path: root/arch/parisc/math-emu/fpudispatch.c

/*
 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
 *
 * Floating-point emulation code
 *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
/*
 * BEGIN_DESC
 *
 *  File:
 *	@(#)	pa/fp/fpudispatch.c		$Revision: 1.1 $
 *
 *  Purpose:
 *	<<please update with a synopsis of the functionality provided by this file>>
 *
 *  External Interfaces:
 *	<<the following list was autogenerated, please review>>
 *	emfpudispatch(ir, dummy1, dummy2, fpregs)
 *	fpudispatch(ir, excp_code, holder, fpregs)
 *
 *  Internal Interfaces:
 *	<<the following list was autogenerated, please review>>
 *	static u_int decode_06(u_int, u_int *)
 *	static u_int decode_0c(u_int, u_int, u_int, u_int *)
 *	static u_int decode_0e(u_int, u_int, u_int, u_int *)
 *	static u_int decode_26(u_int, u_int *)
 *	static u_int decode_2e(u_int, u_int *)
 *	static void update_status_cbit(u_int *, u_int, u_int, u_int)
 *
 *  Theory:
 *	<<please update with a overview of the operation of this file>>
 *
 * END_DESC
*/

#define FPUDEBUG 0

#include "float.h"
#include <linux/bug.h>
#include <linux/kernel.h>
#include <asm/processor.h>
/* #include <sys/debug.h> */
/* #include <machine/sys/mdep_private.h> */

#define COPR_INST 0x30000000

/*
 * definition of extru macro.  If pos and len are constants, the compiler
 * will generate an extru instruction when optimized
 */
#define extru(r,pos,len)	(((r) >> (31-(pos))) & (( 1 << (len)) - 1))
/* definitions of bit field locations in the instruction */
#define fpmajorpos 5
#define fpr1pos	10
#define fpr2pos 15
#define fptpos	31
#define fpsubpos 18
#define fpclass1subpos 16
#define fpclasspos 22
#define fpfmtpos 20
#define fpdfpos 18
#define fpnulpos 26
/*
 * the following are the extra bits for the 0E major op
 */
#define fpxr1pos 24
#define fpxr2pos 19
#define fpxtpos 25
#define fpxpos 23
#define fp0efmtpos 20
/*
 * the following are for the multi-ops
 */
#define fprm1pos 10
#define fprm2pos 15
#define fptmpos 31
#define fprapos 25
#define fptapos 20
#define fpmultifmt 26
/*
 * the following are for the fused FP instructions
 */
     /* fprm1pos 10 */
     /* fprm2pos 15 */
#define fpraupos 18
#define fpxrm2pos 19
     /* fpfmtpos 20 */
#define fpralpos 23
#define fpxrm1pos 24
     /* fpxtpos 25 */
#define fpfusedsubop 26
     /* fptpos	31 */

/*
 * offset to constant zero in the FP emulation registers
 */
#define fpzeroreg (32*sizeof(double)/sizeof(u_int))

/*
 * extract the major opcode from the instruction
 */
#define get_major(op) extru(op,fpmajorpos,6)
/*
 * extract the two bit class field from the FP instruction. The class is at bit
 * positions 21-22
 */
#define get_class(op) extru(op,fpclasspos,2)
/*