;*****************************************************************************
;*
;* 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!
;*
;*****************************************************************************
;
include mdef.inc
include struct.inc
modstart i4fd386
xdefp __I4FD
xdefp __U4FD
;[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
;[]
;[] __I4FD convert signed 32-bit integer in EAX into double float
;[] __U4FD convert unsigned 32-bit integer in EAX into double float
;[] Input: EAX - 32-bit integer
;[] Output: EDX:EAX - double precision representation of integer
;[]
;[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
defpe __I4FD
or EAX,EAX ; if number is negative
_if s ; then
neg EAX ; - negate number
mov EDX,00000BFFh ; - set exponent
_else ; else
; convert unsigned 32-bit integer to double
defpe __U4FD
mov EDX,000003FFh ; - set exponent
_endif ; endif
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
mov CL,31 ; - calculate # of bits to shift by
sub CL,CH ; - ...
shl EAX,CL ; - shift bits into position
_shl EAX,1 ; - one more to get rid of implied 1 bit
mov CL,CH ; - get shift count
movzx ECX,CH ; - get shift count
add ECX,EDX ; - calculate exponent
mov EDX,EAX ; - get the bits
and EDX,0FFFFF000h ; - keep 20 bits
or EDX,ECX ; - get exponent in there
ror EDX,12 ; - rotate into position
shl EAX,20 ; - get last 12 bits into place
pop ECX ; - restore ECX
ret ; - return
_endif ; endif
sub EDX,EDX ; zero EDX
ret ; return
endproc __U4FD
endproc __I4FD
endmod
end