/* * * (c) Copyright 1991 OPEN SOFTWARE FOUNDATION, INC. * (c) Copyright 1991 HEWLETT-PACKARD COMPANY * (c) Copyright 1991 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: ** ** pkieeet.c.h ** ** FACILITY: ** ** IDL Stub Runtime Support ** ** ABSTRACT: ** ** This module contains code to extract information from an ** UNPACKED_REAL structure and to create an IEEE double floating number ** 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 an ** UNPACKED_REAL structure and to create an IEEE double floating number ** 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. ** ** output_value: a pointer to the input parameter. ** ** r: an UNPACKED_REAL structure. ** ** i: a temporary integer variable ** **-- */ if (r[U_R_FLAGS] & U_R_UNUSUAL) { if (r[U_R_FLAGS] & U_R_ZERO) if (r[U_R_FLAGS] & U_R_NEGATIVE) memcpy(output_value, IEEE_T_NEG_ZERO, 8); else memcpy(output_value, IEEE_T_POS_ZERO, 8); else if (r[U_R_FLAGS] & U_R_INFINITY) { if (r[U_R_FLAGS] & U_R_NEGATIVE) memcpy(output_value, IEEE_T_NEG_INFINITY, 8); else memcpy(output_value, IEEE_T_POS_INFINITY, 8); } else if (r[U_R_FLAGS] & U_R_INVALID) { memcpy(output_value, IEEE_T_INVALID, 8); DCETHREAD_RAISE(dcethread_aritherr_e); /* Invalid value */ } } else { /* Precision varies if value will be a denorm */ /* So, figure out where to round (0 <= i <= 53). */ round_bit_position = r[U_R_EXP] - ((U_R_BIAS - 1022) - 52); if (round_bit_position < 0) round_bit_position = 0; else if (round_bit_position > 53) round_bit_position = 53; #include "round.c.h" if (r[U_R_EXP] < (U_R_BIAS - 1021)) { /* Denorm or underflow */ if (r[U_R_EXP] < ((U_R_BIAS - 1021) - 52)) { /* Value is too small for a denorm, so underflow */ if (r[U_R_FLAGS] & U_R_NEGATIVE) memcpy(output_value, IEEE_T_NEG_ZERO, 8); else memcpy(output_value, IEEE_T_POS_ZERO, 8); if (options & CVT_C_ERR_UNDERFLOW) { DCETHREAD_RAISE(dcethread_fltund_e); /* Underflow */ } } else { /* Figure leading zeros for denorm and right-justify fraction */ i = 64 - (r[U_R_EXP] - ((U_R_BIAS - 1022) - 52)); if (i > 31) { i -= 32; r[2] = (r[1] >> i); r[1] = 0; } else { r[2] >>= i; r[2] |= (r[1] << (32 - i)); r[1] >>= i; } /* OR in sign bit */ r[1] |= (r[U_R_FLAGS] << 31); #if (NDR_LOCAL_INT_REP == ndr_c_int_big_endian) if (options & CVT_C_BIG_ENDIAN) { r[0] = r[1]; r[1] = r[2]; } else { r[0] = r[2]; } #else if (options & CVT_C_BIG_ENDIAN) { r[0] = ((r[1] << 24) | (r[1] >> 24)); r[0] |= ((r[1] << 8) & 0x00FF0000L); r[0] |= ((r[1] >> 8) & 0x0000FF00L); r[1] = ((r[2] << 24) | (r[2] >> 24)); r[1] |= ((r[2] << 8) & 0x00FF0000L); r[1] |= ((r[2] >> 8) & 0x0000FF00L); } else { r[0] = r[2]; } #endif memcpy(output_value, r, 8); } } else if (r[U_R_EXP] > (U_R_BIAS + 1024)) { /* Overflow */ if (options & CVT_C_TRUNCATE) { if (r[U_R_FLAGS] & U_R_NEGATIVE) memcpy(output_value, IEEE_T_NEG_HUGE, 8); else memcpy(output_value, IEEE_T_POS_HUGE, 8); } else if ((options & CVT_C_ROUND_TO_POS) && (r[U_R_FLAGS] & U_R_NEGATIVE)) { memcpy(output_value, IEEE_T_NEG_HUGE, 8); } else if ((options & CVT_C_ROUND_TO_NEG) && !(r[U_R_FLAGS] & U_R_NEGATIVE)) { memcpy(output_value, IEEE_T_POS_HUGE, 8); } else { if (r[U_R_FLAGS] & U_R_NEGATIVE) memcpy(output_value, IEEE_T_NEG_INFINITY, 8); else memcpy(output_value, IEEE_T_POS_INFINITY, 8); } DCETHREAD_RAISE(dcethread_fltovf_e); /* Overflow */ } else { /* Adjust bias of exponent */ r[U_R_EXP] -= (U_R_BIAS - 1022); /* Make room for exponent and sign bit */ r[2] >>= 11; r[2] |= (r[1] << 21); r[1] >>= 11; /* Clear implicit bit */ r[1] &= 0x000FFFFFL; /* OR in exponent and sign bit */ r[1] |= (r[U_R_EXP] << 20); r[1] |= (r[U_R_FLAGS] << 31); #if (NDR_LOCAL_INT_REP == ndr_c_int_big_endian) if (options & CVT_C_BIG_ENDIAN) { r[0] = r[1]; r[1] = r[2]; } else { r[0] = r[2]; } #else if (options & CVT_C_BIG_ENDIAN) { r[0] = ((r[1] << 24) | (r[1] >> 24)); r[0] |= ((r[1] << 8) & 0x00FF0000L); r[0] |= ((r[1] >> 8) & 0x0000FF00L); r[1] = ((r[2] << 24) | (r[2] >> 24)); r[1] |= ((r[2] << 8) & 0x00FF0000L); r[1] |= ((r[2] >> 8) & 0x0000FF00L); } else { r[0] = r[2]; } #endif memcpy(output_value, r, 8); } }