kolibrios-gitea/programs/develop/open watcom/trunk/clib/cgsupp/fsc386.asm

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;*****************************************************************************
;*
;* 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!
;*
;*****************************************************************************
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;<>
;<> __FSC compares EAX with EDX
;<> if EAX > EDX, 1 is returned in EAX
;<> if EAX = EDX, 0 is returned in EAX
;<> if EAX < EDX, -1 is returned in EAX
;<>
;<> ========= === =======
;<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
include mdef.inc
include struct.inc
modstart fsc386
xdefp __FSC
defpe __FSC
_guess have_cmp ; guess - comparison done
xor EAX,EDX ; - check if signs differ
_if ns ; - if signs are the same
xor EAX,EDX ; - - restore EAX
sub EAX,EDX ; - - find difference, EAX=0 if equal
_quif e,have_cmp ; - - done if mantissas also equal
; - - carry=1 iff |EAX| < |EDX|
rcr EAX,1 ; - - EAX sign set iff |EAX| < |EDX|
xor EDX,EAX ; - - EDX sign set iff EAX < EDX
not EDX ; - - EDX sign set iff EAX > EDX
_endif ; - endif
sub EAX,EAX ; - clear result
_shl EDX,1 ; - carry=1 iff EAX > EDX
adc EAX,EAX ; - EAX = 1 iff EAX > EDX, else EAX = 0
_shl EAX,1 ; - EAX = 2 iff EAX > EDX, else EAX = 0
dec EAX ; - EAX = 1 iff EAX > EDX, else EAX = -1
_endguess ; endguess
ret ; return with sign in EAX, conditions set
endproc __FSC
endmod
end