NetBSD/sys/arch/pc532/fpu/ieee_ovfl.c

109 lines
2.7 KiB
C

/* $NetBSD: ieee_ovfl.c,v 1.2 1996/10/23 07:43:47 matthias Exp $ */
/*
* IEEE floating point support for NS32081 and NS32381 fpus.
* Copyright (c) 1995 Ian Dall
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* IAN DALL ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.
* IAN DALL DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES
* WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*/
/*
* File: ieee_ovfl.c
* Author: Ian Dall
* Date: November 1995
*
* Handle operations which generated overflow traps.
*
* HISTORY
* 14-Dec-95 Ian Dall (Ian.Dall@dsto.defence.gov.au)
* First release.
*
*/
#include "ieee_internal.h"
#ifdef __NetBSD__
#include <machine/limits.h>
#else
#include <machine/limits.h>
#endif
int ieee_ovfl(struct operand *op1, struct operand *op2,
struct operand *f0_op, int xopcode, state *state)
{
int user_trap = FPC_TT_NONE;
unsigned int fsr = state->FSR;
fsr |= FPC_OVF;
if (fsr & FPC_OVE) {
/* Users trap handler will fix it */
user_trap = FPC_TT_OVFL;
}
else {
/* If destination is float or double, set to +- Infty, else
* if byte, word or long, set to max/min int.
*/
int sign1 = op1->data.d_bits.sign;
int sign2 = op2->data.d_bits.sign;
switch(xopcode) {
case NEGF:
sign1 ^= 1;
/* Fall through */
case MOVF:
case MOVLF:
case MOVFL:
op2->data = infty;
op2->data.d_bits.sign = sign1;
break;
case CMPF:
/* Can't happen */
break;
case SUBF:
sign1 ^= 1;
/* Fall through */
case ADDF:
/* Overflow can only happen if both operands are same sign */
op2->data = infty;
op2->data.d_bits.sign = sign2;
break;
case MULF:
case DIVF:
op2->data = infty;
op2->data.d_bits.sign = sign1 ^ sign2;
break;
case ROUNDFI:
case TRUNCFI:
case FLOORFI:
op2->data.i = sign1? INT_MIN: INT_MAX;
break;
case SCALBF:
op2->data = infty;
op2->data.d_bits.sign = sign1;
break;
case LOGBF:
op2->data = infty;
op2->data.d_bits.sign = ISZERO(op1->data)? 1: 0;
break;
case DOTF:
(void) ieee_dot(op1->data.d, op2->data.d, &f0_op->data.d);
break;
case POLYF:
{
union t_conv t;
t = op2->data;
(void) ieee_dot(f0_op->data.d, op1->data.d, &t.d);
f0_op->data = t;
}
break;
}
}
state->FSR = fsr;
return user_trap;
}