xref: /freebsd/sys/powerpc/fpu/fpu_emu.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*	$NetBSD: fpu_emu.c,v 1.14 2005/12/11 12:18:42 christos Exp $ */
2 
3 /*-
4  * SPDX-License-Identifier: BSD-4-Clause
5  *
6  * Copyright 2001 Wasabi Systems, Inc.
7  * All rights reserved.
8  *
9  * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *      This product includes software developed for the NetBSD Project by
22  *      Wasabi Systems, Inc.
23  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
24  *    or promote products derived from this software without specific prior
25  *    written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Copyright (c) 1992, 1993
42  *	The Regents of the University of California.  All rights reserved.
43  *
44  * This software was developed by the Computer Systems Engineering group
45  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
46  * contributed to Berkeley.
47  *
48  * All advertising materials mentioning features or use of this software
49  * must display the following acknowledgement:
50  *	This product includes software developed by the University of
51  *	California, Lawrence Berkeley Laboratory.
52  *
53  * Redistribution and use in source and binary forms, with or without
54  * modification, are permitted provided that the following conditions
55  * are met:
56  * 1. Redistributions of source code must retain the above copyright
57  *    notice, this list of conditions and the following disclaimer.
58  * 2. Redistributions in binary form must reproduce the above copyright
59  *    notice, this list of conditions and the following disclaimer in the
60  *    documentation and/or other materials provided with the distribution.
61  * 3. Neither the name of the University nor the names of its contributors
62  *    may be used to endorse or promote products derived from this software
63  *    without specific prior written permission.
64  *
65  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
66  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
67  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
68  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
69  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
70  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
71  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
72  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
73  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
74  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
75  * SUCH DAMAGE.
76  *
77  *	@(#)fpu.c	8.1 (Berkeley) 6/11/93
78  */
79 
80 #include <sys/cdefs.h>
81 __FBSDID("$FreeBSD$");
82 
83 #include "opt_ddb.h"
84 
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/kdb.h>
88 #include <sys/kernel.h>
89 #include <sys/proc.h>
90 #include <sys/sysctl.h>
91 #include <sys/signal.h>
92 #include <sys/syslog.h>
93 #include <sys/signalvar.h>
94 
95 #include <machine/fpu.h>
96 #include <machine/reg.h>
97 
98 #include <powerpc/fpu/fpu_emu.h>
99 #include <powerpc/fpu/fpu_extern.h>
100 #include <powerpc/fpu/fpu_instr.h>
101 
102 static SYSCTL_NODE(_hw, OID_AUTO, fpu_emu, CTLFLAG_RW, 0, "FPU emulator");
103 
104 #define	FPU_EMU_EVCNT_DECL(name)					\
105 static u_int fpu_emu_evcnt_##name;					\
106 SYSCTL_INT(_hw_fpu_emu, OID_AUTO, evcnt_##name, CTLFLAG_RD,		\
107     &fpu_emu_evcnt_##name, 0, "")
108 
109 #define	FPU_EMU_EVCNT_INCR(name)	fpu_emu_evcnt_##name++
110 
111 FPU_EMU_EVCNT_DECL(stfiwx);
112 FPU_EMU_EVCNT_DECL(fpstore);
113 FPU_EMU_EVCNT_DECL(fpload);
114 FPU_EMU_EVCNT_DECL(fcmpu);
115 FPU_EMU_EVCNT_DECL(frsp);
116 FPU_EMU_EVCNT_DECL(fctiw);
117 FPU_EMU_EVCNT_DECL(fcmpo);
118 FPU_EMU_EVCNT_DECL(mtfsb1);
119 FPU_EMU_EVCNT_DECL(fnegabs);
120 FPU_EMU_EVCNT_DECL(mcrfs);
121 FPU_EMU_EVCNT_DECL(mtfsb0);
122 FPU_EMU_EVCNT_DECL(fmr);
123 FPU_EMU_EVCNT_DECL(mtfsfi);
124 FPU_EMU_EVCNT_DECL(fnabs);
125 FPU_EMU_EVCNT_DECL(fabs);
126 FPU_EMU_EVCNT_DECL(mffs);
127 FPU_EMU_EVCNT_DECL(mtfsf);
128 FPU_EMU_EVCNT_DECL(fctid);
129 FPU_EMU_EVCNT_DECL(fcfid);
130 FPU_EMU_EVCNT_DECL(fdiv);
131 FPU_EMU_EVCNT_DECL(fsub);
132 FPU_EMU_EVCNT_DECL(fadd);
133 FPU_EMU_EVCNT_DECL(fsqrt);
134 FPU_EMU_EVCNT_DECL(fsel);
135 FPU_EMU_EVCNT_DECL(fpres);
136 FPU_EMU_EVCNT_DECL(fmul);
137 FPU_EMU_EVCNT_DECL(frsqrte);
138 FPU_EMU_EVCNT_DECL(fmulsub);
139 FPU_EMU_EVCNT_DECL(fmuladd);
140 FPU_EMU_EVCNT_DECL(fnmsub);
141 FPU_EMU_EVCNT_DECL(fnmadd);
142 
143 /* FPSR exception masks */
144 #define FPSR_EX_MSK	(FPSCR_VX|FPSCR_OX|FPSCR_UX|FPSCR_ZX|		\
145 			FPSCR_XX|FPSCR_VXSNAN|FPSCR_VXISI|FPSCR_VXIDI|	\
146 			FPSCR_VXZDZ|FPSCR_VXIMZ|FPSCR_VXVC|FPSCR_VXSOFT|\
147 			FPSCR_VXSQRT|FPSCR_VXCVI)
148 #define	FPSR_EX		(FPSCR_VE|FPSCR_OE|FPSCR_UE|FPSCR_ZE|FPSCR_XE)
149 #define	FPSR_EXOP	(FPSR_EX_MSK&(~FPSR_EX))
150 
151 int fpe_debug = 0;
152 
153 #ifdef DEBUG
154 vm_offset_t opc_disasm(vm_offset_t, int);
155 
156 /*
157  * Dump a `fpn' structure.
158  */
159 void
160 fpu_dumpfpn(struct fpn *fp)
161 {
162 	static const char *class[] = {
163 		"SNAN", "QNAN", "ZERO", "NUM", "INF"
164 	};
165 
166 	printf("%s %c.%x %x %x %xE%d", class[fp->fp_class + 2],
167 		fp->fp_sign ? '-' : ' ',
168 		fp->fp_mant[0],	fp->fp_mant[1],
169 		fp->fp_mant[2], fp->fp_mant[3],
170 		fp->fp_exp);
171 }
172 #endif
173 
174 /*
175  * fpu_execute returns the following error numbers (0 = no error):
176  */
177 #define	FPE		1	/* take a floating point exception */
178 #define	NOTFPU		2	/* not an FPU instruction */
179 #define	FAULT		3
180 
181 
182 /*
183  * Emulate a floating-point instruction.
184  * Return zero for success, else signal number.
185  * (Typically: zero, SIGFPE, SIGILL, SIGSEGV)
186  */
187 int
188 fpu_emulate(struct trapframe *frame, struct fpu *fpf)
189 {
190 	union instr insn;
191 	struct fpemu fe;
192 	static int lastill = 0;
193 	int sig;
194 
195 	/* initialize insn.is_datasize to tell it is *not* initialized */
196 	fe.fe_fpstate = fpf;
197 	fe.fe_cx = 0;
198 
199 	/* always set this (to avoid a warning) */
200 
201 	if (copyin((void *) (frame->srr0), &insn.i_int, sizeof (insn.i_int))) {
202 #ifdef DEBUG
203 		printf("fpu_emulate: fault reading opcode\n");
204 #endif
205 		return SIGSEGV;
206 	}
207 
208 	DPRINTF(FPE_EX, ("fpu_emulate: emulating insn %x at %p\n",
209 	    insn.i_int, (void *)frame->srr0));
210 
211 
212 	if ((insn.i_any.i_opcd == OPC_TWI) ||
213 	    ((insn.i_any.i_opcd == OPC_integer_31) &&
214 	    (insn.i_x.i_xo == OPC31_TW))) {
215 		/* Check for the two trap insns. */
216 		DPRINTF(FPE_EX, ("fpu_emulate: SIGTRAP\n"));
217 		return (SIGTRAP);
218 	}
219 	sig = 0;
220 	switch (fpu_execute(frame, &fe, &insn)) {
221 	case 0:
222 		DPRINTF(FPE_EX, ("fpu_emulate: success\n"));
223 		frame->srr0 += 4;
224 		break;
225 
226 	case FPE:
227 		DPRINTF(FPE_EX, ("fpu_emulate: SIGFPE\n"));
228 		sig = SIGFPE;
229 		break;
230 
231 	case FAULT:
232 		DPRINTF(FPE_EX, ("fpu_emulate: SIGSEGV\n"));
233 		sig = SIGSEGV;
234 		break;
235 
236 	case NOTFPU:
237 	default:
238 		DPRINTF(FPE_EX, ("fpu_emulate: SIGILL\n"));
239 #ifdef DEBUG
240 		if (fpe_debug & FPE_EX) {
241 			printf("fpu_emulate:  illegal insn %x at %p:",
242 			insn.i_int, (void *) (frame->srr0));
243 			opc_disasm(frame->srr0, insn.i_int);
244 		}
245 #endif
246 		/*
247 		* XXXX retry an illegal insn once due to cache issues.
248 		*/
249 		if (lastill == frame->srr0) {
250 			sig = SIGILL;
251 #ifdef DEBUG
252 			if (fpe_debug & FPE_EX)
253 				kdb_enter(KDB_WHY_UNSET, "illegal instruction");
254 #endif
255 		}
256 		lastill = frame->srr0;
257 		break;
258 	}
259 
260 	return (sig);
261 }
262 
263 /*
264  * Execute an FPU instruction (one that runs entirely in the FPU; not
265  * FBfcc or STF, for instance).  On return, fe->fe_fs->fs_fsr will be
266  * modified to reflect the setting the hardware would have left.
267  *
268  * Note that we do not catch all illegal opcodes, so you can, for instance,
269  * multiply two integers this way.
270  */
271 int
272 fpu_execute(struct trapframe *tf, struct fpemu *fe, union instr *insn)
273 {
274 	struct fpn *fp;
275 	union instr instr = *insn;
276 	int *a;
277 	vm_offset_t addr;
278 	int ra, rb, rc, rt, type, mask, fsr, cx, bf, setcr;
279 	unsigned int cond;
280 	struct fpu *fs;
281 
282 	/* Setup work. */
283 	fp = NULL;
284 	fs = fe->fe_fpstate;
285 	fe->fe_fpscr = ((int *)&fs->fpscr)[1];
286 
287 	/*
288 	 * On PowerPC all floating point values are stored in registers
289 	 * as doubles, even when used for single precision operations.
290 	 */
291 	type = FTYPE_DBL;
292 	cond = instr.i_any.i_rc;
293 	setcr = 0;
294 	bf = 0;	/* XXX gcc */
295 
296 #if defined(DDB) && defined(DEBUG)
297 	if (fpe_debug & FPE_EX) {
298 		vm_offset_t loc = tf->srr0;
299 
300 		printf("Trying to emulate: %p ", (void *)loc);
301 		opc_disasm(loc, instr.i_int);
302 	}
303 #endif
304 
305 	/*
306 	 * `Decode' and execute instruction.
307 	 */
308 
309 	if ((instr.i_any.i_opcd >= OPC_LFS && instr.i_any.i_opcd <= OPC_STFDU) ||
310 	    instr.i_any.i_opcd == OPC_integer_31) {
311 		/*
312 		 * Handle load/store insns:
313 		 *
314 		 * Convert to/from single if needed, calculate addr,
315 		 * and update index reg if needed.
316 		 */
317 		double buf;
318 		size_t size = sizeof(float);
319 		int store, update;
320 
321 		cond = 0; /* ld/st never set condition codes */
322 
323 
324 		if (instr.i_any.i_opcd == OPC_integer_31) {
325 			if (instr.i_x.i_xo == OPC31_STFIWX) {
326 				FPU_EMU_EVCNT_INCR(stfiwx);
327 
328 				/* Store as integer */
329 				ra = instr.i_x.i_ra;
330 				rb = instr.i_x.i_rb;
331 				DPRINTF(FPE_INSN,
332 					("reg %d has %jx reg %d has %jx\n",
333 					ra, (uintmax_t)tf->fixreg[ra], rb,
334 					(uintmax_t)tf->fixreg[rb]));
335 
336 				addr = tf->fixreg[rb];
337 				if (ra != 0)
338 					addr += tf->fixreg[ra];
339 				rt = instr.i_x.i_rt;
340 				a = (int *)&fs->fpr[rt].fpr;
341 				DPRINTF(FPE_INSN,
342 					("fpu_execute: Store INT %x at %p\n",
343 						a[1], (void *)addr));
344 				if (copyout(&a[1], (void *)addr, sizeof(int)))
345 					return (FAULT);
346 				return (0);
347 			}
348 
349 			if ((instr.i_x.i_xo & OPC31_FPMASK) != OPC31_FPOP)
350 				/* Not an indexed FP load/store op */
351 				return (NOTFPU);
352 
353 			store = (instr.i_x.i_xo & 0x80);
354 			if (instr.i_x.i_xo & 0x40)
355 				size = sizeof(double);
356 			else
357 				type = FTYPE_SNG;
358 			update = (instr.i_x.i_xo & 0x20);
359 
360 			/* calculate EA of load/store */
361 			ra = instr.i_x.i_ra;
362 			rb = instr.i_x.i_rb;
363 			DPRINTF(FPE_INSN, ("reg %d has %jx reg %d has %jx\n",
364 				ra, (uintmax_t)tf->fixreg[ra], rb,
365 				(uintmax_t)tf->fixreg[rb]));
366 			addr = tf->fixreg[rb];
367 			if (ra != 0)
368 				addr += tf->fixreg[ra];
369 			rt = instr.i_x.i_rt;
370 		} else {
371 			store = instr.i_d.i_opcd & 0x4;
372 			if (instr.i_d.i_opcd & 0x2)
373 				size = sizeof(double);
374 			else
375 				type = FTYPE_SNG;
376 			update = instr.i_d.i_opcd & 0x1;
377 
378 			/* calculate EA of load/store */
379 			ra = instr.i_d.i_ra;
380 			addr = instr.i_d.i_d;
381 			DPRINTF(FPE_INSN, ("reg %d has %jx displ %jx\n",
382 				ra, (uintmax_t)tf->fixreg[ra],
383 				(uintmax_t)addr));
384 			if (ra != 0)
385 				addr += tf->fixreg[ra];
386 			rt = instr.i_d.i_rt;
387 		}
388 
389 		if (update && ra == 0)
390 			return (NOTFPU);
391 
392 		if (store) {
393 			/* Store */
394 			FPU_EMU_EVCNT_INCR(fpstore);
395 			if (type != FTYPE_DBL) {
396 				DPRINTF(FPE_INSN,
397 					("fpu_execute: Store SNG at %p\n",
398 						(void *)addr));
399 				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_DBL, rt);
400 				fpu_implode(fe, fp, type, (void *)&buf);
401 				if (copyout(&buf, (void *)addr, size))
402 					return (FAULT);
403 			} else {
404 				DPRINTF(FPE_INSN,
405 					("fpu_execute: Store DBL at %p\n",
406 						(void *)addr));
407 				if (copyout(&fs->fpr[rt].fpr, (void *)addr,
408 				    size))
409 					return (FAULT);
410 			}
411 		} else {
412 			/* Load */
413 			FPU_EMU_EVCNT_INCR(fpload);
414 			DPRINTF(FPE_INSN, ("fpu_execute: Load from %p\n",
415 				(void *)addr));
416 			if (copyin((const void *)addr, &fs->fpr[rt].fpr,
417 			    size))
418 				return (FAULT);
419 			if (type != FTYPE_DBL) {
420 				fpu_explode(fe, fp = &fe->fe_f1, type, rt);
421 				fpu_implode(fe, fp, FTYPE_DBL,
422 					(u_int *)&fs->fpr[rt].fpr);
423 			}
424 		}
425 		if (update)
426 			tf->fixreg[ra] = addr;
427 		/* Complete. */
428 		return (0);
429 #ifdef notyet
430 	} else if (instr.i_any.i_opcd == OPC_load_st_62) {
431 		/* These are 64-bit extensions */
432 		return (NOTFPU);
433 #endif
434 	} else if (instr.i_any.i_opcd == OPC_sp_fp_59 ||
435 		instr.i_any.i_opcd == OPC_dp_fp_63) {
436 
437 
438 		if (instr.i_any.i_opcd == OPC_dp_fp_63 &&
439 		    !(instr.i_a.i_xo & OPC63M_MASK)) {
440 			/* Format X */
441 			rt = instr.i_x.i_rt;
442 			ra = instr.i_x.i_ra;
443 			rb = instr.i_x.i_rb;
444 
445 
446 			/* One of the special opcodes.... */
447 			switch (instr.i_x.i_xo) {
448 			case	OPC63_FCMPU:
449 				FPU_EMU_EVCNT_INCR(fcmpu);
450 				DPRINTF(FPE_INSN, ("fpu_execute: FCMPU\n"));
451 				rt >>= 2;
452 				fpu_explode(fe, &fe->fe_f1, type, ra);
453 				fpu_explode(fe, &fe->fe_f2, type, rb);
454 				fpu_compare(fe, 0);
455 				/* Make sure we do the condition regs. */
456 				cond = 0;
457 				/* N.B.: i_rs is already left shifted by two. */
458 				bf = instr.i_x.i_rs & 0xfc;
459 				setcr = 1;
460 				break;
461 
462 			case	OPC63_FRSP:
463 				/*
464 				 * Convert to single:
465 				 *
466 				 * PowerPC uses this to round a double
467 				 * precision value to single precision,
468 				 * but values in registers are always
469 				 * stored in double precision format.
470 				 */
471 				FPU_EMU_EVCNT_INCR(frsp);
472 				DPRINTF(FPE_INSN, ("fpu_execute: FRSP\n"));
473 				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_DBL, rb);
474 				fpu_implode(fe, fp, FTYPE_SNG,
475 					(u_int *)&fs->fpr[rt].fpr);
476 				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_SNG, rt);
477 				type = FTYPE_DBL;
478 				break;
479 			case	OPC63_FCTIW:
480 			case	OPC63_FCTIWZ:
481 				FPU_EMU_EVCNT_INCR(fctiw);
482 				DPRINTF(FPE_INSN, ("fpu_execute: FCTIW\n"));
483 				fpu_explode(fe, fp = &fe->fe_f1, type, rb);
484 				type = FTYPE_INT;
485 				break;
486 			case	OPC63_FCMPO:
487 				FPU_EMU_EVCNT_INCR(fcmpo);
488 				DPRINTF(FPE_INSN, ("fpu_execute: FCMPO\n"));
489 				rt >>= 2;
490 				fpu_explode(fe, &fe->fe_f1, type, ra);
491 				fpu_explode(fe, &fe->fe_f2, type, rb);
492 				fpu_compare(fe, 1);
493 				/* Make sure we do the condition regs. */
494 				cond = 0;
495 				/* N.B.: i_rs is already left shifted by two. */
496 				bf = instr.i_x.i_rs & 0xfc;
497 				setcr = 1;
498 				break;
499 			case	OPC63_MTFSB1:
500 				FPU_EMU_EVCNT_INCR(mtfsb1);
501 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSB1\n"));
502 				fe->fe_fpscr |=
503 					(~(FPSCR_VX|FPSR_EX) & (1<<(31-rt)));
504 				break;
505 			case	OPC63_FNEG:
506 				FPU_EMU_EVCNT_INCR(fnegabs);
507 				DPRINTF(FPE_INSN, ("fpu_execute: FNEGABS\n"));
508 				memcpy(&fs->fpr[rt].fpr, &fs->fpr[rb].fpr,
509 					sizeof(double));
510 				a = (int *)&fs->fpr[rt].fpr;
511 				*a ^= (1U << 31);
512 				break;
513 			case	OPC63_MCRFS:
514 				FPU_EMU_EVCNT_INCR(mcrfs);
515 				DPRINTF(FPE_INSN, ("fpu_execute: MCRFS\n"));
516 				cond = 0;
517 				rt &= 0x1c;
518 				ra &= 0x1c;
519 				/* Extract the bits we want */
520 				mask = (fe->fe_fpscr >> (28 - ra)) & 0xf;
521 				/* Clear the bits we copied. */
522 				fe->fe_cx =
523 					(FPSR_EX_MSK | (0xf << (28 - ra)));
524 				fe->fe_fpscr &= fe->fe_cx;
525 				/* Now shove them in the right part of cr */
526 				tf->cr &= ~(0xf << (28 - rt));
527 				tf->cr |= (mask << (28 - rt));
528 				break;
529 			case	OPC63_MTFSB0:
530 				FPU_EMU_EVCNT_INCR(mtfsb0);
531 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSB0\n"));
532 				fe->fe_fpscr &=
533 					((FPSCR_VX|FPSR_EX) & ~(1<<(31-rt)));
534 				break;
535 			case	OPC63_FMR:
536 				FPU_EMU_EVCNT_INCR(fmr);
537 				DPRINTF(FPE_INSN, ("fpu_execute: FMR\n"));
538 				memcpy(&fs->fpr[rt].fpr, &fs->fpr[rb].fpr,
539 					sizeof(double));
540 				break;
541 			case	OPC63_MTFSFI:
542 				FPU_EMU_EVCNT_INCR(mtfsfi);
543 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSFI\n"));
544 				rb >>= 1;
545 				rt &= 0x1c; /* Already left-shifted 4 */
546 				fe->fe_cx = rb << (28 - rt);
547 				mask = 0xf<<(28 - rt);
548 				fe->fe_fpscr = (fe->fe_fpscr & ~mask) |
549 					fe->fe_cx;
550 /* XXX weird stuff about OX, FX, FEX, and VX should be handled */
551 				break;
552 			case	OPC63_FNABS:
553 				FPU_EMU_EVCNT_INCR(fnabs);
554 				DPRINTF(FPE_INSN, ("fpu_execute: FABS\n"));
555 				memcpy(&fs->fpr[rt].fpr, &fs->fpr[rb].fpr,
556 					sizeof(double));
557 				a = (int *)&fs->fpr[rt].fpr;
558 				*a |= (1U << 31);
559 				break;
560 			case	OPC63_FABS:
561 				FPU_EMU_EVCNT_INCR(fabs);
562 				DPRINTF(FPE_INSN, ("fpu_execute: FABS\n"));
563 				memcpy(&fs->fpr[rt].fpr, &fs->fpr[rb].fpr,
564 					sizeof(double));
565 				a = (int *)&fs->fpr[rt].fpr;
566 				*a &= ~(1U << 31);
567 				break;
568 			case	OPC63_MFFS:
569 				FPU_EMU_EVCNT_INCR(mffs);
570 				DPRINTF(FPE_INSN, ("fpu_execute: MFFS\n"));
571 				memcpy(&fs->fpr[rt].fpr, &fs->fpscr,
572 					sizeof(fs->fpscr));
573 				break;
574 			case	OPC63_MTFSF:
575 				FPU_EMU_EVCNT_INCR(mtfsf);
576 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSF\n"));
577 				if ((rt = instr.i_xfl.i_flm) == -1)
578 					mask = -1;
579 				else {
580 					mask = 0;
581 					/* Convert 1 bit -> 4 bits */
582 					for (ra = 0; ra < 8; ra ++)
583 						if (rt & (1<<ra))
584 							mask |= (0xf<<(4*ra));
585 				}
586 				a = (int *)&fs->fpr[rt].fpr;
587 				fe->fe_cx = mask & a[1];
588 				fe->fe_fpscr = (fe->fe_fpscr&~mask) |
589 					(fe->fe_cx);
590 /* XXX weird stuff about OX, FX, FEX, and VX should be handled */
591 				break;
592 			case	OPC63_FCTID:
593 			case	OPC63_FCTIDZ:
594 				FPU_EMU_EVCNT_INCR(fctid);
595 				DPRINTF(FPE_INSN, ("fpu_execute: FCTID\n"));
596 				fpu_explode(fe, fp = &fe->fe_f1, type, rb);
597 				type = FTYPE_LNG;
598 				break;
599 			case	OPC63_FCFID:
600 				FPU_EMU_EVCNT_INCR(fcfid);
601 				DPRINTF(FPE_INSN, ("fpu_execute: FCFID\n"));
602 				type = FTYPE_LNG;
603 				fpu_explode(fe, fp = &fe->fe_f1, type, rb);
604 				type = FTYPE_DBL;
605 				break;
606 			default:
607 				return (NOTFPU);
608 				break;
609 			}
610 		} else {
611 			/* Format A */
612 			rt = instr.i_a.i_frt;
613 			ra = instr.i_a.i_fra;
614 			rb = instr.i_a.i_frb;
615 			rc = instr.i_a.i_frc;
616 
617 			/*
618 			 * All arithmetic operations work on registers, which
619 			 * are stored as doubles.
620 			 */
621 			type = FTYPE_DBL;
622 			switch ((unsigned int)instr.i_a.i_xo) {
623 			case	OPC59_FDIVS:
624 				FPU_EMU_EVCNT_INCR(fdiv);
625 				DPRINTF(FPE_INSN, ("fpu_execute: FDIV\n"));
626 				fpu_explode(fe, &fe->fe_f1, type, ra);
627 				fpu_explode(fe, &fe->fe_f2, type, rb);
628 				fp = fpu_div(fe);
629 				break;
630 			case	OPC59_FSUBS:
631 				FPU_EMU_EVCNT_INCR(fsub);
632 				DPRINTF(FPE_INSN, ("fpu_execute: FSUB\n"));
633 				fpu_explode(fe, &fe->fe_f1, type, ra);
634 				fpu_explode(fe, &fe->fe_f2, type, rb);
635 				fp = fpu_sub(fe);
636 				break;
637 			case	OPC59_FADDS:
638 				FPU_EMU_EVCNT_INCR(fadd);
639 				DPRINTF(FPE_INSN, ("fpu_execute: FADD\n"));
640 				fpu_explode(fe, &fe->fe_f1, type, ra);
641 				fpu_explode(fe, &fe->fe_f2, type, rb);
642 				fp = fpu_add(fe);
643 				break;
644 			case	OPC59_FSQRTS:
645 				FPU_EMU_EVCNT_INCR(fsqrt);
646 				DPRINTF(FPE_INSN, ("fpu_execute: FSQRT\n"));
647 				fpu_explode(fe, &fe->fe_f1, type, rb);
648 				fp = fpu_sqrt(fe);
649 				break;
650 			case	OPC63M_FSEL:
651 				FPU_EMU_EVCNT_INCR(fsel);
652 				DPRINTF(FPE_INSN, ("fpu_execute: FSEL\n"));
653 				a = (int *)&fe->fe_fpstate->fpr[ra].fpr;
654 				if ((*a & 0x80000000) && (*a & 0x7fffffff))
655 					/* fra < 0 */
656 					rc = rb;
657 				DPRINTF(FPE_INSN, ("f%d => f%d\n", rc, rt));
658 				memcpy(&fs->fpr[rt].fpr, &fs->fpr[rc].fpr,
659 					sizeof(double));
660 				break;
661 			case	OPC59_FRES:
662 				FPU_EMU_EVCNT_INCR(fpres);
663 				DPRINTF(FPE_INSN, ("fpu_execute: FPRES\n"));
664 				fpu_explode(fe, &fe->fe_f1, type, rb);
665 				fp = fpu_sqrt(fe);
666 				/* now we've gotta overwrite the dest reg */
667 				*((int *)&fe->fe_fpstate->fpr[rt].fpr) = 1;
668 				fpu_explode(fe, &fe->fe_f1, FTYPE_INT, rt);
669 				fpu_div(fe);
670 				break;
671 			case	OPC59_FMULS:
672 				FPU_EMU_EVCNT_INCR(fmul);
673 				DPRINTF(FPE_INSN, ("fpu_execute: FMUL\n"));
674 				fpu_explode(fe, &fe->fe_f1, type, ra);
675 				fpu_explode(fe, &fe->fe_f2, type, rc);
676 				fp = fpu_mul(fe);
677 				break;
678 			case	OPC63M_FRSQRTE:
679 				/* Reciprocal sqrt() estimate */
680 				FPU_EMU_EVCNT_INCR(frsqrte);
681 				DPRINTF(FPE_INSN, ("fpu_execute: FRSQRTE\n"));
682 				fpu_explode(fe, &fe->fe_f1, type, rb);
683 				fp = fpu_sqrt(fe);
684 				fe->fe_f2 = *fp;
685 				/* now we've gotta overwrite the dest reg */
686 				*((int *)&fe->fe_fpstate->fpr[rt].fpr) = 1;
687 				fpu_explode(fe, &fe->fe_f1, FTYPE_INT, rt);
688 				fpu_div(fe);
689 				break;
690 			case	OPC59_FMSUBS:
691 				FPU_EMU_EVCNT_INCR(fmulsub);
692 				DPRINTF(FPE_INSN, ("fpu_execute: FMULSUB\n"));
693 				fpu_explode(fe, &fe->fe_f1, type, ra);
694 				fpu_explode(fe, &fe->fe_f2, type, rc);
695 				fp = fpu_mul(fe);
696 				fe->fe_f1 = *fp;
697 				fpu_explode(fe, &fe->fe_f2, type, rb);
698 				fp = fpu_sub(fe);
699 				break;
700 			case	OPC59_FMADDS:
701 				FPU_EMU_EVCNT_INCR(fmuladd);
702 				DPRINTF(FPE_INSN, ("fpu_execute: FMULADD\n"));
703 				fpu_explode(fe, &fe->fe_f1, type, ra);
704 				fpu_explode(fe, &fe->fe_f2, type, rc);
705 				fp = fpu_mul(fe);
706 				fe->fe_f1 = *fp;
707 				fpu_explode(fe, &fe->fe_f2, type, rb);
708 				fp = fpu_add(fe);
709 				break;
710 			case	OPC59_FNMSUBS:
711 				FPU_EMU_EVCNT_INCR(fnmsub);
712 				DPRINTF(FPE_INSN, ("fpu_execute: FNMSUB\n"));
713 				fpu_explode(fe, &fe->fe_f1, type, ra);
714 				fpu_explode(fe, &fe->fe_f2, type, rc);
715 				fp = fpu_mul(fe);
716 				fe->fe_f1 = *fp;
717 				fpu_explode(fe, &fe->fe_f2, type, rb);
718 				fp = fpu_sub(fe);
719 				/* Negate */
720 				fp->fp_sign ^= 1;
721 				break;
722 			case	OPC59_FNMADDS:
723 				FPU_EMU_EVCNT_INCR(fnmadd);
724 				DPRINTF(FPE_INSN, ("fpu_execute: FNMADD\n"));
725 				fpu_explode(fe, &fe->fe_f1, type, ra);
726 				fpu_explode(fe, &fe->fe_f2, type, rc);
727 				fp = fpu_mul(fe);
728 				fe->fe_f1 = *fp;
729 				fpu_explode(fe, &fe->fe_f2, type, rb);
730 				fp = fpu_add(fe);
731 				/* Negate */
732 				fp->fp_sign ^= 1;
733 				break;
734 			default:
735 				return (NOTFPU);
736 				break;
737 			}
738 
739 			/* If the instruction was single precision, round */
740 			if (!(instr.i_any.i_opcd & 0x4)) {
741 				fpu_implode(fe, fp, FTYPE_SNG,
742 					(u_int *)&fs->fpr[rt].fpr);
743 				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_SNG, rt);
744 			}
745 		}
746 	} else {
747 		return (NOTFPU);
748 	}
749 
750 	/*
751 	 * ALU operation is complete.  Collapse the result and then check
752 	 * for exceptions.  If we got any, and they are enabled, do not
753 	 * alter the destination register, just stop with an exception.
754 	 * Otherwise set new current exceptions and accrue.
755 	 */
756 	if (fp)
757 		fpu_implode(fe, fp, type, (u_int *)&fs->fpr[rt].fpr);
758 	cx = fe->fe_cx;
759 	fsr = fe->fe_fpscr;
760 	if (cx != 0) {
761 		fsr &= ~FPSCR_FX;
762 		if ((cx^fsr)&FPSR_EX_MSK)
763 			fsr |= FPSCR_FX;
764 		mask = fsr & FPSR_EX;
765 		mask <<= (25-3);
766 		if (cx & mask)
767 			fsr |= FPSCR_FEX;
768 		if (cx & FPSCR_FPRF) {
769 			/* Need to replace CC */
770 			fsr &= ~FPSCR_FPRF;
771 		}
772 		if (cx & (FPSR_EXOP))
773 			fsr |= FPSCR_VX;
774 		fsr |= cx;
775 		DPRINTF(FPE_INSN, ("fpu_execute: cx %x, fsr %x\n", cx, fsr));
776 	}
777 
778 	if (cond) {
779 		cond = fsr & 0xf0000000;
780 		/* Isolate condition codes */
781 		cond >>= 28;
782 		/* Move fpu condition codes to cr[1] */
783 		tf->cr &= (0x0f000000);
784 		tf->cr |= (cond<<24);
785 		DPRINTF(FPE_INSN, ("fpu_execute: cr[1] <= %x\n", cond));
786 	}
787 
788 	if (setcr) {
789 		cond = fsr & FPSCR_FPCC;
790 		/* Isolate condition codes */
791 		cond <<= 16;
792 		/* Move fpu condition codes to cr[1] */
793 		tf->cr &= ~(0xf0000000>>bf);
794 		tf->cr |= (cond>>bf);
795 		DPRINTF(FPE_INSN, ("fpu_execute: cr[%d] (cr=%jx) <= %x\n",
796 			bf/4, (uintmax_t)tf->cr, cond));
797 	}
798 
799 	((int *)&fs->fpscr)[1] = fsr;
800 	if (fsr & FPSCR_FEX)
801 		return(FPE);
802 	return (0);	/* success */
803 }
804