;***************************************************************************** ;* ;* Open Watcom Project ;* ;* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved. ;* ;* ======================================================================== ;* ;* This file contains Original Code and/or Modifications of Original ;* Code as defined in and that are subject to the Sybase Open Watcom ;* Public License version 1.0 (the 'License'). You may not use this file ;* except in compliance with the License. BY USING THIS FILE YOU AGREE TO ;* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is ;* provided with the Original Code and Modifications, and is also ;* available at www.sybase.com/developer/opensource. ;* ;* The Original Code and all software distributed under the License are ;* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER ;* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM ;* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF ;* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR ;* NON-INFRINGEMENT. Please see the License for the specific language ;* governing rights and limitations under the License. ;* ;* ======================================================================== ;* ;* Description: WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE ;* DESCRIBE IT HERE! ;* ;***************************************************************************** ;======================================================================== ;== Name: I4FS, U4FS == ;== Operation: Convert Integer types to single precision == ;== Inputs: EAX, unsigned or signed integer == ;== Outputs: EAX single precision floating point == ;== Volatile: none == ;== == ;======================================================================== include mdef.inc include struct.inc modstart i4fs386 xdefp __I4FS xdefp __U4FS defpe __U4FS or EAX,EAX ; if number is not zero _if ne ; then push ECX ; - save ECX bsr ECX,EAX ; - find most significant non-zero bit mov CH,CL ; - save shift count neg CL ; - calculate # of bits to rotate by add CL,23 ; - ... and CL,1fh ; - just keep last 5 bits rol EAX,CL ; - shift bits into position and EAX,007FFFFFh ; - mask out sign and exponent bits mov CL,CH ; - get shift count add CL,7Fh ; - calculate exponent and ECX,0FFh ; - isolate exponent shl ECX,23 ; - shift exponent into position or EAX,ECX ; - place into result pop ECX ; - restore ECX _endif ; endif ret ; return endproc __U4FS defpe __I4FS or EAX,EAX ; check sign jns __U4FS ; if positive, just convert neg EAX ; take absolute value of number call __U4FS ; convert to FS or EAX,80000000h ; set sign bit on ret ; and return endproc __I4FS endmod end