xref: /netbsd-src/sys/arch/powerpc/fpu/fpu_emu.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: fpu_emu.c,v 1.17 2014/08/12 20:27:10 joerg Exp $ */
2 
3 /*
4  * Copyright 2001 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * Copyright (c) 1992, 1993
40  *	The Regents of the University of California.  All rights reserved.
41  *
42  * This software was developed by the Computer Systems Engineering group
43  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
44  * contributed to Berkeley.
45  *
46  * All advertising materials mentioning features or use of this software
47  * must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Lawrence Berkeley Laboratory.
50  *
51  * Redistribution and use in source and binary forms, with or without
52  * modification, are permitted provided that the following conditions
53  * are met:
54  * 1. Redistributions of source code must retain the above copyright
55  *    notice, this list of conditions and the following disclaimer.
56  * 2. Redistributions in binary form must reproduce the above copyright
57  *    notice, this list of conditions and the following disclaimer in the
58  *    documentation and/or other materials provided with the distribution.
59  * 3. Neither the name of the University nor the names of its contributors
60  *    may be used to endorse or promote products derived from this software
61  *    without specific prior written permission.
62  *
63  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
64  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
66  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
67  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
68  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
69  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
70  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
71  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
72  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
73  * SUCH DAMAGE.
74  *
75  *	@(#)fpu.c	8.1 (Berkeley) 6/11/93
76  */
77 
78 #include <sys/cdefs.h>
79 __KERNEL_RCSID(0, "$NetBSD: fpu_emu.c,v 1.17 2014/08/12 20:27:10 joerg Exp $");
80 
81 #include "opt_ddb.h"
82 
83 #include <sys/param.h>
84 #include <sys/proc.h>
85 #include <sys/signal.h>
86 #include <sys/signalvar.h>
87 #include <sys/siginfo.h>
88 #include <sys/systm.h>
89 #include <sys/syslog.h>
90 #include <sys/evcnt.h>
91 
92 #include <powerpc/instr.h>
93 #include <machine/reg.h>
94 #include <machine/fpu.h>
95 #include <machine/trap.h>
96 
97 #include <powerpc/fpu/fpu_emu.h>
98 #include <powerpc/fpu/fpu_extern.h>
99 
100 #define	FPU_EMU_EVCNT_DECL(name)					\
101 static struct evcnt fpu_emu_ev_##name =					\
102     EVCNT_INITIALIZER(EVCNT_TYPE_TRAP, NULL, "fpemu", #name);		\
103 EVCNT_ATTACH_STATIC(fpu_emu_ev_##name)
104 
105 #define	FPU_EMU_EVCNT_INCR(name)					\
106     fpu_emu_ev_##name.ev_count++
107 
108 FPU_EMU_EVCNT_DECL(stfiwx);
109 FPU_EMU_EVCNT_DECL(fpstore);
110 FPU_EMU_EVCNT_DECL(fpload);
111 FPU_EMU_EVCNT_DECL(fcmpu);
112 FPU_EMU_EVCNT_DECL(frsp);
113 FPU_EMU_EVCNT_DECL(fctiw);
114 FPU_EMU_EVCNT_DECL(fcmpo);
115 FPU_EMU_EVCNT_DECL(mtfsb1);
116 FPU_EMU_EVCNT_DECL(fnegabs);
117 FPU_EMU_EVCNT_DECL(mcrfs);
118 FPU_EMU_EVCNT_DECL(mtfsb0);
119 FPU_EMU_EVCNT_DECL(fmr);
120 FPU_EMU_EVCNT_DECL(mtfsfi);
121 FPU_EMU_EVCNT_DECL(fnabs);
122 FPU_EMU_EVCNT_DECL(fabs);
123 FPU_EMU_EVCNT_DECL(mffs);
124 FPU_EMU_EVCNT_DECL(mtfsf);
125 FPU_EMU_EVCNT_DECL(fctid);
126 FPU_EMU_EVCNT_DECL(fcfid);
127 FPU_EMU_EVCNT_DECL(fdiv);
128 FPU_EMU_EVCNT_DECL(fsub);
129 FPU_EMU_EVCNT_DECL(fadd);
130 FPU_EMU_EVCNT_DECL(fsqrt);
131 FPU_EMU_EVCNT_DECL(fsel);
132 FPU_EMU_EVCNT_DECL(fpres);
133 FPU_EMU_EVCNT_DECL(fmul);
134 FPU_EMU_EVCNT_DECL(frsqrte);
135 FPU_EMU_EVCNT_DECL(fmulsub);
136 FPU_EMU_EVCNT_DECL(fmuladd);
137 FPU_EMU_EVCNT_DECL(fnmsub);
138 FPU_EMU_EVCNT_DECL(fnmadd);
139 
140 /* FPSR exception masks */
141 #define FPSR_EX_MSK	(FPSCR_VX|FPSCR_OX|FPSCR_UX|FPSCR_ZX|		\
142 			FPSCR_XX|FPSCR_VXSNAN|FPSCR_VXISI|FPSCR_VXIDI|	\
143 			FPSCR_VXZDZ|FPSCR_VXIMZ|FPSCR_VXVC|FPSCR_VXSOFT|\
144 			FPSCR_VXSQRT|FPSCR_VXCVI)
145 #define	FPSR_EX		(FPSCR_VE|FPSCR_OE|FPSCR_UE|FPSCR_ZE|FPSCR_XE)
146 #define	FPSR_EXOP	(FPSR_EX_MSK&(~FPSR_EX))
147 
148 
149 int fpe_debug = 0;
150 
151 #ifdef DDB
152 extern vaddr_t opc_disasm(vaddr_t loc, int opcode);
153 #endif
154 
155 #ifdef DEBUG
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 bool
188 fpu_emulate(struct trapframe *tf, struct fpreg *fpf, ksiginfo_t *ksi)
189 {
190 	union instr insn;
191 	struct fpemu fe;
192 
193 	KSI_INIT_TRAP(ksi);
194 	ksi->ksi_signo = 0;
195 	ksi->ksi_addr = (void *)tf->tf_srr0;
196 
197 	/* initialize insn.is_datasize to tell it is *not* initialized */
198 	fe.fe_fpstate = fpf;
199 	fe.fe_cx = 0;
200 
201 	/* always set this (to avoid a warning) */
202 
203 	if (copyin((void *) (tf->tf_srr0), &insn.i_int, sizeof (insn.i_int))) {
204 #ifdef DEBUG
205 		printf("fpu_emulate: fault reading opcode\n");
206 #endif
207 		ksi->ksi_signo = SIGSEGV;
208 		ksi->ksi_trap = EXC_ISI;
209 		ksi->ksi_code = SEGV_MAPERR;
210 		ksi->ksi_addr = (void *)tf->tf_srr0;
211 		return true;
212 	}
213 
214 	DPRINTF(FPE_EX, ("fpu_emulate: emulating insn %x at %p\n",
215 	    insn.i_int, (void *)tf->tf_srr0));
216 
217 	if ((insn.i_any.i_opcd == OPC_TWI) ||
218 	    ((insn.i_any.i_opcd == OPC_integer_31) &&
219 	    (insn.i_x.i_xo == OPC31_TW))) {
220 		/* Check for the two trap insns. */
221 		DPRINTF(FPE_EX, ("fpu_emulate: SIGTRAP\n"));
222 		ksi->ksi_signo = SIGTRAP;
223 		ksi->ksi_trap = EXC_PGM;
224 		ksi->ksi_code = TRAP_TRACE;
225 		ksi->ksi_addr = (void *)tf->tf_srr0;
226 		return true;
227 	}
228 	switch (fpu_execute(tf, &fe, &insn)) {
229 	case 0:
230 		DPRINTF(FPE_EX, ("fpu_emulate: success\n"));
231 		tf->tf_srr0 += 4;
232 		return true;
233 
234 	case FPE:
235 		DPRINTF(FPE_EX, ("fpu_emulate: SIGFPE\n"));
236 		ksi->ksi_signo = SIGFPE;
237 		ksi->ksi_trap = EXC_PGM;
238 		return true;
239 
240 	case FAULT:
241 		DPRINTF(FPE_EX, ("fpu_emulate: SIGSEGV\n"));
242 		ksi->ksi_signo = SIGSEGV;
243 		ksi->ksi_trap = EXC_DSI;
244 		ksi->ksi_code = SEGV_MAPERR;
245 		ksi->ksi_addr = (void *)fe.fe_addr;
246 		return true;
247 
248 	case NOTFPU:
249 	default:
250 		DPRINTF(FPE_EX, ("fpu_emulate: SIGILL\n"));
251 #ifdef DEBUG
252 		if (fpe_debug & FPE_EX) {
253 			printf("fpu_emulate:  illegal insn %x at %p:",
254 			insn.i_int, (void *) (tf->tf_srr0));
255 			opc_disasm((vaddr_t)(tf->tf_srr0), insn.i_int);
256 		}
257 #endif
258 #if defined(PPC_IBM4XX) && defined(DEBUG)
259 		/*
260 		* XXXX retry an illegal insn once due to cache issues.
261 		*/
262 		static int lastill = 0;
263 		if (lastill == tf->tf_srr0) {
264 			if (fpe_debug & FPE_EX)
265 				Debugger();
266 		}
267 		lastill = tf->tf_srr0;
268 #endif /* PPC_IBM4XX && DEBUG */
269 		return false;
270 	}
271 }
272 
273 /*
274  * Execute an FPU instruction (one that runs entirely in the FPU; not
275  * FBfcc or STF, for instance).  On return, fe->fe_fs->fs_fsr will be
276  * modified to reflect the setting the hardware would have left.
277  *
278  * Note that we do not catch all illegal opcodes, so you can, for instance,
279  * multiply two integers this way.
280  */
281 int
282 fpu_execute(struct trapframe *tf, struct fpemu *fe, union instr *insn)
283 {
284 	struct fpn *fp;
285 	union instr instr = *insn;
286 	int *a;
287 	vaddr_t addr;
288 	int ra, rb, rc, rt, type, mask, fsr, cx, bf, setcr;
289 	unsigned int cond;
290 	struct fpreg *fs;
291 
292 	/* Setup work. */
293 	fp = NULL;
294 	fs = fe->fe_fpstate;
295 	fe->fe_fpscr = ((int *)&fs->fpscr)[1];
296 
297 	/*
298 	 * On PowerPC all floating point values are stored in registers
299 	 * as doubles, even when used for single precision operations.
300 	 */
301 	type = FTYPE_DBL;
302 	cond = instr.i_any.i_rc;
303 	setcr = 0;
304 	bf = 0;	/* XXX gcc */
305 
306 #if defined(DDB) && defined(DEBUG)
307 	if (fpe_debug & FPE_EX) {
308 		vaddr_t loc = tf->tf_srr0;
309 
310 		printf("Trying to emulate: %p ", (void *)loc);
311 		opc_disasm(loc, instr.i_int);
312 	}
313 #endif
314 
315 	/*
316 	 * `Decode' and execute instruction.
317 	 */
318 
319 	if ((instr.i_any.i_opcd >= OPC_LFS && instr.i_any.i_opcd <= OPC_STFDU) ||
320 	    instr.i_any.i_opcd == OPC_integer_31) {
321 		/*
322 		 * Handle load/store insns:
323 		 *
324 		 * Convert to/from single if needed, calculate addr,
325 		 * and update index reg if needed.
326 		 */
327 		uint64_t buf;
328 		size_t size = sizeof(float);
329 		int store, update;
330 
331 		cond = 0; /* ld/st never set condition codes */
332 
333 
334 		if (instr.i_any.i_opcd == OPC_integer_31) {
335 			if (instr.i_x.i_xo == OPC31_STFIWX) {
336 				FPU_EMU_EVCNT_INCR(stfiwx);
337 
338 				/* Store as integer */
339 				ra = instr.i_x.i_ra;
340 				rb = instr.i_x.i_rb;
341 				DPRINTF(FPE_INSN, ("reg %d has %lx reg %d has %lx\n",
342 					ra, tf->tf_fixreg[ra], rb, tf->tf_fixreg[rb]));
343 
344 				addr = tf->tf_fixreg[rb];
345 				if (ra != 0)
346 					addr += tf->tf_fixreg[ra];
347 				rt = instr.i_x.i_rt;
348 				a = (int *)&fs->fpreg[rt];
349 				DPRINTF(FPE_INSN,
350 					("fpu_execute: Store INT %x at %p\n",
351 						a[1], (void *)addr));
352 				if (copyout(&a[1], (void *)addr, sizeof(int))) {
353 					fe->fe_addr = addr;
354 					return (FAULT);
355 				}
356 				return (0);
357 			}
358 
359 			if ((instr.i_x.i_xo & OPC31_FPMASK) != OPC31_FPOP)
360 				/* Not an indexed FP load/store op */
361 				return (NOTFPU);
362 
363 			store = (instr.i_x.i_xo & 0x80);
364 			if (instr.i_x.i_xo & 0x40)
365 				size = sizeof(double);
366 			else
367 				type = FTYPE_SNG;
368 			update = (instr.i_x.i_xo & 0x20);
369 
370 			/* calculate EA of load/store */
371 			ra = instr.i_x.i_ra;
372 			rb = instr.i_x.i_rb;
373 			DPRINTF(FPE_INSN, ("reg %d has %lx reg %d has %lx\n",
374 				ra, tf->tf_fixreg[ra], rb, tf->tf_fixreg[rb]));
375 			addr = tf->tf_fixreg[rb];
376 			if (ra != 0)
377 				addr += tf->tf_fixreg[ra];
378 			rt = instr.i_x.i_rt;
379 		} else {
380 			store = instr.i_d.i_opcd & 0x4;
381 			if (instr.i_d.i_opcd & 0x2)
382 				size = sizeof(double);
383 			else
384 				type = FTYPE_SNG;
385 			update = instr.i_d.i_opcd & 0x1;
386 
387 			/* calculate EA of load/store */
388 			ra = instr.i_d.i_ra;
389 			addr = instr.i_d.i_d;
390 			DPRINTF(FPE_INSN, ("reg %d has %lx displ %lx\n",
391 				ra, tf->tf_fixreg[ra], addr));
392 			if (ra != 0)
393 				addr += tf->tf_fixreg[ra];
394 			rt = instr.i_d.i_rt;
395 		}
396 
397 		if (update && ra == 0)
398 			return (NOTFPU);
399 
400 		if (store) {
401 			/* Store */
402 			FPU_EMU_EVCNT_INCR(fpstore);
403 			if (type != FTYPE_DBL) {
404 				DPRINTF(FPE_INSN,
405 					("fpu_execute: Store SNG at %p\n",
406 						(void *)addr));
407 				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_DBL, rt);
408 				fpu_implode(fe, fp, type, (void *)&buf);
409 				if (copyout(&buf, (void *)addr, size)) {
410 					fe->fe_addr = addr;
411 					return (FAULT);
412 				}
413 			} else {
414 				DPRINTF(FPE_INSN,
415 					("fpu_execute: Store DBL at %p\n",
416 						(void *)addr));
417 				if (copyout(&fs->fpreg[rt], (void *)addr, size)) {
418 					fe->fe_addr = addr;
419 					return (FAULT);
420 				}
421 			}
422 		} else {
423 			/* Load */
424 			FPU_EMU_EVCNT_INCR(fpload);
425 			DPRINTF(FPE_INSN, ("fpu_execute: Load from %p\n",
426 				(void *)addr));
427 			if (copyin((const void *)addr, &fs->fpreg[rt], size)) {
428 				fe->fe_addr = addr;
429 				return (FAULT);
430 			}
431 			if (type != FTYPE_DBL) {
432 				fpu_explode(fe, fp = &fe->fe_f1, type, rt);
433 				fpu_implode(fe, fp, FTYPE_DBL,
434 					(u_int *)&fs->fpreg[rt]);
435 			}
436 		}
437 		if (update)
438 			tf->tf_fixreg[ra] = addr;
439 		/* Complete. */
440 		return (0);
441 #ifdef notyet
442 	} else if (instr.i_any.i_opcd == OPC_load_st_62) {
443 		/* These are 64-bit extenstions */
444 		return (NOTFPU);
445 #endif
446 	} else if (instr.i_any.i_opcd == OPC_sp_fp_59 ||
447 		instr.i_any.i_opcd == OPC_dp_fp_63) {
448 
449 
450 		if (instr.i_any.i_opcd == OPC_dp_fp_63 &&
451 		    !(instr.i_a.i_xo & OPC63M_MASK)) {
452 			/* Format X */
453 			rt = instr.i_x.i_rt;
454 			ra = instr.i_x.i_ra;
455 			rb = instr.i_x.i_rb;
456 
457 
458 			/* One of the special opcodes.... */
459 			switch (instr.i_x.i_xo) {
460 			case	OPC63_FCMPU:
461 				FPU_EMU_EVCNT_INCR(fcmpu);
462 				DPRINTF(FPE_INSN, ("fpu_execute: FCMPU\n"));
463 				rt >>= 2;
464 				fpu_explode(fe, &fe->fe_f1, type, ra);
465 				fpu_explode(fe, &fe->fe_f2, type, rb);
466 				fpu_compare(fe, 0);
467 				/* Make sure we do the condition regs. */
468 				cond = 0;
469 				/* N.B.: i_rs is already left shifted by two. */
470 				bf = instr.i_x.i_rs & 0xfc;
471 				setcr = 1;
472 				break;
473 
474 			case	OPC63_FRSP:
475 				/*
476 				 * Convert to single:
477 				 *
478 				 * PowerPC uses this to round a double
479 				 * precision value to single precision,
480 				 * but values in registers are always
481 				 * stored in double precision format.
482 				 */
483 				FPU_EMU_EVCNT_INCR(frsp);
484 				DPRINTF(FPE_INSN, ("fpu_execute: FRSP\n"));
485 				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_DBL, rb);
486 				fpu_implode(fe, fp, FTYPE_SNG,
487 					(u_int *)&fs->fpreg[rt]);
488 				fpu_explode(fe, fp = &fe->fe_f1, FTYPE_SNG, rt);
489 				type = FTYPE_DBL;
490 				break;
491 			case	OPC63_FCTIW:
492 			case	OPC63_FCTIWZ:
493 				FPU_EMU_EVCNT_INCR(fctiw);
494 				DPRINTF(FPE_INSN, ("fpu_execute: FCTIW\n"));
495 				fpu_explode(fe, fp = &fe->fe_f1, type, rb);
496 				type = FTYPE_INT;
497 				break;
498 			case	OPC63_FCMPO:
499 				FPU_EMU_EVCNT_INCR(fcmpo);
500 				DPRINTF(FPE_INSN, ("fpu_execute: FCMPO\n"));
501 				rt >>= 2;
502 				fpu_explode(fe, &fe->fe_f1, type, ra);
503 				fpu_explode(fe, &fe->fe_f2, type, rb);
504 				fpu_compare(fe, 1);
505 				/* Make sure we do the condition regs. */
506 				cond = 0;
507 				/* N.B.: i_rs is already left shifted by two. */
508 				bf = instr.i_x.i_rs & 0xfc;
509 				setcr = 1;
510 				break;
511 			case	OPC63_MTFSB1:
512 				FPU_EMU_EVCNT_INCR(mtfsb1);
513 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSB1\n"));
514 				fe->fe_fpscr |=
515 					(~(FPSCR_VX|FPSR_EX) & (1<<(31-rt)));
516 				break;
517 			case	OPC63_FNEG:
518 				FPU_EMU_EVCNT_INCR(fnegabs);
519 				DPRINTF(FPE_INSN, ("fpu_execute: FNEGABS\n"));
520 				memcpy(&fs->fpreg[rt], &fs->fpreg[rb],
521 					sizeof(double));
522 				a = (int *)&fs->fpreg[rt];
523 				*a ^= (1 << 31);
524 				break;
525 			case	OPC63_MCRFS:
526 				FPU_EMU_EVCNT_INCR(mcrfs);
527 				DPRINTF(FPE_INSN, ("fpu_execute: MCRFS\n"));
528 				cond = 0;
529 				rt &= 0x1c;
530 				ra &= 0x1c;
531 				/* Extract the bits we want */
532 				mask = (fe->fe_fpscr >> (28 - ra)) & 0xf;
533 				/* Clear the bits we copied. */
534 				fe->fe_cx =
535 					(FPSR_EX_MSK | (0xf << (28 - ra)));
536 				fe->fe_fpscr &= fe->fe_cx;
537 				/* Now shove them in the right part of cr */
538 				tf->tf_cr &= ~(0xf << (28 - rt));
539 				tf->tf_cr |= (mask << (28 - rt));
540 				break;
541 			case	OPC63_MTFSB0:
542 				FPU_EMU_EVCNT_INCR(mtfsb0);
543 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSB0\n"));
544 				fe->fe_fpscr &=
545 					((FPSCR_VX|FPSR_EX) & ~(1<<(31-rt)));
546 				break;
547 			case	OPC63_FMR:
548 				FPU_EMU_EVCNT_INCR(fmr);
549 				DPRINTF(FPE_INSN, ("fpu_execute: FMR\n"));
550 				memcpy(&fs->fpreg[rt], &fs->fpreg[rb],
551 					sizeof(double));
552 				break;
553 			case	OPC63_MTFSFI:
554 				FPU_EMU_EVCNT_INCR(mtfsfi);
555 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSFI\n"));
556 				rb >>= 1;
557 				rt &= 0x1c; /* Already left-shifted 4 */
558 				fe->fe_cx = rb << (28 - rt);
559 				mask = 0xf<<(28 - rt);
560 				fe->fe_fpscr = (fe->fe_fpscr & ~mask) |
561 					fe->fe_cx;
562 /* XXX weird stuff about OX, FX, FEX, and VX should be handled */
563 				break;
564 			case	OPC63_FNABS:
565 				FPU_EMU_EVCNT_INCR(fnabs);
566 				DPRINTF(FPE_INSN, ("fpu_execute: FABS\n"));
567 				memcpy(&fs->fpreg[rt], &fs->fpreg[rb],
568 					sizeof(double));
569 				a = (int *)&fs->fpreg[rt];
570 				*a |= (1 << 31);
571 				break;
572 			case	OPC63_FABS:
573 				FPU_EMU_EVCNT_INCR(fabs);
574 				DPRINTF(FPE_INSN, ("fpu_execute: FABS\n"));
575 				memcpy(&fs->fpreg[rt], &fs->fpreg[rb],
576 					sizeof(double));
577 				a = (int *)&fs->fpreg[rt];
578 				*a &= ~(1 << 31);
579 				break;
580 			case	OPC63_MFFS:
581 				FPU_EMU_EVCNT_INCR(mffs);
582 				DPRINTF(FPE_INSN, ("fpu_execute: MFFS\n"));
583 				memcpy(&fs->fpreg[rt], &fs->fpscr,
584 					sizeof(fs->fpscr));
585 				break;
586 			case	OPC63_MTFSF:
587 				FPU_EMU_EVCNT_INCR(mtfsf);
588 				DPRINTF(FPE_INSN, ("fpu_execute: MTFSF\n"));
589 				if ((rt = instr.i_xfl.i_flm) == -1)
590 					mask = -1;
591 				else {
592 					mask = 0;
593 					/* Convert 1 bit -> 4 bits */
594 					for (ra = 0; ra < 8; ra ++)
595 						if (rt & (1<<ra))
596 							mask |= (0xf<<(4*ra));
597 				}
598 				a = (int *)&fs->fpreg[rt];
599 				fe->fe_cx = mask & a[1];
600 				fe->fe_fpscr = (fe->fe_fpscr&~mask) |
601 					(fe->fe_cx);
602 /* XXX weird stuff about OX, FX, FEX, and VX should be handled */
603 				break;
604 			case	OPC63_FCTID:
605 			case	OPC63_FCTIDZ:
606 				FPU_EMU_EVCNT_INCR(fctid);
607 				DPRINTF(FPE_INSN, ("fpu_execute: FCTID\n"));
608 				fpu_explode(fe, fp = &fe->fe_f1, type, rb);
609 				type = FTYPE_LNG;
610 				break;
611 			case	OPC63_FCFID:
612 				FPU_EMU_EVCNT_INCR(fcfid);
613 				DPRINTF(FPE_INSN, ("fpu_execute: FCFID\n"));
614 				type = FTYPE_LNG;
615 				fpu_explode(fe, fp = &fe->fe_f1, type, rb);
616 				type = FTYPE_DBL;
617 				break;
618 			default:
619 				return (NOTFPU);
620 				break;
621 			}
622 		} else {
623 			/* Format A */
624 			rt = instr.i_a.i_frt;
625 			ra = instr.i_a.i_fra;
626 			rb = instr.i_a.i_frb;
627 			rc = instr.i_a.i_frc;
628 
629 			type = FTYPE_SNG;
630 			if (instr.i_any.i_opcd & 0x4)
631 				type = FTYPE_DBL;
632 			switch ((unsigned int)instr.i_a.i_xo) {
633 			case	OPC59_FDIVS:
634 				FPU_EMU_EVCNT_INCR(fdiv);
635 				DPRINTF(FPE_INSN, ("fpu_execute: FDIV\n"));
636 				fpu_explode(fe, &fe->fe_f1, type, ra);
637 				fpu_explode(fe, &fe->fe_f2, type, rb);
638 				fp = fpu_div(fe);
639 				break;
640 			case	OPC59_FSUBS:
641 				FPU_EMU_EVCNT_INCR(fsub);
642 				DPRINTF(FPE_INSN, ("fpu_execute: FSUB\n"));
643 				fpu_explode(fe, &fe->fe_f1, type, ra);
644 				fpu_explode(fe, &fe->fe_f2, type, rb);
645 				fp = fpu_sub(fe);
646 				break;
647 			case	OPC59_FADDS:
648 				FPU_EMU_EVCNT_INCR(fadd);
649 				DPRINTF(FPE_INSN, ("fpu_execute: FADD\n"));
650 				fpu_explode(fe, &fe->fe_f1, type, ra);
651 				fpu_explode(fe, &fe->fe_f2, type, rb);
652 				fp = fpu_add(fe);
653 				break;
654 			case	OPC59_FSQRTS:
655 				FPU_EMU_EVCNT_INCR(fsqrt);
656 				DPRINTF(FPE_INSN, ("fpu_execute: FSQRT\n"));
657 				fpu_explode(fe, &fe->fe_f1, type, rb);
658 				fp = fpu_sqrt(fe);
659 				break;
660 			case	OPC63M_FSEL:
661 				FPU_EMU_EVCNT_INCR(fsel);
662 				DPRINTF(FPE_INSN, ("fpu_execute: FSEL\n"));
663 				a = (int *)&fe->fe_fpstate->fpreg[ra];
664 				if ((*a & 0x80000000) && (*a & 0x7fffffff))
665 					/* fra < 0 */
666 					rc = rb;
667 				DPRINTF(FPE_INSN, ("f%d => f%d\n", rc, rt));
668 				memcpy(&fs->fpreg[rt], &fs->fpreg[rc],
669 					sizeof(double));
670 				break;
671 			case	OPC59_FRES:
672 				FPU_EMU_EVCNT_INCR(fpres);
673 				DPRINTF(FPE_INSN, ("fpu_execute: FPRES\n"));
674 				fpu_explode(fe, &fe->fe_f1, type, rb);
675 				fp = fpu_sqrt(fe);
676 				/* now we've gotta overwrite the dest reg */
677 				*((int *)&fe->fe_fpstate->fpreg[rt]) = 1;
678 				fpu_explode(fe, &fe->fe_f1, FTYPE_INT, rt);
679 				fpu_div(fe);
680 				break;
681 			case	OPC59_FMULS:
682 				FPU_EMU_EVCNT_INCR(fmul);
683 				DPRINTF(FPE_INSN, ("fpu_execute: FMUL\n"));
684 				fpu_explode(fe, &fe->fe_f1, type, ra);
685 				fpu_explode(fe, &fe->fe_f2, type, rc);
686 				fp = fpu_mul(fe);
687 				break;
688 			case	OPC63M_FRSQRTE:
689 				/* Reciprocal sqrt() estimate */
690 				FPU_EMU_EVCNT_INCR(frsqrte);
691 				DPRINTF(FPE_INSN, ("fpu_execute: FRSQRTE\n"));
692 				fpu_explode(fe, &fe->fe_f1, type, rb);
693 				fp = fpu_sqrt(fe);
694 				fe->fe_f2 = *fp;
695 				/* now we've gotta overwrite the dest reg */
696 				*((int *)&fe->fe_fpstate->fpreg[rt]) = 1;
697 				fpu_explode(fe, &fe->fe_f1, FTYPE_INT, rt);
698 				fpu_div(fe);
699 				break;
700 			case	OPC59_FMSUBS:
701 				FPU_EMU_EVCNT_INCR(fmulsub);
702 				DPRINTF(FPE_INSN, ("fpu_execute: FMULSUB\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_sub(fe);
709 				break;
710 			case	OPC59_FMADDS:
711 				FPU_EMU_EVCNT_INCR(fmuladd);
712 				DPRINTF(FPE_INSN, ("fpu_execute: FMULADD\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_add(fe);
719 				break;
720 			case	OPC59_FNMSUBS:
721 				FPU_EMU_EVCNT_INCR(fnmsub);
722 				DPRINTF(FPE_INSN, ("fpu_execute: FNMSUB\n"));
723 				fpu_explode(fe, &fe->fe_f1, type, ra);
724 				fpu_explode(fe, &fe->fe_f2, type, rc);
725 				fp = fpu_mul(fe);
726 				fe->fe_f1 = *fp;
727 				fpu_explode(fe, &fe->fe_f2, type, rb);
728 				fp = fpu_sub(fe);
729 				/* Negate */
730 				fp->fp_sign ^= 1;
731 				break;
732 			case	OPC59_FNMADDS:
733 				FPU_EMU_EVCNT_INCR(fnmadd);
734 				DPRINTF(FPE_INSN, ("fpu_execute: FNMADD\n"));
735 				fpu_explode(fe, &fe->fe_f1, type, ra);
736 				fpu_explode(fe, &fe->fe_f2, type, rc);
737 				fp = fpu_mul(fe);
738 				fe->fe_f1 = *fp;
739 				fpu_explode(fe, &fe->fe_f2, type, rb);
740 				fp = fpu_add(fe);
741 				/* Negate */
742 				fp->fp_sign ^= 1;
743 				break;
744 			default:
745 				return (NOTFPU);
746 				break;
747 			}
748 		}
749 	} else {
750 		return (NOTFPU);
751 	}
752 
753 	/*
754 	 * ALU operation is complete.  Collapse the result and then check
755 	 * for exceptions.  If we got any, and they are enabled, do not
756 	 * alter the destination register, just stop with an exception.
757 	 * Otherwise set new current exceptions and accrue.
758 	 */
759 	if (fp)
760 		fpu_implode(fe, fp, type, (u_int *)&fs->fpreg[rt]);
761 	cx = fe->fe_cx;
762 	fsr = fe->fe_fpscr;
763 	if (cx != 0) {
764 		fsr &= ~FPSCR_FX;
765 		if ((cx^fsr)&FPSR_EX_MSK)
766 			fsr |= FPSCR_FX;
767 		mask = fsr & FPSR_EX;
768 		mask <<= (25-3);
769 		if (cx & mask)
770 			fsr |= FPSCR_FEX;
771 		if (cx & FPSCR_FPRF) {
772 			/* Need to replace CC */
773 			fsr &= ~FPSCR_FPRF;
774 		}
775 		if (cx & (FPSR_EXOP))
776 			fsr |= FPSCR_VX;
777 		fsr |= cx;
778 		DPRINTF(FPE_INSN, ("fpu_execute: cx %x, fsr %x\n", cx, fsr));
779 	}
780 
781 	if (cond) {
782 		cond = fsr & 0xf0000000;
783 		/* Isolate condition codes */
784 		cond >>= 28;
785 		/* Move fpu condition codes to cr[1] */
786 		tf->tf_cr &= (0x0f000000);
787 		tf->tf_cr |= (cond<<24);
788 		DPRINTF(FPE_INSN, ("fpu_execute: cr[1] <= %x\n", cond));
789 	}
790 
791 	if (setcr) {
792 		cond = fsr & FPSCR_FPCC;
793 		/* Isolate condition codes */
794 		cond <<= 16;
795 		/* Move fpu condition codes to cr[1] */
796 		tf->tf_cr &= ~(0xf0000000>>bf);
797 		tf->tf_cr |= (cond>>bf);
798 		DPRINTF(FPE_INSN, ("fpu_execute: cr[%d] (cr=%x) <= %x\n", bf/4, tf->tf_cr, cond));
799 	}
800 
801 	((int *)&fs->fpscr)[1] = fsr;
802 	if (fsr & FPSCR_FEX)
803 		return(FPE);
804 	return (0);	/* success */
805 }
806