141     decContextSetRounding(&dfp->context, rnd);
142 }
143 
144 static void dfp_prepare_decimal64(struct PPC_DFP *dfp, ppc_fprp_t *a,
145                                   ppc_fprp_t *b, CPUPPCState *env)
146 {
147     decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
148     dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
149     dfp->env = env;
150 
151     if (a) {
152         get_dfp64(&dfp->va, a);
153         decimal64ToNumber((decimal64 *)&dfp->va.VsrD(1), &dfp->a);
154     } else {
155         dfp->va.VsrD(1) = 0;
156         decNumberZero(&dfp->a);
157     }
158 
159     if (b) {
160         get_dfp64(&dfp->vb, b);
161         decimal64ToNumber((decimal64 *)&dfp->vb.VsrD(1), &dfp->b);
162     } else {
163         dfp->vb.VsrD(1) = 0;
164         decNumberZero(&dfp->b);
165     }
166 }
167 
168 static void dfp_prepare_decimal128(struct PPC_DFP *dfp, ppc_fprp_t *a,
169                                    ppc_fprp_t *b, CPUPPCState *env)
170 {
171     decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
172     dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
173     dfp->env = env;
174 
175     if (a) {
176         get_dfp128(&dfp->va, a);
177         decimal128ToNumber((decimal128 *)&dfp->va, &dfp->a);
178     } else {
179         dfp->va.VsrD(0) = dfp->va.VsrD(1) = 0;
180         decNumberZero(&dfp->a);
181     }
182 
183     if (b) {
184         get_dfp128(&dfp->vb, b);
185         decimal128ToNumber((decimal128 *)&dfp->vb, &dfp->b);
186     } else {
187         dfp->vb.VsrD(0) = dfp->vb.VsrD(1) = 0;
188         decNumberZero(&dfp->b);
189     }
190 }
191 
192 static void dfp_finalize_decimal64(struct PPC_DFP *dfp)
193 {
194     decimal64FromNumber((decimal64 *)&dfp->vt.VsrD(1), &dfp->t, &dfp->context);
195 }
196 
197 static void dfp_finalize_decimal128(struct PPC_DFP *dfp)
198 {
199     decimal128FromNumber((decimal128 *)&dfp->vt, &dfp->t, &dfp->context);
200 }
201 
202 static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
203                 uint64_t enabled)
204 {
205     dfp->env->fpscr |= (flag | FP_FX);
206     if (dfp->env->fpscr & enabled) {
207         dfp->env->fpscr |= FP_FEX;
208     }
209 }
210 
211 static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
212                 decContext *context)
213 {
214     uint64_t fprf = 0;
215 
216     /* construct FPRF */
217     switch (decNumberClass(&dfp->t, context)) {
218     case DEC_CLASS_SNAN:
219         fprf = 0x01;
220         break;
221     case DEC_CLASS_QNAN:
222         fprf = 0x11;
223         break;
224     case DEC_CLASS_NEG_INF:
225         fprf = 0x09;
226         break;
227     case DEC_CLASS_NEG_NORMAL:
228         fprf = 0x08;
229         break;
230     case DEC_CLASS_NEG_SUBNORMAL:
231         fprf = 0x18;
232         break;
233     case DEC_CLASS_NEG_ZERO:
234         fprf = 0x12;
235         break;
236     case DEC_CLASS_POS_ZERO:
237         fprf = 0x02;
238         break;
239     case DEC_CLASS_POS_SUBNORMAL:
240         fprf = 0x14;
241         break;
242     case DEC_CLASS_POS_NORMAL:
243         fprf = 0x04;
244         break;
245     case DEC_CLASS_POS_INF:
246         fprf = 0x05;
247         break;
248     default:
249         assert(0); /* should never get here */
250     }
251     dfp->env->fpscr &= ~FP_FPRF;
252     dfp->env->fpscr |= (fprf << FPSCR_FPRF);
253 }
254 
255 static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
256 {
257     dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
258 }
259 
260 static void dfp_set_FPRF_from_FRT_short(struct PPC_DFP *dfp)
261 {
262     decContext shortContext;
263     decContextDefault(&shortContext, DEC_INIT_DECIMAL32);
264     dfp_set_FPRF_from_FRT_with_context(dfp, &shortContext);
265 }
266 
267 static void dfp_set_FPRF_from_FRT_long(struct PPC_DFP *dfp)
268 {
269     decContext longContext;
270     decContextDefault(&longContext, DEC_INIT_DECIMAL64);
271     dfp_set_FPRF_from_FRT_with_context(dfp, &longContext);
272 }
273 
274 static void dfp_check_for_OX(struct PPC_DFP *dfp)
275 {
276     if (dfp->context.status & DEC_Overflow) {
277         dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
278     }
279 }
280 
281 static void dfp_check_for_UX(struct PPC_DFP *dfp)
282 {
283     if (dfp->context.status & DEC_Underflow) {
284         dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
285     }
286 }
287 
288 static void dfp_check_for_XX(struct PPC_DFP *dfp)
289 {
290     if (dfp->context.status & DEC_Inexact) {
291         dfp_set_FPSCR_flag(dfp, FP_XX | FP_FI, FP_XE);
292     }
293 }
294 
295 static void dfp_check_for_ZX(struct PPC_DFP *dfp)
296 {
297     if (dfp->context.status & DEC_Division_by_zero) {
298         dfp_set_FPSCR_flag(dfp, FP_ZX, FP_ZE);
299     }
300 }
301 
302 static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
303 {
304     if (dfp->context.status & DEC_Invalid_operation) {
305         if (decNumberIsSNaN(&dfp->a) || decNumberIsSNaN(&dfp->b)) {
306             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
307         }
308     }
309 }
310 
311 static void dfp_check_for_VXSNAN_and_convert_to_QNaN(struct PPC_DFP *dfp)
312 {
313     if (decNumberIsSNaN(&dfp->t)) {
314         dfp->t.bits &= ~DECSNAN;
315         dfp->t.bits |= DECNAN;
316         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
317     }
318 }
319 
320 static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
321 {
322     if (dfp->context.status & DEC_Invalid_operation) {
323         if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
324             int same = decNumberClass(&dfp->a, &dfp->context) ==
325                        decNumberClass(&dfp->b, &dfp->context);
326             if ((same && testForSameSign) || (!same && !testForSameSign)) {
327                 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXISI, FP_VE);
328             }
329         }
330     }
331 }
332 
333 static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
334 {
335     dfp_check_for_VXISI(dfp, 0);
336 }
337 
338 static void dfp_check_for_VXISI_subtract(struct PPC_DFP *dfp)
339 {
340     dfp_check_for_VXISI(dfp, 1);
341 }
342 
343 static void dfp_check_for_VXIMZ(struct PPC_DFP *dfp)
344 {
345     if (dfp->context.status & DEC_Invalid_operation) {
346         if ((decNumberIsInfinite(&dfp->a) && decNumberIsZero(&dfp->b)) ||
347             (decNumberIsInfinite(&dfp->b) && decNumberIsZero(&dfp->a))) {
348             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIMZ, FP_VE);
349         }
350     }
351 }
352 
353 static void dfp_check_for_VXZDZ(struct PPC_DFP *dfp)
354 {
355     if (dfp->context.status & DEC_Division_undefined) {
356         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXZDZ, FP_VE);
357     }
358 }
359 
360 static void dfp_check_for_VXIDI(struct PPC_DFP *dfp)
361 {
362     if (dfp->context.status & DEC_Invalid_operation) {
363         if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
364             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIDI, FP_VE);
365         }
366     }
367 }
368 
369 static void dfp_check_for_VXVC(struct PPC_DFP *dfp)
370 {
371     if (decNumberIsNaN(&dfp->a) || decNumberIsNaN(&dfp->b)) {
372         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXVC, FP_VE);
373     }
374 }
375 
376 static void dfp_check_for_VXCVI(struct PPC_DFP *dfp)
377 {
378     if ((dfp->context.status & DEC_Invalid_operation) &&
379         (!decNumberIsSNaN(&dfp->a)) &&
380         (!decNumberIsSNaN(&dfp->b))) {
381         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
382     }
383 }
384 
385 static void dfp_set_CRBF_from_T(struct PPC_DFP *dfp)
386 {
387     if (decNumberIsNaN(&dfp->t)) {
388         dfp->crbf = 1;
389     } else if (decNumberIsZero(&dfp->t)) {
390         dfp->crbf = 2;
391     } else if (decNumberIsNegative(&dfp->t)) {
392         dfp->crbf = 8;
393     } else {
394         dfp->crbf = 4;
395     }
396 }
397 
398 static void dfp_set_FPCC_from_CRBF(struct PPC_DFP *dfp)
399 {
400     dfp->env->fpscr &= ~FP_FPCC;
401     dfp->env->fpscr |= (dfp->crbf << FPSCR_FPCC);
402 }
403 
404 static inline void dfp_makeQNaN(decNumber *dn)
405 {
406     dn->bits &= ~DECSPECIAL;
407     dn->bits |= DECNAN;
408 }
409 
410 static inline int dfp_get_digit(decNumber *dn, int n)
411 {
412     assert(DECDPUN == 3);
413     int unit = n / DECDPUN;
414     int dig = n % DECDPUN;
415     switch (dig) {
416     case 0:
417         return dn->lsu[unit] % 10;
418     case 1:
419         return (dn->lsu[unit] / 10) % 10;
420     case 2:
421         return dn->lsu[unit] / 100;
422     }
423     g_assert_not_reached();
424 }
425 
426 #define DFP_HELPER_TAB(op, dnop, postprocs, size)                              \
427 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a,               \
428                  ppc_fprp_t *b)                                                \
429 {                                                                              \
430     struct PPC_DFP dfp;                                                        \
431     dfp_prepare_decimal##size(&dfp, a, b, env);                                \
432     dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context);                                \
433     dfp_finalize_decimal##size(&dfp);                                          \
434     postprocs(&dfp);                                                           \
435     set_dfp##size(t, &dfp.vt);                                                 \
436 }
437 
438 static void ADD_PPs(struct PPC_DFP *dfp)
439 {
440     dfp_set_FPRF_from_FRT(dfp);
441     dfp_check_for_OX(dfp);
442     dfp_check_for_UX(dfp);
443     dfp_check_for_XX(dfp);
444     dfp_check_for_VXSNAN(dfp);
445     dfp_check_for_VXISI_add(dfp);
446 }
447 
448 DFP_HELPER_TAB(DADD, decNumberAdd, ADD_PPs, 64)
449 DFP_HELPER_TAB(DADDQ, decNumberAdd, ADD_PPs, 128)
450 
451 static void SUB_PPs(struct PPC_DFP *dfp)
452 {
453     dfp_set_FPRF_from_FRT(dfp);
454     dfp_check_for_OX(dfp);
455     dfp_check_for_UX(dfp);
456     dfp_check_for_XX(dfp);
457     dfp_check_for_VXSNAN(dfp);
458     dfp_check_for_VXISI_subtract(dfp);
459 }
460 
461 DFP_HELPER_TAB(DSUB, decNumberSubtract, SUB_PPs, 64)
462 DFP_HELPER_TAB(DSUBQ, decNumberSubtract, SUB_PPs, 128)
463 
464 static void MUL_PPs(struct PPC_DFP *dfp)
465 {
466     dfp_set_FPRF_from_FRT(dfp);
467     dfp_check_for_OX(dfp);
468     dfp_check_for_UX(dfp);
469     dfp_check_for_XX(dfp);
470     dfp_check_for_VXSNAN(dfp);
471     dfp_check_for_VXIMZ(dfp);
472 }
473 
474 DFP_HELPER_TAB(DMUL, decNumberMultiply, MUL_PPs, 64)
475 DFP_HELPER_TAB(DMULQ, decNumberMultiply, MUL_PPs, 128)
476 
477 static void DIV_PPs(struct PPC_DFP *dfp)
478 {
479     dfp_set_FPRF_from_FRT(dfp);
480     dfp_check_for_OX(dfp);
481     dfp_check_for_UX(dfp);
482     dfp_check_for_ZX(dfp);
483     dfp_check_for_XX(dfp);
484     dfp_check_for_VXSNAN(dfp);
485     dfp_check_for_VXZDZ(dfp);
486     dfp_check_for_VXIDI(dfp);
487 }
488 
489 DFP_HELPER_TAB(DDIV, decNumberDivide, DIV_PPs, 64)
490 DFP_HELPER_TAB(DDIVQ, decNumberDivide, DIV_PPs, 128)
491 
492 #define DFP_HELPER_BF_AB(op, dnop, postprocs, size)                            \
493 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, ppc_fprp_t *b)           \
494 {                                                                              \
495     struct PPC_DFP dfp;                                                        \
496     dfp_prepare_decimal##size(&dfp, a, b, env);                                \
497     dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context);                                \
498     dfp_finalize_decimal##size(&dfp);                                          \
499     postprocs(&dfp);                                                           \
500     return dfp.crbf;                                                           \
501 }
502 
503 static void CMPU_PPs(struct PPC_DFP *dfp)
504 {
505     dfp_set_CRBF_from_T(dfp);
506     dfp_set_FPCC_from_CRBF(dfp);
507     dfp_check_for_VXSNAN(dfp);
508 }
509 
510 DFP_HELPER_BF_AB(DCMPU, decNumberCompare, CMPU_PPs, 64)
511 DFP_HELPER_BF_AB(DCMPUQ, decNumberCompare, CMPU_PPs, 128)
512 
513 static void CMPO_PPs(struct PPC_DFP *dfp)
514 {
515     dfp_set_CRBF_from_T(dfp);
516     dfp_set_FPCC_from_CRBF(dfp);
517     dfp_check_for_VXSNAN(dfp);
518     dfp_check_for_VXVC(dfp);
519 }
520 
521 DFP_HELPER_BF_AB(DCMPO, decNumberCompare, CMPO_PPs, 64)
522 DFP_HELPER_BF_AB(DCMPOQ, decNumberCompare, CMPO_PPs, 128)
523 
524 #define DFP_HELPER_TSTDC(op, size)                                       \
525 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, uint32_t dcm)      \
526 {                                                                        \
527     struct PPC_DFP dfp;                                                  \
528     int match = 0;                                                       \
529                                                                          \
530     dfp_prepare_decimal##size(&dfp, a, 0, env);                          \
531                                                                          \
532     match |= (dcm & 0x20) && decNumberIsZero(&dfp.a);                    \
533     match |= (dcm & 0x10) && decNumberIsSubnormal(&dfp.a, &dfp.context); \
534     match |= (dcm & 0x08) && decNumberIsNormal(&dfp.a, &dfp.context);    \
535     match |= (dcm & 0x04) && decNumberIsInfinite(&dfp.a);                \
536     match |= (dcm & 0x02) && decNumberIsQNaN(&dfp.a);                    \
537     match |= (dcm & 0x01) && decNumberIsSNaN(&dfp.a);                    \
538                                                                          \
539     if (decNumberIsNegative(&dfp.a)) {                                   \
540         dfp.crbf = match ? 0xA : 0x8;                                    \
541     } else {                                                             \
542         dfp.crbf = match ? 0x2 : 0x0;                                    \
543     }                                                                    \
544                                                                          \
545     dfp_set_FPCC_from_CRBF(&dfp);                                        \
546     return dfp.crbf;                                                     \
547 }
548 
549 DFP_HELPER_TSTDC(DTSTDC, 64)
550 DFP_HELPER_TSTDC(DTSTDCQ, 128)
551 
552 #define DFP_HELPER_TSTDG(op, size)                                       \
553 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, uint32_t dcm)      \
554 {                                                                        \
555     struct PPC_DFP dfp;                                                  \
556     int minexp, maxexp, nzero_digits, nzero_idx, is_negative, is_zero,   \
557         is_extreme_exp, is_subnormal, is_normal, leftmost_is_nonzero,    \
558         match;                                                           \
559                                                                          \
560     dfp_prepare_decimal##size(&dfp, a, 0, env);                          \
561                                                                          \
562     if ((size) == 64) {                                                  \
563         minexp = -398;                                                   \
564         maxexp = 369;                                                    \
565         nzero_digits = 16;                                               \
566         nzero_idx = 5;                                                   \
567     } else if ((size) == 128) {                                          \
568         minexp = -6176;                                                  \
569         maxexp = 6111;                                                   \
570         nzero_digits = 34;                                               \
571         nzero_idx = 11;                                                  \
572     }                                                                    \
573                                                                          \
574     is_negative = decNumberIsNegative(&dfp.a);                           \
575     is_zero = decNumberIsZero(&dfp.a);                                   \
576     is_extreme_exp = (dfp.a.exponent == maxexp) ||                       \
577                      (dfp.a.exponent == minexp);                         \
578     is_subnormal = decNumberIsSubnormal(&dfp.a, &dfp.context);           \
579     is_normal = decNumberIsNormal(&dfp.a, &dfp.context);                 \
580     leftmost_is_nonzero = (dfp.a.digits == nzero_digits) &&              \
581                           (dfp.a.lsu[nzero_idx] != 0);                   \
582     match = 0;                                                           \
583                                                                          \
584     match |= (dcm & 0x20) && is_zero && !is_extreme_exp;                 \
585     match |= (dcm & 0x10) && is_zero && is_extreme_exp;                  \
586     match |= (dcm & 0x08) &&                                             \
587              (is_subnormal || (is_normal && is_extreme_exp));            \
588     match |= (dcm & 0x04) && is_normal && !is_extreme_exp &&             \
589              !leftmost_is_nonzero;                                       \
590     match |= (dcm & 0x02) && is_normal && !is_extreme_exp &&             \
591              leftmost_is_nonzero;                                        \
592     match |= (dcm & 0x01) && decNumberIsSpecial(&dfp.a);                 \
593                                                                          \
594     if (is_negative) {                                                   \
595         dfp.crbf = match ? 0xA : 0x8;                                    \
596     } else {                                                             \
597         dfp.crbf = match ? 0x2 : 0x0;                                    \
598     }                                                                    \
599                                                                          \
600     dfp_set_FPCC_from_CRBF(&dfp);                                        \
601     return dfp.crbf;                                                     \
602 }
603 
604 DFP_HELPER_TSTDG(DTSTDG, 64)
605 DFP_HELPER_TSTDG(DTSTDGQ, 128)
606 
607 #define DFP_HELPER_TSTEX(op, size)                                       \
608 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, ppc_fprp_t *b)     \
609 {                                                                        \
610     struct PPC_DFP dfp;                                                  \
611     int expa, expb, a_is_special, b_is_special;                          \
612                                                                          \
613     dfp_prepare_decimal##size(&dfp, a, b, env);                          \
614                                                                          \
615     expa = dfp.a.exponent;                                               \
616     expb = dfp.b.exponent;                                               \
617     a_is_special = decNumberIsSpecial(&dfp.a);                           \
618     b_is_special = decNumberIsSpecial(&dfp.b);                           \
619                                                                          \
620     if (a_is_special || b_is_special) {                                  \
621         int atype = a_is_special ? (decNumberIsNaN(&dfp.a) ? 4 : 2) : 1; \
622         int btype = b_is_special ? (decNumberIsNaN(&dfp.b) ? 4 : 2) : 1; \
623         dfp.crbf = (atype ^ btype) ? 0x1 : 0x2;                          \
624     } else if (expa < expb) {                                            \
625         dfp.crbf = 0x8;                                                  \
626     } else if (expa > expb) {                                            \
627         dfp.crbf = 0x4;                                                  \
628     } else {                                                             \
629         dfp.crbf = 0x2;                                                  \
630     }                                                                    \
631                                                                          \
632     dfp_set_FPCC_from_CRBF(&dfp);                                        \
633     return dfp.crbf;                                                     \
634 }
635 
636 DFP_HELPER_TSTEX(DTSTEX, 64)
637 DFP_HELPER_TSTEX(DTSTEXQ, 128)
638 
639 #define DFP_HELPER_TSTSF(op, size)                                       \
640 uint32_t helper_##op(CPUPPCState *env, ppc_fprp_t *a, ppc_fprp_t *b)     \
641 {                                                                        \
642     struct PPC_DFP dfp;                                                  \
643     unsigned k;                                                          \
644     ppc_vsr_t va;                                                        \
645                                                                          \
646     dfp_prepare_decimal##size(&dfp, 0, b, env);                          \
647                                                                          \
648     get_dfp64(&va, a);                                                   \
649     k = va.VsrD(1) & 0x3F;                                               \
650                                                                          \
651     if (unlikely(decNumberIsSpecial(&dfp.b))) {                          \
652         dfp.crbf = 1;                                                    \
653     } else if (k == 0) {                                                 \
654         dfp.crbf = 4;                                                    \
655     } else if (unlikely(decNumberIsZero(&dfp.b))) {                      \
656         /* Zero has no sig digits */                                     \
657         dfp.crbf = 4;                                                    \
658     } else {                                                             \
659         unsigned nsd = dfp.b.digits;                                     \
660         if (k < nsd) {                                                   \
661             dfp.crbf = 8;                                                \
662         } else if (k > nsd) {                                            \
663             dfp.crbf = 4;                                                \
664         } else {                                                         \
665             dfp.crbf = 2;                                                \
666         }                                                                \
667     }                                                                    \
668                                                                          \
669     dfp_set_FPCC_from_CRBF(&dfp);                                        \
670     return dfp.crbf;                                                     \
671 }
672 
673 DFP_HELPER_TSTSF(DTSTSF, 64)
674 DFP_HELPER_TSTSF(DTSTSFQ, 128)
675 
676 #define DFP_HELPER_TSTSFI(op, size)                                     \
677 uint32_t helper_##op(CPUPPCState *env, uint32_t a, ppc_fprp_t *b)       \
678 {                                                                       \
679     struct PPC_DFP dfp;                                                 \
680     unsigned uim;                                                       \
681                                                                         \
682     dfp_prepare_decimal##size(&dfp, 0, b, env);                         \
683                                                                         \
684     uim = a & 0x3F;                                                     \
685                                                                         \
686     if (unlikely(decNumberIsSpecial(&dfp.b))) {                         \
687         dfp.crbf = 1;                                                   \
688     } else if (uim == 0) {                                              \
689         dfp.crbf = 4;                                                   \
690     } else if (unlikely(decNumberIsZero(&dfp.b))) {                     \
691         /* Zero has no sig digits */                                    \
692         dfp.crbf = 4;                                                   \
693     } else {                                                            \
694         unsigned nsd = dfp.b.digits;                                    \
695         if (uim < nsd) {                                                \
696             dfp.crbf = 8;                                               \
697         } else if (uim > nsd) {                                         \
698             dfp.crbf = 4;                                               \
699         } else {                                                        \
700             dfp.crbf = 2;                                               \
701         }                                                               \
702     }                                                                   \
703                                                                         \
704     dfp_set_FPCC_from_CRBF(&dfp);                                       \
705     return dfp.crbf;                                                    \
706 }
707 
708 DFP_HELPER_TSTSFI(DTSTSFI, 64)
709 DFP_HELPER_TSTSFI(DTSTSFIQ, 128)
710 
711 static void QUA_PPs(struct PPC_DFP *dfp)
712 {
713     dfp_set_FPRF_from_FRT(dfp);
714     dfp_check_for_XX(dfp);
715     dfp_check_for_VXSNAN(dfp);
716     dfp_check_for_VXCVI(dfp);
717 }
718 
719 static void dfp_quantize(uint8_t rmc, struct PPC_DFP *dfp)
720 {
721     dfp_set_round_mode_from_immediate(0, rmc, dfp);
722     decNumberQuantize(&dfp->t, &dfp->b, &dfp->a, &dfp->context);
723     if (decNumberIsSNaN(&dfp->a)) {
724         dfp->t = dfp->a;
725         dfp_makeQNaN(&dfp->t);
726     } else if (decNumberIsSNaN(&dfp->b)) {
727         dfp->t = dfp->b;
728         dfp_makeQNaN(&dfp->t);
729     } else if (decNumberIsQNaN(&dfp->a)) {
730         dfp->t = dfp->a;
731     } else if (decNumberIsQNaN(&dfp->b)) {
732         dfp->t = dfp->b;
733     }
734 }
735 
736 #define DFP_HELPER_QUAI(op, size)                                       \
737 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b,        \
738                  uint32_t te, uint32_t rmc)                             \
739 {                                                                       \
740     struct PPC_DFP dfp;                                                 \
741                                                                         \
742     dfp_prepare_decimal##size(&dfp, 0, b, env);                         \
743                                                                         \
744     decNumberFromUInt32(&dfp.a, 1);                                     \
745     dfp.a.exponent = (int32_t)((int8_t)(te << 3) >> 3);                 \
746                                                                         \
747     dfp_quantize(rmc, &dfp);                                            \
748     dfp_finalize_decimal##size(&dfp);                                   \
749     QUA_PPs(&dfp);                                                      \
750                                                                         \
751     set_dfp##size(t, &dfp.vt);                                          \
752 }
753 
754 DFP_HELPER_QUAI(DQUAI, 64)
755 DFP_HELPER_QUAI(DQUAIQ, 128)
756 
757 #define DFP_HELPER_QUA(op, size)                                        \
758 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a,        \
759                  ppc_fprp_t *b, uint32_t rmc)                           \
760 {                                                                       \
761     struct PPC_DFP dfp;                                                 \
762                                                                         \
763     dfp_prepare_decimal##size(&dfp, a, b, env);                         \
764                                                                         \
765     dfp_quantize(rmc, &dfp);                                            \
766     dfp_finalize_decimal##size(&dfp);                                   \
767     QUA_PPs(&dfp);                                                      \
768                                                                         \
769     set_dfp##size(t, &dfp.vt);                                          \
770 }
771 
772 DFP_HELPER_QUA(DQUA, 64)
773 DFP_HELPER_QUA(DQUAQ, 128)
774 
775 static void _dfp_reround(uint8_t rmc, int32_t ref_sig, int32_t xmax,
776                              struct PPC_DFP *dfp)
777 {
778     int msd_orig, msd_rslt;
779 
780     if (unlikely((ref_sig == 0) || (dfp->b.digits <= ref_sig))) {
781         dfp->t = dfp->b;
782         if (decNumberIsSNaN(&dfp->b)) {
783             dfp_makeQNaN(&dfp->t);
784             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FPSCR_VE);
785         }
786         return;
787     }
788 
789     /* Reround is equivalent to quantizing b with 1**E(n) where */
790     /* n = exp(b) + numDigits(b) - reference_significance.      */
791 
792     decNumberFromUInt32(&dfp->a, 1);
793     dfp->a.exponent = dfp->b.exponent + dfp->b.digits - ref_sig;
794 
795     if (unlikely(dfp->a.exponent > xmax)) {
796         dfp->t.digits = 0;
797         dfp->t.bits &= ~DECNEG;
798         dfp_makeQNaN(&dfp->t);
799         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FPSCR_VE);
800         return;
801     }
802 
803     dfp_quantize(rmc, dfp);
804 
805     msd_orig = dfp_get_digit(&dfp->b, dfp->b.digits-1);
806     msd_rslt = dfp_get_digit(&dfp->t, dfp->t.digits-1);
807 
808     /* If the quantization resulted in rounding up to the next magnitude, */
809     /* then we need to shift the significand and adjust the exponent.     */
810 
811     if (unlikely((msd_orig == 9) && (msd_rslt == 1))) {
812 
813         decNumber negone;
814 
815         decNumberFromInt32(&negone, -1);
816         decNumberShift(&dfp->t, &dfp->t, &negone, &dfp->context);
817         dfp->t.exponent++;
818 
819         if (unlikely(dfp->t.exponent > xmax)) {
820             dfp_makeQNaN(&dfp->t);
821             dfp->t.digits = 0;
822             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
823             /* Inhibit XX in this case */
824             decContextClearStatus(&dfp->context, DEC_Inexact);
825         }
826     }
827 }
828 
829 #define DFP_HELPER_RRND(op, size)                                       \
830 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a,        \
831                  ppc_fprp_t *b, uint32_t rmc)                           \
832 {                                                                       \
833     struct PPC_DFP dfp;                                                 \
834     ppc_vsr_t va;                                                       \
835     int32_t ref_sig;                                                    \
836     int32_t xmax = ((size) == 64) ? 369 : 6111;                         \
837                                                                         \
838     dfp_prepare_decimal##size(&dfp, 0, b, env);                         \
839                                                                         \
840     get_dfp64(&va, a);                                                  \
841     ref_sig = va.VsrD(1) & 0x3f;                                        \
842                                                                         \
843     _dfp_reround(rmc, ref_sig, xmax, &dfp);                             \
844     dfp_finalize_decimal##size(&dfp);                                   \
845     QUA_PPs(&dfp);                                                      \
846                                                                         \
847     set_dfp##size(t, &dfp.vt);                                          \
848 }
849 
850 DFP_HELPER_RRND(DRRND, 64)
851 DFP_HELPER_RRND(DRRNDQ, 128)
852 
853 #define DFP_HELPER_RINT(op, postprocs, size)                                   \
854 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b,               \
855              uint32_t r, uint32_t rmc)                                         \
856 {                                                                              \
857     struct PPC_DFP dfp;                                                        \
858                                                                                \
859     dfp_prepare_decimal##size(&dfp, 0, b, env);                                \
860                                                                                \
861     dfp_set_round_mode_from_immediate(r, rmc, &dfp);                           \
862     decNumberToIntegralExact(&dfp.t, &dfp.b, &dfp.context);                    \
863     dfp_finalize_decimal##size(&dfp);                                          \
864     postprocs(&dfp);                                                           \
865                                                                                \
866     set_dfp##size(t, &dfp.vt);                                                 \
867 }
868 
869 static void RINTX_PPs(struct PPC_DFP *dfp)
870 {
871     dfp_set_FPRF_from_FRT(dfp);
872     dfp_check_for_XX(dfp);
873     dfp_check_for_VXSNAN(dfp);
874 }
875 
876 DFP_HELPER_RINT(DRINTX, RINTX_PPs, 64)
877 DFP_HELPER_RINT(DRINTXQ, RINTX_PPs, 128)
878 
879 static void RINTN_PPs(struct PPC_DFP *dfp)
880 {
881     dfp_set_FPRF_from_FRT(dfp);
882     dfp_check_for_VXSNAN(dfp);
883 }
884 
885 DFP_HELPER_RINT(DRINTN, RINTN_PPs, 64)
886 DFP_HELPER_RINT(DRINTNQ, RINTN_PPs, 128)
887 
888 void helper_DCTDP(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
889 {
890     struct PPC_DFP dfp;
891     ppc_vsr_t vb;
892     uint32_t b_short;
893 
894     get_dfp64(&vb, b);
895     b_short = (uint32_t)vb.VsrD(1);
896 
897     dfp_prepare_decimal64(&dfp, 0, 0, env);
898     decimal32ToNumber((decimal32 *)&b_short, &dfp.t);
899     dfp_finalize_decimal64(&dfp);
900     set_dfp64(t, &dfp.vt);
901     dfp_set_FPRF_from_FRT(&dfp);
902 }
903 
904 void helper_DCTQPQ(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
905 {
906     struct PPC_DFP dfp;
907     ppc_vsr_t vb;
908     dfp_prepare_decimal128(&dfp, 0, 0, env);
909     get_dfp64(&vb, b);
910     decimal64ToNumber((decimal64 *)&vb.VsrD(1), &dfp.t);
911 
912     dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
913     dfp_set_FPRF_from_FRT(&dfp);
914 
915     dfp_finalize_decimal128(&dfp);
916     set_dfp128(t, &dfp.vt);
917 }
918 
919 void helper_DRSP(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
920 {
921     struct PPC_DFP dfp;
922     uint32_t t_short = 0;
923     ppc_vsr_t vt;
924     dfp_prepare_decimal64(&dfp, 0, b, env);
925     decimal32FromNumber((decimal32 *)&t_short, &dfp.b, &dfp.context);
926     decimal32ToNumber((decimal32 *)&t_short, &dfp.t);
927 
928     dfp_set_FPRF_from_FRT_short(&dfp);
929     dfp_check_for_OX(&dfp);
930     dfp_check_for_UX(&dfp);
931     dfp_check_for_XX(&dfp);
932 
933     vt.VsrD(1) = (uint64_t)t_short;
934     set_dfp64(t, &vt);
935 }
936 
937 void helper_DRDPQ(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)
938 {
939     struct PPC_DFP dfp;
940     dfp_prepare_decimal128(&dfp, 0, b, env);
941     decimal64FromNumber((decimal64 *)&dfp.vt.VsrD(1), &dfp.b, &dfp.context);
942     decimal64ToNumber((decimal64 *)&dfp.vt.VsrD(1), &dfp.t);
943 
944     dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
945     dfp_set_FPRF_from_FRT_long(&dfp);
946     dfp_check_for_OX(&dfp);
947     dfp_check_for_UX(&dfp);
948     dfp_check_for_XX(&dfp);
949 
950     dfp.vt.VsrD(0) = dfp.vt.VsrD(1) = 0;
951     dfp_finalize_decimal64(&dfp);
952     set_dfp128(t, &dfp.vt);
953 }
954 
955 #define DFP_HELPER_CFFIX(op, size)                                             \
956 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)               \
957 {                                                                              \
958     struct PPC_DFP dfp;                                                        \
959     ppc_vsr_t vb;                                                              \
960     dfp_prepare_decimal##size(&dfp, 0, b, env);                                \
961     get_dfp64(&vb, b);                                                         \
962     decNumberFromInt64(&dfp.t, (int64_t)vb.VsrD(1));                           \
963     dfp_finalize_decimal##size(&dfp);                                          \
964     CFFIX_PPs(&dfp);                                                           \
965                                                                                \
966     set_dfp##size(t, &dfp.vt);                                                 \
967 }
968 
969 static void CFFIX_PPs(struct PPC_DFP *dfp)
970 {
971     dfp_set_FPRF_from_FRT(dfp);
972     dfp_check_for_XX(dfp);
973 }
974 
975 DFP_HELPER_CFFIX(DCFFIX, 64)
976 DFP_HELPER_CFFIX(DCFFIXQ, 128)
977 
978 void helper_DCFFIXQQ(CPUPPCState *env, ppc_fprp_t *t, ppc_avr_t *b)
979 {
980     struct PPC_DFP dfp;
981 
982     dfp_prepare_decimal128(&dfp, NULL, NULL, env);
983     decNumberFromInt128(&dfp.t, (uint64_t)b->VsrD(1), (int64_t)b->VsrD(0));
984     dfp_finalize_decimal128(&dfp);
985     CFFIX_PPs(&dfp);
986 
987     set_dfp128(t, &dfp.vt);
988 }
989 
990 #define DFP_HELPER_CTFIX(op, size)                                            \
991 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b)              \
992 {                                                                             \
993     struct PPC_DFP dfp;                                                       \
994     dfp_prepare_decimal##size(&dfp, 0, b, env);                               \
995                                                                               \
996     if (unlikely(decNumberIsSpecial(&dfp.b))) {                               \
997         uint64_t invalid_flags = FP_VX | FP_VXCVI;                            \
998         if (decNumberIsInfinite(&dfp.b)) {                                    \
999             dfp.vt.VsrD(1) = decNumberIsNegative(&dfp.b) ? INT64_MIN :        \
1000                                                            INT64_MAX;         \
1001         } else { /* NaN */                                                    \
1002             dfp.vt.VsrD(1) = INT64_MIN;                                       \
1003             if (decNumberIsSNaN(&dfp.b)) {                                    \
1004                 invalid_flags |= FP_VXSNAN;                                   \
1005             }                                                                 \
1006         }                                                                     \
1007         dfp_set_FPSCR_flag(&dfp, invalid_flags, FP_VE);                       \
1008     } else if (unlikely(decNumberIsZero(&dfp.b))) {                           \
1009         dfp.vt.VsrD(1) = 0;                                                   \
1010     } else {                                                                  \
1011         decNumberToIntegralExact(&dfp.b, &dfp.b, &dfp.context);               \
1012         dfp.vt.VsrD(1) = decNumberIntegralToInt64(&dfp.b, &dfp.context);      \
1013         if (decContextTestStatus(&dfp.context, DEC_Invalid_operation)) {      \
1014             dfp.vt.VsrD(1) = decNumberIsNegative(&dfp.b) ? INT64_MIN :        \
1015                                                            INT64_MAX;         \
1016             dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FP_VE);                \
1017         } else {                                                              \
1018             dfp_check_for_XX(&dfp);                                           \
1019         }                                                                     \
1020     }                                                                         \
1021                                                                               \
1022     set_dfp64(t, &dfp.vt);                                                    \
1023 }
1024 
1025 DFP_HELPER_CTFIX(DCTFIX, 64)
1026 DFP_HELPER_CTFIX(DCTFIXQ, 128)
1027 
1028 void helper_DCTFIXQQ(CPUPPCState *env, ppc_avr_t *t, ppc_fprp_t *b)
1029 {
1030     struct PPC_DFP dfp;
1031     dfp_prepare_decimal128(&dfp, 0, b, env);
1032 
1033     if (unlikely(decNumberIsSpecial(&dfp.b))) {
1034         uint64_t invalid_flags = FP_VX | FP_VXCVI;
1035         if (decNumberIsInfinite(&dfp.b)) {
1036             if (decNumberIsNegative(&dfp.b)) {
1037                 dfp.vt.VsrD(0) = INT64_MIN;
1038                 dfp.vt.VsrD(1) = 0;
1039             } else {
1040                 dfp.vt.VsrD(0) = INT64_MAX;
1041                 dfp.vt.VsrD(1) = UINT64_MAX;
1042             }
1043         } else { /* NaN */
1044             dfp.vt.VsrD(0) = INT64_MIN;
1045             dfp.vt.VsrD(1) = 0;
1046             if (decNumberIsSNaN(&dfp.b)) {
1047                 invalid_flags |= FP_VXSNAN;
1048             }
1049         }
1050         dfp_set_FPSCR_flag(&dfp, invalid_flags, FP_VE);
1051     } else if (unlikely(decNumberIsZero(&dfp.b))) {
1052         dfp.vt.VsrD(0) = 0;
1053         dfp.vt.VsrD(1) = 0;
1054     } else {
1055         decNumberToIntegralExact(&dfp.b, &dfp.b, &dfp.context);
1056         decNumberIntegralToInt128(&dfp.b, &dfp.context,
1057                 &dfp.vt.VsrD(1), &dfp.vt.VsrD(0));
1058         if (decContextTestStatus(&dfp.context, DEC_Invalid_operation)) {
1059             if (decNumberIsNegative(&dfp.b)) {
1060                 dfp.vt.VsrD(0) = INT64_MIN;
1061                 dfp.vt.VsrD(1) = 0;
1062             } else {
1063                 dfp.vt.VsrD(0) = INT64_MAX;
1064                 dfp.vt.VsrD(1) = UINT64_MAX;
1065             }
1066             dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FP_VE);
1067         } else {
1068             dfp_check_for_XX(&dfp);
1069         }
1070     }
1071 
1072     set_dfp128_to_avr(t, &dfp.vt);
1073 }
1074 
1075 static inline void dfp_set_bcd_digit_64(ppc_vsr_t *t, uint8_t digit,
1076                                         unsigned n)
1077 {
1078     t->VsrD(1) |= ((uint64_t)(digit & 0xF) << (n << 2));
1079 }
1080 
1081 static inline void dfp_set_bcd_digit_128(ppc_vsr_t *t, uint8_t digit,
1082                                          unsigned n)
1083 {
1084     t->VsrD((n & 0x10) ? 0 : 1) |=
1085         ((uint64_t)(digit & 0xF) << ((n & 15) << 2));
1086 }
1087 
1088 static inline void dfp_set_sign_64(ppc_vsr_t *t, uint8_t sgn)
1089 {
1090     t->VsrD(1) <<= 4;
1091     t->VsrD(1) |= (sgn & 0xF);
1092 }
1093 
1094 static inline void dfp_set_sign_128(ppc_vsr_t *t, uint8_t sgn)
1095 {
1096     t->VsrD(0) <<= 4;
1097     t->VsrD(0) |= (t->VsrD(1) >> 60);
1098     t->VsrD(1) <<= 4;
1099     t->VsrD(1) |= (sgn & 0xF);
1100 }
1101 
1102 #define DFP_HELPER_DEDPD(op, size)                                        \
1103 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b,          \
1104                  uint32_t sp)                                             \
1105 {                                                                         \
1106     struct PPC_DFP dfp;                                                   \
1107     uint8_t digits[34];                                                   \
1108     int i, N;                                                             \
1109                                                                           \
1110     dfp_prepare_decimal##size(&dfp, 0, b, env);                           \
1111                                                                           \
1112     decNumberGetBCD(&dfp.b, digits);                                      \
1113     dfp.vt.VsrD(0) = dfp.vt.VsrD(1) = 0;                                  \
1114     N = dfp.b.digits;                                                     \
1115                                                                           \
1116     for (i = 0; (i < N) && (i < (size)/4); i++) {                         \
1117         dfp_set_bcd_digit_##size(&dfp.vt, digits[N - i - 1], i);          \
1118     }                                                                     \
1119                                                                           \
1120     if (sp & 2) {                                                         \
1121         uint8_t sgn;                                                      \
1122                                                                           \
1123         if (decNumberIsNegative(&dfp.b)) {                                \
1124             sgn = 0xD;                                                    \
1125         } else {                                                          \
1126             sgn = ((sp & 1) ? 0xF : 0xC);                                 \
1127         }                                                                 \
1128         dfp_set_sign_##size(&dfp.vt, sgn);                                \
1129     }                                                                     \
1130                                                                           \
1131     set_dfp##size(t, &dfp.vt);                                            \
1132 }
1133 
1134 DFP_HELPER_DEDPD(DDEDPD, 64)
1135 DFP_HELPER_DEDPD(DDEDPDQ, 128)
1136 
1137 static inline uint8_t dfp_get_bcd_digit_64(ppc_vsr_t *t, unsigned n)
1138 {
1139     return t->VsrD(1) >> ((n << 2) & 63) & 15;
1140 }
1141 
1142 static inline uint8_t dfp_get_bcd_digit_128(ppc_vsr_t *t, unsigned n)
1143 {
1144     return t->VsrD((n & 0x10) ? 0 : 1) >> ((n << 2) & 63) & 15;
1145 }
1146 
1147 #define DFP_HELPER_ENBCD(op, size)                                           \
1148 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b,             \
1149                  uint32_t s)                                                 \
1150 {                                                                            \
1151     struct PPC_DFP dfp;                                                      \
1152     uint8_t digits[32];                                                      \
1153     int n = 0, offset = 0, sgn = 0, nonzero = 0;                             \
1154                                                                              \
1155     dfp_prepare_decimal##size(&dfp, 0, b, env);                              \
1156                                                                              \
1157     decNumberZero(&dfp.t);                                                   \
1158                                                                              \
1159     if (s) {                                                                 \
1160         uint8_t sgnNibble = dfp_get_bcd_digit_##size(&dfp.vb, offset++);     \
1161         switch (sgnNibble) {                                                 \
1162         case 0xD:                                                            \
1163         case 0xB:                                                            \
1164             sgn = 1;                                                         \
1165             break;                                                           \
1166         case 0xC:                                                            \
1167         case 0xF:                                                            \
1168         case 0xA:                                                            \
1169         case 0xE:                                                            \
1170             sgn = 0;                                                         \
1171             break;                                                           \
1172         default:                                                             \
1173             dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE);            \
1174             return;                                                          \
1175         }                                                                    \
1176         }                                                                    \
1177                                                                              \
1178     while (offset < (size) / 4) {                                            \
1179         n++;                                                                 \
1180         digits[(size) / 4 - n] = dfp_get_bcd_digit_##size(&dfp.vb,           \
1181                                                           offset++);         \
1182         if (digits[(size) / 4 - n] > 10) {                                   \
1183             dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE);            \
1184             return;                                                          \
1185         } else {                                                             \
1186             nonzero |= (digits[(size) / 4 - n] > 0);                         \
1187         }                                                                    \
1188     }                                                                        \
1189                                                                              \
1190     if (nonzero) {                                                           \
1191         decNumberSetBCD(&dfp.t, digits + ((size) / 4) - n, n);               \
1192     }                                                                        \
1193                                                                              \
1194     if (s && sgn)  {                                                         \
1195         dfp.t.bits |= DECNEG;                                                \
1196     }                                                                        \
1197     dfp_finalize_decimal##size(&dfp);                                        \
1198     dfp_set_FPRF_from_FRT(&dfp);                                             \
1199     set_dfp##size(t, &dfp.vt);                                               \
1200 }
1201 
1202 DFP_HELPER_ENBCD(DENBCD, 64)
1203 DFP_HELPER_ENBCD(DENBCDQ, 128)
1204 
1205 #define DFP_HELPER_XEX(op, size)                               \
1206 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b) \
1207 {                                                              \
1208     struct PPC_DFP dfp;                                        \
1209     ppc_vsr_t vt;                                              \
1210                                                                \
1211     dfp_prepare_decimal##size(&dfp, 0, b, env);                \
1212                                                                \
1213     if (unlikely(decNumberIsSpecial(&dfp.b))) {                \
1214         if (decNumberIsInfinite(&dfp.b)) {                     \
1215             vt.VsrD(1) = -1;                                   \
1216         } else if (decNumberIsSNaN(&dfp.b)) {                  \
1217             vt.VsrD(1) = -3;                                   \
1218         } else if (decNumberIsQNaN(&dfp.b)) {                  \
1219             vt.VsrD(1) = -2;                                   \
1220         } else {                                               \
1221             assert(0);                                         \
1222         }                                                      \
1223         set_dfp64(t, &vt);                                     \
1224     } else {                                                   \
1225         if ((size) == 64) {                                    \
1226             vt.VsrD(1) = dfp.b.exponent + 398;                 \
1227         } else if ((size) == 128) {                            \
1228             vt.VsrD(1) = dfp.b.exponent + 6176;                \
1229         } else {                                               \
1230             assert(0);                                         \
1231         }                                                      \
1232         set_dfp64(t, &vt);                                     \
1233     }                                                          \
1234 }
1235 
1236 DFP_HELPER_XEX(DXEX, 64)
1237 DFP_HELPER_XEX(DXEXQ, 128)
1238 
1239 static void dfp_set_raw_exp_64(ppc_vsr_t *t, uint64_t raw)
1240 {
1241     t->VsrD(1) &= 0x8003ffffffffffffULL;
1242     t->VsrD(1) |= (raw << (63 - 13));
1243 }
1244 
1245 static void dfp_set_raw_exp_128(ppc_vsr_t *t, uint64_t raw)
1246 {
1247     t->VsrD(0) &= 0x80003fffffffffffULL;
1248     t->VsrD(0) |= (raw << (63 - 17));
1249 }
1250 
1251 #define DFP_HELPER_IEX(op, size)                                          \
1252 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a,          \
1253                  ppc_fprp_t *b)                                           \
1254 {                                                                         \
1255     struct PPC_DFP dfp;                                                   \
1256     uint64_t raw_qnan, raw_snan, raw_inf, max_exp;                        \
1257     ppc_vsr_t va;                                                         \
1258     int bias;                                                             \
1259     int64_t exp;                                                          \
1260                                                                           \
1261     get_dfp64(&va, a);                                                    \
1262     exp = (int64_t)va.VsrD(1);                                            \
1263     dfp_prepare_decimal##size(&dfp, 0, b, env);                           \
1264                                                                           \
1265     if ((size) == 64) {                                                   \
1266         max_exp = 767;                                                    \
1267         raw_qnan = 0x1F00;                                                \
1268         raw_snan = 0x1F80;                                                \
1269         raw_inf = 0x1E00;                                                 \
1270         bias = 398;                                                       \
1271     } else if ((size) == 128) {                                           \
1272         max_exp = 12287;                                                  \
1273         raw_qnan = 0x1f000;                                               \
1274         raw_snan = 0x1f800;                                               \
1275         raw_inf = 0x1e000;                                                \
1276         bias = 6176;                                                      \
1277     } else {                                                              \
1278         assert(0);                                                        \
1279     }                                                                     \
1280                                                                           \
1281     if (unlikely((exp < 0) || (exp > max_exp))) {                         \
1282         dfp.vt.VsrD(0) = dfp.vb.VsrD(0);                                  \
1283         dfp.vt.VsrD(1) = dfp.vb.VsrD(1);                                  \
1284         if (exp == -1) {                                                  \
1285             dfp_set_raw_exp_##size(&dfp.vt, raw_inf);                     \
1286         } else if (exp == -3) {                                           \
1287             dfp_set_raw_exp_##size(&dfp.vt, raw_snan);                    \
1288         } else {                                                          \
1289             dfp_set_raw_exp_##size(&dfp.vt, raw_qnan);                    \
1290         }                                                                 \
1291     } else {                                                              \
1292         dfp.t = dfp.b;                                                    \
1293         if (unlikely(decNumberIsSpecial(&dfp.t))) {                       \
1294             dfp.t.bits &= ~DECSPECIAL;                                    \
1295         }                                                                 \
1296         dfp.t.exponent = exp - bias;                                      \
1297         dfp_finalize_decimal##size(&dfp);                                 \
1298     }                                                                     \
1299     set_dfp##size(t, &dfp.vt);                                            \
1300 }
1301 
1302 DFP_HELPER_IEX(DIEX, 64)
1303 DFP_HELPER_IEX(DIEXQ, 128)
1304 
1305 static void dfp_clear_lmd_from_g5msb(uint64_t *t)
1306 {
1307 
1308     /* The most significant 5 bits of the PowerPC DFP format combine bits  */
1309     /* from the left-most decimal digit (LMD) and the biased exponent.     */
1310     /* This  routine clears the LMD bits while preserving the exponent     */
1311     /*  bits.  See "Figure 80: Encoding of bits 0:4 of the G field for     */
1312     /*  Finite Numbers" in the Power ISA for additional details.           */
1313 
1314     uint64_t g5msb = (*t >> 58) & 0x1F;
1315 
1316     if ((g5msb >> 3) < 3) { /* LMD in [0-7] ? */
1317        *t &= ~(7ULL << 58);
1318     } else {
1319        switch (g5msb & 7) {
1320        case 0:
1321        case 1:
1322            g5msb = 0;
1323            break;
1324        case 2:
1325        case 3:
1326            g5msb = 0x8;
1327            break;
1328        case 4:
1329        case 5:
1330            g5msb = 0x10;
1331            break;
1332        case 6:
1333            g5msb = 0x1E;
1334            break;
1335        case 7:
1336            g5msb = 0x1F;
1337            break;
1338        }
1339 
1340         *t &= ~(0x1fULL << 58);
1341         *t |= (g5msb << 58);
1342     }
1343 }
1344 
1345 #define DFP_HELPER_SHIFT(op, size, shift_left)                      \
1346 void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *a,    \
1347                  uint32_t sh)                                       \
1348 {                                                                   \
1349     struct PPC_DFP dfp;                                             \
1350     unsigned max_digits = ((size) == 64) ? 16 : 34;                 \
1351                                                                     \
1352     dfp_prepare_decimal##size(&dfp, a, 0, env);                     \
1353                                                                     \
1354     if (sh <= max_digits) {                                         \
1355                                                                     \
1356         decNumber shd;                                              \
1357         unsigned special = dfp.a.bits & DECSPECIAL;                 \
1358                                                                     \
1359         if (shift_left) {                                           \
1360             decNumberFromUInt32(&shd, sh);                          \
1361         } else {                                                    \
1362             decNumberFromInt32(&shd, -((int32_t)sh));               \
1363         }                                                           \
1364                                                                     \
1365         dfp.a.bits &= ~DECSPECIAL;                                  \
1366         decNumberShift(&dfp.t, &dfp.a, &shd, &dfp.context);         \
1367                                                                     \
1368         dfp.t.bits |= special;                                      \
1369         if (special && (dfp.t.digits >= max_digits)) {              \
1370             dfp.t.digits = max_digits - 1;                          \
1371         }                                                           \
1372                                                                     \
1373         dfp_finalize_decimal##size(&dfp);                           \
1374     } else {                                                        \
1375         if ((size) == 64) {                                         \
1376             dfp.vt.VsrD(1) = dfp.va.VsrD(1) &                       \
1377                              0xFFFC000000000000ULL;                 \
1378             dfp_clear_lmd_from_g5msb(&dfp.vt.VsrD(1));              \
1379         } else {                                                    \
1380             dfp.vt.VsrD(0) = dfp.va.VsrD(0) &                       \
1381                              0xFFFFC00000000000ULL;                 \
1382             dfp_clear_lmd_from_g5msb(&dfp.vt.VsrD(0));              \
1383             dfp.vt.VsrD(1) = 0;                                     \
1384         }                                                           \
1385     }                                                               \
1386                                                                     \
1387     set_dfp##size(t, &dfp.vt);                                      \
1388 }
1389 
1390 DFP_HELPER_SHIFT(DSCLI, 64, 1)
1391 DFP_HELPER_SHIFT(DSCLIQ, 128, 1)
1392 DFP_HELPER_SHIFT(DSCRI, 64, 0)
1393 DFP_HELPER_SHIFT(DSCRIQ, 128, 0)
1394 
1395 target_ulong helper_CDTBCD(target_ulong s)
1396 {
1397     uint64_t res = 0;
1398     uint32_t dec32, declets;
1399     uint8_t bcd[6];
1400     int i, w, sh;
1401     decNumber a;
1402 
1403     for (w = 1; w >= 0; w--) {
1404         res <<= 32;
1405         declets = extract64(s, 32 * w, 20);
1406         if (declets) {
1407             /* decimal32 with zero exponent and word "w" declets */
1408             dec32 = (0x225ULL << 20) | declets;
1409             decimal32ToNumber((decimal32 *)&dec32, &a);
1410             decNumberGetBCD(&a, bcd);
1411             for (i = 0; i < a.digits; i++) {
1412                 sh = 4 * (a.digits - 1 - i);
1413                 res |= (uint64_t)bcd[i] << sh;
1414             }
1415         }
1416     }
1417 
1418     return res;
1419 }
1420 
1421 target_ulong helper_CBCDTD(target_ulong s)
1422 {
1423     uint64_t res = 0;
1424     uint32_t dec32;
1425     uint8_t bcd[6];
1426     int w, i, offs;
1427     decNumber a;
1428     decContext context;
1429 
1430     decContextDefault(&context, DEC_INIT_DECIMAL32);
1431 
1432     for (w = 1; w >= 0; w--) {
1433         res <<= 32;
1434         decNumberZero(&a);
1435         /* Extract each BCD field of word "w" */
1436         for (i = 5; i >= 0; i--) {
1437             offs = 4 * (5 - i) + 32 * w;
1438             bcd[i] = extract64(s, offs, 4);
1439             if (bcd[i] > 9) {
1440                 /*
1441                  * If the field value is greater than 9, the results are
1442                  * undefined. We could use a fixed value like 0 or 9, but
1443                  * an and with 9 seems to better match the hardware behavior.
1444                  */
1445                 bcd[i] &= 9;
1446             }
1447         }
1448 
1449         /* Create a decNumber with the BCD values and convert to decimal32 */
1450         decNumberSetBCD(&a, bcd, 6);
1451         decimal32FromNumber((decimal32 *)&dec32, &a, &context);
1452 
1453         /* Extract the two declets from the decimal32 value */
1454         res |= dec32 & 0xfffff;
1455     }
1456 
1457     return res;
1458 }
1459