linux/arch/sparc/math-emu/math_64.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * arch/sparc64/math-emu/math.c
   4 *
   5 * Copyright (C) 1997,1999 Jakub Jelinek (jj@ultra.linux.cz)
   6 * Copyright (C) 1999 David S. Miller (davem@redhat.com)
   7 *
   8 * Emulation routines originate from soft-fp package, which is part
   9 * of glibc and has appropriate copyrights in it.
  10 */
  11
  12#include <linux/types.h>
  13#include <linux/sched.h>
  14#include <linux/errno.h>
  15#include <linux/perf_event.h>
  16
  17#include <asm/fpumacro.h>
  18#include <asm/ptrace.h>
  19#include <linux/uaccess.h>
  20#include <asm/cacheflush.h>
  21
  22#include "sfp-util_64.h"
  23#include <math-emu/soft-fp.h>
  24#include <math-emu/single.h>
  25#include <math-emu/double.h>
  26#include <math-emu/quad.h>
  27
  28/* QUAD - ftt == 3 */
  29#define FMOVQ   0x003
  30#define FNEGQ   0x007
  31#define FABSQ   0x00b
  32#define FSQRTQ  0x02b
  33#define FADDQ   0x043
  34#define FSUBQ   0x047
  35#define FMULQ   0x04b
  36#define FDIVQ   0x04f
  37#define FDMULQ  0x06e
  38#define FQTOX   0x083
  39#define FXTOQ   0x08c
  40#define FQTOS   0x0c7
  41#define FQTOD   0x0cb
  42#define FITOQ   0x0cc
  43#define FSTOQ   0x0cd
  44#define FDTOQ   0x0ce
  45#define FQTOI   0x0d3
  46/* SUBNORMAL - ftt == 2 */
  47#define FSQRTS  0x029
  48#define FSQRTD  0x02a
  49#define FADDS   0x041
  50#define FADDD   0x042
  51#define FSUBS   0x045
  52#define FSUBD   0x046
  53#define FMULS   0x049
  54#define FMULD   0x04a
  55#define FDIVS   0x04d
  56#define FDIVD   0x04e
  57#define FSMULD  0x069
  58#define FSTOX   0x081
  59#define FDTOX   0x082
  60#define FDTOS   0x0c6
  61#define FSTOD   0x0c9
  62#define FSTOI   0x0d1
  63#define FDTOI   0x0d2
  64#define FXTOS   0x084 /* Only Ultra-III generates this. */
  65#define FXTOD   0x088 /* Only Ultra-III generates this. */
  66#if 0   /* Optimized inline in sparc64/kernel/entry.S */
  67#define FITOS   0x0c4 /* Only Ultra-III generates this. */
  68#endif
  69#define FITOD   0x0c8 /* Only Ultra-III generates this. */
  70/* FPOP2 */
  71#define FCMPQ   0x053
  72#define FCMPEQ  0x057
  73#define FMOVQ0  0x003
  74#define FMOVQ1  0x043
  75#define FMOVQ2  0x083
  76#define FMOVQ3  0x0c3
  77#define FMOVQI  0x103
  78#define FMOVQX  0x183
  79#define FMOVQZ  0x027
  80#define FMOVQLE 0x047
  81#define FMOVQLZ 0x067
  82#define FMOVQNZ 0x0a7
  83#define FMOVQGZ 0x0c7
  84#define FMOVQGE 0x0e7
  85
  86#define FSR_TEM_SHIFT   23UL
  87#define FSR_TEM_MASK    (0x1fUL << FSR_TEM_SHIFT)
  88#define FSR_AEXC_SHIFT  5UL
  89#define FSR_AEXC_MASK   (0x1fUL << FSR_AEXC_SHIFT)
  90#define FSR_CEXC_SHIFT  0UL
  91#define FSR_CEXC_MASK   (0x1fUL << FSR_CEXC_SHIFT)
  92
  93/* All routines returning an exception to raise should detect
  94 * such exceptions _before_ rounding to be consistent with
  95 * the behavior of the hardware in the implemented cases
  96 * (and thus with the recommendations in the V9 architecture
  97 * manual).
  98 *
  99 * We return 0 if a SIGFPE should be sent, 1 otherwise.
 100 */
 101static inline int record_exception(struct pt_regs *regs, int eflag)
 102{
 103        u64 fsr = current_thread_info()->xfsr[0];
 104        int would_trap;
 105
 106        /* Determine if this exception would have generated a trap. */
 107        would_trap = (fsr & ((long)eflag << FSR_TEM_SHIFT)) != 0UL;
 108
 109        /* If trapping, we only want to signal one bit. */
 110        if(would_trap != 0) {
 111                eflag &= ((fsr & FSR_TEM_MASK) >> FSR_TEM_SHIFT);
 112                if((eflag & (eflag - 1)) != 0) {
 113                        if(eflag & FP_EX_INVALID)
 114                                eflag = FP_EX_INVALID;
 115                        else if(eflag & FP_EX_OVERFLOW)
 116                                eflag = FP_EX_OVERFLOW;
 117                        else if(eflag & FP_EX_UNDERFLOW)
 118                                eflag = FP_EX_UNDERFLOW;
 119                        else if(eflag & FP_EX_DIVZERO)
 120                                eflag = FP_EX_DIVZERO;
 121                        else if(eflag & FP_EX_INEXACT)
 122                                eflag = FP_EX_INEXACT;
 123                }
 124        }
 125
 126        /* Set CEXC, here is the rule:
 127         *
 128         *    In general all FPU ops will set one and only one
 129         *    bit in the CEXC field, this is always the case
 130         *    when the IEEE exception trap is enabled in TEM.
 131         */
 132        fsr &= ~(FSR_CEXC_MASK);
 133        fsr |= ((long)eflag << FSR_CEXC_SHIFT);
 134
 135        /* Set the AEXC field, rule is:
 136         *
 137         *    If a trap would not be generated, the
 138         *    CEXC just generated is OR'd into the
 139         *    existing value of AEXC.
 140         */
 141        if(would_trap == 0)
 142                fsr |= ((long)eflag << FSR_AEXC_SHIFT);
 143
 144        /* If trapping, indicate fault trap type IEEE. */
 145        if(would_trap != 0)
 146                fsr |= (1UL << 14);
 147
 148        current_thread_info()->xfsr[0] = fsr;
 149
 150        /* If we will not trap, advance the program counter over
 151         * the instruction being handled.
 152         */
 153        if(would_trap == 0) {
 154                regs->tpc = regs->tnpc;
 155                regs->tnpc += 4;
 156        }
 157
 158        return (would_trap ? 0 : 1);
 159}
 160
 161typedef union {
 162        u32 s;
 163        u64 d;
 164        u64 q[2];
 165} *argp;
 166
 167int do_mathemu(struct pt_regs *regs, struct fpustate *f, bool illegal_insn_trap)
 168{
 169        unsigned long pc = regs->tpc;
 170        unsigned long tstate = regs->tstate;
 171        u32 insn = 0;
 172        int type = 0;
 173        /* ftt tells which ftt it may happen in, r is rd, b is rs2 and a is rs1. The *u arg tells
 174           whether the argument should be packed/unpacked (0 - do not unpack/pack, 1 - unpack/pack)
 175           non-u args tells the size of the argument (0 - no argument, 1 - single, 2 - double, 3 - quad */
 176#define TYPE(ftt, r, ru, b, bu, a, au) type = (au << 2) | (a << 0) | (bu << 5) | (b << 3) | (ru << 8) | (r << 6) | (ftt << 9)
 177        int freg;
 178        static u64 zero[2] = { 0L, 0L };
 179        int flags;
 180        FP_DECL_EX;
 181        FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);
 182        FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR);
 183        FP_DECL_Q(QA); FP_DECL_Q(QB); FP_DECL_Q(QR);
 184        int IR;
 185        long XR, xfsr;
 186
 187        if (tstate & TSTATE_PRIV)
 188                die_if_kernel("unfinished/unimplemented FPop from kernel", regs);
 189        perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 190        if (test_thread_flag(TIF_32BIT))
 191                pc = (u32)pc;
 192        if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 193                if ((insn & 0xc1f80000) == 0x81a00000) /* FPOP1 */ {
 194                        switch ((insn >> 5) & 0x1ff) {
 195                        /* QUAD - ftt == 3 */
 196                        case FMOVQ:
 197                        case FNEGQ:
 198                        case FABSQ: TYPE(3,3,0,3,0,0,0); break;
 199                        case FSQRTQ: TYPE(3,3,1,3,1,0,0); break;
 200                        case FADDQ:
 201                        case FSUBQ:
 202                        case FMULQ:
 203                        case FDIVQ: TYPE(3,3,1,3,1,3,1); break;
 204                        case FDMULQ: TYPE(3,3,1,2,1,2,1); break;
 205                        case FQTOX: TYPE(3,2,0,3,1,0,0); break;
 206                        case FXTOQ: TYPE(3,3,1,2,0,0,0); break;
 207                        case FQTOS: TYPE(3,1,1,3,1,0,0); break;
 208                        case FQTOD: TYPE(3,2,1,3,1,0,0); break;
 209                        case FITOQ: TYPE(3,3,1,1,0,0,0); break;
 210                        case FSTOQ: TYPE(3,3,1,1,1,0,0); break;
 211                        case FDTOQ: TYPE(3,3,1,2,1,0,0); break;
 212                        case FQTOI: TYPE(3,1,0,3,1,0,0); break;
 213
 214                        /* We can get either unimplemented or unfinished
 215                         * for these cases.  Pre-Niagara systems generate
 216                         * unfinished fpop for SUBNORMAL cases, and Niagara
 217                         * always gives unimplemented fpop for fsqrt{s,d}.
 218                         */
 219                        case FSQRTS: {
 220                                unsigned long x = current_thread_info()->xfsr[0];
 221
 222                                x = (x >> 14) & 0x7;
 223                                TYPE(x,1,1,1,1,0,0);
 224                                break;
 225                        }
 226
 227                        case FSQRTD: {
 228                                unsigned long x = current_thread_info()->xfsr[0];
 229
 230                                x = (x >> 14) & 0x7;
 231                                TYPE(x,2,1,2,1,0,0);
 232                                break;
 233                        }
 234
 235                        /* SUBNORMAL - ftt == 2 */
 236                        case FADDD:
 237                        case FSUBD:
 238                        case FMULD:
 239                        case FDIVD: TYPE(2,2,1,2,1,2,1); break;
 240                        case FADDS:
 241                        case FSUBS:
 242                        case FMULS:
 243                        case FDIVS: TYPE(2,1,1,1,1,1,1); break;
 244                        case FSMULD: TYPE(2,2,1,1,1,1,1); break;
 245                        case FSTOX: TYPE(2,2,0,1,1,0,0); break;
 246                        case FDTOX: TYPE(2,2,0,2,1,0,0); break;
 247                        case FDTOS: TYPE(2,1,1,2,1,0,0); break;
 248                        case FSTOD: TYPE(2,2,1,1,1,0,0); break;
 249                        case FSTOI: TYPE(2,1,0,1,1,0,0); break;
 250                        case FDTOI: TYPE(2,1,0,2,1,0,0); break;
 251
 252                        /* Only Ultra-III generates these */
 253                        case FXTOS: TYPE(2,1,1,2,0,0,0); break;
 254                        case FXTOD: TYPE(2,2,1,2,0,0,0); break;
 255#if 0                   /* Optimized inline in sparc64/kernel/entry.S */
 256                        case FITOS: TYPE(2,1,1,1,0,0,0); break;
 257#endif
 258                        case FITOD: TYPE(2,2,1,1,0,0,0); break;
 259                        }
 260                }
 261                else if ((insn & 0xc1f80000) == 0x81a80000) /* FPOP2 */ {
 262                        IR = 2;
 263                        switch ((insn >> 5) & 0x1ff) {
 264                        case FCMPQ: TYPE(3,0,0,3,1,3,1); break;
 265                        case FCMPEQ: TYPE(3,0,0,3,1,3,1); break;
 266                        /* Now the conditional fmovq support */
 267                        case FMOVQ0:
 268                        case FMOVQ1:
 269                        case FMOVQ2:
 270                        case FMOVQ3:
 271                                /* fmovq %fccX, %fY, %fZ */
 272                                if (!((insn >> 11) & 3))
 273                                        XR = current_thread_info()->xfsr[0] >> 10;
 274                                else
 275                                        XR = current_thread_info()->xfsr[0] >> (30 + ((insn >> 10) & 0x6));
 276                                XR &= 3;
 277                                IR = 0;
 278                                switch ((insn >> 14) & 0x7) {
 279                                /* case 0: IR = 0; break; */                    /* Never */
 280                                case 1: if (XR) IR = 1; break;                  /* Not Equal */
 281                                case 2: if (XR == 1 || XR == 2) IR = 1; break;  /* Less or Greater */
 282                                case 3: if (XR & 1) IR = 1; break;              /* Unordered or Less */
 283                                case 4: if (XR == 1) IR = 1; break;             /* Less */
 284                                case 5: if (XR & 2) IR = 1; break;              /* Unordered or Greater */
 285                                case 6: if (XR == 2) IR = 1; break;             /* Greater */
 286                                case 7: if (XR == 3) IR = 1; break;             /* Unordered */
 287                                }
 288                                if ((insn >> 14) & 8)
 289                                        IR ^= 1;
 290                                break;
 291                        case FMOVQI:
 292                        case FMOVQX:
 293                                /* fmovq %[ix]cc, %fY, %fZ */
 294                                XR = regs->tstate >> 32;
 295                                if ((insn >> 5) & 0x80)
 296                                        XR >>= 4;
 297                                XR &= 0xf;
 298                                IR = 0;
 299                                freg = ((XR >> 2) ^ XR) & 2;
 300                                switch ((insn >> 14) & 0x7) {
 301                                /* case 0: IR = 0; break; */                    /* Never */
 302                                case 1: if (XR & 4) IR = 1; break;              /* Equal */
 303                                case 2: if ((XR & 4) || freg) IR = 1; break;    /* Less or Equal */
 304                                case 3: if (freg) IR = 1; break;                /* Less */
 305                                case 4: if (XR & 5) IR = 1; break;              /* Less or Equal Unsigned */
 306                                case 5: if (XR & 1) IR = 1; break;              /* Carry Set */
 307                                case 6: if (XR & 8) IR = 1; break;              /* Negative */
 308                                case 7: if (XR & 2) IR = 1; break;              /* Overflow Set */
 309                                }
 310                                if ((insn >> 14) & 8)
 311                                        IR ^= 1;
 312                                break;
 313                        case FMOVQZ:
 314                        case FMOVQLE:
 315                        case FMOVQLZ:
 316                        case FMOVQNZ:
 317                        case FMOVQGZ:
 318                        case FMOVQGE:
 319                                freg = (insn >> 14) & 0x1f;
 320                                if (!freg)
 321                                        XR = 0;
 322                                else if (freg < 16)
 323                                        XR = regs->u_regs[freg];
 324                                else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) {
 325                                        struct reg_window32 __user *win32;
 326                                        flushw_user ();
 327                                        win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
 328                                        get_user(XR, &win32->locals[freg - 16]);
 329                                } else {
 330                                        struct reg_window __user *win;
 331                                        flushw_user ();
 332                                        win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
 333                                        get_user(XR, &win->locals[freg - 16]);
 334                                }
 335                                IR = 0;
 336                                switch ((insn >> 10) & 3) {
 337                                case 1: if (!XR) IR = 1; break;                 /* Register Zero */
 338                                case 2: if (XR <= 0) IR = 1; break;             /* Register Less Than or Equal to Zero */
 339                                case 3: if (XR < 0) IR = 1; break;              /* Register Less Than Zero */
 340                                }
 341                                if ((insn >> 10) & 4)
 342                                        IR ^= 1;
 343                                break;
 344                        }
 345                        if (IR == 0) {
 346                                /* The fmov test was false. Do a nop instead */
 347                                current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK);
 348                                regs->tpc = regs->tnpc;
 349                                regs->tnpc += 4;
 350                                return 1;
 351                        } else if (IR == 1) {
 352                                /* Change the instruction into plain fmovq */
 353                                insn = (insn & 0x3e00001f) | 0x81a00060;
 354                                TYPE(3,3,0,3,0,0,0); 
 355                        }
 356                }
 357        }
 358        if (type) {
 359                argp rs1 = NULL, rs2 = NULL, rd = NULL;
 360                
 361                /* Starting with UltraSPARC-T2, the cpu does not set the FP Trap
 362                 * Type field in the %fsr to unimplemented_FPop.  Nor does it
 363                 * use the fp_exception_other trap.  Instead it signals an
 364                 * illegal instruction and leaves the FP trap type field of
 365                 * the %fsr unchanged.
 366                 */
 367                if (!illegal_insn_trap) {
 368                        int ftt = (current_thread_info()->xfsr[0] >> 14) & 0x7;
 369                        if (ftt != (type >> 9))
 370                                goto err;
 371                }
 372                current_thread_info()->xfsr[0] &= ~0x1c000;
 373                freg = ((insn >> 14) & 0x1f);
 374                switch (type & 0x3) {
 375                case 3: if (freg & 2) {
 376                                current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 377                                goto err;
 378                        }
 379                case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
 380                case 1: rs1 = (argp)&f->regs[freg];
 381                        flags = (freg < 32) ? FPRS_DL : FPRS_DU; 
 382                        if (!(current_thread_info()->fpsaved[0] & flags))
 383                                rs1 = (argp)&zero;
 384                        break;
 385                }
 386                switch (type & 0x7) {
 387                case 7: FP_UNPACK_QP (QA, rs1); break;
 388                case 6: FP_UNPACK_DP (DA, rs1); break;
 389                case 5: FP_UNPACK_SP (SA, rs1); break;
 390                }
 391                freg = (insn & 0x1f);
 392                switch ((type >> 3) & 0x3) {
 393                case 3: if (freg & 2) {
 394                                current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 395                                goto err;
 396                        }
 397                case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
 398                case 1: rs2 = (argp)&f->regs[freg];
 399                        flags = (freg < 32) ? FPRS_DL : FPRS_DU; 
 400                        if (!(current_thread_info()->fpsaved[0] & flags))
 401                                rs2 = (argp)&zero;
 402                        break;
 403                }
 404                switch ((type >> 3) & 0x7) {
 405                case 7: FP_UNPACK_QP (QB, rs2); break;
 406                case 6: FP_UNPACK_DP (DB, rs2); break;
 407                case 5: FP_UNPACK_SP (SB, rs2); break;
 408                }
 409                freg = ((insn >> 25) & 0x1f);
 410                switch ((type >> 6) & 0x3) {
 411                case 3: if (freg & 2) {
 412                                current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 413                                goto err;
 414                        }
 415                case 2: freg = ((freg & 1) << 5) | (freg & 0x1e);
 416                case 1: rd = (argp)&f->regs[freg];
 417                        flags = (freg < 32) ? FPRS_DL : FPRS_DU; 
 418                        if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
 419                                current_thread_info()->fpsaved[0] = FPRS_FEF;
 420                                current_thread_info()->gsr[0] = 0;
 421                        }
 422                        if (!(current_thread_info()->fpsaved[0] & flags)) {
 423                                if (freg < 32)
 424                                        memset(f->regs, 0, 32*sizeof(u32));
 425                                else
 426                                        memset(f->regs+32, 0, 32*sizeof(u32));
 427                        }
 428                        current_thread_info()->fpsaved[0] |= flags;
 429                        break;
 430                }
 431                switch ((insn >> 5) & 0x1ff) {
 432                /* + */
 433                case FADDS: FP_ADD_S (SR, SA, SB); break;
 434                case FADDD: FP_ADD_D (DR, DA, DB); break;
 435                case FADDQ: FP_ADD_Q (QR, QA, QB); break;
 436                /* - */
 437                case FSUBS: FP_SUB_S (SR, SA, SB); break;
 438                case FSUBD: FP_SUB_D (DR, DA, DB); break;
 439                case FSUBQ: FP_SUB_Q (QR, QA, QB); break;
 440                /* * */
 441                case FMULS: FP_MUL_S (SR, SA, SB); break;
 442                case FSMULD: FP_CONV (D, S, 1, 1, DA, SA);
 443                             FP_CONV (D, S, 1, 1, DB, SB);
 444                case FMULD: FP_MUL_D (DR, DA, DB); break;
 445                case FDMULQ: FP_CONV (Q, D, 2, 1, QA, DA);
 446                             FP_CONV (Q, D, 2, 1, QB, DB);
 447                case FMULQ: FP_MUL_Q (QR, QA, QB); break;
 448                /* / */
 449                case FDIVS: FP_DIV_S (SR, SA, SB); break;
 450                case FDIVD: FP_DIV_D (DR, DA, DB); break;
 451                case FDIVQ: FP_DIV_Q (QR, QA, QB); break;
 452                /* sqrt */
 453                case FSQRTS: FP_SQRT_S (SR, SB); break;
 454                case FSQRTD: FP_SQRT_D (DR, DB); break;
 455                case FSQRTQ: FP_SQRT_Q (QR, QB); break;
 456                /* mov */
 457                case FMOVQ: rd->q[0] = rs2->q[0]; rd->q[1] = rs2->q[1]; break;
 458                case FABSQ: rd->q[0] = rs2->q[0] & 0x7fffffffffffffffUL; rd->q[1] = rs2->q[1]; break;
 459                case FNEGQ: rd->q[0] = rs2->q[0] ^ 0x8000000000000000UL; rd->q[1] = rs2->q[1]; break;
 460                /* float to int */
 461                case FSTOI: FP_TO_INT_S (IR, SB, 32, 1); break;
 462                case FDTOI: FP_TO_INT_D (IR, DB, 32, 1); break;
 463                case FQTOI: FP_TO_INT_Q (IR, QB, 32, 1); break;
 464                case FSTOX: FP_TO_INT_S (XR, SB, 64, 1); break;
 465                case FDTOX: FP_TO_INT_D (XR, DB, 64, 1); break;
 466                case FQTOX: FP_TO_INT_Q (XR, QB, 64, 1); break;
 467                /* int to float */
 468                case FITOQ: IR = rs2->s; FP_FROM_INT_Q (QR, IR, 32, int); break;
 469                case FXTOQ: XR = rs2->d; FP_FROM_INT_Q (QR, XR, 64, long); break;
 470                /* Only Ultra-III generates these */
 471                case FXTOS: XR = rs2->d; FP_FROM_INT_S (SR, XR, 64, long); break;
 472                case FXTOD: XR = rs2->d; FP_FROM_INT_D (DR, XR, 64, long); break;
 473#if 0           /* Optimized inline in sparc64/kernel/entry.S */
 474                case FITOS: IR = rs2->s; FP_FROM_INT_S (SR, IR, 32, int); break;
 475#endif
 476                case FITOD: IR = rs2->s; FP_FROM_INT_D (DR, IR, 32, int); break;
 477                /* float to float */
 478                case FSTOD: FP_CONV (D, S, 1, 1, DR, SB); break;
 479                case FSTOQ: FP_CONV (Q, S, 2, 1, QR, SB); break;
 480                case FDTOQ: FP_CONV (Q, D, 2, 1, QR, DB); break;
 481                case FDTOS: FP_CONV (S, D, 1, 1, SR, DB); break;
 482                case FQTOS: FP_CONV (S, Q, 1, 2, SR, QB); break;
 483                case FQTOD: FP_CONV (D, Q, 1, 2, DR, QB); break;
 484                /* comparison */
 485                case FCMPQ:
 486                case FCMPEQ:
 487                        FP_CMP_Q(XR, QB, QA, 3);
 488                        if (XR == 3 &&
 489                            (((insn >> 5) & 0x1ff) == FCMPEQ ||
 490                             FP_ISSIGNAN_Q(QA) ||
 491                             FP_ISSIGNAN_Q(QB)))
 492                                FP_SET_EXCEPTION (FP_EX_INVALID);
 493                }
 494                if (!FP_INHIBIT_RESULTS) {
 495                        switch ((type >> 6) & 0x7) {
 496                        case 0: xfsr = current_thread_info()->xfsr[0];
 497                                if (XR == -1) XR = 2;
 498                                switch (freg & 3) {
 499                                /* fcc0, 1, 2, 3 */
 500                                case 0: xfsr &= ~0xc00; xfsr |= (XR << 10); break;
 501                                case 1: xfsr &= ~0x300000000UL; xfsr |= (XR << 32); break;
 502                                case 2: xfsr &= ~0xc00000000UL; xfsr |= (XR << 34); break;
 503                                case 3: xfsr &= ~0x3000000000UL; xfsr |= (XR << 36); break;
 504                                }
 505                                current_thread_info()->xfsr[0] = xfsr;
 506                                break;
 507                        case 1: rd->s = IR; break;
 508                        case 2: rd->d = XR; break;
 509                        case 5: FP_PACK_SP (rd, SR); break;
 510                        case 6: FP_PACK_DP (rd, DR); break;
 511                        case 7: FP_PACK_QP (rd, QR); break;
 512                        }
 513                }
 514
 515                if(_fex != 0)
 516                        return record_exception(regs, _fex);
 517
 518                /* Success and no exceptions detected. */
 519                current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK);
 520                regs->tpc = regs->tnpc;
 521                regs->tnpc += 4;
 522                return 1;
 523        }
 524err:    return 0;
 525}
 526