/* * * (c) Copyright 1989 OPEN SOFTWARE FOUNDATION, INC. * (c) Copyright 1989 HEWLETT-PACKARD COMPANY * (c) Copyright 1989 DIGITAL EQUIPMENT CORPORATION * To anyone who acknowledges that this file is provided "AS IS" * without any express or implied warranty: * permission to use, copy, modify, and distribute this * file for any purpose is hereby granted without fee, provided that * the above copyright notices and this notice appears in all source * code copies, and that none of the names of Open Software * Foundation, Inc., Hewlett-Packard Company, or Digital Equipment * Corporation be used in advertising or publicity pertaining to * distribution of the software without specific, written prior * permission. Neither Open Software Foundation, Inc., Hewlett- * Packard Company, nor Digital Equipment Corporation makes any * representations about the suitability of this software for any * purpose. * */ /* */ /* ** ** NAME: ** ** upkvaxf.c.h ** ** FACILITY: ** ** IDL Stub Runtime Support ** ** ABSTRACT: ** ** This module contains code to extract information from a VAX ** f_floating number and to initialize an UNPACKED_REAL structure ** with those bits. ** ** This module is meant to be used as an include file. ** ** VERSION: DCE 1.0 ** */ #if HAVE_CONFIG_H #include #endif /* **++ ** Functional Description: ** ** This module contains code to extract information from a VAX ** f_floating number and to initialize an UNPACKED_REAL structure ** with those bits. ** ** See the header files for a description of the UNPACKED_REAL ** structure. ** ** A VAX f_floating number in (16 bit words) looks like: ** ** [0]: Sign bit, 8 exp bits (bias 128), 7 fraction bits ** [1]: 16 more fraction bits ** ** 0.5 <= fraction < 1.0, MSB implicit ** ** ** Implicit parameters: ** ** input_value: a pointer to the input parameter. ** ** r: an UNPACKED_REAL structure ** **-- */ memcpy(&r[1], input_value, 4); /* Initialize FLAGS and perhaps set NEGATIVE bit */ r[U_R_FLAGS] = (r[1] >> 15) & U_R_NEGATIVE; /* Extract VAX biased exponent */ r[U_R_EXP] = (r[1] >> 7) & 0x000000FFL; if (r[U_R_EXP] == 0) { if (r[U_R_FLAGS]) r[U_R_FLAGS] |= U_R_INVALID; else r[U_R_FLAGS] = U_R_ZERO; } else { /* Adjust for VAX 16 bit floating format */ r[1] = ((r[1] << 16) | (r[1] >> 16)); /* Add unpacked real bias and subtract VAX bias */ r[U_R_EXP] += (U_R_BIAS - 128); /* Set hidden bit */ r[1] |= 0x00800000L; /* Left justify fraction bits */ r[1] <<= 8; /* Clear uninitialized parts for unpacked real */ r[2] = 0; r[3] = 0; r[4] = 0; }