/* file: cvt_vax_f.c */ /* ** ** COPYRIGHT (c) 1989, 1990 BY ** DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASSACHUSETTS. ** ALL RIGHTS RESERVED. ** ** THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND COPIED ** ONLY IN ACCORDANCE WITH THE TERMS OF SUCH LICENSE AND WITH THE ** INCLUSION OF THE ABOVE COPYRIGHT NOTICE. THIS SOFTWARE OR ANY OTHER ** COPIES THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY ** OTHER PERSON. NO TITLE TO AND OWNERSHIP OF THE SOFTWARE IS HEREBY ** TRANSFERRED. ** ** THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE WITHOUT NOTICE ** AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY DIGITAL EQUIPMENT ** CORPORATION. ** ** DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR RELIABILITY OF ITS ** SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL. ** */ /* **++ ** Facility: ** ** CVT Run-Time Library ** ** Abstract: ** ** This module contains routines to convert VAX F_Float floating ** point data into other supported floating point formats. ** ** Authors: ** ** Math RTL ** ** Creation Date: December 5, 1989. ** ** Modification History: ** ** 1-001 Original created. MRTL 5-Dec-1989. ** 1-002 Add VMS and F77 bindings. TS 26-Mar-1990. ** **-- */ /* ** ** TABLE OF CONTENTS ** ** cvt_vax_f_to_cray ** cvt_vax_f_to_ibm_short ** cvt_vax_f_to_ieee_single ** */ #include #include #include #include "cvt.h" #include "cvtpvt.h" // // Added for the MS NT environment // #include /* * C binding */ void cvt_vax_f_to_ieee_single( CVT_VAX_F input_value, CVT_SIGNED_INT options, CVT_IEEE_SINGLE output_value ) { int i, round_bit_position; UNPACKED_REAL r; switch ( options & ~(CVT_C_BIG_ENDIAN | CVT_C_ERR_UNDERFLOW) ) { case 0 : options |= CVT_C_ROUND_TO_NEAREST; case CVT_C_ROUND_TO_NEAREST : case CVT_C_TRUNCATE : case CVT_C_ROUND_TO_POS : case CVT_C_ROUND_TO_NEG : case CVT_C_VAX_ROUNDING : break; default : RAISE(cvt__invalid_option); } // =========================================================================== // // This file used to be included as a separate file. //#include "unp_vaxf.c" // // =========================================================================== /* file: unpack_vax_f.c */ /* ** ** COPYRIGHT (c) 1989 BY ** DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASSACHUSETTS. ** ALL RIGHTS RESERVED. ** ** THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND COPIED ** ONLY IN ACCORDANCE WITH THE TERMS OF SUCH LICENSE AND WITH THE ** INCLUSION OF THE ABOVE COPYRIGHT NOTICE. THIS SOFTWARE OR ANY OTHER ** COPIES THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY ** OTHER PERSON. NO TITLE TO AND OWNERSHIP OF THE SOFTWARE IS HEREBY ** TRANSFERRED. ** ** THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE WITHOUT NOTICE ** AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY DIGITAL EQUIPMENT ** CORPORATION. ** ** DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR RELIABILITY OF ITS ** SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL. ** */ /* **++ ** Facility: ** ** CVT Run-Time Library ** ** 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. ** ** Author: Math RTL ** ** Creation Date: November 24, 1989. ** ** Modification History: ** **-- */ /* **++ ** 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 ** **-- */ RpcpMemoryCopy(&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; } // end of file: unpack_vax_f.c // // =========================================================================== // // This file used to be included as a separate file. //#include "pack_ies.c" // // =========================================================================== /* file: pack_ieee_s.c */ /* ** ** COPYRIGHT (c) 1989 BY ** DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASSACHUSETTS. ** ALL RIGHTS RESERVED. ** ** THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED AND COPIED ** ONLY IN ACCORDANCE WITH THE TERMS OF SUCH LICENSE AND WITH THE ** INCLUSION OF THE ABOVE COPYRIGHT NOTICE. THIS SOFTWARE OR ANY OTHER ** COPIES THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE AVAILABLE TO ANY ** OTHER PERSON. NO TITLE TO AND OWNERSHIP OF THE SOFTWARE IS HEREBY ** TRANSFERRED. ** ** THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO CHANGE WITHOUT NOTICE ** AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY DIGITAL EQUIPMENT ** CORPORATION. ** ** DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR RELIABILITY OF ITS ** SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL. ** */ /* **++ ** Facility: ** ** CVT Run-Time Library ** ** Abstract: ** ** This module contains code to extract information from an ** UNPACKED_REAL structure and to create an IEEE single floating number ** with those bits. ** ** This module is meant to be used as an include file. ** ** Author: Math RTL ** ** Creation Date: November 24, 1989. ** ** Modification History: ** **-- */ /* **++ ** Functional Description: ** ** This module contains code to extract information from an ** UNPACKED_REAL structure and to create an IEEE single number ** with those bits. ** ** See the header files for a description of the UNPACKED_REAL ** structure. ** ** A normalized IEEE single precision floating number looks like: ** ** Sign bit, 8 exp bits (bias 127), 23 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. ** **-- */ if (r[U_R_FLAGS] & U_R_UNUSUAL) { if (r[U_R_FLAGS] & U_R_ZERO) if (r[U_R_FLAGS] & U_R_NEGATIVE) RpcpMemoryCopy(output_value, IEEE_S_NEG_ZERO, 4); else RpcpMemoryCopy(output_value, IEEE_S_POS_ZERO, 4); else if (r[U_R_FLAGS] & U_R_INFINITY) { if (r[U_R_FLAGS] & U_R_NEGATIVE) RpcpMemoryCopy(output_value, IEEE_S_NEG_INFINITY, 4); else RpcpMemoryCopy(output_value, IEEE_S_POS_INFINITY, 4); } else if (r[U_R_FLAGS] & U_R_INVALID) { RpcpMemoryCopy(output_value, IEEE_S_INVALID, 4); RAISE(cvt__invalid_value); } } else { /* Precision varies if value will be a denorm */ /* So, figure out where to round (0 <= i <= 24). */ round_bit_position = r[U_R_EXP] - ((U_R_BIAS - 126) - 23); if (round_bit_position < 0) round_bit_position = 0; else if (round_bit_position > 24) round_bit_position = 24; #include "round.cxx" if (r[U_R_EXP] < (U_R_BIAS - 125)) { /* Denorm or underflow */ if (r[U_R_EXP] < ((U_R_BIAS - 125) - 23)) { /* Value is too small for a denorm, so underflow */ if (r[U_R_FLAGS] & U_R_NEGATIVE) RpcpMemoryCopy(output_value, IEEE_S_NEG_ZERO, 4); else RpcpMemoryCopy(output_value, IEEE_S_POS_ZERO, 4); if (options & CVT_C_ERR_UNDERFLOW) { RAISE(cvt__underflow); } } else { /* Figure leading zeros for denorm and right-justify fraction */ i = 32 - (r[U_R_EXP] - ((U_R_BIAS - 126) - 23)); r[1] >>= i; /* Set sign bit */ r[1] |= (r[U_R_FLAGS] << 31); 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); RpcpMemoryCopy(output_value, r, 4); } else { RpcpMemoryCopy(output_value, &r[1], 4); } } } else if (r[U_R_EXP] > (U_R_BIAS + 128)) { /* Overflow */ if (options & CVT_C_TRUNCATE) { if (r[U_R_FLAGS] & U_R_NEGATIVE) RpcpMemoryCopy(output_value, IEEE_S_NEG_HUGE, 4); else RpcpMemoryCopy(output_value, IEEE_S_POS_HUGE, 4); } else if ((options & CVT_C_ROUND_TO_POS) && (r[U_R_FLAGS] & U_R_NEGATIVE)) { RpcpMemoryCopy(output_value, IEEE_S_NEG_HUGE, 4); } else if ((options & CVT_C_ROUND_TO_NEG) && !(r[U_R_FLAGS] & U_R_NEGATIVE)) { RpcpMemoryCopy(output_value, IEEE_S_POS_HUGE, 4); } else { if (r[U_R_FLAGS] & U_R_NEGATIVE) RpcpMemoryCopy(output_value, IEEE_S_NEG_INFINITY, 4); else RpcpMemoryCopy(output_value, IEEE_S_POS_INFINITY, 4); } RAISE(cvt__overflow); } else { /* Adjust bias of exponent */ r[U_R_EXP] -= (U_R_BIAS - 126); /* Make room for exponent and sign bit */ r[1] >>= 8; /* Clear implicit bit */ r[1] &= 0x007FFFFFL; /* OR in exponent and sign bit */ r[1] |= (r[U_R_EXP] << 23); r[1] |= (r[U_R_FLAGS] << 31); 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); RpcpMemoryCopy(output_value, r, 4); } else { RpcpMemoryCopy(output_value, &r[1], 4); } } } // end of file: pack_ies.c }