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[mirror_qemu.git] / target-ppc / dfp_helper.c
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7b0c0d66
TM		 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 "cpu.h"
21#include "exec/helper-proto.h"
22
23#define DECNUMDIGITS 34
24#include "libdecnumber/decContext.h"
25#include "libdecnumber/decNumber.h"
26#include "libdecnumber/dpd/decimal32.h"
27#include "libdecnumber/dpd/decimal64.h"
28#include "libdecnumber/dpd/decimal128.h"
29
30#if defined(HOST_WORDS_BIGENDIAN)
31#define HI_IDX 0
32#define LO_IDX 1
33#else
34#define HI_IDX 1
35#define LO_IDX 0
36#endif
37
38struct PPC_DFP {
39 CPUPPCState *env;
40 uint64_t t64[2], a64[2], b64[2];
41 decNumber t, a, b;
42 decContext context;
43 uint8_t crbf;
44};
45
46static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
47{
48 enum rounding rnd;
49
50 switch ((fpscr >> 32) & 0x7) {
51 case 0:
52 rnd = DEC_ROUND_HALF_EVEN;
53 break;
54 case 1:
55 rnd = DEC_ROUND_DOWN;
56 break;
57 case 2:
58 rnd = DEC_ROUND_CEILING;
59 break;
60 case 3:
61 rnd = DEC_ROUND_FLOOR;
62 break;
63 case 4:
64 rnd = DEC_ROUND_HALF_UP;
65 break;
66 case 5:
67 rnd = DEC_ROUND_HALF_DOWN;
68 break;
69 case 6:
70 rnd = DEC_ROUND_UP;
71 break;
72 case 7:
73 rnd = DEC_ROUND_05UP;
74 break;
75 default:
76 g_assert_not_reached();
77 }
78
79 decContextSetRounding(context, rnd);
80}
81
5826ebe2
TM		 82static void dfp_set_round_mode_from_immediate(uint8_t r, uint8_t rmc,
83 struct PPC_DFP *dfp)
84{
85 enum rounding rnd;
86 if (r == 0) {
87 switch (rmc & 3) {
88 case 0:
89 rnd = DEC_ROUND_HALF_EVEN;
90 break;
91 case 1:
92 rnd = DEC_ROUND_DOWN;
93 break;
94 case 2:
95 rnd = DEC_ROUND_HALF_UP;
96 break;
97 case 3: /* use FPSCR rounding mode */
98 return;
99 default:
100 assert(0); /* cannot get here */
101 }
102 } else { /* r == 1 */
103 switch (rmc & 3) {
104 case 0:
105 rnd = DEC_ROUND_CEILING;
106 break;
107 case 1:
108 rnd = DEC_ROUND_FLOOR;
109 break;
110 case 2:
111 rnd = DEC_ROUND_UP;
112 break;
113 case 3:
114 rnd = DEC_ROUND_HALF_DOWN;
115 break;
116 default:
117 assert(0); /* cannot get here */
118 }
119 }
120 decContextSetRounding(&dfp->context, rnd);
121}
122
7b0c0d66
TM		 123static void dfp_prepare_decimal64(struct PPC_DFP *dfp, uint64_t *a,
124 uint64_t *b, CPUPPCState *env)
125{
126 decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
127 dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
128 dfp->env = env;
129
130 if (a) {
131 dfp->a64[0] = *a;
132 decimal64ToNumber((decimal64 *)dfp->a64, &dfp->a);
133 } else {
134 dfp->a64[0] = 0;
135 decNumberZero(&dfp->a);
136 }
137
138 if (b) {
139 dfp->b64[0] = *b;
140 decimal64ToNumber((decimal64 *)dfp->b64, &dfp->b);
141 } else {
142 dfp->b64[0] = 0;
143 decNumberZero(&dfp->b);
144 }
145}
146
7b0c0d66
TM		 147static void dfp_prepare_decimal128(struct PPC_DFP *dfp, uint64_t *a,
148 uint64_t *b, CPUPPCState *env)
149{
150 decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
151 dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
152 dfp->env = env;
153
154 if (a) {
155 dfp->a64[0] = a[HI_IDX];
156 dfp->a64[1] = a[LO_IDX];
157 decimal128ToNumber((decimal128 *)dfp->a64, &dfp->a);
158 } else {
159 dfp->a64[0] = dfp->a64[1] = 0;
160 decNumberZero(&dfp->a);
161 }
162
163 if (b) {
164 dfp->b64[0] = b[HI_IDX];
165 dfp->b64[1] = b[LO_IDX];
166 decimal128ToNumber((decimal128 *)dfp->b64, &dfp->b);
167 } else {
168 dfp->b64[0] = dfp->b64[1] = 0;
169 decNumberZero(&dfp->b);
170 }
171}
27722744 172
27722744
TM		 173static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
174 uint64_t enabled)
175{
176 dfp->env->fpscr |= (flag | FP_FX);
177 if (dfp->env->fpscr & enabled) {
178 dfp->env->fpscr |= FP_FEX;
179 }
180}
a9d7ba03
TM		 181
182static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
183 decContext *context)
184{
185 uint64_t fprf = 0;
186
187 /* construct FPRF */
188 switch (decNumberClass(&dfp->t, context)) {
189 case DEC_CLASS_SNAN:
190 fprf = 0x01;
191 break;
192 case DEC_CLASS_QNAN:
193 fprf = 0x11;
194 break;
195 case DEC_CLASS_NEG_INF:
196 fprf = 0x09;
197 break;
198 case DEC_CLASS_NEG_NORMAL:
199 fprf = 0x08;
200 break;
201 case DEC_CLASS_NEG_SUBNORMAL:
202 fprf = 0x18;
203 break;
204 case DEC_CLASS_NEG_ZERO:
205 fprf = 0x12;
206 break;
207 case DEC_CLASS_POS_ZERO:
208 fprf = 0x02;
209 break;
210 case DEC_CLASS_POS_SUBNORMAL:
211 fprf = 0x14;
212 break;
213 case DEC_CLASS_POS_NORMAL:
214 fprf = 0x04;
215 break;
216 case DEC_CLASS_POS_INF:
217 fprf = 0x05;
218 break;
219 default:
220 assert(0); /* should never get here */
221 }
222 dfp->env->fpscr &= ~(0x1F << 12);
223 dfp->env->fpscr |= (fprf << 12);
224}
225
226static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
227{
228 dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
229}
230
ca603eb4
TM		 231static void dfp_set_FPRF_from_FRT_short(struct PPC_DFP *dfp)
232{
233 decContext shortContext;
234 decContextDefault(&shortContext, DEC_INIT_DECIMAL32);
235 dfp_set_FPRF_from_FRT_with_context(dfp, &shortContext);
236}
237
238static void dfp_set_FPRF_from_FRT_long(struct PPC_DFP *dfp)
239{
240 decContext longContext;
241 decContextDefault(&longContext, DEC_INIT_DECIMAL64);
242 dfp_set_FPRF_from_FRT_with_context(dfp, &longContext);
243}
244
a9d7ba03
TM		 245static void dfp_check_for_OX(struct PPC_DFP *dfp)
246{
247 if (dfp->context.status & DEC_Overflow) {
248 dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
249 }
250}
251
252static void dfp_check_for_UX(struct PPC_DFP *dfp)
253{
254 if (dfp->context.status & DEC_Underflow) {
255 dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
256 }
257}
258
259static void dfp_check_for_XX(struct PPC_DFP *dfp)
260{
261 if (dfp->context.status & DEC_Inexact) {
262 dfp_set_FPSCR_flag(dfp, FP_XX | FP_FI, FP_XE);
263 }
264}
265
9024ff40
TM		 266static void dfp_check_for_ZX(struct PPC_DFP *dfp)
267{
268 if (dfp->context.status & DEC_Division_by_zero) {
269 dfp_set_FPSCR_flag(dfp, FP_ZX, FP_ZE);
270 }
271}
272
a9d7ba03
TM		 273static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
274{
275 if (dfp->context.status & DEC_Invalid_operation) {
276 if (decNumberIsSNaN(&dfp->a) || decNumberIsSNaN(&dfp->b)) {
277 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
278 }
279 }
280}
281
290d9ee5
TM		 282static void dfp_check_for_VXSNAN_and_convert_to_QNaN(struct PPC_DFP *dfp)
283{
284 if (decNumberIsSNaN(&dfp->t)) {
285 dfp->t.bits &= ~DECSNAN;
286 dfp->t.bits |= DECNAN;
287 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
288 }
289}
290
a9d7ba03
TM		 291static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
292{
293 if (dfp->context.status & DEC_Invalid_operation) {
294 if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
295 int same = decNumberClass(&dfp->a, &dfp->context) ==
296 decNumberClass(&dfp->b, &dfp->context);
297 if ((same && testForSameSign) || (!same && !testForSameSign)) {
298 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXISI, FP_VE);
299 }
300 }
301 }
302}
303
304static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
305{
306 dfp_check_for_VXISI(dfp, 0);
307}
308
2128f8a5
TM		 309static void dfp_check_for_VXISI_subtract(struct PPC_DFP *dfp)
310{
311 dfp_check_for_VXISI(dfp, 1);
312}
313
8de6a1cc
TM		 314static void dfp_check_for_VXIMZ(struct PPC_DFP *dfp)
315{
316 if (dfp->context.status & DEC_Invalid_operation) {
317 if ((decNumberIsInfinite(&dfp->a) && decNumberIsZero(&dfp->b)) ||
318 (decNumberIsInfinite(&dfp->b) && decNumberIsZero(&dfp->a))) {
319 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIMZ, FP_VE);
320 }
321 }
322}
323
9024ff40
TM		 324static void dfp_check_for_VXZDZ(struct PPC_DFP *dfp)
325{
326 if (dfp->context.status & DEC_Division_undefined) {
327 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXZDZ, FP_VE);
328 }
329}
330
331static void dfp_check_for_VXIDI(struct PPC_DFP *dfp)
332{
333 if (dfp->context.status & DEC_Invalid_operation) {
334 if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
335 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIDI, FP_VE);
336 }
337 }
338}
339
5833505b
TM		 340static void dfp_check_for_VXVC(struct PPC_DFP *dfp)
341{
342 if (decNumberIsNaN(&dfp->a) || decNumberIsNaN(&dfp->b)) {
343 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXVC, FP_VE);
344 }
345}
346
5826ebe2
TM		 347static void dfp_check_for_VXCVI(struct PPC_DFP *dfp)
348{
349 if ((dfp->context.status & DEC_Invalid_operation) &&
350 (!decNumberIsSNaN(&dfp->a)) &&
351 (!decNumberIsSNaN(&dfp->b))) {
352 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
353 }
354}
355
5833505b
TM		 356static void dfp_set_CRBF_from_T(struct PPC_DFP *dfp)
357{
358 if (decNumberIsNaN(&dfp->t)) {
359 dfp->crbf = 1;
360 } else if (decNumberIsZero(&dfp->t)) {
361 dfp->crbf = 2;
362 } else if (decNumberIsNegative(&dfp->t)) {
363 dfp->crbf = 8;
364 } else {
365 dfp->crbf = 4;
366 }
367}
368
369static void dfp_set_FPCC_from_CRBF(struct PPC_DFP *dfp)
370{
371 dfp->env->fpscr &= ~(0xF << 12);
372 dfp->env->fpscr |= (dfp->crbf << 12);
373}
374
5826ebe2
TM		 375static inline void dfp_makeQNaN(decNumber *dn)
376{
377 dn->bits &= ~DECSPECIAL;
378 dn->bits |= DECNAN;
379}
380
512918aa
TM		 381static inline int dfp_get_digit(decNumber *dn, int n)
382{
383 assert(DECDPUN == 3);
384 int unit = n / DECDPUN;
385 int dig = n % DECDPUN;
386 switch (dig) {
387 case 0:
388 return dn->lsu[unit] % 10;
389 case 1:
390 return (dn->lsu[unit] / 10) % 10;
391 case 2:
392 return dn->lsu[unit] / 100;
512918aa 393 }
0211b5cf 394 g_assert_not_reached();
512918aa
TM		 395}
396
a9d7ba03
TM		 397#define DFP_HELPER_TAB(op, dnop, postprocs, size) \
398void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b) \
399{ \
400 struct PPC_DFP dfp; \
401 dfp_prepare_decimal##size(&dfp, a, b, env); \
402 dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context); \
403 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
404 postprocs(&dfp); \
405 if (size == 64) { \
406 t[0] = dfp.t64[0]; \
407 } else if (size == 128) { \
408 t[0] = dfp.t64[HI_IDX]; \
409 t[1] = dfp.t64[LO_IDX]; \
410 } \
411}
412
413static void ADD_PPs(struct PPC_DFP *dfp)
414{
415 dfp_set_FPRF_from_FRT(dfp);
416 dfp_check_for_OX(dfp);
417 dfp_check_for_UX(dfp);
418 dfp_check_for_XX(dfp);
419 dfp_check_for_VXSNAN(dfp);
420 dfp_check_for_VXISI_add(dfp);
421}
422
423DFP_HELPER_TAB(dadd, decNumberAdd, ADD_PPs, 64)
424DFP_HELPER_TAB(daddq, decNumberAdd, ADD_PPs, 128)
2128f8a5
TM		 425
426static void SUB_PPs(struct PPC_DFP *dfp)
427{
428 dfp_set_FPRF_from_FRT(dfp);
429 dfp_check_for_OX(dfp);
430 dfp_check_for_UX(dfp);
431 dfp_check_for_XX(dfp);
432 dfp_check_for_VXSNAN(dfp);
433 dfp_check_for_VXISI_subtract(dfp);
434}
435
436DFP_HELPER_TAB(dsub, decNumberSubtract, SUB_PPs, 64)
437DFP_HELPER_TAB(dsubq, decNumberSubtract, SUB_PPs, 128)
8de6a1cc
TM		 438
439static void MUL_PPs(struct PPC_DFP *dfp)
440{
441 dfp_set_FPRF_from_FRT(dfp);
442 dfp_check_for_OX(dfp);
443 dfp_check_for_UX(dfp);
444 dfp_check_for_XX(dfp);
445 dfp_check_for_VXSNAN(dfp);
446 dfp_check_for_VXIMZ(dfp);
447}
448
449DFP_HELPER_TAB(dmul, decNumberMultiply, MUL_PPs, 64)
450DFP_HELPER_TAB(dmulq, decNumberMultiply, MUL_PPs, 128)
9024ff40
TM		 451
452static void DIV_PPs(struct PPC_DFP *dfp)
453{
454 dfp_set_FPRF_from_FRT(dfp);
455 dfp_check_for_OX(dfp);
456 dfp_check_for_UX(dfp);
457 dfp_check_for_ZX(dfp);
458 dfp_check_for_XX(dfp);
459 dfp_check_for_VXSNAN(dfp);
460 dfp_check_for_VXZDZ(dfp);
461 dfp_check_for_VXIDI(dfp);
462}
463
464DFP_HELPER_TAB(ddiv, decNumberDivide, DIV_PPs, 64)
465DFP_HELPER_TAB(ddivq, decNumberDivide, DIV_PPs, 128)
5833505b
TM		 466
467#define DFP_HELPER_BF_AB(op, dnop, postprocs, size) \
468uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b) \
469{ \
470 struct PPC_DFP dfp; \
471 dfp_prepare_decimal##size(&dfp, a, b, env); \
472 dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context); \
473 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
474 postprocs(&dfp); \
475 return dfp.crbf; \
476}
477
478static void CMPU_PPs(struct PPC_DFP *dfp)
479{
480 dfp_set_CRBF_from_T(dfp);
481 dfp_set_FPCC_from_CRBF(dfp);
482 dfp_check_for_VXSNAN(dfp);
483}
484
485DFP_HELPER_BF_AB(dcmpu, decNumberCompare, CMPU_PPs, 64)
486DFP_HELPER_BF_AB(dcmpuq, decNumberCompare, CMPU_PPs, 128)
487
488static void CMPO_PPs(struct PPC_DFP *dfp)
489{
490 dfp_set_CRBF_from_T(dfp);
491 dfp_set_FPCC_from_CRBF(dfp);
492 dfp_check_for_VXSNAN(dfp);
493 dfp_check_for_VXVC(dfp);
494}
495
496DFP_HELPER_BF_AB(dcmpo, decNumberCompare, CMPO_PPs, 64)
497DFP_HELPER_BF_AB(dcmpoq, decNumberCompare, CMPO_PPs, 128)
e601c1ee
TM		 498
499#define DFP_HELPER_TSTDC(op, size) \
500uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm) \
501{ \
502 struct PPC_DFP dfp; \
503 int match = 0; \
504 \
505 dfp_prepare_decimal##size(&dfp, a, 0, env); \
506 \
507 match |= (dcm & 0x20) && decNumberIsZero(&dfp.a); \
508 match |= (dcm & 0x10) && decNumberIsSubnormal(&dfp.a, &dfp.context); \
509 match |= (dcm & 0x08) && decNumberIsNormal(&dfp.a, &dfp.context); \
510 match |= (dcm & 0x04) && decNumberIsInfinite(&dfp.a); \
511 match |= (dcm & 0x02) && decNumberIsQNaN(&dfp.a); \
512 match |= (dcm & 0x01) && decNumberIsSNaN(&dfp.a); \
513 \
514 if (decNumberIsNegative(&dfp.a)) { \
515 dfp.crbf = match ? 0xA : 0x8; \
516 } else { \
517 dfp.crbf = match ? 0x2 : 0x0; \
518 } \
519 \
520 dfp_set_FPCC_from_CRBF(&dfp); \
521 return dfp.crbf; \
522}
523
524DFP_HELPER_TSTDC(dtstdc, 64)
525DFP_HELPER_TSTDC(dtstdcq, 128)
1bf9c0e1
TM		 526
527#define DFP_HELPER_TSTDG(op, size) \
528uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm) \
529{ \
530 struct PPC_DFP dfp; \
531 int minexp, maxexp, nzero_digits, nzero_idx, is_negative, is_zero, \
532 is_extreme_exp, is_subnormal, is_normal, leftmost_is_nonzero, \
533 match; \
534 \
535 dfp_prepare_decimal##size(&dfp, a, 0, env); \
536 \
537 if ((size) == 64) { \
538 minexp = -398; \
539 maxexp = 369; \
540 nzero_digits = 16; \
541 nzero_idx = 5; \
542 } else if ((size) == 128) { \
543 minexp = -6176; \
544 maxexp = 6111; \
545 nzero_digits = 34; \
546 nzero_idx = 11; \
547 } \
548 \
549 is_negative = decNumberIsNegative(&dfp.a); \
550 is_zero = decNumberIsZero(&dfp.a); \
551 is_extreme_exp = (dfp.a.exponent == maxexp) || \
552 (dfp.a.exponent == minexp); \
553 is_subnormal = decNumberIsSubnormal(&dfp.a, &dfp.context); \
554 is_normal = decNumberIsNormal(&dfp.a, &dfp.context); \
555 leftmost_is_nonzero = (dfp.a.digits == nzero_digits) && \
556 (dfp.a.lsu[nzero_idx] != 0); \
557 match = 0; \
558 \
559 match |= (dcm & 0x20) && is_zero && !is_extreme_exp; \
560 match |= (dcm & 0x10) && is_zero && is_extreme_exp; \
561 match |= (dcm & 0x08) && \
562 (is_subnormal || (is_normal && is_extreme_exp)); \
563 match |= (dcm & 0x04) && is_normal && !is_extreme_exp && \
564 !leftmost_is_nonzero; \
565 match |= (dcm & 0x02) && is_normal && !is_extreme_exp && \
566 leftmost_is_nonzero; \
567 match |= (dcm & 0x01) && decNumberIsSpecial(&dfp.a); \
568 \
569 if (is_negative) { \
570 dfp.crbf = match ? 0xA : 0x8; \
571 } else { \
572 dfp.crbf = match ? 0x2 : 0x0; \
573 } \
574 \
575 dfp_set_FPCC_from_CRBF(&dfp); \
576 return dfp.crbf; \
577}
578
579DFP_HELPER_TSTDG(dtstdg, 64)
580DFP_HELPER_TSTDG(dtstdgq, 128)
f3d2b0bc
TM		 581
582#define DFP_HELPER_TSTEX(op, size) \
583uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b) \
584{ \
585 struct PPC_DFP dfp; \
586 int expa, expb, a_is_special, b_is_special; \
587 \
588 dfp_prepare_decimal##size(&dfp, a, b, env); \
589 \
590 expa = dfp.a.exponent; \
591 expb = dfp.b.exponent; \
592 a_is_special = decNumberIsSpecial(&dfp.a); \
593 b_is_special = decNumberIsSpecial(&dfp.b); \
594 \
595 if (a_is_special || b_is_special) { \
596 int atype = a_is_special ? (decNumberIsNaN(&dfp.a) ? 4 : 2) : 1; \
597 int btype = b_is_special ? (decNumberIsNaN(&dfp.b) ? 4 : 2) : 1; \
598 dfp.crbf = (atype ^ btype) ? 0x1 : 0x2; \
599 } else if (expa < expb) { \
600 dfp.crbf = 0x8; \
601 } else if (expa > expb) { \
602 dfp.crbf = 0x4; \
603 } else { \
604 dfp.crbf = 0x2; \
605 } \
606 \
607 dfp_set_FPCC_from_CRBF(&dfp); \
608 return dfp.crbf; \
609}
610
611DFP_HELPER_TSTEX(dtstex, 64)
612DFP_HELPER_TSTEX(dtstexq, 128)
f6022a76
TM		 613
614#define DFP_HELPER_TSTSF(op, size) \
615uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b) \
616{ \
617 struct PPC_DFP dfp; \
618 unsigned k; \
619 \
620 dfp_prepare_decimal##size(&dfp, 0, b, env); \
621 \
622 k = *a & 0x3F; \
623 \
624 if (unlikely(decNumberIsSpecial(&dfp.b))) { \
625 dfp.crbf = 1; \
626 } else if (k == 0) { \
627 dfp.crbf = 4; \
628 } else if (unlikely(decNumberIsZero(&dfp.b))) { \
629 /* Zero has no sig digits */ \
630 dfp.crbf = 4; \
631 } else { \
632 unsigned nsd = dfp.b.digits; \
633 if (k < nsd) { \
634 dfp.crbf = 8; \
635 } else if (k > nsd) { \
636 dfp.crbf = 4; \
637 } else { \
638 dfp.crbf = 2; \
639 } \
640 } \
641 \
642 dfp_set_FPCC_from_CRBF(&dfp); \
643 return dfp.crbf; \
644}
645
646DFP_HELPER_TSTSF(dtstsf, 64)
647DFP_HELPER_TSTSF(dtstsfq, 128)
5826ebe2
TM		 648
649static void QUA_PPs(struct PPC_DFP *dfp)
650{
651 dfp_set_FPRF_from_FRT(dfp);
652 dfp_check_for_XX(dfp);
653 dfp_check_for_VXSNAN(dfp);
654 dfp_check_for_VXCVI(dfp);
655}
656
657static void dfp_quantize(uint8_t rmc, struct PPC_DFP *dfp)
658{
659 dfp_set_round_mode_from_immediate(0, rmc, dfp);
660 decNumberQuantize(&dfp->t, &dfp->b, &dfp->a, &dfp->context);
661 if (decNumberIsSNaN(&dfp->a)) {
662 dfp->t = dfp->a;
663 dfp_makeQNaN(&dfp->t);
664 } else if (decNumberIsSNaN(&dfp->b)) {
665 dfp->t = dfp->b;
666 dfp_makeQNaN(&dfp->t);
667 } else if (decNumberIsQNaN(&dfp->a)) {
668 dfp->t = dfp->a;
669 } else if (decNumberIsQNaN(&dfp->b)) {
670 dfp->t = dfp->b;
671 }
672}
673
674#define DFP_HELPER_QUAI(op, size) \
675void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, \
676 uint32_t te, uint32_t rmc) \
677{ \
678 struct PPC_DFP dfp; \
679 \
680 dfp_prepare_decimal##size(&dfp, 0, b, env); \
681 \
682 decNumberFromUInt32(&dfp.a, 1); \
683 dfp.a.exponent = (int32_t)((int8_t)(te << 3) >> 3); \
684 \
685 dfp_quantize(rmc, &dfp); \
686 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
687 &dfp.context); \
688 QUA_PPs(&dfp); \
689 \
690 if (size == 64) { \
691 t[0] = dfp.t64[0]; \
692 } else if (size == 128) { \
693 t[0] = dfp.t64[HI_IDX]; \
694 t[1] = dfp.t64[LO_IDX]; \
695 } \
696}
697
698DFP_HELPER_QUAI(dquai, 64)
699DFP_HELPER_QUAI(dquaiq, 128)
700
701#define DFP_HELPER_QUA(op, size) \
702void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, \
703 uint64_t *b, uint32_t rmc) \
704{ \
705 struct PPC_DFP dfp; \
706 \
707 dfp_prepare_decimal##size(&dfp, a, b, env); \
708 \
709 dfp_quantize(rmc, &dfp); \
710 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
711 &dfp.context); \
712 QUA_PPs(&dfp); \
713 \
714 if (size == 64) { \
715 t[0] = dfp.t64[0]; \
716 } else if (size == 128) { \
717 t[0] = dfp.t64[HI_IDX]; \
718 t[1] = dfp.t64[LO_IDX]; \
719 } \
720}
721
722DFP_HELPER_QUA(dqua, 64)
723DFP_HELPER_QUA(dquaq, 128)
512918aa
TM		 724
725static void _dfp_reround(uint8_t rmc, int32_t ref_sig, int32_t xmax,
726 struct PPC_DFP *dfp)
727{
728 int msd_orig, msd_rslt;
729
730 if (unlikely((ref_sig == 0) || (dfp->b.digits <= ref_sig))) {
731 dfp->t = dfp->b;
732 if (decNumberIsSNaN(&dfp->b)) {
733 dfp_makeQNaN(&dfp->t);
734 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FPSCR_VE);
735 }
736 return;
737 }
738
739 /* Reround is equivalent to quantizing b with 1**E(n) where */
740 /* n = exp(b) + numDigits(b) - reference_significance. */
741
742 decNumberFromUInt32(&dfp->a, 1);
743 dfp->a.exponent = dfp->b.exponent + dfp->b.digits - ref_sig;
744
745 if (unlikely(dfp->a.exponent > xmax)) {
746 dfp->t.digits = 0;
747 dfp->t.bits &= ~DECNEG;
748 dfp_makeQNaN(&dfp->t);
749 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FPSCR_VE);
750 return;
751 }
752
753 dfp_quantize(rmc, dfp);
754
755 msd_orig = dfp_get_digit(&dfp->b, dfp->b.digits-1);
756 msd_rslt = dfp_get_digit(&dfp->t, dfp->t.digits-1);
757
758 /* If the quantization resulted in rounding up to the next magnitude, */
759 /* then we need to shift the significand and adjust the exponent. */
760
761 if (unlikely((msd_orig == 9) && (msd_rslt == 1))) {
762
763 decNumber negone;
764
765 decNumberFromInt32(&negone, -1);
766 decNumberShift(&dfp->t, &dfp->t, &negone, &dfp->context);
767 dfp->t.exponent++;
768
769 if (unlikely(dfp->t.exponent > xmax)) {
770 dfp_makeQNaN(&dfp->t);
771 dfp->t.digits = 0;
772 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
773 /* Inhibit XX in this case */
774 decContextClearStatus(&dfp->context, DEC_Inexact);
775 }
776 }
777}
778
779#define DFP_HELPER_RRND(op, size) \
780void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, \
781 uint64_t *b, uint32_t rmc) \
782{ \
783 struct PPC_DFP dfp; \
784 int32_t ref_sig = *a & 0x3F; \
785 int32_t xmax = ((size) == 64) ? 369 : 6111; \
786 \
787 dfp_prepare_decimal##size(&dfp, 0, b, env); \
788 \
789 _dfp_reround(rmc, ref_sig, xmax, &dfp); \
790 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
791 &dfp.context); \
792 QUA_PPs(&dfp); \
793 \
794 if (size == 64) { \
795 t[0] = dfp.t64[0]; \
796 } else if (size == 128) { \
797 t[0] = dfp.t64[HI_IDX]; \
798 t[1] = dfp.t64[LO_IDX]; \
799 } \
800}
801
802DFP_HELPER_RRND(drrnd, 64)
803DFP_HELPER_RRND(drrndq, 128)
97c0d930
TM		 804
805#define DFP_HELPER_RINT(op, postprocs, size) \
806void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, \
807 uint32_t r, uint32_t rmc) \
808{ \
809 struct PPC_DFP dfp; \
810 \
811 dfp_prepare_decimal##size(&dfp, 0, b, env); \
812 \
813 dfp_set_round_mode_from_immediate(r, rmc, &dfp); \
814 decNumberToIntegralExact(&dfp.t, &dfp.b, &dfp.context); \
815 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
816 postprocs(&dfp); \
817 \
818 if (size == 64) { \
819 t[0] = dfp.t64[0]; \
820 } else if (size == 128) { \
821 t[0] = dfp.t64[HI_IDX]; \
822 t[1] = dfp.t64[LO_IDX]; \
823 } \
824}
825
826static void RINTX_PPs(struct PPC_DFP *dfp)
827{
828 dfp_set_FPRF_from_FRT(dfp);
829 dfp_check_for_XX(dfp);
830 dfp_check_for_VXSNAN(dfp);
831}
832
833DFP_HELPER_RINT(drintx, RINTX_PPs, 64)
834DFP_HELPER_RINT(drintxq, RINTX_PPs, 128)
835
836static void RINTN_PPs(struct PPC_DFP *dfp)
837{
838 dfp_set_FPRF_from_FRT(dfp);
839 dfp_check_for_VXSNAN(dfp);
840}
841
842DFP_HELPER_RINT(drintn, RINTN_PPs, 64)
843DFP_HELPER_RINT(drintnq, RINTN_PPs, 128)
290d9ee5
TM		 844
845void helper_dctdp(CPUPPCState *env, uint64_t *t, uint64_t *b)
846{
847 struct PPC_DFP dfp;
848 uint32_t b_short = *b;
849 dfp_prepare_decimal64(&dfp, 0, 0, env);
850 decimal32ToNumber((decimal32 *)&b_short, &dfp.t);
851 decimal64FromNumber((decimal64 *)t, &dfp.t, &dfp.context);
852 dfp_set_FPRF_from_FRT(&dfp);
853}
854
855void helper_dctqpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
856{
857 struct PPC_DFP dfp;
858 dfp_prepare_decimal128(&dfp, 0, 0, env);
859 decimal64ToNumber((decimal64 *)b, &dfp.t);
860
861 dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
862 dfp_set_FPRF_from_FRT(&dfp);
863
864 decimal128FromNumber((decimal128 *)&dfp.t64, &dfp.t, &dfp.context);
865 t[0] = dfp.t64[HI_IDX];
866 t[1] = dfp.t64[LO_IDX];
867}
ca603eb4
TM		 868
869void helper_drsp(CPUPPCState *env, uint64_t *t, uint64_t *b)
870{
871 struct PPC_DFP dfp;
872 uint32_t t_short = 0;
873 dfp_prepare_decimal64(&dfp, 0, b, env);
874 decimal32FromNumber((decimal32 *)&t_short, &dfp.b, &dfp.context);
875 decimal32ToNumber((decimal32 *)&t_short, &dfp.t);
876
877 dfp_set_FPRF_from_FRT_short(&dfp);
878 dfp_check_for_OX(&dfp);
879 dfp_check_for_UX(&dfp);
880 dfp_check_for_XX(&dfp);
881
882 *t = t_short;
883}
884
885void helper_drdpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
886{
887 struct PPC_DFP dfp;
888 dfp_prepare_decimal128(&dfp, 0, b, env);
889 decimal64FromNumber((decimal64 *)&dfp.t64, &dfp.b, &dfp.context);
890 decimal64ToNumber((decimal64 *)&dfp.t64, &dfp.t);
891
892 dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
893 dfp_set_FPRF_from_FRT_long(&dfp);
894 dfp_check_for_OX(&dfp);
895 dfp_check_for_UX(&dfp);
896 dfp_check_for_XX(&dfp);
897
898 decimal64FromNumber((decimal64 *)dfp.t64, &dfp.t, &dfp.context);
899 t[0] = dfp.t64[0];
900 t[1] = 0;
901}
f1214193
TM		 902
903#define DFP_HELPER_CFFIX(op, size) \
904void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b) \
905{ \
906 struct PPC_DFP dfp; \
907 dfp_prepare_decimal##size(&dfp, 0, b, env); \
908 decNumberFromInt64(&dfp.t, (int64_t)(*b)); \
909 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
910 CFFIX_PPs(&dfp); \
911 \
912 if (size == 64) { \
913 t[0] = dfp.t64[0]; \
914 } else if (size == 128) { \
915 t[0] = dfp.t64[HI_IDX]; \
916 t[1] = dfp.t64[LO_IDX]; \
917 } \
918}
919
920static void CFFIX_PPs(struct PPC_DFP *dfp)
921{
922 dfp_set_FPRF_from_FRT(dfp);
923 dfp_check_for_XX(dfp);
924}
925
926DFP_HELPER_CFFIX(dcffix, 64)
927DFP_HELPER_CFFIX(dcffixq, 128)
bea0dd79
TM		 928
929#define DFP_HELPER_CTFIX(op, size) \
930void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b) \
931{ \
932 struct PPC_DFP dfp; \
933 dfp_prepare_decimal##size(&dfp, 0, b, env); \
934 \
935 if (unlikely(decNumberIsSpecial(&dfp.b))) { \
936 uint64_t invalid_flags = FP_VX | FP_VXCVI; \
937 if (decNumberIsInfinite(&dfp.b)) { \
938 dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
939 } else { /* NaN */ \
940 dfp.t64[0] = INT64_MIN; \
941 if (decNumberIsSNaN(&dfp.b)) { \
942 invalid_flags |= FP_VXSNAN; \
943 } \
944 } \
945 dfp_set_FPSCR_flag(&dfp, invalid_flags, FP_VE); \
946 } else if (unlikely(decNumberIsZero(&dfp.b))) { \
947 dfp.t64[0] = 0; \
948 } else { \
949 decNumberToIntegralExact(&dfp.b, &dfp.b, &dfp.context); \
950 dfp.t64[0] = decNumberIntegralToInt64(&dfp.b, &dfp.context); \
951 if (decContextTestStatus(&dfp.context, DEC_Invalid_operation)) { \
952 dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
953 dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FP_VE); \
954 } else { \
955 dfp_check_for_XX(&dfp); \
956 } \
957 } \
958 \
959 *t = dfp.t64[0]; \
960}
961
962DFP_HELPER_CTFIX(dctfix, 64)
963DFP_HELPER_CTFIX(dctfixq, 128)
7796676f
TM		 964
965static inline void dfp_set_bcd_digit_64(uint64_t *t, uint8_t digit,
966 unsigned n)
967{
968 *t |= ((uint64_t)(digit & 0xF) << (n << 2));
969}
970
971static inline void dfp_set_bcd_digit_128(uint64_t *t, uint8_t digit,
972 unsigned n)
973{
974 t[(n & 0x10) ? HI_IDX : LO_IDX] |=
975 ((uint64_t)(digit & 0xF) << ((n & 15) << 2));
976}
977
978static inline void dfp_set_sign_64(uint64_t *t, uint8_t sgn)
979{
980 *t <<= 4;
981 *t |= (sgn & 0xF);
982}
983
984static inline void dfp_set_sign_128(uint64_t *t, uint8_t sgn)
985{
986 t[HI_IDX] <<= 4;
987 t[HI_IDX] |= (t[LO_IDX] >> 60);
988 t[LO_IDX] <<= 4;
989 t[LO_IDX] |= (sgn & 0xF);
990}
991
992#define DFP_HELPER_DEDPD(op, size) \
993void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t sp) \
994{ \
995 struct PPC_DFP dfp; \
996 uint8_t digits[34]; \
997 int i, N; \
998 \
999 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1000 \
1001 decNumberGetBCD(&dfp.b, digits); \
1002 dfp.t64[0] = dfp.t64[1] = 0; \
1003 N = dfp.b.digits; \
1004 \
1005 for (i = 0; (i < N) && (i < (size)/4); i++) { \
1006 dfp_set_bcd_digit_##size(dfp.t64, digits[N-i-1], i); \
1007 } \
1008 \
1009 if (sp & 2) { \
1010 uint8_t sgn; \
1011 \
1012 if (decNumberIsNegative(&dfp.b)) { \
1013 sgn = 0xD; \
1014 } else { \
1015 sgn = ((sp & 1) ? 0xF : 0xC); \
1016 } \
1017 dfp_set_sign_##size(dfp.t64, sgn); \
1018 } \
1019 \
1020 if (size == 64) { \
1021 t[0] = dfp.t64[0]; \
1022 } else if (size == 128) { \
1023 t[0] = dfp.t64[HI_IDX]; \
1024 t[1] = dfp.t64[LO_IDX]; \
1025 } \
1026}
1027
1028DFP_HELPER_DEDPD(ddedpd, 64)
1029DFP_HELPER_DEDPD(ddedpdq, 128)
013c3ac0
TM		 1030
1031static inline uint8_t dfp_get_bcd_digit_64(uint64_t *t, unsigned n)
1032{
1033 return *t >> ((n << 2) & 63) & 15;
1034}
1035
1036static inline uint8_t dfp_get_bcd_digit_128(uint64_t *t, unsigned n)
1037{
1038 return t[(n & 0x10) ? HI_IDX : LO_IDX] >> ((n << 2) & 63) & 15;
1039}
1040
1041#define DFP_HELPER_ENBCD(op, size) \
1042void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t s) \
1043{ \
1044 struct PPC_DFP dfp; \
1045 uint8_t digits[32]; \
1046 int n = 0, offset = 0, sgn = 0, nonzero = 0; \
1047 \
1048 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1049 \
1050 decNumberZero(&dfp.t); \
1051 \
1052 if (s) { \
1053 uint8_t sgnNibble = dfp_get_bcd_digit_##size(dfp.b64, offset++); \
1054 switch (sgnNibble) { \
1055 case 0xD: \
1056 case 0xB: \
1057 sgn = 1; \
1058 break; \
1059 case 0xC: \
1060 case 0xF: \
1061 case 0xA: \
1062 case 0xE: \
1063 sgn = 0; \
1064 break; \
1065 default: \
1066 dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE); \
1067 return; \
1068 } \
1069 } \
1070 \
1071 while (offset < (size)/4) { \
1072 n++; \
1073 digits[(size)/4-n] = dfp_get_bcd_digit_##size(dfp.b64, offset++); \
1074 if (digits[(size)/4-n] > 10) { \
1075 dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE); \
1076 return; \
1077 } else { \
1078 nonzero |= (digits[(size)/4-n] > 0); \
1079 } \
1080 } \
1081 \
1082 if (nonzero) { \
1083 decNumberSetBCD(&dfp.t, digits+((size)/4)-n, n); \
1084 } \
1085 \
1086 if (s && sgn) { \
1087 dfp.t.bits |= DECNEG; \
1088 } \
1089 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
1090 &dfp.context); \
1091 dfp_set_FPRF_from_FRT(&dfp); \
1092 if ((size) == 64) { \
1093 t[0] = dfp.t64[0]; \
1094 } else if ((size) == 128) { \
1095 t[0] = dfp.t64[HI_IDX]; \
1096 t[1] = dfp.t64[LO_IDX]; \
1097 } \
1098}
1099
1100DFP_HELPER_ENBCD(denbcd, 64)
1101DFP_HELPER_ENBCD(denbcdq, 128)
e8a48460
TM		 1102
1103#define DFP_HELPER_XEX(op, size) \
1104void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b) \
1105{ \
1106 struct PPC_DFP dfp; \
1107 \
1108 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1109 \
1110 if (unlikely(decNumberIsSpecial(&dfp.b))) { \
1111 if (decNumberIsInfinite(&dfp.b)) { \
1112 *t = -1; \
1113 } else if (decNumberIsSNaN(&dfp.b)) { \
1114 *t = -3; \
1115 } else if (decNumberIsQNaN(&dfp.b)) { \
1116 *t = -2; \
1117 } else { \
1118 assert(0); \
1119 } \
1120 } else { \
1121 if ((size) == 64) { \
1122 *t = dfp.b.exponent + 398; \
1123 } else if ((size) == 128) { \
1124 *t = dfp.b.exponent + 6176; \
1125 } else { \
1126 assert(0); \
1127 } \
1128 } \
1129}
1130
1131DFP_HELPER_XEX(dxex, 64)
1132DFP_HELPER_XEX(dxexq, 128)
297666eb
TM		 1133
1134static void dfp_set_raw_exp_64(uint64_t *t, uint64_t raw)
1135{
1136 *t &= 0x8003ffffffffffffULL;
1137 *t |= (raw << (63-13));
1138}
1139
1140static void dfp_set_raw_exp_128(uint64_t *t, uint64_t raw)
1141{
1142 t[HI_IDX] &= 0x80003fffffffffffULL;
1143 t[HI_IDX] |= (raw << (63-17));
1144}
1145
1146#define DFP_HELPER_IEX(op, size) \
1147void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b) \
1148{ \
1149 struct PPC_DFP dfp; \
1150 uint64_t raw_qnan, raw_snan, raw_inf, max_exp; \
1151 int bias; \
1152 int64_t exp = *((int64_t *)a); \
1153 \
1154 dfp_prepare_decimal##size(&dfp, 0, b, env); \
1155 \
1156 if ((size) == 64) { \
1157 max_exp = 767; \
1158 raw_qnan = 0x1F00; \
1159 raw_snan = 0x1F80; \
1160 raw_inf = 0x1E00; \
1161 bias = 398; \
1162 } else if ((size) == 128) { \
1163 max_exp = 12287; \
1164 raw_qnan = 0x1f000; \
1165 raw_snan = 0x1f800; \
1166 raw_inf = 0x1e000; \
1167 bias = 6176; \
1168 } else { \
1169 assert(0); \
1170 } \
1171 \
1172 if (unlikely((exp < 0) || (exp > max_exp))) { \
1173 dfp.t64[0] = dfp.b64[0]; \
1174 dfp.t64[1] = dfp.b64[1]; \
1175 if (exp == -1) { \
1176 dfp_set_raw_exp_##size(dfp.t64, raw_inf); \
1177 } else if (exp == -3) { \
1178 dfp_set_raw_exp_##size(dfp.t64, raw_snan); \
1179 } else { \
1180 dfp_set_raw_exp_##size(dfp.t64, raw_qnan); \
1181 } \
1182 } else { \
1183 dfp.t = dfp.b; \
1184 if (unlikely(decNumberIsSpecial(&dfp.t))) { \
1185 dfp.t.bits &= ~DECSPECIAL; \
1186 } \
1187 dfp.t.exponent = exp - bias; \
1188 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
1189 &dfp.context); \
1190 } \
1191 if (size == 64) { \
1192 t[0] = dfp.t64[0]; \
1193 } else if (size == 128) { \
1194 t[0] = dfp.t64[HI_IDX]; \
1195 t[1] = dfp.t64[LO_IDX]; \
1196 } \
1197}
1198
1199DFP_HELPER_IEX(diex, 64)
1200DFP_HELPER_IEX(diexq, 128)
804e654a
TM		 1201
1202static void dfp_clear_lmd_from_g5msb(uint64_t *t)
1203{
1204
1205 /* The most significant 5 bits of the PowerPC DFP format combine bits */
1206 /* from the left-most decimal digit (LMD) and the biased exponent. */
1207 /* This routine clears the LMD bits while preserving the exponent */
1208 /* bits. See "Figure 80: Encoding of bits 0:4 of the G field for */
1209 /* Finite Numbers" in the Power ISA for additional details. */
1210
1211 uint64_t g5msb = (*t >> 58) & 0x1F;
1212
1213 if ((g5msb >> 3) < 3) { /* LMD in [0-7] ? */
1214 *t &= ~(7ULL << 58);
1215 } else {
1216 switch (g5msb & 7) {
1217 case 0:
1218 case 1:
1219 g5msb = 0;
1220 break;
1221 case 2:
1222 case 3:
1223 g5msb = 0x8;
1224 break;
1225 case 4:
1226 case 5:
1227 g5msb = 0x10;
1228 break;
1229 case 6:
1230 g5msb = 0x1E;
1231 break;
1232 case 7:
1233 g5msb = 0x1F;
1234 break;
1235 }
1236
1237 *t &= ~(0x1fULL << 58);
1238 *t |= (g5msb << 58);
1239 }
1240}
1241
1242#define DFP_HELPER_SHIFT(op, size, shift_left) \
1243void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, \
1244 uint32_t sh) \
1245{ \
1246 struct PPC_DFP dfp; \
1247 unsigned max_digits = ((size) == 64) ? 16 : 34; \
1248 \
1249 dfp_prepare_decimal##size(&dfp, a, 0, env); \
1250 \
1251 if (sh <= max_digits) { \
1252 \
1253 decNumber shd; \
1254 unsigned special = dfp.a.bits & DECSPECIAL; \
1255 \
1256 if (shift_left) { \
1257 decNumberFromUInt32(&shd, sh); \
1258 } else { \
1259 decNumberFromInt32(&shd, -((int32_t)sh)); \
1260 } \
1261 \
1262 dfp.a.bits &= ~DECSPECIAL; \
1263 decNumberShift(&dfp.t, &dfp.a, &shd, &dfp.context); \
1264 \
1265 dfp.t.bits |= special; \
1266 if (special && (dfp.t.digits >= max_digits)) { \
1267 dfp.t.digits = max_digits - 1; \
1268 } \
1269 \
1270 decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
1271 &dfp.context); \
1272 } else { \
1273 if ((size) == 64) { \
1274 dfp.t64[0] = dfp.a64[0] & 0xFFFC000000000000ULL; \
1275 dfp_clear_lmd_from_g5msb(dfp.t64); \
1276 } else { \
1277 dfp.t64[HI_IDX] = dfp.a64[HI_IDX] & \
1278 0xFFFFC00000000000ULL; \
1279 dfp_clear_lmd_from_g5msb(dfp.t64 + HI_IDX); \
1280 dfp.t64[LO_IDX] = 0; \
1281 } \
1282 } \
1283 \
1284 if ((size) == 64) { \
1285 t[0] = dfp.t64[0]; \
1286 } else { \
1287 t[0] = dfp.t64[HI_IDX]; \
1288 t[1] = dfp.t64[LO_IDX]; \
1289 } \
1290}
1291
1292DFP_HELPER_SHIFT(dscli, 64, 1)
1293DFP_HELPER_SHIFT(dscliq, 128, 1)
1294DFP_HELPER_SHIFT(dscri, 64, 0)
1295DFP_HELPER_SHIFT(dscriq, 128, 0)
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