fp.s

早期freebsd实现

/*
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)fp.s	8.1 (Berkeley) 6/10/93
 */

/*
 * Standard header stuff.
 */

#include <machine/regdef.h>
#include <machine/machAsmDefs.h>
#include <machine/machConst.h>

#include "assym.h"

#define SEXP_INF	0xff
#define DEXP_INF	0x7ff
#define SEXP_BIAS	127
#define DEXP_BIAS	1023
#define SEXP_MIN	-126
#define DEXP_MIN	-1022
#define SEXP_MAX	127
#define DEXP_MAX	1023
#define WEXP_MAX	30		/* maximum unbiased exponent for int */
#define WEXP_MIN	-1		/* minimum unbiased exponent for int */
#define SFRAC_BITS	23
#define DFRAC_BITS	52
#define SIMPL_ONE	0x00800000
#define DIMPL_ONE	0x00100000
#define SLEAD_ZEROS	31 - 23
#define DLEAD_ZEROS	31 - 20
#define STICKYBIT	1
#define GUARDBIT	0x80000000
#define SSIGNAL_NAN	0x00400000
#define DSIGNAL_NAN	0x00080000
#define SQUIET_NAN	0x003fffff
#define DQUIET_NAN0	0x0007ffff
#define DQUIET_NAN1	0xffffffff
#define INT_MIN		0x80000000
#define INT_MAX		0x7fffffff

#define COND_UNORDERED	0x1
#define COND_EQUAL	0x2
#define COND_LESS	0x4
#define COND_SIGNAL	0x8

/*----------------------------------------------------------------------------
 *
 * MachEmulateFP --
 *
 *	Emulate unimplemented floating point operations.
 *	This routine should only be called by MachFPInterrupt().
 *
 *	MachEmulateFP(instr)
 *		unsigned instr;
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Floating point registers are modified according to instruction.
 *
 *----------------------------------------------------------------------------
 */
NON_LEAF(MachEmulateFP, STAND_FRAME_SIZE, ra)
	subu	sp, sp, STAND_FRAME_SIZE
	sw	ra, STAND_RA_OFFSET(sp)
/*
 * Decode the FMT field (bits 24-21) and FUNCTION field (bits 5-0).
 */
	srl	v0, a0, 21 - 2			# get FMT field
	and	v0, v0, 0xF << 2		# mask FMT field
	and	v1, a0, 0x3F			# mask FUNC field
	sll	v1, v1, 5			# align for table lookup
	bgt	v0, 4 << 2, ill			# illegal format

	or	v1, v1, v0
	cfc1	a1, MACH_FPC_CSR		# get exception register
	lw	a3, func_fmt_tbl(v1)		# switch on FUNC & FMT
	and	a1, a1, ~MACH_FPC_EXCEPTION_UNIMPL	# clear exception
	ctc1	a1, MACH_FPC_CSR
	j	a3

	.rdata
func_fmt_tbl:
	.word	add_s		# 0
	.word	add_d		# 0
	.word	ill		# 0
	.word	ill		# 0
	.word	ill		# 0
	.word	ill		# 0
	.word	ill		# 0
	.word	ill		# 0
	.word	sub_s		# 1
	.word	sub_d		# 1
	.word	ill		# 1
	.word	ill		# 1
	.word	ill		# 1
	.word	ill		# 1
	.word	ill		# 1
	.word	ill		# 1
	.word	mul_s		# 2
	.word	mul_d		# 2
	.word	ill		# 2
	.word	ill		# 2
	.word	ill		# 2
	.word	ill		# 2
	.word	ill		# 2
	.word	ill		# 2
	.word	div_s		# 3
	.word	div_d		# 3
	.word	ill		# 3
	.word	ill		# 3
	.word	ill		# 3
	.word	ill		# 3
	.word	ill		# 3
	.word	ill		# 3
	.word	ill		# 4
	.word	ill		# 4
	.word	ill		# 4
	.word	ill		# 4
	.word	ill		# 4
	.word	ill		# 4
	.word	ill		# 4
	.word	ill		# 4
	.word	abs_s		# 5
	.word	abs_d		# 5
	.word	ill		# 5
	.word	ill		# 5
	.word	ill		# 5
	.word	ill		# 5
	.word	ill		# 5
	.word	ill		# 5
	.word	mov_s		# 6
	.word	mov_d		# 6
	.word	ill		# 6
	.word	ill		# 6
	.word	ill		# 6
	.word	ill		# 6
	.word	ill		# 6
	.word	ill		# 6
	.word	neg_s		# 7
	.word	neg_d		# 7
	.word	ill		# 7
	.word	ill		# 7
	.word	ill		# 7
	.word	ill		# 7
	.word	ill		# 7
	.word	ill		# 7
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	.word	ill		# 12
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	.word	ill		# 27
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	.word	ill		# 27
	.word	ill		# 27
	.word	ill		# 28
	.word	ill		# 28
	.word	ill		# 28
	.word	ill		# 28
	.word	ill		# 28
	.word	ill		# 28
	.word	ill		# 28
	.word	ill		# 28
	.word	ill		# 29
	.word	ill		# 29
	.word	ill		# 29
	.word	ill		# 29
	.word	ill		# 29
	.word	ill		# 29
	.word	ill		# 29
	.word	ill		# 29
	.word	ill		# 30
	.word	ill		# 30
	.word	ill		# 30
	.word	ill		# 30
	.word	ill		# 30
	.word	ill		# 30
	.word	ill		# 30
	.word	ill		# 30
	.word	ill		# 31
	.word	ill		# 31
	.word	ill		# 31
	.word	ill		# 31
	.word	ill		# 31
	.word	ill		# 31
	.word	ill		# 31
	.word	ill		# 31
	.word	ill		# 32
	.word	cvt_s_d		# 32
	.word	ill		# 32
	.word	ill		# 32
	.word	cvt_s_w		# 32
	.word	ill		# 32
	.word	ill		# 32
	.word	ill		# 32
	.word	cvt_d_s		# 33
	.word	ill		# 33
	.word	ill		# 33
	.word	ill		# 33
	.word	cvt_d_w		# 33
	.word	ill		# 33
	.word	ill		# 33
	.word	ill		# 33
	.word	ill		# 34
	.word	ill		# 34
	.word	ill		# 34
	.word	ill		# 34
	.word	ill		# 34
	.word	ill		# 34
	.word	ill		# 34
	.word	ill		# 34
	.word	ill		# 35
	.word	ill		# 35
	.word	ill		# 35
	.word	ill		# 35
	.word	ill		# 35
	.word	ill		# 35
	.word	ill		# 35
	.word	ill		# 35
	.word	cvt_w_s		# 36
	.word	cvt_w_d		# 36
	.word	ill		# 36
	.word	ill		# 36
	.word	ill		# 36
	.word	ill		# 36
	.word	ill		# 36
	.word	ill		# 36
	.word	ill		# 37
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	.word	ill		# 38
	.word	ill		# 38
	.word	ill		# 38
	.word	ill		# 38
	.word	ill		# 38
	.word	ill		# 39
	.word	ill		# 39
	.word	ill		# 39
	.word	ill		# 39
	.word	ill		# 39
	.word	ill		# 39
	.word	ill		# 39
	.word	ill		# 39
	.word	ill		# 40
	.word	ill		# 40
	.word	ill		# 40
	.word	ill		# 40
	.word	ill		# 40
	.word	ill		# 40
	.word	ill		# 40
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	.word	ill		# 43
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	.word	ill		# 44
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	.word	ill		# 45
	.word	ill		# 45
	.word	ill		# 45
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	.word	ill		# 45
	.word	ill		# 45
	.word	ill		# 45
	.word	ill		# 45
	.word	ill		# 46
	.word	ill		# 46
	.word	ill		# 46
	.word	ill		# 46
	.word	ill		# 46
	.word	ill		# 46
	.word	ill		# 46
	.word	ill		# 46
	.word	ill		# 47
	.word	ill		# 47
	.word	ill		# 47
	.word	ill		# 47
	.word	ill		# 47
	.word	ill		# 47
	.word	ill		# 47
	.word	ill		# 47
	.word	cmp_s		# 48
	.word	cmp_d		# 48
	.word	ill		# 48
	.word	ill		# 48
	.word	ill		# 48
	.word	ill		# 48
	.word	ill		# 48
	.word	ill		# 48
	.word	cmp_s		# 49
	.word	cmp_d		# 49
	.word	ill		# 49
	.word	ill		# 49
	.word	ill		# 49
	.word	ill		# 49
	.word	ill		# 49
	.word	ill		# 49
	.word	cmp_s		# 50
	.word	cmp_d		# 50
	.word	ill		# 50
	.word	ill		# 50
	.word	ill		# 50
	.word	ill		# 50
	.word	ill		# 50
	.word	ill		# 50
	.word	cmp_s		# 51
	.word	cmp_d		# 51
	.word	ill		# 51
	.word	ill		# 51
	.word	ill		# 51
	.word	ill		# 51
	.word	ill		# 51
	.word	ill		# 51
	.word	cmp_s		# 52
	.word	cmp_d		# 52
	.word	ill		# 52
	.word	ill		# 52
	.word	ill		# 52
	.word	ill		# 52
	.word	ill		# 52
	.word	ill		# 52
	.word	cmp_s		# 53
	.word	cmp_d		# 53
	.word	ill		# 53
	.word	ill		# 53
	.word	ill		# 53
	.word	ill		# 53
	.word	ill		# 53
	.word	ill		# 53
	.word	cmp_s		# 54
	.word	cmp_d		# 54
	.word	ill		# 54
	.word	ill		# 54
	.word	ill		# 54
	.word	ill		# 54
	.word	ill		# 54
	.word	ill		# 54
	.word	cmp_s		# 55