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fpu.c revision 1.24
      1 /*	$NetBSD: fpu.c,v 1.24 2005/05/31 00:57:40 christos Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * All advertising materials mentioning features or use of this software
     12  * must display the following acknowledgement:
     13  *	This product includes software developed by the University of
     14  *	California, Lawrence Berkeley Laboratory.
     15  *
     16  * Redistribution and use in source and binary forms, with or without
     17  * modification, are permitted provided that the following conditions
     18  * are met:
     19  * 1. Redistributions of source code must retain the above copyright
     20  *    notice, this list of conditions and the following disclaimer.
     21  * 2. Redistributions in binary form must reproduce the above copyright
     22  *    notice, this list of conditions and the following disclaimer in the
     23  *    documentation and/or other materials provided with the distribution.
     24  * 3. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  *	@(#)fpu.c	8.1 (Berkeley) 6/11/93
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 __KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.24 2005/05/31 00:57:40 christos Exp $");
     45 
     46 #include <sys/param.h>
     47 #include <sys/proc.h>
     48 #include <sys/signal.h>
     49 #include <sys/systm.h>
     50 #include <sys/syslog.h>
     51 #include <sys/signalvar.h>
     52 
     53 #include <machine/instr.h>
     54 #include <machine/reg.h>
     55 
     56 #include <sparc/fpu/fpu_emu.h>
     57 #include <sparc/fpu/fpu_extern.h>
     58 
     59 int fpe_debug = 0;
     60 
     61 #ifdef DEBUG
     62 /*
     63  * Dump a `fpn' structure.
     64  */
     65 void
     66 fpu_dumpfpn(struct fpn *fp)
     67 {
     68 	static const char *class[] = {
     69 		"SNAN", "QNAN", "ZERO", "NUM", "INF"
     70 	};
     71 
     72 	printf("%s %c.%x %x %x %xE%d", class[fp->fp_class + 2],
     73 		fp->fp_sign ? '-' : ' ',
     74 		fp->fp_mant[0],	fp->fp_mant[1],
     75 		fp->fp_mant[2], fp->fp_mant[3],
     76 		fp->fp_exp);
     77 }
     78 #endif
     79 
     80 /*
     81  * fpu_execute returns the following error numbers (0 = no error):
     82  */
     83 #define	FPE		1	/* take a floating point exception */
     84 #define	NOTFPU		2	/* not an FPU instruction */
     85 
     86 /*
     87  * Translate current exceptions into `first' exception.  The
     88  * bits go the wrong way for ffs() (0x10 is most important, etc).
     89  * There are only 5, so do it the obvious way.
     90  */
     91 #define	X1(x) x
     92 #define	X2(x) x,x
     93 #define	X4(x) x,x,x,x
     94 #define	X8(x) X4(x),X4(x)
     95 #define	X16(x) X8(x),X8(x)
     96 
     97 static char cx_to_trapx[] = {
     98 	X1(FSR_NX),
     99 	X2(FSR_DZ),
    100 	X4(FSR_UF),
    101 	X8(FSR_OF),
    102 	X16(FSR_NV)
    103 };
    104 static u_char fpu_codes_native[] = {
    105 	X1(FPE_FLTRES),
    106 	X2(FPE_FLTDIV),
    107 	X4(FPE_FLTUND),
    108 	X8(FPE_FLTOVF),
    109 	X16(FPE_FLTINV)
    110 };
    111 #if defined(COMPAT_SUNOS)
    112 static u_char fpu_codes_sunos[] = {
    113 	X1(FPE_FLTINEX_TRAP),
    114 	X2(FPE_FLTDIV_TRAP),
    115 	X4(FPE_FLTUND_TRAP),
    116 	X8(FPE_FLTOVF_TRAP),
    117 	X16(FPE_FLTOPERR_TRAP)
    118 };
    119 extern struct emul emul_sunos;
    120 #endif /* SUNOS_COMPAT */
    121 /* Note: SVR4(Solaris) FPE_* codes happen to be compatible with ours */
    122 
    123 /*
    124  * The FPU gave us an exception.  Clean up the mess.  Note that the
    125  * fp queue can only have FPops in it, never load/store FP registers
    126  * nor FBfcc instructions.  Experiments with `crashme' prove that
    127  * unknown FPops do enter the queue, however.
    128  */
    129 int
    130 fpu_cleanup(l, fs)
    131 	struct lwp *l;
    132 #ifndef SUN4U
    133 	struct fpstate *fs;
    134 #else /* SUN4U */
    135 	struct fpstate64 *fs;
    136 #endif /* SUN4U */
    137 {
    138 	int i, fsr = fs->fs_fsr, error;
    139 	struct proc *p = l->l_proc;
    140 	union instr instr;
    141 	struct fpemu fe;
    142 	u_char *fpu_codes;
    143 	int code = 0;
    144 
    145 	fpu_codes =
    146 #ifdef COMPAT_SUNOS
    147 		(p->p_emul == &emul_sunos) ? fpu_codes_sunos :
    148 #endif
    149 		fpu_codes_native;
    150 
    151 	switch ((fsr >> FSR_FTT_SHIFT) & FSR_FTT_MASK) {
    152 
    153 	case FSR_TT_NONE:
    154 		panic("fpu_cleanup: No fault");	/* ??? */
    155 		break;
    156 
    157 	case FSR_TT_IEEE:
    158 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_IEEE\n"));
    159 		/* XXX missing trap address! */
    160 		if ((i = fsr & FSR_CX) == 0)
    161 			panic("fpu ieee trap, but no exception");
    162 		code = fpu_codes[i - 1];
    163 		break;		/* XXX should return, but queue remains */
    164 
    165 	case FSR_TT_UNFIN:
    166 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_UNFIN\n"));
    167 #ifdef SUN4U
    168 		if (fs->fs_qsize == 0) {
    169 			printf("fpu_cleanup: unfinished fpop");
    170 			/* The book sez reexecute or emulate. */
    171 			return (0);
    172 		}
    173 		break;
    174 
    175 #endif /* SUN4U */
    176 	case FSR_TT_UNIMP:
    177 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_UNIMP\n"));
    178 		if (fs->fs_qsize == 0)
    179 			panic("fpu_cleanup: unimplemented fpop");
    180 		break;
    181 
    182 	case FSR_TT_SEQ:
    183 		panic("fpu sequence error");
    184 		/* NOTREACHED */
    185 
    186 	case FSR_TT_HWERR:
    187 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_HWERR\n"));
    188 		log(LOG_ERR, "fpu hardware error (%s[%d])\n",
    189 		    p->p_comm, p->p_pid);
    190 		uprintf("%s[%d]: fpu hardware error\n", p->p_comm, p->p_pid);
    191 		code = SI_NOINFO;
    192 		goto out;
    193 
    194 	default:
    195 		printf("fsr=0x%x\n", fsr);
    196 		panic("fpu error");
    197 	}
    198 
    199 	/* emulate the instructions left in the queue */
    200 	fe.fe_fpstate = fs;
    201 	for (i = 0; i < fs->fs_qsize; i++) {
    202 		instr.i_int = fs->fs_queue[i].fq_instr;
    203 		if (instr.i_any.i_op != IOP_reg ||
    204 		    (instr.i_op3.i_op3 != IOP3_FPop1 &&
    205 		     instr.i_op3.i_op3 != IOP3_FPop2))
    206 			panic("bogus fpu queue");
    207 		error = fpu_execute(&fe, instr);
    208 		if (error == 0)
    209 			continue;
    210 
    211 		switch (error) {
    212 		case FPE:
    213 			code = fpu_codes[(fs->fs_fsr & FSR_CX) - 1];
    214 			break;
    215 
    216 		case NOTFPU:
    217 #ifdef SUN4U
    218 #ifdef DEBUG
    219 			printf("fpu_cleanup: not an FPU error -- sending SIGILL\n");
    220 #endif
    221 #endif /* SUN4U */
    222 			code = SI_NOINFO;
    223 			break;
    224 
    225 		default:
    226 			panic("fpu_cleanup 3");
    227 			/* NOTREACHED */
    228 		}
    229 		/* XXX should stop here, but queue remains */
    230 	}
    231 out:
    232 	fs->fs_qsize = 0;
    233 	return (code);
    234 }
    235 
    236 #ifdef notyet
    237 /*
    238  * If we have no FPU at all (are there any machines like this out
    239  * there!?) we have to emulate each instruction, and we need a pointer
    240  * to the trapframe so that we can step over them and do FBfcc's.
    241  * We know the `queue' is empty, though; we just want to emulate
    242  * the instruction at tf->tf_pc.
    243  */
    244 fpu_emulate(l, tf, fs)
    245 	struct lwp *l;
    246 	struct trapframe *tf;
    247 #ifndef SUN4U
    248 	struct fpstate *fs;
    249 #else /* SUN4U */
    250 	struct fpstate64 *fs;
    251 #endif /* SUN4U */
    252 {
    253 
    254 	do {
    255 		fetch instr from pc
    256 		decode
    257 		if (integer instr) {
    258 			/*
    259 			 * We do this here, rather than earlier, to avoid
    260 			 * losing even more badly than usual.
    261 			 */
    262 			if (l->l_addr->u_pcb.pcb_uw) {
    263 				write_user_windows();
    264 				if (rwindow_save(l))
    265 					sigexit(l, SIGILL);
    266 			}
    267 			if (loadstore) {
    268 				do_it;
    269 				pc = npc, npc += 4
    270 			} else if (fbfcc) {
    271 				do_annul_stuff;
    272 			} else
    273 				return;
    274 		} else if (fpu instr) {
    275 			fe.fe_fsr = fs->fs_fsr &= ~FSR_CX;
    276 			error = fpu_execute(&fe, fs, instr);
    277 			switch (error) {
    278 				etc;
    279 			}
    280 		} else
    281 			return;
    282 		if (want to reschedule)
    283 			return;
    284 	} while (error == 0);
    285 }
    286 #endif
    287 
    288 /*
    289  * Execute an FPU instruction (one that runs entirely in the FPU; not
    290  * FBfcc or STF, for instance).  On return, fe->fe_fs->fs_fsr will be
    291  * modified to reflect the setting the hardware would have left.
    292  *
    293  * Note that we do not catch all illegal opcodes, so you can, for instance,
    294  * multiply two integers this way.
    295  */
    296 int
    297 fpu_execute(fe, instr)
    298 	struct fpemu *fe;
    299 	union instr instr;
    300 {
    301 	struct fpn *fp;
    302 #ifndef SUN4U
    303 	int opf, rs1, rs2, rd, type, mask, fsr, cx;
    304 	struct fpstate *fs;
    305 #else /* SUN4U */
    306 	int opf, rs1, rs2, rd, type, mask, fsr, cx, i, cond;
    307 	struct fpstate64 *fs;
    308 #endif /* SUN4U */
    309 	u_int space[4];
    310 
    311 	/*
    312 	 * `Decode' and execute instruction.  Start with no exceptions.
    313 	 * The type of any i_opf opcode is in the bottom two bits, so we
    314 	 * squish them out here.
    315 	 */
    316 	opf = instr.i_opf.i_opf;
    317 	/*
    318 	 * The low two bits of the opf field for floating point insns usually
    319 	 * correspond to the operation width:
    320 	 *
    321 	 *	0:	Invalid
    322 	 *	1:	Single precision float
    323 	 *	2:	Double precision float
    324 	 *	3:	Quad precision float
    325 	 *
    326 	 * The exceptions are the integer to float conversion instructions.
    327 	 *
    328 	 * For double and quad precision, the low bit if the rs or rd field
    329 	 * is actually the high bit of the register number.
    330 	 */
    331 
    332 	type = opf & 3;
    333 	mask = 0x3 >> (3 - type);
    334 
    335 	rs1 = instr.i_opf.i_rs1;
    336 	rs1 = (rs1 & ~mask) | ((rs1 & mask & 0x1) << 5);
    337 	rs2 = instr.i_opf.i_rs2;
    338 	rs2 = (rs2 & ~mask) | ((rs2 & mask & 0x1) << 5);
    339 	rd = instr.i_opf.i_rd;
    340 	rd = (rd & ~mask) | ((rd & mask & 0x1) << 5);
    341 #ifdef DIAGNOSTIC
    342 	if ((rs1 | rs2 | rd) & mask)
    343 		/* This may be an FPU insn but it is illegal. */
    344 		return (NOTFPU);
    345 #endif
    346 	fs = fe->fe_fpstate;
    347 	fe->fe_fsr = fs->fs_fsr & ~FSR_CX;
    348 	fe->fe_cx = 0;
    349 #ifdef SUN4U
    350 	/*
    351 	 * Check to see if we're dealing with a fancy cmove and handle
    352 	 * it first.
    353 	 */
    354 	if (instr.i_op3.i_op3 == IOP3_FPop2 && (opf&0xff0) != (FCMP&0xff0)) {
    355 		switch (opf >>= 2) {
    356 		case FMVFC0 >> 2:
    357 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC0\n"));
    358 			cond = (fs->fs_fsr>>FSR_FCC_SHIFT)&FSR_FCC_MASK;
    359 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
    360 			rs1 = fs->fs_regs[rs2];
    361 			goto mov;
    362 		case FMVFC1 >> 2:
    363 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC1\n"));
    364 			cond = (fs->fs_fsr>>FSR_FCC1_SHIFT)&FSR_FCC_MASK;
    365 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
    366 			rs1 = fs->fs_regs[rs2];
    367 			goto mov;
    368 		case FMVFC2 >> 2:
    369 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC2\n"));
    370 			cond = (fs->fs_fsr>>FSR_FCC2_SHIFT)&FSR_FCC_MASK;
    371 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
    372 			rs1 = fs->fs_regs[rs2];
    373 			goto mov;
    374 		case FMVFC3 >> 2:
    375 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC3\n"));
    376 			cond = (fs->fs_fsr>>FSR_FCC3_SHIFT)&FSR_FCC_MASK;
    377 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
    378 			rs1 = fs->fs_regs[rs2];
    379 			goto mov;
    380 		case FMVIC >> 2:
    381 			/* Presume we're curlwp */
    382 			DPRINTF(FPE_INSN, ("fpu_execute: FMVIC\n"));
    383 			cond = (curlwp->l_md.md_tf->tf_tstate>>TSTATE_CCR_SHIFT)&PSR_ICC;
    384 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
    385 			rs1 = fs->fs_regs[rs2];
    386 			goto mov;
    387 		case FMVXC >> 2:
    388 			/* Presume we're curlwp */
    389 			DPRINTF(FPE_INSN, ("fpu_execute: FMVXC\n"));
    390 			cond = (curlwp->l_md.md_tf->tf_tstate>>(TSTATE_CCR_SHIFT+XCC_SHIFT))&PSR_ICC;
    391 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
    392 			rs1 = fs->fs_regs[rs2];
    393 			goto mov;
    394 		case FMVRZ >> 2:
    395 			/* Presume we're curlwp */
    396 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRZ\n"));
    397 			rs1 = instr.i_fmovr.i_rs1;
    398 			if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] != 0)
    399 				return (0); /* success */
    400 			rs1 = fs->fs_regs[rs2];
    401 			goto mov;
    402 		case FMVRLEZ >> 2:
    403 			/* Presume we're curlwp */
    404 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRLEZ\n"));
    405 			rs1 = instr.i_fmovr.i_rs1;
    406 			if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] > 0)
    407 				return (0); /* success */
    408 			rs1 = fs->fs_regs[rs2];
    409 			goto mov;
    410 		case FMVRLZ >> 2:
    411 			/* Presume we're curlwp */
    412 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRLZ\n"));
    413 			rs1 = instr.i_fmovr.i_rs1;
    414 			if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] >= 0)
    415 				return (0); /* success */
    416 			rs1 = fs->fs_regs[rs2];
    417 			goto mov;
    418 		case FMVRNZ >> 2:
    419 			/* Presume we're curlwp */
    420 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRNZ\n"));
    421 			rs1 = instr.i_fmovr.i_rs1;
    422 			if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] == 0)
    423 				return (0); /* success */
    424 			rs1 = fs->fs_regs[rs2];
    425 			goto mov;
    426 		case FMVRGZ >> 2:
    427 			/* Presume we're curlwp */
    428 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRGZ\n"));
    429 			rs1 = instr.i_fmovr.i_rs1;
    430 			if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] <= 0)
    431 				return (0); /* success */
    432 			rs1 = fs->fs_regs[rs2];
    433 			goto mov;
    434 		case FMVRGEZ >> 2:
    435 			/* Presume we're curlwp */
    436 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRGEZ\n"));
    437 			rs1 = instr.i_fmovr.i_rs1;
    438 			if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] < 0)
    439 				return (0); /* success */
    440 			rs1 = fs->fs_regs[rs2];
    441 			goto mov;
    442 		default:
    443 			DPRINTF(FPE_INSN,
    444 				("fpu_execute: unknown v9 FP inst %x opf %x\n",
    445 					instr.i_int, opf));
    446 			return (NOTFPU);
    447 		}
    448 	}
    449 #endif /* SUN4U */
    450 	switch (opf >>= 2) {
    451 
    452 	default:
    453 		DPRINTF(FPE_INSN,
    454 			("fpu_execute: unknown basic FP inst %x opf %x\n",
    455 				instr.i_int, opf));
    456 		return (NOTFPU);
    457 
    458 	case FMOV >> 2:		/* these should all be pretty obvious */
    459 		DPRINTF(FPE_INSN, ("fpu_execute: FMOV\n"));
    460 		rs1 = fs->fs_regs[rs2];
    461 		goto mov;
    462 
    463 	case FNEG >> 2:
    464 		DPRINTF(FPE_INSN, ("fpu_execute: FNEG\n"));
    465 		rs1 = fs->fs_regs[rs2] ^ (1 << 31);
    466 		goto mov;
    467 
    468 	case FABS >> 2:
    469 		DPRINTF(FPE_INSN, ("fpu_execute: FABS\n"));
    470 		rs1 = fs->fs_regs[rs2] & ~(1 << 31);
    471 	mov:
    472 #ifndef SUN4U
    473 		fs->fs_regs[rd] = rs1;
    474 #else /* SUN4U */
    475 		i = 1<<(type-1);
    476 		fs->fs_regs[rd++] = rs1;
    477 		while (--i > 0)
    478 			fs->fs_regs[rd++] = fs->fs_regs[++rs2];
    479 #endif /* SUN4U */
    480 		fs->fs_fsr = fe->fe_fsr;
    481 		return (0);	/* success */
    482 
    483 	case FSQRT >> 2:
    484 		DPRINTF(FPE_INSN, ("fpu_execute: FSQRT\n"));
    485 		fpu_explode(fe, &fe->fe_f1, type, rs2);
    486 		fp = fpu_sqrt(fe);
    487 		break;
    488 
    489 	case FADD >> 2:
    490 		DPRINTF(FPE_INSN, ("fpu_execute: FADD\n"));
    491 		fpu_explode(fe, &fe->fe_f1, type, rs1);
    492 		fpu_explode(fe, &fe->fe_f2, type, rs2);
    493 		fp = fpu_add(fe);
    494 		break;
    495 
    496 	case FSUB >> 2:
    497 		DPRINTF(FPE_INSN, ("fpu_execute: FSUB\n"));
    498 		fpu_explode(fe, &fe->fe_f1, type, rs1);
    499 		fpu_explode(fe, &fe->fe_f2, type, rs2);
    500 		fp = fpu_sub(fe);
    501 		break;
    502 
    503 	case FMUL >> 2:
    504 		DPRINTF(FPE_INSN, ("fpu_execute: FMUL\n"));
    505 		fpu_explode(fe, &fe->fe_f1, type, rs1);
    506 		fpu_explode(fe, &fe->fe_f2, type, rs2);
    507 		fp = fpu_mul(fe);
    508 		break;
    509 
    510 	case FDIV >> 2:
    511 		DPRINTF(FPE_INSN, ("fpu_execute: FDIV\n"));
    512 		fpu_explode(fe, &fe->fe_f1, type, rs1);
    513 		fpu_explode(fe, &fe->fe_f2, type, rs2);
    514 		fp = fpu_div(fe);
    515 		break;
    516 
    517 	case FCMP >> 2:
    518 		DPRINTF(FPE_INSN, ("fpu_execute: FCMP\n"));
    519 		fpu_explode(fe, &fe->fe_f1, type, rs1);
    520 		fpu_explode(fe, &fe->fe_f2, type, rs2);
    521 		fpu_compare(fe, 0);
    522 		goto cmpdone;
    523 
    524 	case FCMPE >> 2:
    525 		DPRINTF(FPE_INSN, ("fpu_execute: FCMPE\n"));
    526 		fpu_explode(fe, &fe->fe_f1, type, rs1);
    527 		fpu_explode(fe, &fe->fe_f2, type, rs2);
    528 		fpu_compare(fe, 1);
    529 	cmpdone:
    530 		/*
    531 		 * The only possible exception here is NV; catch it
    532 		 * early and get out, as there is no result register.
    533 		 */
    534 		cx = fe->fe_cx;
    535 		fsr = fe->fe_fsr | (cx << FSR_CX_SHIFT);
    536 		if (cx != 0) {
    537 			if (fsr & (FSR_NV << FSR_TEM_SHIFT)) {
    538 				fs->fs_fsr = (fsr & ~FSR_FTT) |
    539 				    (FSR_TT_IEEE << FSR_FTT_SHIFT);
    540 				return (FPE);
    541 			}
    542 			fsr |= FSR_NV << FSR_AX_SHIFT;
    543 		}
    544 		fs->fs_fsr = fsr;
    545 		return (0);
    546 
    547 	case FSMULD >> 2:
    548 	case FDMULX >> 2:
    549 		DPRINTF(FPE_INSN, ("fpu_execute: FSMULx\n"));
    550 		if (type == FTYPE_EXT)
    551 			return (NOTFPU);
    552 		fpu_explode(fe, &fe->fe_f1, type, rs1);
    553 		fpu_explode(fe, &fe->fe_f2, type, rs2);
    554 		type++;	/* single to double, or double to quad */
    555 		fp = fpu_mul(fe);
    556 		break;
    557 
    558 #ifdef SUN4U
    559 	case FXTOS >> 2:
    560 	case FXTOD >> 2:
    561 	case FXTOQ >> 2:
    562 		DPRINTF(FPE_INSN, ("fpu_execute: FXTOx\n"));
    563 		type = FTYPE_LNG;
    564 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
    565 		type = opf & 3;	/* sneaky; depends on instruction encoding */
    566 		break;
    567 
    568 	case FTOX >> 2:
    569 		DPRINTF(FPE_INSN, ("fpu_execute: FTOX\n"));
    570 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
    571 		type = FTYPE_LNG;
    572 		/* Recalculate destination register */
    573 		rd = instr.i_opf.i_rd;
    574 		break;
    575 
    576 #endif /* SUN4U */
    577 	case FTOI >> 2:
    578 		DPRINTF(FPE_INSN, ("fpu_execute: FTOI\n"));
    579 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
    580 		type = FTYPE_INT;
    581 		/* Recalculate destination register */
    582 		rd = instr.i_opf.i_rd;
    583 		break;
    584 
    585 	case FTOS >> 2:
    586 	case FTOD >> 2:
    587 	case FTOQ >> 2:
    588 		DPRINTF(FPE_INSN, ("fpu_execute: FTOx\n"));
    589 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
    590 		/* Recalculate rd with correct type info. */
    591 		type = opf & 3;	/* sneaky; depends on instruction encoding */
    592 		mask = 0x3 >> (3 - type);
    593 		rd = instr.i_opf.i_rd;
    594 		rd = (rd & ~mask) | ((rd & mask & 0x1) << 5);
    595 		break;
    596 	}
    597 
    598 	/*
    599 	 * ALU operation is complete.  Collapse the result and then check
    600 	 * for exceptions.  If we got any, and they are enabled, do not
    601 	 * alter the destination register, just stop with an exception.
    602 	 * Otherwise set new current exceptions and accrue.
    603 	 */
    604 	fpu_implode(fe, fp, type, space);
    605 	cx = fe->fe_cx;
    606 	fsr = fe->fe_fsr;
    607 	if (cx != 0) {
    608 		mask = (fsr >> FSR_TEM_SHIFT) & FSR_TEM_MASK;
    609 		if (cx & mask) {
    610 			/* not accrued??? */
    611 			fs->fs_fsr = (fsr & ~FSR_FTT) |
    612 			    (FSR_TT_IEEE << FSR_FTT_SHIFT) |
    613 			    (cx_to_trapx[(cx & mask) - 1] << FSR_CX_SHIFT);
    614 			return (FPE);
    615 		}
    616 		fsr |= (cx << FSR_CX_SHIFT) | (cx << FSR_AX_SHIFT);
    617 	}
    618 	fs->fs_fsr = fsr;
    619 	DPRINTF(FPE_REG, ("-> %c%d\n", (type == FTYPE_LNG) ? 'x' :
    620 		((type == FTYPE_INT) ? 'i' :
    621 			((type == FTYPE_SNG) ? 's' :
    622 				((type == FTYPE_DBL) ? 'd' :
    623 					((type == FTYPE_EXT) ? 'q' : '?')))),
    624 		rd));
    625 	fs->fs_regs[rd] = space[0];
    626 	if (type >= FTYPE_DBL || type == FTYPE_LNG) {
    627 		fs->fs_regs[rd + 1] = space[1];
    628 		if (type > FTYPE_DBL) {
    629 			fs->fs_regs[rd + 2] = space[2];
    630 			fs->fs_regs[rd + 3] = space[3];
    631 		}
    632 	}
    633 	return (0);	/* success */
    634 }
    635