xref: /netbsd-src/sys/arch/sparc/fpu/fpu.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: fpu.c,v 1.25 2005/11/16 23:24:44 uwe 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 1.25 2005/11/16 23:24:44 uwe 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(struct fpemu *fe, union instr instr)
298 {
299 	struct fpn *fp;
300 #ifndef SUN4U
301 	int opf, rs1, rs2, rd, type, mask, fsr, cx;
302 	struct fpstate *fs;
303 #else /* SUN4U */
304 	int opf, rs1, rs2, rd, type, mask, fsr, cx, i, cond;
305 	struct fpstate64 *fs;
306 #endif /* SUN4U */
307 	u_int space[4];
308 
309 	/*
310 	 * `Decode' and execute instruction.  Start with no exceptions.
311 	 * The type of any i_opf opcode is in the bottom two bits, so we
312 	 * squish them out here.
313 	 */
314 	opf = instr.i_opf.i_opf;
315 	/*
316 	 * The low two bits of the opf field for floating point insns usually
317 	 * correspond to the operation width:
318 	 *
319 	 *	0:	Invalid
320 	 *	1:	Single precision float
321 	 *	2:	Double precision float
322 	 *	3:	Quad precision float
323 	 *
324 	 * The exceptions are the integer to float conversion instructions.
325 	 *
326 	 * For double and quad precision, the low bit if the rs or rd field
327 	 * is actually the high bit of the register number.
328 	 */
329 
330 	type = opf & 3;
331 	mask = 0x3 >> (3 - type);
332 
333 	rs1 = instr.i_opf.i_rs1;
334 	rs1 = (rs1 & ~mask) | ((rs1 & mask & 0x1) << 5);
335 	rs2 = instr.i_opf.i_rs2;
336 	rs2 = (rs2 & ~mask) | ((rs2 & mask & 0x1) << 5);
337 	rd = instr.i_opf.i_rd;
338 	rd = (rd & ~mask) | ((rd & mask & 0x1) << 5);
339 #ifdef DIAGNOSTIC
340 	if ((rs1 | rs2 | rd) & mask)
341 		/* This may be an FPU insn but it is illegal. */
342 		return (NOTFPU);
343 #endif
344 	fs = fe->fe_fpstate;
345 	fe->fe_fsr = fs->fs_fsr & ~FSR_CX;
346 	fe->fe_cx = 0;
347 #ifdef SUN4U
348 	/*
349 	 * Check to see if we're dealing with a fancy cmove and handle
350 	 * it first.
351 	 */
352 	if (instr.i_op3.i_op3 == IOP3_FPop2 && (opf&0xff0) != (FCMP&0xff0)) {
353 		switch (opf >>= 2) {
354 		case FMVFC0 >> 2:
355 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC0\n"));
356 			cond = (fs->fs_fsr>>FSR_FCC_SHIFT)&FSR_FCC_MASK;
357 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
358 			rs1 = fs->fs_regs[rs2];
359 			goto mov;
360 		case FMVFC1 >> 2:
361 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC1\n"));
362 			cond = (fs->fs_fsr>>FSR_FCC1_SHIFT)&FSR_FCC_MASK;
363 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
364 			rs1 = fs->fs_regs[rs2];
365 			goto mov;
366 		case FMVFC2 >> 2:
367 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC2\n"));
368 			cond = (fs->fs_fsr>>FSR_FCC2_SHIFT)&FSR_FCC_MASK;
369 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
370 			rs1 = fs->fs_regs[rs2];
371 			goto mov;
372 		case FMVFC3 >> 2:
373 			DPRINTF(FPE_INSN, ("fpu_execute: FMVFC3\n"));
374 			cond = (fs->fs_fsr>>FSR_FCC3_SHIFT)&FSR_FCC_MASK;
375 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
376 			rs1 = fs->fs_regs[rs2];
377 			goto mov;
378 		case FMVIC >> 2:
379 			/* Presume we're curlwp */
380 			DPRINTF(FPE_INSN, ("fpu_execute: FMVIC\n"));
381 			cond = (curlwp->l_md.md_tf->tf_tstate>>TSTATE_CCR_SHIFT)&PSR_ICC;
382 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
383 			rs1 = fs->fs_regs[rs2];
384 			goto mov;
385 		case FMVXC >> 2:
386 			/* Presume we're curlwp */
387 			DPRINTF(FPE_INSN, ("fpu_execute: FMVXC\n"));
388 			cond = (curlwp->l_md.md_tf->tf_tstate>>(TSTATE_CCR_SHIFT+XCC_SHIFT))&PSR_ICC;
389 			if (instr.i_fmovcc.i_cond != cond) return(0); /* success */
390 			rs1 = fs->fs_regs[rs2];
391 			goto mov;
392 		case FMVRZ >> 2:
393 			/* Presume we're curlwp */
394 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRZ\n"));
395 			rs1 = instr.i_fmovr.i_rs1;
396 			if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] != 0)
397 				return (0); /* success */
398 			rs1 = fs->fs_regs[rs2];
399 			goto mov;
400 		case FMVRLEZ >> 2:
401 			/* Presume we're curlwp */
402 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRLEZ\n"));
403 			rs1 = instr.i_fmovr.i_rs1;
404 			if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] > 0)
405 				return (0); /* success */
406 			rs1 = fs->fs_regs[rs2];
407 			goto mov;
408 		case FMVRLZ >> 2:
409 			/* Presume we're curlwp */
410 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRLZ\n"));
411 			rs1 = instr.i_fmovr.i_rs1;
412 			if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] >= 0)
413 				return (0); /* success */
414 			rs1 = fs->fs_regs[rs2];
415 			goto mov;
416 		case FMVRNZ >> 2:
417 			/* Presume we're curlwp */
418 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRNZ\n"));
419 			rs1 = instr.i_fmovr.i_rs1;
420 			if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] == 0)
421 				return (0); /* success */
422 			rs1 = fs->fs_regs[rs2];
423 			goto mov;
424 		case FMVRGZ >> 2:
425 			/* Presume we're curlwp */
426 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRGZ\n"));
427 			rs1 = instr.i_fmovr.i_rs1;
428 			if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] <= 0)
429 				return (0); /* success */
430 			rs1 = fs->fs_regs[rs2];
431 			goto mov;
432 		case FMVRGEZ >> 2:
433 			/* Presume we're curlwp */
434 			DPRINTF(FPE_INSN, ("fpu_execute: FMVRGEZ\n"));
435 			rs1 = instr.i_fmovr.i_rs1;
436 			if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] < 0)
437 				return (0); /* success */
438 			rs1 = fs->fs_regs[rs2];
439 			goto mov;
440 		default:
441 			DPRINTF(FPE_INSN,
442 				("fpu_execute: unknown v9 FP inst %x opf %x\n",
443 					instr.i_int, opf));
444 			return (NOTFPU);
445 		}
446 	}
447 #endif /* SUN4U */
448 	switch (opf >>= 2) {
449 
450 	default:
451 		DPRINTF(FPE_INSN,
452 			("fpu_execute: unknown basic FP inst %x opf %x\n",
453 				instr.i_int, opf));
454 		return (NOTFPU);
455 
456 	case FMOV >> 2:		/* these should all be pretty obvious */
457 		DPRINTF(FPE_INSN, ("fpu_execute: FMOV\n"));
458 		rs1 = fs->fs_regs[rs2];
459 		goto mov;
460 
461 	case FNEG >> 2:
462 		DPRINTF(FPE_INSN, ("fpu_execute: FNEG\n"));
463 		rs1 = fs->fs_regs[rs2] ^ (1 << 31);
464 		goto mov;
465 
466 	case FABS >> 2:
467 		DPRINTF(FPE_INSN, ("fpu_execute: FABS\n"));
468 		rs1 = fs->fs_regs[rs2] & ~(1 << 31);
469 	mov:
470 #ifndef SUN4U
471 		fs->fs_regs[rd] = rs1;
472 #else /* SUN4U */
473 		i = 1<<(type-1);
474 		fs->fs_regs[rd++] = rs1;
475 		while (--i > 0)
476 			fs->fs_regs[rd++] = fs->fs_regs[++rs2];
477 #endif /* SUN4U */
478 		fs->fs_fsr = fe->fe_fsr;
479 		return (0);	/* success */
480 
481 	case FSQRT >> 2:
482 		DPRINTF(FPE_INSN, ("fpu_execute: FSQRT\n"));
483 		fpu_explode(fe, &fe->fe_f1, type, rs2);
484 		fp = fpu_sqrt(fe);
485 		break;
486 
487 	case FADD >> 2:
488 		DPRINTF(FPE_INSN, ("fpu_execute: FADD\n"));
489 		fpu_explode(fe, &fe->fe_f1, type, rs1);
490 		fpu_explode(fe, &fe->fe_f2, type, rs2);
491 		fp = fpu_add(fe);
492 		break;
493 
494 	case FSUB >> 2:
495 		DPRINTF(FPE_INSN, ("fpu_execute: FSUB\n"));
496 		fpu_explode(fe, &fe->fe_f1, type, rs1);
497 		fpu_explode(fe, &fe->fe_f2, type, rs2);
498 		fp = fpu_sub(fe);
499 		break;
500 
501 	case FMUL >> 2:
502 		DPRINTF(FPE_INSN, ("fpu_execute: FMUL\n"));
503 		fpu_explode(fe, &fe->fe_f1, type, rs1);
504 		fpu_explode(fe, &fe->fe_f2, type, rs2);
505 		fp = fpu_mul(fe);
506 		break;
507 
508 	case FDIV >> 2:
509 		DPRINTF(FPE_INSN, ("fpu_execute: FDIV\n"));
510 		fpu_explode(fe, &fe->fe_f1, type, rs1);
511 		fpu_explode(fe, &fe->fe_f2, type, rs2);
512 		fp = fpu_div(fe);
513 		break;
514 
515 	case FCMP >> 2:
516 		DPRINTF(FPE_INSN, ("fpu_execute: FCMP\n"));
517 		fpu_explode(fe, &fe->fe_f1, type, rs1);
518 		fpu_explode(fe, &fe->fe_f2, type, rs2);
519 		fpu_compare(fe, 0);
520 		goto cmpdone;
521 
522 	case FCMPE >> 2:
523 		DPRINTF(FPE_INSN, ("fpu_execute: FCMPE\n"));
524 		fpu_explode(fe, &fe->fe_f1, type, rs1);
525 		fpu_explode(fe, &fe->fe_f2, type, rs2);
526 		fpu_compare(fe, 1);
527 	cmpdone:
528 		/*
529 		 * The only possible exception here is NV; catch it
530 		 * early and get out, as there is no result register.
531 		 */
532 		cx = fe->fe_cx;
533 		fsr = fe->fe_fsr | (cx << FSR_CX_SHIFT);
534 		if (cx != 0) {
535 			if (fsr & (FSR_NV << FSR_TEM_SHIFT)) {
536 				fs->fs_fsr = (fsr & ~FSR_FTT) |
537 				    (FSR_TT_IEEE << FSR_FTT_SHIFT);
538 				return (FPE);
539 			}
540 			fsr |= FSR_NV << FSR_AX_SHIFT;
541 		}
542 		fs->fs_fsr = fsr;
543 		return (0);
544 
545 	case FSMULD >> 2:
546 	case FDMULX >> 2:
547 		DPRINTF(FPE_INSN, ("fpu_execute: FSMULx\n"));
548 		if (type == FTYPE_EXT)
549 			return (NOTFPU);
550 		fpu_explode(fe, &fe->fe_f1, type, rs1);
551 		fpu_explode(fe, &fe->fe_f2, type, rs2);
552 		type++;	/* single to double, or double to quad */
553 		fp = fpu_mul(fe);
554 		break;
555 
556 #ifdef SUN4U
557 	case FXTOS >> 2:
558 	case FXTOD >> 2:
559 	case FXTOQ >> 2:
560 		DPRINTF(FPE_INSN, ("fpu_execute: FXTOx\n"));
561 		type = FTYPE_LNG;
562 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
563 		type = opf & 3;	/* sneaky; depends on instruction encoding */
564 		break;
565 
566 	case FTOX >> 2:
567 		DPRINTF(FPE_INSN, ("fpu_execute: FTOX\n"));
568 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
569 		type = FTYPE_LNG;
570 		/* Recalculate destination register */
571 		rd = instr.i_opf.i_rd;
572 		break;
573 
574 #endif /* SUN4U */
575 	case FTOI >> 2:
576 		DPRINTF(FPE_INSN, ("fpu_execute: FTOI\n"));
577 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
578 		type = FTYPE_INT;
579 		/* Recalculate destination register */
580 		rd = instr.i_opf.i_rd;
581 		break;
582 
583 	case FTOS >> 2:
584 	case FTOD >> 2:
585 	case FTOQ >> 2:
586 		DPRINTF(FPE_INSN, ("fpu_execute: FTOx\n"));
587 		fpu_explode(fe, fp = &fe->fe_f1, type, rs2);
588 		/* Recalculate rd with correct type info. */
589 		type = opf & 3;	/* sneaky; depends on instruction encoding */
590 		mask = 0x3 >> (3 - type);
591 		rd = instr.i_opf.i_rd;
592 		rd = (rd & ~mask) | ((rd & mask & 0x1) << 5);
593 		break;
594 	}
595 
596 	/*
597 	 * ALU operation is complete.  Collapse the result and then check
598 	 * for exceptions.  If we got any, and they are enabled, do not
599 	 * alter the destination register, just stop with an exception.
600 	 * Otherwise set new current exceptions and accrue.
601 	 */
602 	fpu_implode(fe, fp, type, space);
603 	cx = fe->fe_cx;
604 	fsr = fe->fe_fsr;
605 	if (cx != 0) {
606 		mask = (fsr >> FSR_TEM_SHIFT) & FSR_TEM_MASK;
607 		if (cx & mask) {
608 			/* not accrued??? */
609 			fs->fs_fsr = (fsr & ~FSR_FTT) |
610 			    (FSR_TT_IEEE << FSR_FTT_SHIFT) |
611 			    (cx_to_trapx[(cx & mask) - 1] << FSR_CX_SHIFT);
612 			return (FPE);
613 		}
614 		fsr |= (cx << FSR_CX_SHIFT) | (cx << FSR_AX_SHIFT);
615 	}
616 	fs->fs_fsr = fsr;
617 	DPRINTF(FPE_REG, ("-> %c%d\n", (type == FTYPE_LNG) ? 'x' :
618 		((type == FTYPE_INT) ? 'i' :
619 			((type == FTYPE_SNG) ? 's' :
620 				((type == FTYPE_DBL) ? 'd' :
621 					((type == FTYPE_EXT) ? 'q' : '?')))),
622 		rd));
623 	fs->fs_regs[rd] = space[0];
624 	if (type >= FTYPE_DBL || type == FTYPE_LNG) {
625 		fs->fs_regs[rd + 1] = space[1];
626 		if (type > FTYPE_DBL) {
627 			fs->fs_regs[rd + 2] = space[2];
628 			fs->fs_regs[rd + 3] = space[3];
629 		}
630 	}
631 	return (0);	/* success */
632 }
633