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File: [local] / OpenXM_contrib / gnuplot / Attic / ctrl87.h (download)
Revision 1.1.1.2 (vendor branch), Sat Jan 22 14:15:50 2000 UTC (24 years, 7 months ago) by maekawa
Import gnuplot 3.7.1 |
/* $Id: ctrl87.h,v 1.1.1.2 1998/04/15 19:22:17 lhecking Exp $ */ /* GNUPLOT - ctrl87.h */ /*[ * Copyright 1986 - 1993, 1998 Thomas Williams, Colin Kelley * * Permission to use, copy, and distribute this software and its * documentation for any purpose with or without fee is hereby granted, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. * * Permission to modify the software is granted, but not the right to * distribute the complete modified source code. Modifications are to * be distributed as patches to the released version. Permission to * distribute binaries produced by compiling modified sources is granted, * provided you * 1. distribute the corresponding source modifications from the * released version in the form of a patch file along with the binaries, * 2. add special version identification to distinguish your version * in addition to the base release version number, * 3. provide your name and address as the primary contact for the * support of your modified version, and * 4. retain our contact information in regard to use of the base * software. * Permission to distribute the released version of the source code along * with corresponding source modifications in the form of a patch file is * granted with same provisions 2 through 4 for binary distributions. * * This software is provided "as is" without express or implied warranty * to the extent permitted by applicable law. ]*/ #ifndef __CONTROL87_H__ #define __CONTROL87_H__ #ifdef __CONTROL87_C__ #define EXTERN #else #define EXTERN extern #endif /* 8087/80287 Status Word format */ #define SW_INVALID 0x0001 /* Invalid operation */ #define SW_DENORMAL 0x0002 /* Denormalized operand */ #define SW_ZERODIVIDE 0x0004 /* Zero divide */ #define SW_OVERFLOW 0x0008 /* Overflow */ #define SW_UNDERFLOW 0x0010 /* Underflow */ #define SW_INEXACT 0x0020 /* Precision (Inexact result) */ /* 8087/80287 Control Word format */ #define MCW_EM 0x003f /* interrupt Exception Masks*/ #define EM_INVALID 0x0001 /* invalid */ #define EM_DENORMAL 0x0002 /* denormal */ #define EM_ZERODIVIDE 0x0004 /* zero divide */ #define EM_OVERFLOW 0x0008 /* overflow */ #define EM_UNDERFLOW 0x0010 /* underflow */ #define EM_INEXACT 0x0020 /* inexact (precision) */ #define MCW_IC 0x1000 /* Infinity Control */ #define IC_AFFINE 0x1000 /* affine */ #define IC_PROJECTIVE 0x0000 /* projective */ #define MCW_RC 0x0c00 /* Rounding Control */ #define RC_CHOP 0x0c00 /* chop */ #define RC_UP 0x0800 /* up */ #define RC_DOWN 0x0400 /* down */ #define RC_NEAR 0x0000 /* near */ #define MCW_PC 0x0300 /* Precision Control */ #define PC_24 0x0000 /* 24 bits */ #define PC_53 0x0200 /* 53 bits */ #define PC_64 0x0300 /* 64 bits */ /**************************************************************************/ /************************* Type declarations **************************/ /**************************************************************************/ /**************************************************************************/ /************************ Function declarations ***********************/ /**************************************************************************/ /* _control87 changes floating-point control word. Declaration: ------------ unsigned short _control87(unsigned short newcw, unsigned short mask); Remarks: -------- _control87 retrieves or changes the floating-point control word. The floating-point control word is an unsigned short that specifies the following modes in the 80x87 FPU: o allowed exceptions o infinity mode o rounding mode o precision mode Changing these modes allows you to mask or unmask floating-point exceptions. _control87 matches the bits in mask to the bits in newcw. If any mask bit = 1, the corresponding bit in newcw contains the new value for the same bit in the floating-point control word. If mask = 0000, _control87 returns the floating-point control word without altering it. Examples: --------- Switching to projective infinity mode: _control87(IC_PROJECTIVE, MCW_IC); Disabling all exceptions: _control87(MCW_EM, MCW_EM); Return Value: ------------- The bits in the value returned reflect the new floating-point control word. */ EXTERN unsigned short _control87(unsigned short newcw, unsigned short mask); /**************************************************************************/ /************************** Global variables **************************/ /**************************************************************************/ #ifdef __CONTROL87_C__ #else #endif #undef EXTERN #endif