qemu/target-ppc/dfp_helper.c

   1 /*
   2  *  PowerPC Decimal Floating Point (DPF) emulation helpers for QEMU.
   3  *
   4  *  Copyright (c) 2014 IBM Corporation.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "cpu.h"
  22 #include "exec/helper-proto.h"
  23
  24 #define DECNUMDIGITS 34
  25 #include "libdecnumber/decContext.h"
  26 #include "libdecnumber/decNumber.h"
  27 #include "libdecnumber/dpd/decimal32.h"
  28 #include "libdecnumber/dpd/decimal64.h"
  29 #include "libdecnumber/dpd/decimal128.h"
  30
  31 #if defined(HOST_WORDS_BIGENDIAN)
  32 #define HI_IDX 0
  33 #define LO_IDX 1
  34 #else
  35 #define HI_IDX 1
  36 #define LO_IDX 0
  37 #endif
  38
  39 struct PPC_DFP {
  40     CPUPPCState *env;
  41     uint64_t t64[2], a64[2], b64[2];
  42     decNumber t, a, b;
  43     decContext context;
  44     uint8_t crbf;
  45 };
  46
  47 static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
  48 {
  49     enum rounding rnd;
  50
  51     switch ((fpscr >> 32) & 0x7) {
  52     case 0:
  53         rnd = DEC_ROUND_HALF_EVEN;
  54         break;
  55     case 1:
  56         rnd = DEC_ROUND_DOWN;
  57         break;
  58     case 2:
  59          rnd = DEC_ROUND_CEILING;
  60          break;
  61     case 3:
  62          rnd = DEC_ROUND_FLOOR;
  63          break;
  64     case 4:
  65          rnd = DEC_ROUND_HALF_UP;
  66          break;
  67     case 5:
  68          rnd = DEC_ROUND_HALF_DOWN;
  69          break;
  70     case 6:
  71          rnd = DEC_ROUND_UP;
  72          break;
  73     case 7:
  74          rnd = DEC_ROUND_05UP;
  75          break;
  76     default:
  77         g_assert_not_reached();
  78     }
  79
  80     decContextSetRounding(context, rnd);
  81 }
  82
  83 static void dfp_set_round_mode_from_immediate(uint8_t r, uint8_t rmc,
  84                                                   struct PPC_DFP *dfp)
  85 {
  86     enum rounding rnd;
  87     if (r == 0) {
  88         switch (rmc & 3) {
  89         case 0:
  90             rnd = DEC_ROUND_HALF_EVEN;
  91             break;
  92         case 1:
  93             rnd = DEC_ROUND_DOWN;
  94             break;
  95         case 2:
  96             rnd = DEC_ROUND_HALF_UP;
  97             break;
  98         case 3: /* use FPSCR rounding mode */
  99             return;
 100         default:
 101             assert(0); /* cannot get here */
 102         }
 103     } else { /* r == 1 */
 104         switch (rmc & 3) {
 105         case 0:
 106             rnd = DEC_ROUND_CEILING;
 107             break;
 108         case 1:
 109             rnd = DEC_ROUND_FLOOR;
 110             break;
 111         case 2:
 112             rnd = DEC_ROUND_UP;
 113             break;
 114         case 3:
 115             rnd = DEC_ROUND_HALF_DOWN;
 116             break;
 117         default:
 118             assert(0); /* cannot get here */
 119         }
 120     }
 121     decContextSetRounding(&dfp->context, rnd);
 122 }
 123
 124 static void dfp_prepare_decimal64(struct PPC_DFP *dfp, uint64_t *a,
 125                 uint64_t *b, CPUPPCState *env)
 126 {
 127     decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
 128     dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
 129     dfp->env = env;
 130
 131     if (a) {
 132         dfp->a64[0] = *a;
 133         decimal64ToNumber((decimal64 *)dfp->a64, &dfp->a);
 134     } else {
 135         dfp->a64[0] = 0;
 136         decNumberZero(&dfp->a);
 137     }
 138
 139     if (b) {
 140         dfp->b64[0] = *b;
 141         decimal64ToNumber((decimal64 *)dfp->b64, &dfp->b);
 142     } else {
 143         dfp->b64[0] = 0;
 144         decNumberZero(&dfp->b);
 145     }
 146 }
 147
 148 static void dfp_prepare_decimal128(struct PPC_DFP *dfp, uint64_t *a,
 149                 uint64_t *b, CPUPPCState *env)
 150 {
 151     decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
 152     dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
 153     dfp->env = env;
 154
 155     if (a) {
 156         dfp->a64[0] = a[HI_IDX];
 157         dfp->a64[1] = a[LO_IDX];
 158         decimal128ToNumber((decimal128 *)dfp->a64, &dfp->a);
 159     } else {
 160         dfp->a64[0] = dfp->a64[1] = 0;
 161         decNumberZero(&dfp->a);
 162     }
 163
 164     if (b) {
 165         dfp->b64[0] = b[HI_IDX];
 166         dfp->b64[1] = b[LO_IDX];
 167         decimal128ToNumber((decimal128 *)dfp->b64, &dfp->b);
 168     } else {
 169         dfp->b64[0] = dfp->b64[1] = 0;
 170         decNumberZero(&dfp->b);
 171     }
 172 }
 173
 174 static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
 175                 uint64_t enabled)
 176 {
 177     dfp->env->fpscr |= (flag | FP_FX);
 178     if (dfp->env->fpscr & enabled) {
 179         dfp->env->fpscr |= FP_FEX;
 180     }
 181 }
 182
 183 static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
 184                 decContext *context)
 185 {
 186     uint64_t fprf = 0;
 187
 188     /* construct FPRF */
 189     switch (decNumberClass(&dfp->t, context)) {
 190     case DEC_CLASS_SNAN:
 191         fprf = 0x01;
 192         break;
 193     case DEC_CLASS_QNAN:
 194         fprf = 0x11;
 195         break;
 196     case DEC_CLASS_NEG_INF:
 197         fprf = 0x09;
 198         break;
 199     case DEC_CLASS_NEG_NORMAL:
 200         fprf = 0x08;
 201         break;
 202     case DEC_CLASS_NEG_SUBNORMAL:
 203         fprf = 0x18;
 204         break;
 205     case DEC_CLASS_NEG_ZERO:
 206         fprf = 0x12;
 207         break;
 208     case DEC_CLASS_POS_ZERO:
 209         fprf = 0x02;
 210         break;
 211     case DEC_CLASS_POS_SUBNORMAL:
 212         fprf = 0x14;
 213         break;
 214     case DEC_CLASS_POS_NORMAL:
 215         fprf = 0x04;
 216         break;
 217     case DEC_CLASS_POS_INF:
 218         fprf = 0x05;
 219         break;
 220     default:
 221         assert(0); /* should never get here */
 222     }
 223     dfp->env->fpscr &= ~(0x1F << 12);
 224     dfp->env->fpscr |= (fprf << 12);
 225 }
 226
 227 static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
 228 {
 229     dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
 230 }
 231
 232 static void dfp_set_FPRF_from_FRT_short(struct PPC_DFP *dfp)
 233 {
 234     decContext shortContext;
 235     decContextDefault(&shortContext, DEC_INIT_DECIMAL32);
 236     dfp_set_FPRF_from_FRT_with_context(dfp, &shortContext);
 237 }
 238
 239 static void dfp_set_FPRF_from_FRT_long(struct PPC_DFP *dfp)
 240 {
 241     decContext longContext;
 242     decContextDefault(&longContext, DEC_INIT_DECIMAL64);
 243     dfp_set_FPRF_from_FRT_with_context(dfp, &longContext);
 244 }
 245
 246 static void dfp_check_for_OX(struct PPC_DFP *dfp)
 247 {
 248     if (dfp->context.status & DEC_Overflow) {
 249         dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
 250     }
 251 }
 252
 253 static void dfp_check_for_UX(struct PPC_DFP *dfp)
 254 {
 255     if (dfp->context.status & DEC_Underflow) {
 256         dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
 257     }
 258 }
 259
 260 static void dfp_check_for_XX(struct PPC_DFP *dfp)
 261 {
 262     if (dfp->context.status & DEC_Inexact) {
 263         dfp_set_FPSCR_flag(dfp, FP_XX | FP_FI, FP_XE);
 264     }
 265 }
 266
 267 static void dfp_check_for_ZX(struct PPC_DFP *dfp)
 268 {
 269     if (dfp->context.status & DEC_Division_by_zero) {
 270         dfp_set_FPSCR_flag(dfp, FP_ZX, FP_ZE);
 271     }
 272 }
 273
 274 static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
 275 {
 276     if (dfp->context.status & DEC_Invalid_operation) {
 277         if (decNumberIsSNaN(&dfp->a) || decNumberIsSNaN(&dfp->b)) {
 278             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
 279         }
 280     }
 281 }
 282
 283 static void dfp_check_for_VXSNAN_and_convert_to_QNaN(struct PPC_DFP *dfp)
 284 {
 285     if (decNumberIsSNaN(&dfp->t)) {
 286         dfp->t.bits &= ~DECSNAN;
 287         dfp->t.bits |= DECNAN;
 288         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
 289     }
 290 }
 291
 292 static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
 293 {
 294     if (dfp->context.status & DEC_Invalid_operation) {
 295         if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
 296             int same = decNumberClass(&dfp->a, &dfp->context) ==
 297                        decNumberClass(&dfp->b, &dfp->context);
 298             if ((same && testForSameSign) || (!same && !testForSameSign)) {
 299                 dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXISI, FP_VE);
 300             }
 301         }
 302     }
 303 }
 304
 305 static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
 306 {
 307     dfp_check_for_VXISI(dfp, 0);
 308 }
 309
 310 static void dfp_check_for_VXISI_subtract(struct PPC_DFP *dfp)
 311 {
 312     dfp_check_for_VXISI(dfp, 1);
 313 }
 314
 315 static void dfp_check_for_VXIMZ(struct PPC_DFP *dfp)
 316 {
 317     if (dfp->context.status & DEC_Invalid_operation) {
 318         if ((decNumberIsInfinite(&dfp->a) && decNumberIsZero(&dfp->b)) ||
 319             (decNumberIsInfinite(&dfp->b) && decNumberIsZero(&dfp->a))) {
 320             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIMZ, FP_VE);
 321         }
 322     }
 323 }
 324
 325 static void dfp_check_for_VXZDZ(struct PPC_DFP *dfp)
 326 {
 327     if (dfp->context.status & DEC_Division_undefined) {
 328         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXZDZ, FP_VE);
 329     }
 330 }
 331
 332 static void dfp_check_for_VXIDI(struct PPC_DFP *dfp)
 333 {
 334     if (dfp->context.status & DEC_Invalid_operation) {
 335         if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
 336             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXIDI, FP_VE);
 337         }
 338     }
 339 }
 340
 341 static void dfp_check_for_VXVC(struct PPC_DFP *dfp)
 342 {
 343     if (decNumberIsNaN(&dfp->a) || decNumberIsNaN(&dfp->b)) {
 344         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXVC, FP_VE);
 345     }
 346 }
 347
 348 static void dfp_check_for_VXCVI(struct PPC_DFP *dfp)
 349 {
 350     if ((dfp->context.status & DEC_Invalid_operation) &&
 351         (!decNumberIsSNaN(&dfp->a)) &&
 352         (!decNumberIsSNaN(&dfp->b))) {
 353         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
 354     }
 355 }
 356
 357 static void dfp_set_CRBF_from_T(struct PPC_DFP *dfp)
 358 {
 359     if (decNumberIsNaN(&dfp->t)) {
 360         dfp->crbf = 1;
 361     } else if (decNumberIsZero(&dfp->t)) {
 362         dfp->crbf = 2;
 363     } else if (decNumberIsNegative(&dfp->t)) {
 364         dfp->crbf = 8;
 365     } else {
 366         dfp->crbf = 4;
 367     }
 368 }
 369
 370 static void dfp_set_FPCC_from_CRBF(struct PPC_DFP *dfp)
 371 {
 372     dfp->env->fpscr &= ~(0xF << 12);
 373     dfp->env->fpscr |= (dfp->crbf << 12);
 374 }
 375
 376 static inline void dfp_makeQNaN(decNumber *dn)
 377 {
 378     dn->bits &= ~DECSPECIAL;
 379     dn->bits |= DECNAN;
 380 }
 381
 382 static inline int dfp_get_digit(decNumber *dn, int n)
 383 {
 384     assert(DECDPUN == 3);
 385     int unit = n / DECDPUN;
 386     int dig = n % DECDPUN;
 387     switch (dig) {
 388     case 0:
 389         return dn->lsu[unit] % 10;
 390     case 1:
 391         return (dn->lsu[unit] / 10) % 10;
 392     case 2:
 393         return dn->lsu[unit] / 100;
 394     }
 395     g_assert_not_reached();
 396 }
 397
 398 #define DFP_HELPER_TAB(op, dnop, postprocs, size)                              \
 399 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b)      \
 400 {                                                                              \
 401     struct PPC_DFP dfp;                                                        \
 402     dfp_prepare_decimal##size(&dfp, a, b, env);                                \
 403     dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context);                                \
 404     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
 405     postprocs(&dfp);                                                           \
 406     if (size == 64) {                                                          \
 407         t[0] = dfp.t64[0];                                                     \
 408     } else if (size == 128) {                                                  \
 409         t[0] = dfp.t64[HI_IDX];                                                \
 410         t[1] = dfp.t64[LO_IDX];                                                \
 411     }                                                                          \
 412 }
 413
 414 static void ADD_PPs(struct PPC_DFP *dfp)
 415 {
 416     dfp_set_FPRF_from_FRT(dfp);
 417     dfp_check_for_OX(dfp);
 418     dfp_check_for_UX(dfp);
 419     dfp_check_for_XX(dfp);
 420     dfp_check_for_VXSNAN(dfp);
 421     dfp_check_for_VXISI_add(dfp);
 422 }
 423
 424 DFP_HELPER_TAB(dadd, decNumberAdd, ADD_PPs, 64)
 425 DFP_HELPER_TAB(daddq, decNumberAdd, ADD_PPs, 128)
 426
 427 static void SUB_PPs(struct PPC_DFP *dfp)
 428 {
 429     dfp_set_FPRF_from_FRT(dfp);
 430     dfp_check_for_OX(dfp);
 431     dfp_check_for_UX(dfp);
 432     dfp_check_for_XX(dfp);
 433     dfp_check_for_VXSNAN(dfp);
 434     dfp_check_for_VXISI_subtract(dfp);
 435 }
 436
 437 DFP_HELPER_TAB(dsub, decNumberSubtract, SUB_PPs, 64)
 438 DFP_HELPER_TAB(dsubq, decNumberSubtract, SUB_PPs, 128)
 439
 440 static void MUL_PPs(struct PPC_DFP *dfp)
 441 {
 442     dfp_set_FPRF_from_FRT(dfp);
 443     dfp_check_for_OX(dfp);
 444     dfp_check_for_UX(dfp);
 445     dfp_check_for_XX(dfp);
 446     dfp_check_for_VXSNAN(dfp);
 447     dfp_check_for_VXIMZ(dfp);
 448 }
 449
 450 DFP_HELPER_TAB(dmul, decNumberMultiply, MUL_PPs, 64)
 451 DFP_HELPER_TAB(dmulq, decNumberMultiply, MUL_PPs, 128)
 452
 453 static void DIV_PPs(struct PPC_DFP *dfp)
 454 {
 455     dfp_set_FPRF_from_FRT(dfp);
 456     dfp_check_for_OX(dfp);
 457     dfp_check_for_UX(dfp);
 458     dfp_check_for_ZX(dfp);
 459     dfp_check_for_XX(dfp);
 460     dfp_check_for_VXSNAN(dfp);
 461     dfp_check_for_VXZDZ(dfp);
 462     dfp_check_for_VXIDI(dfp);
 463 }
 464
 465 DFP_HELPER_TAB(ddiv, decNumberDivide, DIV_PPs, 64)
 466 DFP_HELPER_TAB(ddivq, decNumberDivide, DIV_PPs, 128)
 467
 468 #define DFP_HELPER_BF_AB(op, dnop, postprocs, size)                            \
 469 uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b)               \
 470 {                                                                              \
 471     struct PPC_DFP dfp;                                                        \
 472     dfp_prepare_decimal##size(&dfp, a, b, env);                                \
 473     dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context);                                \
 474     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
 475     postprocs(&dfp);                                                           \
 476     return dfp.crbf;                                                           \
 477 }
 478
 479 static void CMPU_PPs(struct PPC_DFP *dfp)
 480 {
 481     dfp_set_CRBF_from_T(dfp);
 482     dfp_set_FPCC_from_CRBF(dfp);
 483     dfp_check_for_VXSNAN(dfp);
 484 }
 485
 486 DFP_HELPER_BF_AB(dcmpu, decNumberCompare, CMPU_PPs, 64)
 487 DFP_HELPER_BF_AB(dcmpuq, decNumberCompare, CMPU_PPs, 128)
 488
 489 static void CMPO_PPs(struct PPC_DFP *dfp)
 490 {
 491     dfp_set_CRBF_from_T(dfp);
 492     dfp_set_FPCC_from_CRBF(dfp);
 493     dfp_check_for_VXSNAN(dfp);
 494     dfp_check_for_VXVC(dfp);
 495 }
 496
 497 DFP_HELPER_BF_AB(dcmpo, decNumberCompare, CMPO_PPs, 64)
 498 DFP_HELPER_BF_AB(dcmpoq, decNumberCompare, CMPO_PPs, 128)
 499
 500 #define DFP_HELPER_TSTDC(op, size)                                       \
 501 uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm)        \
 502 {                                                                        \
 503     struct PPC_DFP dfp;                                                  \
 504     int match = 0;                                                       \
 505                                                                          \
 506     dfp_prepare_decimal##size(&dfp, a, 0, env);                          \
 507                                                                          \
 508     match |= (dcm & 0x20) && decNumberIsZero(&dfp.a);                    \
 509     match |= (dcm & 0x10) && decNumberIsSubnormal(&dfp.a, &dfp.context); \
 510     match |= (dcm & 0x08) && decNumberIsNormal(&dfp.a, &dfp.context);    \
 511     match |= (dcm & 0x04) && decNumberIsInfinite(&dfp.a);                \
 512     match |= (dcm & 0x02) && decNumberIsQNaN(&dfp.a);                    \
 513     match |= (dcm & 0x01) && decNumberIsSNaN(&dfp.a);                    \
 514                                                                          \
 515     if (decNumberIsNegative(&dfp.a)) {                                   \
 516         dfp.crbf = match ? 0xA : 0x8;                                    \
 517     } else {                                                             \
 518         dfp.crbf = match ? 0x2 : 0x0;                                    \
 519     }                                                                    \
 520                                                                          \
 521     dfp_set_FPCC_from_CRBF(&dfp);                                        \
 522     return dfp.crbf;                                                     \
 523 }
 524
 525 DFP_HELPER_TSTDC(dtstdc, 64)
 526 DFP_HELPER_TSTDC(dtstdcq, 128)
 527
 528 #define DFP_HELPER_TSTDG(op, size)                                       \
 529 uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint32_t dcm)        \
 530 {                                                                        \
 531     struct PPC_DFP dfp;                                                  \
 532     int minexp, maxexp, nzero_digits, nzero_idx, is_negative, is_zero,   \
 533         is_extreme_exp, is_subnormal, is_normal, leftmost_is_nonzero,    \
 534         match;                                                           \
 535                                                                          \
 536     dfp_prepare_decimal##size(&dfp, a, 0, env);                          \
 537                                                                          \
 538     if ((size) == 64) {                                                  \
 539         minexp = -398;                                                   \
 540         maxexp = 369;                                                    \
 541         nzero_digits = 16;                                               \
 542         nzero_idx = 5;                                                   \
 543     } else if ((size) == 128) {                                          \
 544         minexp = -6176;                                                  \
 545         maxexp = 6111;                                                   \
 546         nzero_digits = 34;                                               \
 547         nzero_idx = 11;                                                  \
 548     }                                                                    \
 549                                                                          \
 550     is_negative = decNumberIsNegative(&dfp.a);                           \
 551     is_zero = decNumberIsZero(&dfp.a);                                   \
 552     is_extreme_exp = (dfp.a.exponent == maxexp) ||                       \
 553                      (dfp.a.exponent == minexp);                         \
 554     is_subnormal = decNumberIsSubnormal(&dfp.a, &dfp.context);           \
 555     is_normal = decNumberIsNormal(&dfp.a, &dfp.context);                 \
 556     leftmost_is_nonzero = (dfp.a.digits == nzero_digits) &&              \
 557                           (dfp.a.lsu[nzero_idx] != 0);                   \
 558     match = 0;                                                           \
 559                                                                          \
 560     match |= (dcm & 0x20) && is_zero && !is_extreme_exp;                 \
 561     match |= (dcm & 0x10) && is_zero && is_extreme_exp;                  \
 562     match |= (dcm & 0x08) &&                                             \
 563              (is_subnormal || (is_normal && is_extreme_exp));            \
 564     match |= (dcm & 0x04) && is_normal && !is_extreme_exp &&             \
 565              !leftmost_is_nonzero;                                       \
 566     match |= (dcm & 0x02) && is_normal && !is_extreme_exp &&             \
 567              leftmost_is_nonzero;                                        \
 568     match |= (dcm & 0x01) && decNumberIsSpecial(&dfp.a);                 \
 569                                                                          \
 570     if (is_negative) {                                                   \
 571         dfp.crbf = match ? 0xA : 0x8;                                    \
 572     } else {                                                             \
 573         dfp.crbf = match ? 0x2 : 0x0;                                    \
 574     }                                                                    \
 575                                                                          \
 576     dfp_set_FPCC_from_CRBF(&dfp);                                        \
 577     return dfp.crbf;                                                     \
 578 }
 579
 580 DFP_HELPER_TSTDG(dtstdg, 64)
 581 DFP_HELPER_TSTDG(dtstdgq, 128)
 582
 583 #define DFP_HELPER_TSTEX(op, size)                                       \
 584 uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b)         \
 585 {                                                                        \
 586     struct PPC_DFP dfp;                                                  \
 587     int expa, expb, a_is_special, b_is_special;                          \
 588                                                                          \
 589     dfp_prepare_decimal##size(&dfp, a, b, env);                          \
 590                                                                          \
 591     expa = dfp.a.exponent;                                               \
 592     expb = dfp.b.exponent;                                               \
 593     a_is_special = decNumberIsSpecial(&dfp.a);                           \
 594     b_is_special = decNumberIsSpecial(&dfp.b);                           \
 595                                                                          \
 596     if (a_is_special || b_is_special) {                                  \
 597         int atype = a_is_special ? (decNumberIsNaN(&dfp.a) ? 4 : 2) : 1; \
 598         int btype = b_is_special ? (decNumberIsNaN(&dfp.b) ? 4 : 2) : 1; \
 599         dfp.crbf = (atype ^ btype) ? 0x1 : 0x2;                          \
 600     } else if (expa < expb) {                                            \
 601         dfp.crbf = 0x8;                                                  \
 602     } else if (expa > expb) {                                            \
 603         dfp.crbf = 0x4;                                                  \
 604     } else {                                                             \
 605         dfp.crbf = 0x2;                                                  \
 606     }                                                                    \
 607                                                                          \
 608     dfp_set_FPCC_from_CRBF(&dfp);                                        \
 609     return dfp.crbf;                                                     \
 610 }
 611
 612 DFP_HELPER_TSTEX(dtstex, 64)
 613 DFP_HELPER_TSTEX(dtstexq, 128)
 614
 615 #define DFP_HELPER_TSTSF(op, size)                                       \
 616 uint32_t helper_##op(CPUPPCState *env, uint64_t *a, uint64_t *b)         \
 617 {                                                                        \
 618     struct PPC_DFP dfp;                                                  \
 619     unsigned k;                                                          \
 620                                                                          \
 621     dfp_prepare_decimal##size(&dfp, 0, b, env);                          \
 622                                                                          \
 623     k = *a & 0x3F;                                                       \
 624                                                                          \
 625     if (unlikely(decNumberIsSpecial(&dfp.b))) {                          \
 626         dfp.crbf = 1;                                                    \
 627     } else if (k == 0) {                                                 \
 628         dfp.crbf = 4;                                                    \
 629     } else if (unlikely(decNumberIsZero(&dfp.b))) {                      \
 630         /* Zero has no sig digits */                                     \
 631         dfp.crbf = 4;                                                    \
 632     } else {                                                             \
 633         unsigned nsd = dfp.b.digits;                                     \
 634         if (k < nsd) {                                                   \
 635             dfp.crbf = 8;                                                \
 636         } else if (k > nsd) {                                            \
 637             dfp.crbf = 4;                                                \
 638         } else {                                                         \
 639             dfp.crbf = 2;                                                \
 640         }                                                                \
 641     }                                                                    \
 642                                                                          \
 643     dfp_set_FPCC_from_CRBF(&dfp);                                        \
 644     return dfp.crbf;                                                     \
 645 }
 646
 647 DFP_HELPER_TSTSF(dtstsf, 64)
 648 DFP_HELPER_TSTSF(dtstsfq, 128)
 649
 650 static void QUA_PPs(struct PPC_DFP *dfp)
 651 {
 652     dfp_set_FPRF_from_FRT(dfp);
 653     dfp_check_for_XX(dfp);
 654     dfp_check_for_VXSNAN(dfp);
 655     dfp_check_for_VXCVI(dfp);
 656 }
 657
 658 static void dfp_quantize(uint8_t rmc, struct PPC_DFP *dfp)
 659 {
 660     dfp_set_round_mode_from_immediate(0, rmc, dfp);
 661     decNumberQuantize(&dfp->t, &dfp->b, &dfp->a, &dfp->context);
 662     if (decNumberIsSNaN(&dfp->a)) {
 663         dfp->t = dfp->a;
 664         dfp_makeQNaN(&dfp->t);
 665     } else if (decNumberIsSNaN(&dfp->b)) {
 666         dfp->t = dfp->b;
 667         dfp_makeQNaN(&dfp->t);
 668     } else if (decNumberIsQNaN(&dfp->a)) {
 669         dfp->t = dfp->a;
 670     } else if (decNumberIsQNaN(&dfp->b)) {
 671         dfp->t = dfp->b;
 672     }
 673 }
 674
 675 #define DFP_HELPER_QUAI(op, size)                                       \
 676 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b,            \
 677                  uint32_t te, uint32_t rmc)                             \
 678 {                                                                       \
 679     struct PPC_DFP dfp;                                                 \
 680                                                                         \
 681     dfp_prepare_decimal##size(&dfp, 0, b, env);                         \
 682                                                                         \
 683     decNumberFromUInt32(&dfp.a, 1);                                     \
 684     dfp.a.exponent = (int32_t)((int8_t)(te << 3) >> 3);                 \
 685                                                                         \
 686     dfp_quantize(rmc, &dfp);                                            \
 687     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,         \
 688                               &dfp.context);                            \
 689     QUA_PPs(&dfp);                                                      \
 690                                                                         \
 691     if (size == 64) {                                                   \
 692         t[0] = dfp.t64[0];                                              \
 693     } else if (size == 128) {                                           \
 694         t[0] = dfp.t64[HI_IDX];                                         \
 695         t[1] = dfp.t64[LO_IDX];                                         \
 696     }                                                                   \
 697 }
 698
 699 DFP_HELPER_QUAI(dquai, 64)
 700 DFP_HELPER_QUAI(dquaiq, 128)
 701
 702 #define DFP_HELPER_QUA(op, size)                                        \
 703 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,            \
 704                  uint64_t *b, uint32_t rmc)                             \
 705 {                                                                       \
 706     struct PPC_DFP dfp;                                                 \
 707                                                                         \
 708     dfp_prepare_decimal##size(&dfp, a, b, env);                         \
 709                                                                         \
 710     dfp_quantize(rmc, &dfp);                                            \
 711     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,         \
 712                               &dfp.context);                            \
 713     QUA_PPs(&dfp);                                                      \
 714                                                                         \
 715     if (size == 64) {                                                   \
 716         t[0] = dfp.t64[0];                                              \
 717     } else if (size == 128) {                                           \
 718         t[0] = dfp.t64[HI_IDX];                                         \
 719         t[1] = dfp.t64[LO_IDX];                                         \
 720     }                                                                   \
 721 }
 722
 723 DFP_HELPER_QUA(dqua, 64)
 724 DFP_HELPER_QUA(dquaq, 128)
 725
 726 static void _dfp_reround(uint8_t rmc, int32_t ref_sig, int32_t xmax,
 727                              struct PPC_DFP *dfp)
 728 {
 729     int msd_orig, msd_rslt;
 730
 731     if (unlikely((ref_sig == 0) || (dfp->b.digits <= ref_sig))) {
 732         dfp->t = dfp->b;
 733         if (decNumberIsSNaN(&dfp->b)) {
 734             dfp_makeQNaN(&dfp->t);
 735             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FPSCR_VE);
 736         }
 737         return;
 738     }
 739
 740     /* Reround is equivalent to quantizing b with 1**E(n) where */
 741     /* n = exp(b) + numDigits(b) - reference_significance.      */
 742
 743     decNumberFromUInt32(&dfp->a, 1);
 744     dfp->a.exponent = dfp->b.exponent + dfp->b.digits - ref_sig;
 745
 746     if (unlikely(dfp->a.exponent > xmax)) {
 747         dfp->t.digits = 0;
 748         dfp->t.bits &= ~DECNEG;
 749         dfp_makeQNaN(&dfp->t);
 750         dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FPSCR_VE);
 751         return;
 752     }
 753
 754     dfp_quantize(rmc, dfp);
 755
 756     msd_orig = dfp_get_digit(&dfp->b, dfp->b.digits-1);
 757     msd_rslt = dfp_get_digit(&dfp->t, dfp->t.digits-1);
 758
 759     /* If the quantization resulted in rounding up to the next magnitude, */
 760     /* then we need to shift the significand and adjust the exponent.     */
 761
 762     if (unlikely((msd_orig == 9) && (msd_rslt == 1))) {
 763
 764         decNumber negone;
 765
 766         decNumberFromInt32(&negone, -1);
 767         decNumberShift(&dfp->t, &dfp->t, &negone, &dfp->context);
 768         dfp->t.exponent++;
 769
 770         if (unlikely(dfp->t.exponent > xmax)) {
 771             dfp_makeQNaN(&dfp->t);
 772             dfp->t.digits = 0;
 773             dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FP_VE);
 774             /* Inhibit XX in this case */
 775             decContextClearStatus(&dfp->context, DEC_Inexact);
 776         }
 777     }
 778 }
 779
 780 #define DFP_HELPER_RRND(op, size)                                       \
 781 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,            \
 782                  uint64_t *b, uint32_t rmc)                             \
 783 {                                                                       \
 784     struct PPC_DFP dfp;                                                 \
 785     int32_t ref_sig = *a & 0x3F;                                        \
 786     int32_t xmax = ((size) == 64) ? 369 : 6111;                         \
 787                                                                         \
 788     dfp_prepare_decimal##size(&dfp, 0, b, env);                         \
 789                                                                         \
 790     _dfp_reround(rmc, ref_sig, xmax, &dfp);                             \
 791     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,         \
 792                               &dfp.context);                            \
 793     QUA_PPs(&dfp);                                                      \
 794                                                                         \
 795     if (size == 64) {                                                   \
 796         t[0] = dfp.t64[0];                                              \
 797     } else if (size == 128) {                                           \
 798         t[0] = dfp.t64[HI_IDX];                                         \
 799         t[1] = dfp.t64[LO_IDX];                                         \
 800     }                                                                   \
 801 }
 802
 803 DFP_HELPER_RRND(drrnd, 64)
 804 DFP_HELPER_RRND(drrndq, 128)
 805
 806 #define DFP_HELPER_RINT(op, postprocs, size)                                   \
 807 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b,                   \
 808              uint32_t r, uint32_t rmc)                                         \
 809 {                                                                              \
 810     struct PPC_DFP dfp;                                                        \
 811                                                                                \
 812     dfp_prepare_decimal##size(&dfp, 0, b, env);                                \
 813                                                                                \
 814     dfp_set_round_mode_from_immediate(r, rmc, &dfp);                           \
 815     decNumberToIntegralExact(&dfp.t, &dfp.b, &dfp.context);                    \
 816     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
 817     postprocs(&dfp);                                                           \
 818                                                                                \
 819     if (size == 64) {                                                          \
 820         t[0] = dfp.t64[0];                                                     \
 821     } else if (size == 128) {                                                  \
 822         t[0] = dfp.t64[HI_IDX];                                                \
 823         t[1] = dfp.t64[LO_IDX];                                                \
 824     }                                                                          \
 825 }
 826
 827 static void RINTX_PPs(struct PPC_DFP *dfp)
 828 {
 829     dfp_set_FPRF_from_FRT(dfp);
 830     dfp_check_for_XX(dfp);
 831     dfp_check_for_VXSNAN(dfp);
 832 }
 833
 834 DFP_HELPER_RINT(drintx, RINTX_PPs, 64)
 835 DFP_HELPER_RINT(drintxq, RINTX_PPs, 128)
 836
 837 static void RINTN_PPs(struct PPC_DFP *dfp)
 838 {
 839     dfp_set_FPRF_from_FRT(dfp);
 840     dfp_check_for_VXSNAN(dfp);
 841 }
 842
 843 DFP_HELPER_RINT(drintn, RINTN_PPs, 64)
 844 DFP_HELPER_RINT(drintnq, RINTN_PPs, 128)
 845
 846 void helper_dctdp(CPUPPCState *env, uint64_t *t, uint64_t *b)
 847 {
 848     struct PPC_DFP dfp;
 849     uint32_t b_short = *b;
 850     dfp_prepare_decimal64(&dfp, 0, 0, env);
 851     decimal32ToNumber((decimal32 *)&b_short, &dfp.t);
 852     decimal64FromNumber((decimal64 *)t, &dfp.t, &dfp.context);
 853     dfp_set_FPRF_from_FRT(&dfp);
 854 }
 855
 856 void helper_dctqpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
 857 {
 858     struct PPC_DFP dfp;
 859     dfp_prepare_decimal128(&dfp, 0, 0, env);
 860     decimal64ToNumber((decimal64 *)b, &dfp.t);
 861
 862     dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
 863     dfp_set_FPRF_from_FRT(&dfp);
 864
 865     decimal128FromNumber((decimal128 *)&dfp.t64, &dfp.t, &dfp.context);
 866     t[0] = dfp.t64[HI_IDX];
 867     t[1] = dfp.t64[LO_IDX];
 868 }
 869
 870 void helper_drsp(CPUPPCState *env, uint64_t *t, uint64_t *b)
 871 {
 872     struct PPC_DFP dfp;
 873     uint32_t t_short = 0;
 874     dfp_prepare_decimal64(&dfp, 0, b, env);
 875     decimal32FromNumber((decimal32 *)&t_short, &dfp.b, &dfp.context);
 876     decimal32ToNumber((decimal32 *)&t_short, &dfp.t);
 877
 878     dfp_set_FPRF_from_FRT_short(&dfp);
 879     dfp_check_for_OX(&dfp);
 880     dfp_check_for_UX(&dfp);
 881     dfp_check_for_XX(&dfp);
 882
 883     *t = t_short;
 884 }
 885
 886 void helper_drdpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
 887 {
 888     struct PPC_DFP dfp;
 889     dfp_prepare_decimal128(&dfp, 0, b, env);
 890     decimal64FromNumber((decimal64 *)&dfp.t64, &dfp.b, &dfp.context);
 891     decimal64ToNumber((decimal64 *)&dfp.t64, &dfp.t);
 892
 893     dfp_check_for_VXSNAN_and_convert_to_QNaN(&dfp);
 894     dfp_set_FPRF_from_FRT_long(&dfp);
 895     dfp_check_for_OX(&dfp);
 896     dfp_check_for_UX(&dfp);
 897     dfp_check_for_XX(&dfp);
 898
 899     decimal64FromNumber((decimal64 *)dfp.t64, &dfp.t, &dfp.context);
 900     t[0] = dfp.t64[0];
 901     t[1] = 0;
 902 }
 903
 904 #define DFP_HELPER_CFFIX(op, size)                                             \
 905 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)                   \
 906 {                                                                              \
 907     struct PPC_DFP dfp;                                                        \
 908     dfp_prepare_decimal##size(&dfp, 0, b, env);                                \
 909     decNumberFromInt64(&dfp.t, (int64_t)(*b));                                 \
 910     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
 911     CFFIX_PPs(&dfp);                                                           \
 912                                                                                \
 913     if (size == 64) {                                                          \
 914         t[0] = dfp.t64[0];                                                     \
 915     } else if (size == 128) {                                                  \
 916         t[0] = dfp.t64[HI_IDX];                                                \
 917         t[1] = dfp.t64[LO_IDX];                                                \
 918     }                                                                          \
 919 }
 920
 921 static void CFFIX_PPs(struct PPC_DFP *dfp)
 922 {
 923     dfp_set_FPRF_from_FRT(dfp);
 924     dfp_check_for_XX(dfp);
 925 }
 926
 927 DFP_HELPER_CFFIX(dcffix, 64)
 928 DFP_HELPER_CFFIX(dcffixq, 128)
 929
 930 #define DFP_HELPER_CTFIX(op, size)                                            \
 931 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)                  \
 932 {                                                                             \
 933     struct PPC_DFP dfp;                                                       \
 934     dfp_prepare_decimal##size(&dfp, 0, b, env);                               \
 935                                                                               \
 936     if (unlikely(decNumberIsSpecial(&dfp.b))) {                               \
 937         uint64_t invalid_flags = FP_VX | FP_VXCVI;                            \
 938         if (decNumberIsInfinite(&dfp.b)) {                                    \
 939             dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
 940         } else { /* NaN */                                                    \
 941             dfp.t64[0] = INT64_MIN;                                           \
 942             if (decNumberIsSNaN(&dfp.b)) {                                    \
 943                 invalid_flags |= FP_VXSNAN;                                   \
 944             }                                                                 \
 945         }                                                                     \
 946         dfp_set_FPSCR_flag(&dfp, invalid_flags, FP_VE);                       \
 947     } else if (unlikely(decNumberIsZero(&dfp.b))) {                           \
 948         dfp.t64[0] = 0;                                                       \
 949     } else {                                                                  \
 950         decNumberToIntegralExact(&dfp.b, &dfp.b, &dfp.context);               \
 951         dfp.t64[0] = decNumberIntegralToInt64(&dfp.b, &dfp.context);          \
 952         if (decContextTestStatus(&dfp.context, DEC_Invalid_operation)) {      \
 953             dfp.t64[0] = decNumberIsNegative(&dfp.b) ? INT64_MIN : INT64_MAX; \
 954             dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FP_VE);                \
 955         } else {                                                              \
 956             dfp_check_for_XX(&dfp);                                           \
 957         }                                                                     \
 958     }                                                                         \
 959                                                                               \
 960     *t = dfp.t64[0];                                                          \
 961 }
 962
 963 DFP_HELPER_CTFIX(dctfix, 64)
 964 DFP_HELPER_CTFIX(dctfixq, 128)
 965
 966 static inline void dfp_set_bcd_digit_64(uint64_t *t, uint8_t digit,
 967                                             unsigned n)
 968 {
 969     *t |= ((uint64_t)(digit & 0xF) << (n << 2));
 970 }
 971
 972 static inline void dfp_set_bcd_digit_128(uint64_t *t, uint8_t digit,
 973                                              unsigned n)
 974 {
 975     t[(n & 0x10) ? HI_IDX : LO_IDX] |=
 976         ((uint64_t)(digit & 0xF) << ((n & 15) << 2));
 977 }
 978
 979 static inline void dfp_set_sign_64(uint64_t *t, uint8_t sgn)
 980 {
 981     *t <<= 4;
 982     *t |= (sgn & 0xF);
 983 }
 984
 985 static inline void dfp_set_sign_128(uint64_t *t, uint8_t sgn)
 986 {
 987     t[HI_IDX] <<= 4;
 988     t[HI_IDX] |= (t[LO_IDX] >> 60);
 989     t[LO_IDX] <<= 4;
 990     t[LO_IDX] |= (sgn & 0xF);
 991 }
 992
 993 #define DFP_HELPER_DEDPD(op, size)                                        \
 994 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t sp) \
 995 {                                                                         \
 996     struct PPC_DFP dfp;                                                   \
 997     uint8_t digits[34];                                                   \
 998     int i, N;                                                             \
 999                                                                           \
1000     dfp_prepare_decimal##size(&dfp, 0, b, env);                           \
1001                                                                           \
1002     decNumberGetBCD(&dfp.b, digits);                                      \
1003     dfp.t64[0] = dfp.t64[1] = 0;                                          \
1004     N = dfp.b.digits;                                                     \
1005                                                                           \
1006     for (i = 0; (i < N) && (i < (size)/4); i++) {                         \
1007         dfp_set_bcd_digit_##size(dfp.t64, digits[N-i-1], i);              \
1008     }                                                                     \
1009                                                                           \
1010     if (sp & 2) {                                                         \
1011         uint8_t sgn;                                                      \
1012                                                                           \
1013         if (decNumberIsNegative(&dfp.b)) {                                \
1014             sgn = 0xD;                                                    \
1015         } else {                                                          \
1016             sgn = ((sp & 1) ? 0xF : 0xC);                                 \
1017         }                                                                 \
1018         dfp_set_sign_##size(dfp.t64, sgn);                                \
1019     }                                                                     \
1020                                                                           \
1021     if (size == 64) {                                                     \
1022         t[0] = dfp.t64[0];                                                \
1023     } else if (size == 128) {                                             \
1024         t[0] = dfp.t64[HI_IDX];                                           \
1025         t[1] = dfp.t64[LO_IDX];                                           \
1026     }                                                                     \
1027 }
1028
1029 DFP_HELPER_DEDPD(ddedpd, 64)
1030 DFP_HELPER_DEDPD(ddedpdq, 128)
1031
1032 static inline uint8_t dfp_get_bcd_digit_64(uint64_t *t, unsigned n)
1033 {
1034     return *t >> ((n << 2) & 63) & 15;
1035 }
1036
1037 static inline uint8_t dfp_get_bcd_digit_128(uint64_t *t, unsigned n)
1038 {
1039     return t[(n & 0x10) ? HI_IDX : LO_IDX] >> ((n << 2) & 63) & 15;
1040 }
1041
1042 #define DFP_HELPER_ENBCD(op, size)                                           \
1043 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t s)     \
1044 {                                                                            \
1045     struct PPC_DFP dfp;                                                      \
1046     uint8_t digits[32];                                                      \
1047     int n = 0, offset = 0, sgn = 0, nonzero = 0;                             \
1048                                                                              \
1049     dfp_prepare_decimal##size(&dfp, 0, b, env);                              \
1050                                                                              \
1051     decNumberZero(&dfp.t);                                                   \
1052                                                                              \
1053     if (s) {                                                                 \
1054         uint8_t sgnNibble = dfp_get_bcd_digit_##size(dfp.b64, offset++);     \
1055         switch (sgnNibble) {                                                 \
1056         case 0xD:                                                            \
1057         case 0xB:                                                            \
1058             sgn = 1;                                                         \
1059             break;                                                           \
1060         case 0xC:                                                            \
1061         case 0xF:                                                            \
1062         case 0xA:                                                            \
1063         case 0xE:                                                            \
1064             sgn = 0;                                                         \
1065             break;                                                           \
1066         default:                                                             \
1067             dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE);            \
1068             return;                                                          \
1069         }                                                                    \
1070         }                                                                    \
1071                                                                              \
1072     while (offset < (size)/4) {                                              \
1073         n++;                                                                 \
1074         digits[(size)/4-n] = dfp_get_bcd_digit_##size(dfp.b64, offset++);    \
1075         if (digits[(size)/4-n] > 10) {                                       \
1076             dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE);            \
1077             return;                                                          \
1078         } else {                                                             \
1079             nonzero |= (digits[(size)/4-n] > 0);                             \
1080         }                                                                    \
1081     }                                                                        \
1082                                                                              \
1083     if (nonzero) {                                                           \
1084         decNumberSetBCD(&dfp.t, digits+((size)/4)-n, n);                     \
1085     }                                                                        \
1086                                                                              \
1087     if (s && sgn)  {                                                         \
1088         dfp.t.bits |= DECNEG;                                                \
1089     }                                                                        \
1090     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,              \
1091                               &dfp.context);                                 \
1092     dfp_set_FPRF_from_FRT(&dfp);                                             \
1093     if ((size) == 64) {                                                      \
1094         t[0] = dfp.t64[0];                                                   \
1095     } else if ((size) == 128) {                                              \
1096         t[0] = dfp.t64[HI_IDX];                                              \
1097         t[1] = dfp.t64[LO_IDX];                                              \
1098     }                                                                        \
1099 }
1100
1101 DFP_HELPER_ENBCD(denbcd, 64)
1102 DFP_HELPER_ENBCD(denbcdq, 128)
1103
1104 #define DFP_HELPER_XEX(op, size)                               \
1105 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)   \
1106 {                                                              \
1107     struct PPC_DFP dfp;                                        \
1108                                                                \
1109     dfp_prepare_decimal##size(&dfp, 0, b, env);                \
1110                                                                \
1111     if (unlikely(decNumberIsSpecial(&dfp.b))) {                \
1112         if (decNumberIsInfinite(&dfp.b)) {                     \
1113             *t = -1;                                           \
1114         } else if (decNumberIsSNaN(&dfp.b)) {                  \
1115             *t = -3;                                           \
1116         } else if (decNumberIsQNaN(&dfp.b)) {                  \
1117             *t = -2;                                           \
1118         } else {                                               \
1119             assert(0);                                         \
1120         }                                                      \
1121     } else {                                                   \
1122         if ((size) == 64) {                                    \
1123             *t = dfp.b.exponent + 398;                         \
1124         } else if ((size) == 128) {                            \
1125             *t = dfp.b.exponent + 6176;                        \
1126         } else {                                               \
1127             assert(0);                                         \
1128         }                                                      \
1129     }                                                          \
1130 }
1131
1132 DFP_HELPER_XEX(dxex, 64)
1133 DFP_HELPER_XEX(dxexq, 128)
1134
1135 static void dfp_set_raw_exp_64(uint64_t *t, uint64_t raw)
1136 {
1137     *t &= 0x8003ffffffffffffULL;
1138     *t |= (raw << (63-13));
1139 }
1140
1141 static void dfp_set_raw_exp_128(uint64_t *t, uint64_t raw)
1142 {
1143     t[HI_IDX] &= 0x80003fffffffffffULL;
1144     t[HI_IDX] |= (raw << (63-17));
1145 }
1146
1147 #define DFP_HELPER_IEX(op, size)                                          \
1148 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b) \
1149 {                                                                         \
1150     struct PPC_DFP dfp;                                                   \
1151     uint64_t raw_qnan, raw_snan, raw_inf, max_exp;                        \
1152     int bias;                                                             \
1153     int64_t exp = *((int64_t *)a);                                        \
1154                                                                           \
1155     dfp_prepare_decimal##size(&dfp, 0, b, env);                           \
1156                                                                           \
1157     if ((size) == 64) {                                                   \
1158         max_exp = 767;                                                    \
1159         raw_qnan = 0x1F00;                                                \
1160         raw_snan = 0x1F80;                                                \
1161         raw_inf = 0x1E00;                                                 \
1162         bias = 398;                                                       \
1163     } else if ((size) == 128) {                                           \
1164         max_exp = 12287;                                                  \
1165         raw_qnan = 0x1f000;                                               \
1166         raw_snan = 0x1f800;                                               \
1167         raw_inf = 0x1e000;                                                \
1168         bias = 6176;                                                      \
1169     } else {                                                              \
1170         assert(0);                                                        \
1171     }                                                                     \
1172                                                                           \
1173     if (unlikely((exp < 0) || (exp > max_exp))) {                         \
1174         dfp.t64[0] = dfp.b64[0];                                          \
1175         dfp.t64[1] = dfp.b64[1];                                          \
1176         if (exp == -1) {                                                  \
1177             dfp_set_raw_exp_##size(dfp.t64, raw_inf);                     \
1178         } else if (exp == -3) {                                           \
1179             dfp_set_raw_exp_##size(dfp.t64, raw_snan);                    \
1180         } else {                                                          \
1181             dfp_set_raw_exp_##size(dfp.t64, raw_qnan);                    \
1182         }                                                                 \
1183     } else {                                                              \
1184         dfp.t = dfp.b;                                                    \
1185         if (unlikely(decNumberIsSpecial(&dfp.t))) {                       \
1186             dfp.t.bits &= ~DECSPECIAL;                                    \
1187         }                                                                 \
1188         dfp.t.exponent = exp - bias;                                      \
1189         decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t,       \
1190                                   &dfp.context);                          \
1191     }                                                                     \
1192     if (size == 64) {                                                     \
1193         t[0] = dfp.t64[0];                                                \
1194     } else if (size == 128) {                                             \
1195         t[0] = dfp.t64[HI_IDX];                                           \
1196         t[1] = dfp.t64[LO_IDX];                                           \
1197     }                                                                     \
1198 }
1199
1200 DFP_HELPER_IEX(diex, 64)
1201 DFP_HELPER_IEX(diexq, 128)
1202
1203 static void dfp_clear_lmd_from_g5msb(uint64_t *t)
1204 {
1205
1206     /* The most significant 5 bits of the PowerPC DFP format combine bits  */
1207     /* from the left-most decimal digit (LMD) and the biased exponent.     */
1208     /* This  routine clears the LMD bits while preserving the exponent     */
1209     /*  bits.  See "Figure 80: Encoding of bits 0:4 of the G field for     */
1210     /*  Finite Numbers" in the Power ISA for additional details.           */
1211
1212     uint64_t g5msb = (*t >> 58) & 0x1F;
1213
1214     if ((g5msb >> 3) < 3) { /* LMD in [0-7] ? */
1215        *t &= ~(7ULL << 58);
1216     } else {
1217        switch (g5msb & 7) {
1218        case 0:
1219        case 1:
1220            g5msb = 0;
1221            break;
1222        case 2:
1223        case 3:
1224            g5msb = 0x8;
1225            break;
1226        case 4:
1227        case 5:
1228            g5msb = 0x10;
1229            break;
1230        case 6:
1231            g5msb = 0x1E;
1232            break;
1233        case 7:
1234            g5msb = 0x1F;
1235            break;
1236        }
1237
1238         *t &= ~(0x1fULL << 58);
1239         *t |= (g5msb << 58);
1240     }
1241 }
1242
1243 #define DFP_HELPER_SHIFT(op, size, shift_left)                      \
1244 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,        \
1245                  uint32_t sh)                                       \
1246 {                                                                   \
1247     struct PPC_DFP dfp;                                             \
1248     unsigned max_digits = ((size) == 64) ? 16 : 34;                 \
1249                                                                     \
1250     dfp_prepare_decimal##size(&dfp, a, 0, env);                     \
1251                                                                     \
1252     if (sh <= max_digits) {                                         \
1253                                                                     \
1254         decNumber shd;                                              \
1255         unsigned special = dfp.a.bits & DECSPECIAL;                 \
1256                                                                     \
1257         if (shift_left) {                                           \
1258             decNumberFromUInt32(&shd, sh);                          \
1259         } else {                                                    \
1260             decNumberFromInt32(&shd, -((int32_t)sh));               \
1261         }                                                           \
1262                                                                     \
1263         dfp.a.bits &= ~DECSPECIAL;                                  \
1264         decNumberShift(&dfp.t, &dfp.a, &shd, &dfp.context);         \
1265                                                                     \
1266         dfp.t.bits |= special;                                      \
1267         if (special && (dfp.t.digits >= max_digits)) {              \
1268             dfp.t.digits = max_digits - 1;                          \
1269         }                                                           \
1270                                                                     \
1271         decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, \
1272                                   &dfp.context);                    \
1273     } else {                                                        \
1274         if ((size) == 64) {                                         \
1275             dfp.t64[0] = dfp.a64[0] & 0xFFFC000000000000ULL;        \
1276             dfp_clear_lmd_from_g5msb(dfp.t64);                      \
1277         } else {                                                    \
1278             dfp.t64[HI_IDX] = dfp.a64[HI_IDX] &                     \
1279                               0xFFFFC00000000000ULL;                \
1280             dfp_clear_lmd_from_g5msb(dfp.t64 + HI_IDX);             \
1281             dfp.t64[LO_IDX] = 0;                                    \
1282         }                                                           \
1283     }                                                               \
1284                                                                     \
1285     if ((size) == 64) {                                             \
1286         t[0] = dfp.t64[0];                                          \
1287     } else {                                                        \
1288         t[0] = dfp.t64[HI_IDX];                                     \
1289         t[1] = dfp.t64[LO_IDX];                                     \
1290     }                                                               \
1291 }
1292
1293 DFP_HELPER_SHIFT(dscli, 64, 1)
1294 DFP_HELPER_SHIFT(dscliq, 128, 1)
1295 DFP_HELPER_SHIFT(dscri, 64, 0)
1296 DFP_HELPER_SHIFT(dscriq, 128, 0)