arch/sparc64/math-emu/math.c

   1 /* $Id: math.c,v 1.11 1999/12/20 05:02:25 davem Exp $
   2  * arch/sparc64/math-emu/math.c
   3  *
   4  * Copyright (C) 1997,1999 Jakub Jelinek (jj@ultra.linux.cz)
   5  * Copyright (C) 1999 David S. Miller (davem@redhat.com)
   6  *
   7  * Emulation routines originate from soft-fp package, which is part
   8  * of glibc and has appropriate copyrights in it.
   9  */
  10
  11 #include <linux/types.h>
  12 #include <linux/sched.h>
  13 #include <linux/errno.h>
  14
  15 #include <asm/fpumacro.h>
  16 #include <asm/ptrace.h>
  17 #include <asm/uaccess.h>
  18
  19 #include "sfp-util.h"
  20 #include <math-emu/soft-fp.h>
  21 #include <math-emu/single.h>
  22 #include <math-emu/double.h>
  23 #include <math-emu/quad.h>
  24
  25 /* QUAD - ftt == 3 */
  26 #define FMOVQ   0x003
  27 #define FNEGQ   0x007
  28 #define FABSQ   0x00b
  29 #define FSQRTQ  0x02b
  30 #define FADDQ   0x043
  31 #define FSUBQ   0x047
  32 #define FMULQ   0x04b
  33 #define FDIVQ   0x04f
  34 #define FDMULQ  0x06e
  35 #define FQTOX   0x083
  36 #define FXTOQ   0x08c
  37 #define FQTOS   0x0c7
  38 #define FQTOD   0x0cb
  39 #define FITOQ   0x0cc
  40 #define FSTOQ   0x0cd
  41 #define FDTOQ   0x0ce
  42 #define FQTOI   0x0d3
  43 /* SUBNORMAL - ftt == 2 */
  44 #define FSQRTS  0x029
  45 #define FSQRTD  0x02a
  46 #define FADDS   0x041
  47 #define FADDD   0x042
  48 #define FSUBS   0x045
  49 #define FSUBD   0x046
  50 #define FMULS   0x049
  51 #define FMULD   0x04a
  52 #define FDIVS   0x04d
  53 #define FDIVD   0x04e
  54 #define FSMULD  0x069
  55 #define FSTOX   0x081
  56 #define FDTOX   0x082
  57 #define FDTOS   0x0c6
  58 #define FSTOD   0x0c9
  59 #define FSTOI   0x0d1
  60 #define FDTOI   0x0d2
  61 #define FXTOS   0x084 /* Only Ultra-III generates this. */
  62 #define FXTOD   0x088 /* Only Ultra-III generates this. */
  63 #if 0   /* Optimized inline in sparc64/kernel/entry.S */
  64 #define FITOS   0x0c4 /* Only Ultra-III generates this. */
  65 #endif
  66 #define FITOD   0x0c8 /* Only Ultra-III generates this. */
  67 /* FPOP2 */
  68 #define FCMPQ   0x053
  69 #define FCMPEQ  0x057
  70 #define FMOVQ0  0x003
  71 #define FMOVQ1  0x043
  72 #define FMOVQ2  0x083
  73 #define FMOVQ3  0x0c3
  74 #define FMOVQI  0x103
  75 #define FMOVQX  0x183
  76 #define FMOVQZ  0x027
  77 #define FMOVQLE 0x047
  78 #define FMOVQLZ 0x067
  79 #define FMOVQNZ 0x0a7
  80 #define FMOVQGZ 0x0c7
  81 #define FMOVQGE 0x0e7
  82
  83 #define FSR_TEM_SHIFT   23UL
  84 #define FSR_TEM_MASK    (0x1fUL << FSR_TEM_SHIFT)
  85 #define FSR_AEXC_SHIFT  5UL
  86 #define FSR_AEXC_MASK   (0x1fUL << FSR_AEXC_SHIFT)
  87 #define FSR_CEXC_SHIFT  0UL
  88 #define FSR_CEXC_MASK   (0x1fUL << FSR_CEXC_SHIFT)
  89
  90 /* All routines returning an exception to raise should detect
  91  * such exceptions _before_ rounding to be consistent with
  92  * the behavior of the hardware in the implemented cases
  93  * (and thus with the recommendations in the V9 architecture
  94  * manual).
  95  *
  96  * We return 0 if a SIGFPE should be sent, 1 otherwise.
  97  */
  98 static inline int record_exception(struct pt_regs *regs, int eflag)
  99 {
 100         u64 fsr = current_thread_info()->xfsr[0];
 101         int would_trap;
 102
 103         /* Determine if this exception would have generated a trap. */
 104         would_trap = (fsr & ((long)eflag << FSR_TEM_SHIFT)) != 0UL;
 105
 106         /* If trapping, we only want to signal one bit. */
 107         if(would_trap != 0) {
 108                 eflag &= ((fsr & FSR_TEM_MASK) >> FSR_TEM_SHIFT);
 109                 if((eflag & (eflag - 1)) != 0) {
 110                         if(eflag & FP_EX_INVALID)
 111                                 eflag = FP_EX_INVALID;
 112                         else if(eflag & FP_EX_OVERFLOW)
 113                                 eflag = FP_EX_OVERFLOW;
 114                         else if(eflag & FP_EX_UNDERFLOW)
 115                                 eflag = FP_EX_UNDERFLOW;
 116                         else if(eflag & FP_EX_DIVZERO)
 117                                 eflag = FP_EX_DIVZERO;
 118                         else if(eflag & FP_EX_INEXACT)
 119                                 eflag = FP_EX_INEXACT;
 120                 }
 121         }
 122
 123         /* Set CEXC, here is the rule:
 124          *
 125          *    In general all FPU ops will set one and only one
 126          *    bit in the CEXC field, this is always the case
 127          *    when the IEEE exception trap is enabled in TEM.
 128          */
 129         fsr &= ~(FSR_CEXC_MASK);
 130         fsr |= ((long)eflag << FSR_CEXC_SHIFT);
 131
 132         /* Set the AEXC field, rule is:
 133          *
 134          *    If a trap would not be generated, the
 135          *    CEXC just generated is OR'd into the
 136          *    existing value of AEXC.
 137          */
 138         if(would_trap == 0)
 139                 fsr |= ((long)eflag << FSR_AEXC_SHIFT);
 140
 141         /* If trapping, indicate fault trap type IEEE. */
 142         if(would_trap != 0)
 143                 fsr |= (1UL << 14);
 144
 145         current_thread_info()->xfsr[0] = fsr;
 146
 147         /* If we will not trap, advance the program counter over
 148          * the instruction being handled.
 149          */
 150         if(would_trap == 0) {
 151                 regs->tpc = regs->tnpc;
 152                 regs->tnpc += 4;
 153         }
 154
 155         return (would_trap ? 0 : 1);
 156 }
 157
 158 typedef union {
 159         u32 s;
 160         u64 d;
 161         u64 q[2];
 162 } *argp;
 163
 164 int do_mathemu(struct pt_regs *regs, struct fpustate *f)
 165 {
 166         unsigned long pc = regs->tpc;
 167         unsigned long tstate = regs->tstate;
 168         u32 insn = 0;
 169         int type = 0;
 170         /* ftt tells which ftt it may happen in, r is rd, b is rs2 and a is rs1. The *u arg tells
 171            whether the argument should be packed/unpacked (0 - do not unpack/pack, 1 - unpack/pack)
 172            non-u args tells the size of the argument (0 - no argument, 1 - single, 2 - double, 3 - quad */
 173 #define TYPE(ftt, r, ru, b, bu, a, au) type = (au << 2) | (a << 0) | (bu << 5) | (b << 3) | (ru << 8) | (r << 6) | (ftt << 9)
 174         int freg;
 175         static u64 zero[2] = { 0L, 0L };
 176         int flags;
 177         FP_DECL_EX;
 178         FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);
 179         FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR);
 180         FP_DECL_Q(QA); FP_DECL_Q(QB); FP_DECL_Q(QR);
 181         int IR;
 182         long XR, xfsr;
 183
 184         if (tstate & TSTATE_PRIV)
 185                 die_if_kernel("unfinished/unimplemented FPop from kernel", regs);
 186         if (test_thread_flag(TIF_32BIT))
 187                 pc = (u32)pc;
 188         if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 189                 if ((insn & 0xc1f80000) == 0x81a00000) /* FPOP1 */ {
 190                         switch ((insn >> 5) & 0x1ff) {
 191                         /* QUAD - ftt == 3 */
 192                         case FMOVQ:
 193                         case FNEGQ:
 194                         case FABSQ: TYPE(3,3,0,3,0,0,0); break;
 195                         case FSQRTQ: TYPE(3,3,1,3,1,0,0); break;
 196                         case FADDQ:
 197                         case FSUBQ:
 198                         case FMULQ:
 199                         case FDIVQ: TYPE(3,3,1,3,1,3,1); break;
 200                         case FDMULQ: TYPE(3,3,1,2,1,2,1); break;
 201                         case FQTOX: TYPE(3,2,0,3,1,0,0); break;
 202                         case FXTOQ: TYPE(3,3,1,2,0,0,0); break;
 203                         case FQTOS: TYPE(3,1,1,3,1,0,0); break;
 204                         case FQTOD: TYPE(3,2,1,3,1,0,0); break;
 205                         case FITOQ: TYPE(3,3,1,1,0,0,0); break;
 206                         case FSTOQ: TYPE(3,3,1,1,1,0,0); break;
 207                         case FDTOQ: TYPE(3,3,1,2,1,0,0); break;
 208                         case FQTOI: TYPE(3,1,0,3,1,0,0); break;
 209                         /* SUBNORMAL - ftt == 2 */
 210                         case FSQRTS: TYPE(2,1,1,1,1,0,0); break;
 211                         case FSQRTD: TYPE(2,2,1,2,1,0,0); break;
 212                         case FADDD:
 213                         case FSUBD:
 214                         case FMULD:
 215                         case FDIVD: TYPE(2,2,1,2,1,2,1); break;
 216                         case FADDS:
 217                         case FSUBS:
 218                         case FMULS:
 219                         case FDIVS: TYPE(2,1,1,1,1,1,1); break;
 220                         case FSMULD: TYPE(2,2,1,1,1,1,1); break;
 221                         case FSTOX: TYPE(2,2,0,1,1,0,0); break;
 222                         case FDTOX: TYPE(2,2,0,2,1,0,0); break;
 223                         case FDTOS: TYPE(2,1,1,2,1,0,0); break;
 224                         case FSTOD: TYPE(2,2,1,1,1,0,0); break;
 225                         case FSTOI: TYPE(2,1,0,1,1,0,0); break;
 226                         case FDTOI: TYPE(2,1,0,2,1,0,0); break;
 227
 228                         /* Only Ultra-III generates these */
 229                         case FXTOS: TYPE(2,1,1,2,0,0,0); break;
 230                         case FXTOD: TYPE(2,2,1,2,0,0,0); break;
 231 #if 0                   /* Optimized inline in sparc64/kernel/entry.S */
 232                         case FITOS: TYPE(2,1,1,1,0,0,0); break;
 233 #endif
 234                         case FITOD: TYPE(2,2,1,1,0,0,0); break;
 235                         }
 236                 }
 237                 else if ((insn & 0xc1f80000) == 0x81a80000) /* FPOP2 */ {
 238                         IR = 2;
 239                         switch ((insn >> 5) & 0x1ff) {
 240                         case FCMPQ: TYPE(3,0,0,3,1,3,1); break;
 241                         case FCMPEQ: TYPE(3,0,0,3,1,3,1); break;
 242                         /* Now the conditional fmovq support */
 243                         case FMOVQ0:
 244                         case FMOVQ1:
 245                         case FMOVQ2:
 246                         case FMOVQ3:
 247                                 /* fmovq %fccX, %fY, %fZ */
 248                                 if (!((insn >> 11) & 3))
 249                                         XR = current_thread_info()->xfsr[0] >> 10;
 250                                 else
 251                                         XR = current_thread_info()->xfsr[0] >> (30 + ((insn >> 10) & 0x6));
 252                                 XR &= 3;
 253                                 IR = 0;
 254                                 switch ((insn >> 14) & 0x7) {
 255                                 /* case 0: IR = 0; break; */                    /* Never */
 256                                 case 1: if (XR) IR = 1; break;                  /* Not Equal */
 257                                 case 2: if (XR == 1 || XR == 2) IR = 1; break;  /* Less or Greater */
 258                                 case 3: if (XR & 1) IR = 1; break;              /* Unordered or Less */
 259                                 case 4: if (XR == 1) IR = 1; break;             /* Less */
 260                                 case 5: if (XR & 2) IR = 1; break;              /* Unordered or Greater */
 261                                 case 6: if (XR == 2) IR = 1; break;             /* Greater */
 262                                 case 7: if (XR == 3) IR = 1; break;             /* Unordered */
 263                                 }
 264                                 if ((insn >> 14) & 8)
 265                                         IR ^= 1;
 266                                 break;
 267                         case FMOVQI:
 268                         case FMOVQX:
 269                                 /* fmovq %[ix]cc, %fY, %fZ */
 270                                 XR = regs->tstate >> 32;
 271                                 if ((insn >> 5) & 0x80)
 272                                         XR >>= 4;
 273                                 XR &= 0xf;
 274                                 IR = 0;
 275                                 freg = ((XR >> 2) ^ XR) & 2;
 276                                 switch ((insn >> 14) & 0x7) {
 277                                 /* case 0: IR = 0; break; */                    /* Never */
 278                                 case 1: if (XR & 4) IR = 1; break;              /* Equal */
 279                                 case 2: if ((XR & 4) || freg) IR = 1; break;    /* Less or Equal */
 280                                 case 3: if (freg) IR = 1; break;                /* Less */
 281                                 case 4: if (XR & 5) IR = 1; break;              /* Less or Equal Unsigned */
 282                                 case 5: if (XR & 1) IR = 1; break;              /* Carry Set */
 283                                 case 6: if (XR & 8) IR = 1; break;              /* Negative */
 284                                 case 7: if (XR & 2) IR = 1; break;              /* Overflow Set */
 285                                 }
 286                                 if ((insn >> 14) & 8)
 287                                         IR ^= 1;
 288                                 break;
 289                         case FMOVQZ:
 290                         case FMOVQLE:
 291                         case FMOVQLZ:
 292                         case FMOVQNZ:
 293                         case FMOVQGZ:
 294                         case FMOVQGE:
 295                                 freg = (insn >> 14) & 0x1f;
 296                                 if (!freg)
 297                                         XR = 0;
 298                                 else if (freg < 16)
 299                                         XR = regs->u_regs[freg];
 300                                 else if (test_thread_flag(TIF_32BIT)) {
 301                                         struct reg_window32 __user *win32;
 302                                         flushw_user ();
 303                                         win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
 304                                         get_user(XR, &win32->locals[freg - 16]);
 305                                 } else {
 306                                         struct reg_window __user *win;
 307                                         flushw_user ();
 308                                         win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
 309                                         get_user(XR, &win->locals[freg - 16]);
 310                                 }
 311                                 IR = 0;
 312                                 switch ((insn >> 10) & 3) {
 313                                 case 1: if (!XR) IR = 1; break;                 /* Register Zero */
 314                                 case 2: if (XR <= 0) IR = 1; break;             /* Register Less Than or Equal to Zero */
 315                                 case 3: if (XR < 0) IR = 1; break;              /* Register Less Than Zero */
 316                                 }
 317                                 if ((insn >> 10) & 4)
 318                                         IR ^= 1;
 319                                 break;
 320                         }
 321                         if (IR == 0) {
 322                                 /* The fmov test was false. Do a nop instead */
 323                                 current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK);
 324                                 regs->tpc = regs->tnpc;
 325                                 regs->tnpc += 4;
 326                                 return 1;
 327                         } else if (IR == 1) {
 328                                 /* Change the instruction into plain fmovq */
 329                                 insn = (insn & 0x3e00001f) | 0x81a00060;
 330                                 TYPE(3,3,0,3,0,0,0);
 331                         }
 332                 }
 333         }
 334         if (type) {
 335                 argp rs1 = NULL, rs2 = NULL, rd = NULL;
 336
 337                 freg = (current_thread_info()->xfsr[0] >> 14) & 0xf;
 338                 if (freg != (type >> 9))
 339                         goto err;
 340                 current_thread_info()->xfsr[0] &= ~0x1c000;
 341                 freg = ((insn >> 14) & 0x1f);
 342                 switch (type & 0x3) {
 343                 case 3: if (freg & 2) {
 344                                 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 345                                 goto err;
 346                         }
 347                 case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
 348                 case 1: rs1 = (argp)&f->regs[freg];
 349                         flags = (freg < 32) ? FPRS_DL : FPRS_DU;
 350                         if (!(current_thread_info()->fpsaved[0] & flags))
 351                                 rs1 = (argp)&zero;
 352                         break;
 353                 }
 354                 switch (type & 0x7) {
 355                 case 7: FP_UNPACK_QP (QA, rs1); break;
 356                 case 6: FP_UNPACK_DP (DA, rs1); break;
 357                 case 5: FP_UNPACK_SP (SA, rs1); break;
 358                 }
 359                 freg = (insn & 0x1f);
 360                 switch ((type >> 3) & 0x3) {
 361                 case 3: if (freg & 2) {
 362                                 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 363                                 goto err;
 364                         }
 365                 case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
 366                 case 1: rs2 = (argp)&f->regs[freg];
 367                         flags = (freg < 32) ? FPRS_DL : FPRS_DU;
 368                         if (!(current_thread_info()->fpsaved[0] & flags))
 369                                 rs2 = (argp)&zero;
 370                         break;
 371                 }
 372                 switch ((type >> 3) & 0x7) {
 373                 case 7: FP_UNPACK_QP (QB, rs2); break;
 374                 case 6: FP_UNPACK_DP (DB, rs2); break;
 375                 case 5: FP_UNPACK_SP (SB, rs2); break;
 376                 }
 377                 freg = ((insn >> 25) & 0x1f);
 378                 switch ((type >> 6) & 0x3) {
 379                 case 3: if (freg & 2) {
 380                                 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 381                                 goto err;
 382                         }
 383                 case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
 384                 case 1: rd = (argp)&f->regs[freg];
 385                         flags = (freg < 32) ? FPRS_DL : FPRS_DU;
 386                         if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 387                                 current_thread_info()->fpsaved[0] = FPRS_FEF;
 388                                 current_thread_info()->gsr[0] = 0;
 389                         }
 390                         if (!(current_thread_info()->fpsaved[0] & flags)) {
 391                                 if (freg < 32)
 392                                         memset(f->regs, 0, 32*sizeof(u32));
 393                                 else
 394                                         memset(f->regs+32, 0, 32*sizeof(u32));
 395                         }
 396                         current_thread_info()->fpsaved[0] |= flags;
 397                         break;
 398                 }
 399                 switch ((insn >> 5) & 0x1ff) {
 400                 /* + */
 401                 case FADDS: FP_ADD_S (SR, SA, SB); break;
 402                 case FADDD: FP_ADD_D (DR, DA, DB); break;
 403                 case FADDQ: FP_ADD_Q (QR, QA, QB); break;
 404                 /* - */
 405                 case FSUBS: FP_SUB_S (SR, SA, SB); break;
 406                 case FSUBD: FP_SUB_D (DR, DA, DB); break;
 407                 case FSUBQ: FP_SUB_Q (QR, QA, QB); break;
 408                 /* * */
 409                 case FMULS: FP_MUL_S (SR, SA, SB); break;
 410                 case FSMULD: FP_CONV (D, S, 1, 1, DA, SA);
 411                              FP_CONV (D, S, 1, 1, DB, SB);
 412                 case FMULD: FP_MUL_D (DR, DA, DB); break;
 413                 case FDMULQ: FP_CONV (Q, D, 2, 1, QA, DA);
 414                              FP_CONV (Q, D, 2, 1, QB, DB);
 415                 case FMULQ: FP_MUL_Q (QR, QA, QB); break;
 416                 /* / */
 417                 case FDIVS: FP_DIV_S (SR, SA, SB); break;
 418                 case FDIVD: FP_DIV_D (DR, DA, DB); break;
 419                 case FDIVQ: FP_DIV_Q (QR, QA, QB); break;
 420                 /* sqrt */
 421                 case FSQRTS: FP_SQRT_S (SR, SB); break;
 422                 case FSQRTD: FP_SQRT_D (DR, DB); break;
 423                 case FSQRTQ: FP_SQRT_Q (QR, QB); break;
 424                 /* mov */
 425                 case FMOVQ: rd->q[0] = rs2->q[0]; rd->q[1] = rs2->q[1]; break;
 426                 case FABSQ: rd->q[0] = rs2->q[0] & 0x7fffffffffffffffUL; rd->q[1] = rs2->q[1]; break;
 427                 case FNEGQ: rd->q[0] = rs2->q[0] ^ 0x8000000000000000UL; rd->q[1] = rs2->q[1]; break;
 428                 /* float to int */
 429                 case FSTOI: FP_TO_INT_S (IR, SB, 32, 1); break;
 430                 case FDTOI: FP_TO_INT_D (IR, DB, 32, 1); break;
 431                 case FQTOI: FP_TO_INT_Q (IR, QB, 32, 1); break;
 432                 case FSTOX: FP_TO_INT_S (XR, SB, 64, 1); break;
 433                 case FDTOX: FP_TO_INT_D (XR, DB, 64, 1); break;
 434                 case FQTOX: FP_TO_INT_Q (XR, QB, 64, 1); break;
 435                 /* int to float */
 436                 case FITOQ: IR = rs2->s; FP_FROM_INT_Q (QR, IR, 32, int); break;
 437                 case FXTOQ: XR = rs2->d; FP_FROM_INT_Q (QR, XR, 64, long); break;
 438                 /* Only Ultra-III generates these */
 439                 case FXTOS: XR = rs2->d; FP_FROM_INT_S (SR, XR, 64, long); break;
 440                 case FXTOD: XR = rs2->d; FP_FROM_INT_D (DR, XR, 64, long); break;
 441 #if 0           /* Optimized inline in sparc64/kernel/entry.S */
 442                 case FITOS: IR = rs2->s; FP_FROM_INT_S (SR, IR, 32, int); break;
 443 #endif
 444                 case FITOD: IR = rs2->s; FP_FROM_INT_D (DR, IR, 32, int); break;
 445                 /* float to float */
 446                 case FSTOD: FP_CONV (D, S, 1, 1, DR, SB); break;
 447                 case FSTOQ: FP_CONV (Q, S, 2, 1, QR, SB); break;
 448                 case FDTOQ: FP_CONV (Q, D, 2, 1, QR, DB); break;
 449                 case FDTOS: FP_CONV (S, D, 1, 1, SR, DB); break;
 450                 case FQTOS: FP_CONV (S, Q, 1, 2, SR, QB); break;
 451                 case FQTOD: FP_CONV (D, Q, 1, 2, DR, QB); break;
 452                 /* comparison */
 453                 case FCMPQ:
 454                 case FCMPEQ:
 455                         FP_CMP_Q(XR, QB, QA, 3);
 456                         if (XR == 3 &&
 457                             (((insn >> 5) & 0x1ff) == FCMPEQ ||
 458                              FP_ISSIGNAN_Q(QA) ||
 459                              FP_ISSIGNAN_Q(QB)))
 460                                 FP_SET_EXCEPTION (FP_EX_INVALID);
 461                 }
 462                 if (!FP_INHIBIT_RESULTS) {
 463                         switch ((type >> 6) & 0x7) {
 464                         case 0: xfsr = current_thread_info()->xfsr[0];
 465                                 if (XR == -1) XR = 2;
 466                                 switch (freg & 3) {
 467                                 /* fcc0, 1, 2, 3 */
 468                                 case 0: xfsr &= ~0xc00; xfsr |= (XR << 10); break;
 469                                 case 1: xfsr &= ~0x300000000UL; xfsr |= (XR << 32); break;
 470                                 case 2: xfsr &= ~0xc00000000UL; xfsr |= (XR << 34); break;
 471                                 case 3: xfsr &= ~0x3000000000UL; xfsr |= (XR << 36); break;
 472                                 }
 473                                 current_thread_info()->xfsr[0] = xfsr;
 474                                 break;
 475                         case 1: rd->s = IR; break;
 476                         case 2: rd->d = XR; break;
 477                         case 5: FP_PACK_SP (rd, SR); break;
 478                         case 6: FP_PACK_DP (rd, DR); break;
 479                         case 7: FP_PACK_QP (rd, QR); break;
 480                         }
 481                 }
 482
 483                 if(_fex != 0)
 484                         return record_exception(regs, _fex);
 485
 486                 /* Success and no exceptions detected. */
 487                 current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK);
 488                 regs->tpc = regs->tnpc;
 489                 regs->tnpc += 4;
 490                 return 1;
 491         }
 492 err:    return 0;
 493 }