609 lines
15 KiB
C
609 lines
15 KiB
C
/*
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* errors.c
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*
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* The error handling functions for wm-FPU-emu
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*
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*
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* Copyright (C) 1992,1993,1994
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* W. Metzenthen, 22 Parker St, Ormond, Vic 3163,
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* Australia. E-mail billm@vaxc.cc.monash.edu.au
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* All rights reserved.
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*
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* This copyright notice covers the redistribution and use of the
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* FPU emulator developed by W. Metzenthen. It covers only its use
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* in the 386BSD, FreeBSD and NetBSD operating systems. Any other
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* use is not permitted under this copyright.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must include information specifying
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* that source code for the emulator is freely available and include
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* either:
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* a) an offer to provide the source code for a nominal distribution
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* fee, or
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* b) list at least two alternative methods whereby the source
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* can be obtained, e.g. a publically accessible bulletin board
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* and an anonymous ftp site from which the software can be
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* downloaded.
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* 3. All advertising materials specifically mentioning features or use of
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* this emulator must acknowledge that it was developed by W. Metzenthen.
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* 4. The name of W. Metzenthen may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* W. METZENTHEN BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*
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* The purpose of this copyright, based upon the Berkeley copyright, is to
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* ensure that the covered software remains freely available to everyone.
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*
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* The software (with necessary differences) is also available, but under
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* the terms of the GNU copyleft, for the Linux operating system and for
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* the djgpp ms-dos extender.
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*
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* W. Metzenthen June 1994.
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*
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*
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* $FreeBSD$
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*
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*/
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/*---------------------------------------------------------------------------+
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| Note: |
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| The file contains code which accesses user memory. |
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| Emulator static data may change when user memory is accessed, due to |
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| other processes using the emulator while swapping is in progress. |
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+---------------------------------------------------------------------------*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <machine/pcb.h>
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#include <gnu/i386/fpemul/fpu_emu.h>
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#include <gnu/i386/fpemul/fpu_system.h>
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#include <gnu/i386/fpemul/exception.h>
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#include <gnu/i386/fpemul/status_w.h>
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#include <gnu/i386/fpemul/control_w.h>
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#include <gnu/i386/fpemul/reg_constant.h>
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#include <gnu/i386/fpemul/version.h>
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/* */
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#undef PRINT_MESSAGES
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/* */
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void
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Un_impl(void)
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{
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unsigned char byte1, FPU_modrm;
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REENTRANT_CHECK(OFF);
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byte1 = fubyte((unsigned char *) FPU_ORIG_EIP);
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FPU_modrm = fubyte(1 + (unsigned char *) FPU_ORIG_EIP);
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printf("Unimplemented FPU Opcode at eip=%#08x : %02x ",
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FPU_ORIG_EIP, byte1);
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if (FPU_modrm >= 0300)
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printf("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7);
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else
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printf("/%d\n", (FPU_modrm >> 3) & 7);
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REENTRANT_CHECK(ON);
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EXCEPTION(EX_Invalid);
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}
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void
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emu_printall()
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{
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int i;
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static char *tag_desc[] = {"Valid", "Zero", "ERROR", "ERROR",
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"DeNorm", "Inf", "NaN", "Empty"};
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unsigned char byte1, FPU_modrm;
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REENTRANT_CHECK(OFF);
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byte1 = fubyte((unsigned char *) FPU_ORIG_EIP);
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FPU_modrm = fubyte(1 + (unsigned char *) FPU_ORIG_EIP);
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#ifdef DEBUGGING
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if (status_word & SW_Backward)
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printf("SW: backward compatibility\n");
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if (status_word & SW_C3)
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printf("SW: condition bit 3\n");
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if (status_word & SW_C2)
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printf("SW: condition bit 2\n");
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if (status_word & SW_C1)
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printf("SW: condition bit 1\n");
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if (status_word & SW_C0)
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printf("SW: condition bit 0\n");
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if (status_word & SW_Summary)
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printf("SW: exception summary\n");
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if (status_word & SW_Stack_Fault)
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printf("SW: stack fault\n");
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if (status_word & SW_Precision)
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printf("SW: loss of precision\n");
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if (status_word & SW_Underflow)
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printf("SW: underflow\n");
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if (status_word & SW_Overflow)
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printf("SW: overflow\n");
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if (status_word & SW_Zero_Div)
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printf("SW: divide by zero\n");
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if (status_word & SW_Denorm_Op)
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printf("SW: denormalized operand\n");
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if (status_word & SW_Invalid)
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printf("SW: invalid operation\n");
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#endif /* DEBUGGING */
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status_word = status_word & ~SW_Top;
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status_word |= (top & 7) << SW_Top_Shift;
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printf("At %#08x: %02x ", FPU_ORIG_EIP, byte1);
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if (FPU_modrm >= 0300)
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printf("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7);
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else
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printf("/%d, mod=%d rm=%d\n",
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(FPU_modrm >> 3) & 7, (FPU_modrm >> 6) & 3, FPU_modrm & 7);
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printf(" SW: b=%d st=%d es=%d sf=%d cc=%d%d%d%d ef=%d%d%d%d%d%d\n",
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status_word & 0x8000 ? 1 : 0, /* busy */
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(int)((status_word & 0x3800) >> 11), /* stack top pointer */
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status_word & 0x80 ? 1 : 0, /* Error summary status */
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status_word & 0x40 ? 1 : 0, /* Stack flag */
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status_word & SW_C3 ? 1 : 0, status_word & SW_C2 ? 1 : 0, /* cc */
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status_word & SW_C1 ? 1 : 0, status_word & SW_C0 ? 1 : 0, /* cc */
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status_word & SW_Precision ? 1 : 0, status_word & SW_Underflow ? 1 : 0,
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status_word & SW_Overflow ? 1 : 0, status_word & SW_Zero_Div ? 1 : 0,
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status_word & SW_Denorm_Op ? 1 : 0, status_word & SW_Invalid ? 1 : 0);
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printf(" CW: ic=%d rc=%d%d pc=%d%d iem=%d ef=%d%d%d%d%d%d\n",
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control_word & 0x1000 ? 1 : 0,
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(int)((control_word & 0x800) >> 11),
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(int)((control_word & 0x400) >> 10),
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(int)((control_word & 0x200) >> 9),
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(int)((control_word & 0x100) >> 8),
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control_word & 0x80 ? 1 : 0,
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control_word & SW_Precision ? 1 : 0, control_word & SW_Underflow ? 1 : 0,
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control_word & SW_Overflow ? 1 : 0, control_word & SW_Zero_Div ? 1 : 0,
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control_word & SW_Denorm_Op ? 1 : 0, control_word & SW_Invalid ? 1 : 0);
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for (i = 0; i < 8; i++) {
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FPU_REG *r = &st(i);
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switch (r->tag) {
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case TW_Empty:
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continue;
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break;
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case TW_Zero:
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printf("st(%d) %c .0000 0000 0000 0000 ",
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i, r->sign ? '-' : '+');
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break;
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case TW_Valid:
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case TW_NaN:
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case TW_Denormal:
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case TW_Infinity:
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printf("st(%d) %c .%04lx %04lx %04lx %04lx e%+-6ld ",
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i, r->sign ? '-' : '+', r->sigh >> 16,
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r->sigh & 0xFFFF, r->sigl >> 16, r->sigl & 0xFFFF,
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r->exp - EXP_BIAS + 1);
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break;
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default:
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printf("Whoops! Error in errors.c ");
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break;
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}
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printf("%s\n", tag_desc[(int) (unsigned) r->tag]);
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}
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printf("[data] %c .%04lx %04lx %04lx %04lx e%+-6ld ",
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FPU_loaded_data.sign ? '-' : '+', FPU_loaded_data.sigh >> 16,
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FPU_loaded_data.sigh & 0xFFFF, FPU_loaded_data.sigl >> 16,
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FPU_loaded_data.sigl & 0xFFFF, FPU_loaded_data.exp - EXP_BIAS + 1);
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printf("%s\n", tag_desc[(int) (unsigned) FPU_loaded_data.tag]);
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REENTRANT_CHECK(ON);
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}
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static struct {
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int type;
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char *name;
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} exception_names[] = {
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{
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EX_StackOver, "stack overflow"
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},
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{
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EX_StackUnder, "stack underflow"
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},
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{
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EX_Precision, "loss of precision"
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},
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{
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EX_Underflow, "underflow"
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},
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{
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EX_Overflow, "overflow"
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},
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{
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EX_ZeroDiv, "divide by zero"
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},
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{
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EX_Denormal, "denormalized operand"
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},
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{
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EX_Invalid, "invalid operation"
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},
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{
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EX_INTERNAL, "INTERNAL BUG in " FPU_VERSION
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},
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{
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0, NULL
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}
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};
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/*
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EX_INTERNAL is always given with a code which indicates where the
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error was detected.
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Internal error types:
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0x14 in e14.c
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0x1nn in a *.c file:
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0x101 in reg_add_sub.c
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0x102 in reg_mul.c
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0x103 in poly_sin.c
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0x104 in poly_tan.c
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0x105 in reg_mul.c
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0x106 in reg_mov.c
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0x107 in fpu_trig.c
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0x108 in reg_compare.c
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0x109 in reg_compare.c
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0x110 in reg_add_sub.c
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0x111 in interface.c
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0x112 in fpu_trig.c
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0x113 in reg_add_sub.c
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0x114 in reg_ld_str.c
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0x115 in fpu_trig.c
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0x116 in fpu_trig.c
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0x117 in fpu_trig.c
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0x118 in fpu_trig.c
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0x119 in fpu_trig.c
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0x120 in poly_atan.c
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0x121 in reg_compare.c
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0x122 in reg_compare.c
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0x123 in reg_compare.c
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0x2nn in an *.s file:
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0x201 in reg_u_add.S
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0x202 in reg_u_div.S
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0x203 in reg_u_div.S
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0x204 in reg_u_div.S
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0x205 in reg_u_mul.S
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0x206 in reg_u_sub.S
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0x207 in wm_sqrt.S
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0x208 in reg_div.S
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0x209 in reg_u_sub.S
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0x210 in reg_u_sub.S
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0x211 in reg_u_sub.S
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0x212 in reg_u_sub.S
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0x213 in wm_sqrt.S
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0x214 in wm_sqrt.S
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0x215 in wm_sqrt.S
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0x216 in reg_round.S
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0x217 in reg_round.S
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0x218 in reg_round.S
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*/
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void
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exception(int n)
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{
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int i, int_type;
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int_type = 0; /* Needed only to stop compiler warnings */
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if (n & EX_INTERNAL) {
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int_type = n - EX_INTERNAL;
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n = EX_INTERNAL;
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/* Set lots of exception bits! */
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status_word |= (SW_Exc_Mask | SW_Summary | FPU_BUSY);
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} else {
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/* Extract only the bits which we use to set the status word */
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n &= (SW_Exc_Mask);
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/* Set the corresponding exception bit */
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status_word |= n;
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if (status_word & ~control_word & CW_Exceptions)
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status_word |= SW_Summary;
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if (n & (SW_Stack_Fault | EX_Precision)) {
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if (!(n & SW_C1))
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/* This bit distinguishes over- from underflow
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* for a stack fault, and roundup from
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* round-down for precision loss. */
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status_word &= ~SW_C1;
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}
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}
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REENTRANT_CHECK(OFF);
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if ((~control_word & n & CW_Exceptions) || (n == EX_INTERNAL)) {
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#ifdef PRINT_MESSAGES
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/* My message from the sponsor */
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printf(FPU_VERSION " " __DATE__ " (C) W. Metzenthen.\n");
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#endif /* PRINT_MESSAGES */
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/* Get a name string for error reporting */
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for (i = 0; exception_names[i].type; i++)
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if ((exception_names[i].type & n) == exception_names[i].type)
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break;
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if (exception_names[i].type) {
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#ifdef PRINT_MESSAGES
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printf("FP Exception: %s!\n", exception_names[i].name);
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#endif /* PRINT_MESSAGES */
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} else
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printf("FP emulator: Unknown Exception: 0x%04x!\n", n);
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if (n == EX_INTERNAL) {
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printf("FP emulator: Internal error type 0x%04x\n", int_type);
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emu_printall();
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}
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#ifdef PRINT_MESSAGES
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else
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emu_printall();
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#endif /* PRINT_MESSAGES */
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/* The 80486 generates an interrupt on the next non-control
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* FPU instruction. So we need some means of flagging it. We
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* use the ES (Error Summary) bit for this, assuming that this
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* is the way a real FPU does it (until I can check it out),
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* if not, then some method such as the following kludge might
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* be needed. */
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/* regs[0].tag |= TW_FPU_Interrupt; */
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}
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REENTRANT_CHECK(ON);
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#ifdef __DEBUG__
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math_abort(SIGFPE);
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#endif /* __DEBUG__ */
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}
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/* Real operation attempted on two operands, one a NaN */
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void
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real_2op_NaN(FPU_REG * a, FPU_REG * b, FPU_REG * dest)
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{
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FPU_REG *x;
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int signalling;
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x = a;
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if (a->tag == TW_NaN) {
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if (b->tag == TW_NaN) {
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signalling = !(a->sigh & b->sigh & 0x40000000);
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/* find the "larger" */
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if (*(long long *) &(a->sigl) < *(long long *) &(b->sigl))
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x = b;
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} else {
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/* return the quiet version of the NaN in a */
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signalling = !(a->sigh & 0x40000000);
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}
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} else
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#ifdef PARANOID
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if (b->tag == TW_NaN)
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#endif /* PARANOID */
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{
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signalling = !(b->sigh & 0x40000000);
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x = b;
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}
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#ifdef PARANOID
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else {
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signalling = 0;
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EXCEPTION(EX_INTERNAL | 0x113);
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x = &CONST_QNaN;
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}
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#endif /* PARANOID */
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if (!signalling) {
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if (!(x->sigh & 0x80000000)) /* pseudo-NaN ? */
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x = &CONST_QNaN;
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reg_move(x, dest);
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return;
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}
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if (control_word & CW_Invalid) {
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/* The masked response */
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if (!(x->sigh & 0x80000000)) /* pseudo-NaN ? */
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x = &CONST_QNaN;
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reg_move(x, dest);
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/* ensure a Quiet NaN */
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dest->sigh |= 0x40000000;
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}
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EXCEPTION(EX_Invalid);
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return;
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}
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/* Invalid arith operation on Valid registers */
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void
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arith_invalid(FPU_REG * dest)
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{
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if (control_word & CW_Invalid) {
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/* The masked response */
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reg_move(&CONST_QNaN, dest);
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}
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EXCEPTION(EX_Invalid);
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return;
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}
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/* Divide a finite number by zero */
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void
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divide_by_zero(int sign, FPU_REG * dest)
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{
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if (control_word & CW_ZeroDiv) {
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/* The masked response */
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reg_move(&CONST_INF, dest);
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dest->sign = (unsigned char) sign;
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}
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EXCEPTION(EX_ZeroDiv);
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return;
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}
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/* This may be called often, so keep it lean */
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void
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set_precision_flag_up(void)
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{
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if (control_word & CW_Precision)
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status_word |= (SW_Precision | SW_C1); /* The masked response */
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else
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exception(EX_Precision | SW_C1);
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}
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/* This may be called often, so keep it lean */
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void
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set_precision_flag_down(void)
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{
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if (control_word & CW_Precision) { /* The masked response */
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status_word &= ~SW_C1;
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status_word |= SW_Precision;
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} else
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exception(EX_Precision);
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}
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int
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denormal_operand(void)
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{
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if (control_word & CW_Denormal) { /* The masked response */
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status_word |= SW_Denorm_Op;
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return 0;
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} else {
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exception(EX_Denormal);
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return 1;
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}
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}
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void
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|
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;
|
|
|
|
}
|