/* * * (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: ** ** upkieeet.c.h ** ** FACILITY: ** ** IDL Stub Runtime Support ** ** ABSTRACT: ** ** This module contains code to extract information from a IEEE ** double 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 IEEE ** double 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 normalized IEEE double precision floating number looks like: ** ** [0]: 32 low order fraction bits ** [1]: Sign bit, 11 exp bits (bias 1023), 20 fraction bits ** ** 1.0 <= fraction < 2.0, MSB implicit ** ** For more details see "Mips R2000 Risc Architecture" ** by Gerry Kane, page 6-8 or ANSI/IEEE Std 754-1985. ** ** ** Implicit parameters: ** ** options: a word of flags, see include files. ** ** input_value: a pointer to the input parameter. ** ** r: an UNPACKED_REAL structure. ** ** i: a temporary integer variable. ** **-- */ memcpy(r, input_value, 8); #if (NDR_LOCAL_INT_REP == ndr_c_int_big_endian) memcpy(&r[1], input_value, 8); #else if (options & CVT_C_BIG_ENDIAN) { /* Shuffle bytes to little endian format */ r[2] = ((r[1] << 24) | (r[1] >> 24)); r[2] |= ((r[1] << 8) & 0x00FF0000L); r[2] |= ((r[1] >> 8) & 0x0000FF00L); r[1] = ((r[0] << 24) | (r[0] >> 24)); r[1] |= ((r[0] << 8) & 0x00FF0000L); r[1] |= ((r[0] >> 8) & 0x0000FF00L); } else { r[2] = r[0]; } #endif /* Initialize FLAGS and perhaps set NEGATIVE bit */ r[U_R_FLAGS] = (r[1] >> 31); /* Extract biased exponent */ r[U_R_EXP] = (r[1] >> 20) & 0x000007FFL; /* Check for denormalized values */ if (r[U_R_EXP] == 0) { /* Clear sign bit */ r[1] &= 0x7FFFFFFFL; /* If fraction is non-zero then normalize it */ if (r[1]) { /* Count leading zeros in fraction */ i = 0; while (!(r[1] & 0x00080000L)) { r[1] <<= 1; i += 1; } /* Adjust exponent and normalize fraction */ r[U_R_EXP] = U_R_BIAS - 1022 - i; r[1] <<= 12; i += 12; r[1] |= (r[2] >> (32 - i)); r[2] <<= i; /* Clear uninitialized part of unpacked real */ r[3] = 0; r[4] = 0; } else if (r[2]) { r[1] = r[2]; /* Count leading zeros in fraction */ i = 20; while (!(r[1] & 0x80000000L)) { r[1] <<= 1; i += 1; } /* Adjust exponent */ r[U_R_EXP] = U_R_BIAS - 1022 - i; /* Clear uninitialized part of unpacked real */ r[2] = 0; r[3] = 0; r[4] = 0; } else { r[U_R_FLAGS] |= U_R_ZERO; } /* Check for NANs and INFINITIES */ } else if (r[U_R_EXP] == 2047) { /* Clear sign and exponent */ r[1] &= 0x000FFFFFL; if (r[1] | r[2]) r[U_R_FLAGS] |= U_R_INVALID; else r[U_R_FLAGS] |= U_R_INFINITY; } else { /* Adjust exponent bias */ r[U_R_EXP] += (U_R_BIAS - 1022); /* Set hidden bit */ r[1] |= 0x00100000L; /* Left justify fraction bits */ r[1] <<= 11; r[1] |= (r[2] >> 21); r[2] <<= 11; /* Clear uninitialized part of unpacked real */ r[3] = 0; r[4] = 0; }