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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 553 | serge | 1 | ;***************************************************************************** |
| 2 | ;* |
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| 3 | ;* Open Watcom Project |
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| 4 | ;* |
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| 5 | ;* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved. |
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| 6 | ;* |
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| 7 | ;* ======================================================================== |
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| 8 | ;* |
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| 9 | ;* This file contains Original Code and/or Modifications of Original |
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| 10 | ;* Code as defined in and that are subject to the Sybase Open Watcom |
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| 11 | ;* Public License version 1.0 (the 'License'). You may not use this file |
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| 12 | ;* except in compliance with the License. BY USING THIS FILE YOU AGREE TO |
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| 13 | ;* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is |
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| 14 | ;* provided with the Original Code and Modifications, and is also |
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| 15 | ;* available at www.sybase.com/developer/opensource. |
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| 16 | ;* |
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| 17 | ;* The Original Code and all software distributed under the License are |
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| 18 | ;* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
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| 19 | ;* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM |
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| 20 | ;* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF |
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| 21 | ;* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR |
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| 22 | ;* NON-INFRINGEMENT. Please see the License for the specific language |
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| 23 | ;* governing rights and limitations under the License. |
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| 24 | ;* |
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| 25 | ;* ======================================================================== |
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| 26 | ;* |
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| 27 | ;* Description: WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE |
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| 28 | ;* DESCRIBE IT HERE! |
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| 29 | ;* |
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| 30 | ;***************************************************************************** |
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| 31 | |||
| 32 | |||
| 33 | ;======================================================================== |
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| 34 | ;== Name: I4FS, U4FS == |
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| 35 | ;== Operation: Convert Integer types to single precision == |
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| 36 | ;== Inputs: EAX, unsigned or signed integer == |
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| 37 | ;== Outputs: EAX single precision floating point == |
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| 38 | ;== Volatile: none == |
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| 39 | ;== == |
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| 40 | ;======================================================================== |
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| 41 | include mdef.inc |
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| 42 | include struct.inc |
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| 43 | |||
| 44 | modstart i4fs386 |
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| 45 | |||
| 46 | xdefp __I4FS |
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| 47 | xdefp __U4FS |
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| 48 | |||
| 49 | |||
| 50 | defpe __U4FS |
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| 51 | or EAX,EAX ; if number is not zero |
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| 52 | _if ne ; then |
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| 53 | push ECX ; - save ECX |
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| 54 | bsr ECX,EAX ; - find most significant non-zero bit |
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| 55 | mov CH,CL ; - save shift count |
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| 56 | neg CL ; - calculate # of bits to rotate by |
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| 57 | add CL,23 ; - ... |
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| 58 | and CL,1fh ; - just keep last 5 bits |
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| 59 | rol EAX,CL ; - shift bits into position |
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| 60 | and EAX,007FFFFFh ; - mask out sign and exponent bits |
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| 61 | mov CL,CH ; - get shift count |
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| 62 | add CL,7Fh ; - calculate exponent |
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| 63 | and ECX,0FFh ; - isolate exponent |
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| 64 | shl ECX,23 ; - shift exponent into position |
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| 65 | or EAX,ECX ; - place into result |
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| 66 | pop ECX ; - restore ECX |
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| 67 | _endif ; endif |
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| 68 | ret ; return |
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| 69 | |||
| 70 | endproc __U4FS |
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| 71 | |||
| 72 | defpe __I4FS |
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| 73 | or EAX,EAX ; check sign |
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| 74 | jns __U4FS ; if positive, just convert |
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| 75 | neg EAX ; take absolute value of number |
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| 76 | call __U4FS ; convert to FS |
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| 77 | or EAX,80000000h ; set sign bit on |
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| 78 | ret ; and return |
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| 79 | endproc __I4FS |
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| 80 | |||
| 81 | endmod |
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| 82 | end |