/* $NetBSD: npx.h,v 1.11 1994/10/27 04:16:11 cgd Exp $ */ /*- * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz. * * 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. * * @(#)npx.h 5.3 (Berkeley) 1/18/91 */ /* * 287/387 NPX Coprocessor Data Structures and Constants * W. Jolitz 1/90 */ #ifndef _I386_NPX_H_ #define _I386_NPX_H_ /* Environment information of floating point unit */ struct env87 { long en_cw; /* control word (16bits) */ long en_sw; /* status word (16bits) */ long en_tw; /* tag word (16bits) */ long en_fip; /* floating point instruction pointer */ u_short en_fcs; /* floating code segment selector */ u_short en_opcode; /* opcode last executed (11 bits ) */ long en_foo; /* floating operand offset */ long en_fos; /* floating operand segment selector */ }; #define EN_SW_IE 0x0001 /* invalid operation */ #define EN_SW_DE 0x0002 /* denormal */ #define EN_SW_ZE 0x0004 /* divide by zero */ #define EN_SW_OE 0x0008 /* overflow */ #define EN_SW_UE 0x0010 /* underflow */ #define EN_SW_PE 0x0020 /* loss of precision */ /* Contents of each floating point accumulator */ struct fpacc87 { #ifdef dontdef /* too unportable */ u_long fp_mantlo; /* mantissa low (31:0) */ u_long fp_manthi; /* mantissa high (63:32) */ int fp_exp:15; /* exponent */ int fp_sgn:1; /* mantissa sign */ #else u_char fp_bytes[10]; #endif }; #ifdef GPL_MATH_EMULATE #include <gnu/arch/i386/fpemul/math_emu.h> #endif /* Floating point and emulator context */ struct save87 { struct env87 sv_env; /* floating point control/status */ struct fpacc87 sv_ac[8]; /* accumulator contents, 0-7 */ u_long sv_ex_sw; /* status word for last exception */ u_long sv_ex_tw; /* tag word for last exception */ }; /* For the pcb. */ union fsave87 { struct save87 npx; #ifdef GPL_MATH_EMULATE union i387_union gplemu; #else u_char emupad[176]; /* sizeof(i387_union) */ #endif }; /* Cyrix EMC memory - mapped coprocessor context switch information */ struct emcsts { long em_msw; /* memory mapped status register when swtched */ long em_tar; /* memory mapped temp A register when swtched */ long em_dl; /* memory mapped D low register when swtched */ }; /* Intel prefers long real (53 bit) precision */ #define __iBCS_NPXCW__ 0x262 #define __BDE_NPXCW__ 0x1272 /* FreeBSD */ #define __OpenBSD_NPXCW__ 0x127f /* * The standard control word from finit is 0x37F, giving: * round to nearest * 64-bit precision * all exceptions masked. * * Now we want: * affine mode (if we decide to support 287's) * round to nearest * 53-bit precision * all exceptions masked. * * 64-bit precision often gives bad results with high level languages * because it makes the results of calculations depend on whether * intermediate values are stored in memory or in FPU registers. * * The iBCS control word has underflow, overflow, zero divide, and invalid * operation exceptions unmasked. But that causes an unexpected exception * in the test program 'paranoia' and makes denormals useless (DBL_MIN / 2 * underflows). It doesn't make a lot of sense to trap underflow without * trapping denormals. */ #define __INITIAL_NPXCW__ __OpenBSD_NPXCW__ #endif /* !_I386_NPX_H_ */