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;*****************************************************************************
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;*
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;*                            Open Watcom Project
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;*
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;*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
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;*
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;*  ========================================================================
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;*
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;*    This file contains Original Code and/or Modifications of Original
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;*    Code as defined in and that are subject to the Sybase Open Watcom
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;*    Public License version 1.0 (the 'License'). You may not use this file
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;*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
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;*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
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;*    provided with the Original Code and Modifications, and is also
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;*    available at www.sybase.com/developer/opensource.
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;*
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;*    The Original Code and all software distributed under the License are
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;*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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;*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
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;*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
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;*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
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;*    NON-INFRINGEMENT. Please see the License for the specific language
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;*    governing rights and limitations under the License.
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;*
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;*  ========================================================================
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;*
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;* Description:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
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;*               DESCRIBE IT HERE!
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;*
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;*****************************************************************************
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include mdef.inc
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include struct.inc
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        modstart        i8fs386
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        xref    __I8LS
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        xref    __I8RS
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; Convert signed 64-bit integer to single precision float
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; Input: [EDX, EAX] = 64-bit integer
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; Output: [EAX] = 32-bit float
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        xdefp   __I8FS
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        defp    __I8FS
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        or      EDX,EDX         ; check sign
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        jns     __U8FS          ; if positive, just convert
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        neg     EDX             ;
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        neg     EAX             ; take absolute value of number
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        sbb     EDX,0           ;
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        call    __U8FS          ; convert to FS
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        or      EAX,80000000h   ; set sign bit on
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        ret                     ; return
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        endproc __I8FS
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; Convert unsigned 64-bit integer to single precision float
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; Input: [EDX, EAX] = 64-bit integer
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; Output: [EAX] = 32-bit float
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        xdefp   __U8FS
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        defp    __U8FS
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        or      EAX,EAX         ; if lo is zero
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        _if     e               ;
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        or      EDX,EDX         ; and if hi is zero
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          _if   e               ;
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            ret                 ; - return
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          _endif
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        _endif                  ; endif
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        push    ECX             ; save ECX
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        push    EBX             ; save EBX
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        bsr     ECX,EDX         ; find most significant non-zero bit in hi
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        _if     e               ; if all zero bits
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          bsr   ECX,EAX         ; - find most significant non-zero bit in lo
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        _else                   ; else
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          add   CL,32           ; - adjust shift count since hi was not 0
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        _endif                  ; endif
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        push    ECX             ; save shift count
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        neg     CL              ; calculate # of bits to shift by
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        add     CL,63-8         ; ...
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        mov     EBX,ECX         ; set up for call
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        or      CL,CL           ; if mantissa should move left
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        _if     ge              ; then
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          call  __I8LS          ; - shift left
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        _else                   ; else
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          neg   BL              ; - make positive
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          call  __I8RS          ; - shift right
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        _endif                  ; endif
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        pop     ECX             ; restore shift count
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        and     EDX,007FFFFFh   ; mask out sign and exponent bits
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        add     CL,127          ; calculate exponent (excess 127)
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;       and     ECX,0FFh        ; isolate exponent (not required)
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        shl     ECX,23          ; shift exponent into position
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        or      EDX,ECX         ; place into result
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        mov     EAX,EDX         ; single precision is only 32 bits
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        pop     EBX             ; restore EBX
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        pop     ECX             ; restore ECX
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        ret                     ; return
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        endproc __U8FS
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        endmod
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        end