HardenedBSD/sys/gnu/i386/fpemul/errors.c
Rich Murphey b95c0fbacd Copyright changes per the author.
Added specific permissions for redistribution with FreeBSD and NetBSD.
Fixed author's email address.
1994-06-10 07:45:04 +00:00

613 lines
15 KiB
C

/*
* errors.c
*
* The error handling functions for wm-FPU-emu
*
*
* Copyright (C) 1992,1993,1994
* W. Metzenthen, 22 Parker St, Ormond, Vic 3163,
* Australia. E-mail billm@vaxc.cc.monash.edu.au
* All rights reserved.
*
* This copyright notice covers the redistribution and use of the
* FPU emulator developed by W. Metzenthen. It covers only its use
* in the 386BSD, FreeBSD and NetBSD operating systems. Any other
* use is not permitted under this copyright.
*
* 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 include information specifying
* that source code for the emulator is freely available and include
* either:
* a) an offer to provide the source code for a nominal distribution
* fee, or
* b) list at least two alternative methods whereby the source
* can be obtained, e.g. a publically accessible bulletin board
* and an anonymous ftp site from which the software can be
* downloaded.
* 3. All advertising materials specifically mentioning features or use of
* this emulator must acknowledge that it was developed by W. Metzenthen.
* 4. The name of W. Metzenthen may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED ``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
* W. METZENTHEN 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.
*
*
* The purpose of this copyright, based upon the Berkeley copyright, is to
* ensure that the covered software remains freely available to everyone.
*
* The software (with necessary differences) is also available, but under
* the terms of the GNU copyleft, for the Linux operating system and for
* the djgpp ms-dos extender.
*
* W. Metzenthen June 1994.
*
*
* $Id: errors.c,v 1.2 1994/04/29 21:07:12 gclarkii Exp $
*
*/
/*---------------------------------------------------------------------------+
| Note: |
| The file contains code which accesses user memory. |
| Emulator static data may change when user memory is accessed, due to |
| other processes using the emulator while swapping is in progress. |
+---------------------------------------------------------------------------*/
#include "param.h"
#include "proc.h"
#include "machine/cpu.h"
#include "machine/pcb.h"
#include "fpu_emu.h"
#include "fpu_system.h"
#include "exception.h"
#include "status_w.h"
#include "control_w.h"
#include "reg_constant.h"
#include "version.h"
/* */
#undef PRINT_MESSAGES
/* */
void
Un_impl(void)
{
unsigned char byte1, FPU_modrm;
REENTRANT_CHECK(OFF);
byte1 = fubyte((unsigned char *) FPU_ORIG_EIP);
FPU_modrm = fubyte(1 + (unsigned char *) FPU_ORIG_EIP);
printf("Unimplemented FPU Opcode at eip=%p : %02x ",
FPU_ORIG_EIP, byte1);
if (FPU_modrm >= 0300)
printf("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7);
else
printf("/%d\n", (FPU_modrm >> 3) & 7);
REENTRANT_CHECK(ON);
EXCEPTION(EX_Invalid);
}
void
emu_printall()
{
int i;
static char *tag_desc[] = {"Valid", "Zero", "ERROR", "ERROR",
"DeNorm", "Inf", "NaN", "Empty"};
unsigned char byte1, FPU_modrm;
REENTRANT_CHECK(OFF);
byte1 = fubyte((unsigned char *) FPU_ORIG_EIP);
FPU_modrm = fubyte(1 + (unsigned char *) FPU_ORIG_EIP);
#ifdef DEBUGGING
if (status_word & SW_Backward)
printf("SW: backward compatibility\n");
if (status_word & SW_C3)
printf("SW: condition bit 3\n");
if (status_word & SW_C2)
printf("SW: condition bit 2\n");
if (status_word & SW_C1)
printf("SW: condition bit 1\n");
if (status_word & SW_C0)
printf("SW: condition bit 0\n");
if (status_word & SW_Summary)
printf("SW: exception summary\n");
if (status_word & SW_Stack_Fault)
printf("SW: stack fault\n");
if (status_word & SW_Precision)
printf("SW: loss of precision\n");
if (status_word & SW_Underflow)
printf("SW: underflow\n");
if (status_word & SW_Overflow)
printf("SW: overflow\n");
if (status_word & SW_Zero_Div)
printf("SW: divide by zero\n");
if (status_word & SW_Denorm_Op)
printf("SW: denormalized operand\n");
if (status_word & SW_Invalid)
printf("SW: invalid operation\n");
#endif /* DEBUGGING */
status_word = status_word & ~SW_Top;
status_word |= (top & 7) << SW_Top_Shift;
printf("At %p: %02x ", FPU_ORIG_EIP, byte1);
if (FPU_modrm >= 0300)
printf("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7);
else
printf("/%d, mod=%d rm=%d\n",
(FPU_modrm >> 3) & 7, (FPU_modrm >> 6) & 3, FPU_modrm & 7);
printf(" SW: b=%d st=%d es=%d sf=%d cc=%d%d%d%d ef=%d%d%d%d%d%d\n",
status_word & 0x8000 ? 1 : 0, /* busy */
(status_word & 0x3800) >> 11, /* stack top pointer */
status_word & 0x80 ? 1 : 0, /* Error summary status */
status_word & 0x40 ? 1 : 0, /* Stack flag */
status_word & SW_C3 ? 1 : 0, status_word & SW_C2 ? 1 : 0, /* cc */
status_word & SW_C1 ? 1 : 0, status_word & SW_C0 ? 1 : 0, /* cc */
status_word & SW_Precision ? 1 : 0, status_word & SW_Underflow ? 1 : 0,
status_word & SW_Overflow ? 1 : 0, status_word & SW_Zero_Div ? 1 : 0,
status_word & SW_Denorm_Op ? 1 : 0, status_word & SW_Invalid ? 1 : 0);
printf(" CW: ic=%d rc=%d%d pc=%d%d iem=%d ef=%d%d%d%d%d%d\n",
control_word & 0x1000 ? 1 : 0,
(control_word & 0x800) >> 11, (control_word & 0x400) >> 10,
(control_word & 0x200) >> 9, (control_word & 0x100) >> 8,
control_word & 0x80 ? 1 : 0,
control_word & SW_Precision ? 1 : 0, control_word & SW_Underflow ? 1 : 0,
control_word & SW_Overflow ? 1 : 0, control_word & SW_Zero_Div ? 1 : 0,
control_word & SW_Denorm_Op ? 1 : 0, control_word & SW_Invalid ? 1 : 0);
for (i = 0; i < 8; i++) {
FPU_REG *r = &st(i);
switch (r->tag) {
case TW_Empty:
continue;
break;
case TW_Zero:
printf("st(%d) %c .0000 0000 0000 0000 ",
i, r->sign ? '-' : '+');
break;
case TW_Valid:
case TW_NaN:
case TW_Denormal:
case TW_Infinity:
printf("st(%d) %c .%04x %04x %04x %04x e%+-6d ", i,
r->sign ? '-' : '+',
(long) (r->sigh >> 16),
(long) (r->sigh & 0xFFFF),
(long) (r->sigl >> 16),
(long) (r->sigl & 0xFFFF),
r->exp - EXP_BIAS + 1);
break;
default:
printf("Whoops! Error in errors.c ");
break;
}
printf("%s\n", tag_desc[(int) (unsigned) r->tag]);
}
printf("[data] %c .%04x %04x %04x %04x e%+-6d ",
FPU_loaded_data.sign ? '-' : '+',
(long) (FPU_loaded_data.sigh >> 16),
(long) (FPU_loaded_data.sigh & 0xFFFF),
(long) (FPU_loaded_data.sigl >> 16),
(long) (FPU_loaded_data.sigl & 0xFFFF),
FPU_loaded_data.exp - EXP_BIAS + 1);
printf("%s\n", tag_desc[(int) (unsigned) FPU_loaded_data.tag]);
REENTRANT_CHECK(ON);
}
static struct {
int type;
char *name;
} exception_names[] = {
{
EX_StackOver, "stack overflow"
},
{
EX_StackUnder, "stack underflow"
},
{
EX_Precision, "loss of precision"
},
{
EX_Underflow, "underflow"
},
{
EX_Overflow, "overflow"
},
{
EX_ZeroDiv, "divide by zero"
},
{
EX_Denormal, "denormalized operand"
},
{
EX_Invalid, "invalid operation"
},
{
EX_INTERNAL, "INTERNAL BUG in " FPU_VERSION
},
{
0, NULL
}
};
/*
EX_INTERNAL is always given with a code which indicates where the
error was detected.
Internal error types:
0x14 in e14.c
0x1nn in a *.c file:
0x101 in reg_add_sub.c
0x102 in reg_mul.c
0x103 in poly_sin.c
0x104 in poly_tan.c
0x105 in reg_mul.c
0x106 in reg_mov.c
0x107 in fpu_trig.c
0x108 in reg_compare.c
0x109 in reg_compare.c
0x110 in reg_add_sub.c
0x111 in interface.c
0x112 in fpu_trig.c
0x113 in reg_add_sub.c
0x114 in reg_ld_str.c
0x115 in fpu_trig.c
0x116 in fpu_trig.c
0x117 in fpu_trig.c
0x118 in fpu_trig.c
0x119 in fpu_trig.c
0x120 in poly_atan.c
0x121 in reg_compare.c
0x122 in reg_compare.c
0x123 in reg_compare.c
0x2nn in an *.s file:
0x201 in reg_u_add.S
0x202 in reg_u_div.S
0x203 in reg_u_div.S
0x204 in reg_u_div.S
0x205 in reg_u_mul.S
0x206 in reg_u_sub.S
0x207 in wm_sqrt.S
0x208 in reg_div.S
0x209 in reg_u_sub.S
0x210 in reg_u_sub.S
0x211 in reg_u_sub.S
0x212 in reg_u_sub.S
0x213 in wm_sqrt.S
0x214 in wm_sqrt.S
0x215 in wm_sqrt.S
0x216 in reg_round.S
0x217 in reg_round.S
0x218 in reg_round.S
*/
void
exception(int n)
{
int i, int_type;
int_type = 0; /* Needed only to stop compiler warnings */
if (n & EX_INTERNAL) {
int_type = n - EX_INTERNAL;
n = EX_INTERNAL;
/* Set lots of exception bits! */
status_word |= (SW_Exc_Mask | SW_Summary | FPU_BUSY);
} else {
/* Extract only the bits which we use to set the status word */
n &= (SW_Exc_Mask);
/* Set the corresponding exception bit */
status_word |= n;
if (status_word & ~control_word & CW_Exceptions)
status_word |= SW_Summary;
if (n & (SW_Stack_Fault | EX_Precision)) {
if (!(n & SW_C1))
/* This bit distinguishes over- from underflow
* for a stack fault, and roundup from
* round-down for precision loss. */
status_word &= ~SW_C1;
}
}
REENTRANT_CHECK(OFF);
if ((~control_word & n & CW_Exceptions) || (n == EX_INTERNAL)) {
#ifdef PRINT_MESSAGES
/* My message from the sponsor */
printf(FPU_VERSION " " __DATE__ " (C) W. Metzenthen.\n");
#endif /* PRINT_MESSAGES */
/* Get a name string for error reporting */
for (i = 0; exception_names[i].type; i++)
if ((exception_names[i].type & n) == exception_names[i].type)
break;
if (exception_names[i].type) {
#ifdef PRINT_MESSAGES
printf("FP Exception: %s!\n", exception_names[i].name);
#endif /* PRINT_MESSAGES */
} else
printf("FP emulator: Unknown Exception: 0x%04x!\n", n);
if (n == EX_INTERNAL) {
printf("FP emulator: Internal error type 0x%04x\n", int_type);
emu_printall();
}
#ifdef PRINT_MESSAGES
else
emu_printall();
#endif /* PRINT_MESSAGES */
/* The 80486 generates an interrupt on the next non-control
* FPU instruction. So we need some means of flagging it. We
* use the ES (Error Summary) bit for this, assuming that this
* is the way a real FPU does it (until I can check it out),
* if not, then some method such as the following kludge might
* be needed. */
/* regs[0].tag |= TW_FPU_Interrupt; */
}
REENTRANT_CHECK(ON);
#ifdef __DEBUG__
math_abort(SIGFPE);
#endif /* __DEBUG__ */
}
/* Real operation attempted on two operands, one a NaN */
void
real_2op_NaN(FPU_REG * a, FPU_REG * b, FPU_REG * dest)
{
FPU_REG *x;
int signalling;
x = a;
if (a->tag == TW_NaN) {
if (b->tag == TW_NaN) {
signalling = !(a->sigh & b->sigh & 0x40000000);
/* find the "larger" */
if (*(long long *) &(a->sigl) < *(long long *) &(b->sigl))
x = b;
} else {
/* return the quiet version of the NaN in a */
signalling = !(a->sigh & 0x40000000);
}
} else
#ifdef PARANOID
if (b->tag == TW_NaN)
#endif /* PARANOID */
{
signalling = !(b->sigh & 0x40000000);
x = b;
}
#ifdef PARANOID
else {
signalling = 0;
EXCEPTION(EX_INTERNAL | 0x113);
x = &CONST_QNaN;
}
#endif /* PARANOID */
if (!signalling) {
if (!(x->sigh & 0x80000000)) /* pseudo-NaN ? */
x = &CONST_QNaN;
reg_move(x, dest);
return;
}
if (control_word & CW_Invalid) {
/* The masked response */
if (!(x->sigh & 0x80000000)) /* pseudo-NaN ? */
x = &CONST_QNaN;
reg_move(x, dest);
/* ensure a Quiet NaN */
dest->sigh |= 0x40000000;
}
EXCEPTION(EX_Invalid);
return;
}
/* Invalid arith operation on Valid registers */
void
arith_invalid(FPU_REG * dest)
{
if (control_word & CW_Invalid) {
/* The masked response */
reg_move(&CONST_QNaN, dest);
}
EXCEPTION(EX_Invalid);
return;
}
/* Divide a finite number by zero */
void
divide_by_zero(int sign, FPU_REG * dest)
{
if (control_word & CW_ZeroDiv) {
/* The masked response */
reg_move(&CONST_INF, dest);
dest->sign = (unsigned char) sign;
}
EXCEPTION(EX_ZeroDiv);
return;
}
/* This may be called often, so keep it lean */
void
set_precision_flag_up(void)
{
if (control_word & CW_Precision)
status_word |= (SW_Precision | SW_C1); /* The masked response */
else
exception(EX_Precision | SW_C1);
}
/* This may be called often, so keep it lean */
void
set_precision_flag_down(void)
{
if (control_word & CW_Precision) { /* The masked response */
status_word &= ~SW_C1;
status_word |= SW_Precision;
} else
exception(EX_Precision);
}
int
denormal_operand(void)
{
if (control_word & CW_Denormal) { /* The masked response */
status_word |= SW_Denorm_Op;
return 0;
} else {
exception(EX_Denormal);
return 1;
}
}
void
arith_overflow(FPU_REG * dest)
{
if (control_word & CW_Overflow) {
char sign;
/* The masked response */
/* **** The response here depends upon the rounding mode */
sign = dest->sign;
reg_move(&CONST_INF, dest);
dest->sign = sign;
} else {
/* Subtract the magic number from the exponent */
dest->exp -= (3 * (1 << 13));
}
/* By definition, precision is lost. It appears that the roundup bit
* (C1) is also set by convention. */
EXCEPTION(EX_Overflow | EX_Precision | SW_C1);
return;
}
void
arith_underflow(FPU_REG * dest)
{
if (control_word & CW_Underflow) {
/* The masked response */
if (dest->exp <= EXP_UNDER - 63)
reg_move(&CONST_Z, dest);
} else {
/* Add the magic number to the exponent */
dest->exp += (3 * (1 << 13));
}
EXCEPTION(EX_Underflow);
return;
}
void
stack_overflow(void)
{
if (control_word & CW_Invalid) {
/* The masked response */
top--;
reg_move(&CONST_QNaN, FPU_st0_ptr = &st(0));
}
EXCEPTION(EX_StackOver);
return;
}
void
stack_underflow(void)
{
if (control_word & CW_Invalid) {
/* The masked response */
reg_move(&CONST_QNaN, FPU_st0_ptr);
}
EXCEPTION(EX_StackUnder);
return;
}
void
stack_underflow_i(int i)
{
if (control_word & CW_Invalid) {
/* The masked response */
reg_move(&CONST_QNaN, &(st(i)));
}
EXCEPTION(EX_StackUnder);
return;
}
void
stack_underflow_pop(int i)
{
if (control_word & CW_Invalid) {
/* The masked response */
reg_move(&CONST_QNaN, &(st(i)));
pop();
}
EXCEPTION(EX_StackUnder);
return;
}