xref: /netbsd-src/sys/arch/sparc/fpu/fpu.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: fpu.c,v 1.27 2012/02/12 16:34:10 matt 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 1.27 2012/02/12 16:34:10 matt 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(
131 	struct lwp *l,
132 #ifndef SUN4U
133 	struct fpstate *fs
134 #else /* SUN4U */
135 	struct fpstate64 *fs
136 #endif /* SUN4U */
137 	)
138 {
139 	int i, fsr = fs->fs_fsr, error;
140 	struct proc *p = l->l_proc;
141 	union instr instr;
142 	struct fpemu fe;
143 	u_char *fpu_codes;
144 	int code = 0;
145 
146 	fpu_codes =
147 #ifdef COMPAT_SUNOS
148 		(p->p_emul == &emul_sunos) ? fpu_codes_sunos :
149 #endif
150 		fpu_codes_native;
151 
152 	switch ((fsr >> FSR_FTT_SHIFT) & FSR_FTT_MASK) {
153 
154 	case FSR_TT_NONE:
155 		panic("fpu_cleanup: No fault");	/* ??? */
156 		break;
157 
158 	case FSR_TT_IEEE:
159 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_IEEE\n"));
160 		/* XXX missing trap address! */
161 		if ((i = fsr & FSR_CX) == 0)
162 			panic("fpu ieee trap, but no exception");
163 		code = fpu_codes[i - 1];
164 		break;		/* XXX should return, but queue remains */
165 
166 	case FSR_TT_UNFIN:
167 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_UNFIN\n"));
168 #ifdef SUN4U
169 		if (fs->fs_qsize == 0) {
170 			printf("fpu_cleanup: unfinished fpop");
171 			/* The book sez reexecute or emulate. */
172 			return (0);
173 		}
174 		break;
175 
176 #endif /* SUN4U */
177 	case FSR_TT_UNIMP:
178 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_UNIMP\n"));
179 		if (fs->fs_qsize == 0)
180 			panic("fpu_cleanup: unimplemented fpop");
181 		break;
182 
183 	case FSR_TT_SEQ:
184 		panic("fpu sequence error");
185 		/* NOTREACHED */
186 
187 	case FSR_TT_HWERR:
188 		DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_HWERR\n"));
189 		log(LOG_ERR, "fpu hardware error (%s[%d])\n",
190 		    p->p_comm, p->p_pid);
191 		uprintf("%s[%d]: fpu hardware error\n", p->p_comm, p->p_pid);
192 		code = SI_NOINFO;
193 		goto out;
194 
195 	default:
196 		printf("fsr=0x%x\n", fsr);
197 		panic("fpu error");
198 	}
199 
200 	/* emulate the instructions left in the queue */
201 	fe.fe_fpstate = fs;
202 	for (i = 0; i < fs->fs_qsize; i++) {
203 		instr.i_int = fs->fs_queue[i].fq_instr;
204 		if (instr.i_any.i_op != IOP_reg ||
205 		    (instr.i_op3.i_op3 != IOP3_FPop1 &&
206 		     instr.i_op3.i_op3 != IOP3_FPop2))
207 			panic("bogus fpu queue");
208 		error = fpu_execute(&fe, instr);
209 		if (error == 0)
210 			continue;
211 
212 		switch (error) {
213 		case FPE:
214 			code = fpu_codes[(fs->fs_fsr & FSR_CX) - 1];
215 			break;
216 
217 		case NOTFPU:
218 #ifdef SUN4U
219 #ifdef DEBUG
220 			printf("fpu_cleanup: not an FPU error -- sending SIGILL\n");
221 #endif
222 #endif /* SUN4U */
223 			code = SI_NOINFO;
224 			break;
225 
226 		default:
227 			panic("fpu_cleanup 3");
228 			/* NOTREACHED */
229 		}
230 		/* XXX should stop here, but queue remains */
231 	}
232 out:
233 	fs->fs_qsize = 0;
234 	return (code);
235 }
236 
237 #ifdef notyet
238 /*
239  * If we have no FPU at all (are there any machines like this out
240  * there!?) we have to emulate each instruction, and we need a pointer
241  * to the trapframe so that we can step over them and do FBfcc's.
242  * We know the `queue' is empty, though; we just want to emulate
243  * the instruction at tf->tf_pc.
244  */
245 fpu_emulate(l, tf, fs)
246 	struct lwp *l;
247 	struct trapframe *tf;
248 #ifndef SUN4U
249 	struct fpstate *fs;
250 #else /* SUN4U */
251 	struct fpstate64 *fs;
252 #endif /* SUN4U */
253 {
254 
255 	do {
256 		fetch instr from pc
257 		decode
258 		if (integer instr) {
259 			struct pcb *pcb = lwp_getpcb(l);
260 			/*
261 			 * We do this here, rather than earlier, to avoid
262 			 * losing even more badly than usual.
263 			 */
264 			if (pcb->pcb_uw) {
265 				write_user_windows();
266 				if (rwindow_save(l))
267 					sigexit(l, SIGILL);
268 			}
269 			if (loadstore) {
270 				do_it;
271 				pc = npc, npc += 4
272 			} else if (fbfcc) {
273 				do_annul_stuff;
274 			} else
275 				return;
276 		} else if (fpu instr) {
277 			fe.fe_fsr = fs->fs_fsr &= ~FSR_CX;
278 			error = fpu_execute(&fe, fs, instr);
279 			switch (error) {
280 				etc;
281 			}
282 		} else
283 			return;
284 		if (want to reschedule)
285 			return;
286 	} while (error == 0);
287 }
288 #endif
289 
290 /*
291  * Execute an FPU instruction (one that runs entirely in the FPU; not
292  * FBfcc or STF, for instance).  On return, fe->fe_fs->fs_fsr will be
293  * modified to reflect the setting the hardware would have left.
294  *
295  * Note that we do not catch all illegal opcodes, so you can, for instance,
296  * multiply two integers this way.
297  */
298 int
299 fpu_execute(struct fpemu *fe, 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