mirror of
https://github.com/KolibriOS/kolibrios.git
synced 2024-12-17 12:22:35 +03:00
151 lines
5.6 KiB
NASM
151 lines
5.6 KiB
NASM
;*****************************************************************************
|
|
;*
|
|
;* 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!
|
|
;*
|
|
;*****************************************************************************
|
|
|
|
|
|
;
|
|
; from float to signed/unsigned int64
|
|
;
|
|
include mdef.inc
|
|
include struct.inc
|
|
|
|
modstart fsi8386
|
|
|
|
xref __U8LS
|
|
xref __U8RS
|
|
|
|
; Convert single precision float to unsigned 64-bit integer with truncation
|
|
; Input: [EAX] = 32-bit float
|
|
; Output: [EDX, EAX] = 64-bit integer
|
|
|
|
xdefp __FSU8
|
|
defp __FSU8
|
|
push ECX ; save ECX
|
|
mov CL,7fh+64 ; maximum number 2^64-1
|
|
call __FSU ; convert float to unsigned __int64
|
|
pop ECX ; restore ECX
|
|
ret ; return
|
|
endproc __FSU8
|
|
|
|
; Convert single precision float to signed 64-bit integer with truncation
|
|
; Input: [EAX] = 32-bit float
|
|
; Output: [EDX, EAX] = 64-bit integer
|
|
|
|
xdefp __FSI8
|
|
defp __FSI8
|
|
push ECX ; save ECX
|
|
mov CL,7fh+63 ; maximum number 2^63-1
|
|
call __FSI ; convert float to signed __int64
|
|
pop ECX ; restore ECX
|
|
ret ; return
|
|
endproc __FSI8
|
|
|
|
__FSI proc near
|
|
__FSU: ; what? they both do the same thing
|
|
or EAX,EAX ; check sign bit
|
|
jns short __FSAbs ; treat as unsigned if positive
|
|
call __FSAbs ; otherwise convert number
|
|
neg EDX ; negate the result
|
|
neg EAX ;
|
|
sbb EDX,0 ;
|
|
ret ; return
|
|
endproc __FSI
|
|
|
|
__FSAbs proc near
|
|
or EAX,EAX ; check if number 0
|
|
je short fltzero ; if so, just return 0
|
|
_shl EAX,1 ; shift mantissa over
|
|
rol EAX,8 ; get exponent to bottom
|
|
cmp AL,7fh ; quit if number < 1.0
|
|
jb short fltuflow ; ...
|
|
push EBX ; save EBX
|
|
mov CH,AL ; save exponent
|
|
stc ; set carry for implied bit
|
|
rcr EAX,1 ; put implied '1' bit in
|
|
shr EAX,8 ; remove exponent and extra bit
|
|
mov EDX,EAX ; put into 64-bit hi part
|
|
xor EAX,EAX ; zero 64-bit lo part
|
|
cmp CH,CL ; check if exponent exceeds maximum
|
|
jae short fltmax ; return maximum value if so
|
|
sub CH,7fh+55 ; calculate amount to shift (+ve -> left)
|
|
jae short fltm_left ; jump if left shift/no shift
|
|
xchg CH,CL ; get shift count
|
|
neg CL ; make positive
|
|
mov BX,CX
|
|
call __U8RS ; shift mantissa right
|
|
pop EBX ; restore EBX
|
|
ret ; return
|
|
|
|
fltm_left:
|
|
_if ne ; done if exponent exactly 55
|
|
mov BL,CH ; - get shift count
|
|
call __U8LS ; - shift mantissa left
|
|
_endif ; endif
|
|
pop EBX ; restore EBX
|
|
ret ; return
|
|
|
|
; CL = 7fh+64 for unsigned
|
|
; 7fh+63 for signed
|
|
fltmax:
|
|
mov EAX,0FFFFFFFFh ; return maximum value
|
|
mov EDX,EAX ;
|
|
sub CL,7fh+64 ; subtract bias + 64, results in 0 or -1
|
|
neg CL ; get shift count
|
|
mov BL,CL ; set shift count
|
|
call __U8RS ; shift mantissa right 1 bit for signed
|
|
pop EBX ; restore EBX
|
|
ret ; return
|
|
|
|
fltuflow:
|
|
sub EAX,EAX ; ensure entire number 0
|
|
fltzero:
|
|
sub EDX,EDX ;
|
|
ret ; return
|
|
endproc __FSAbs
|
|
|
|
; Convert single precision float to unsigned 64-bit integer with rounding
|
|
; Input: [EAX] = 32-bit float
|
|
|
|
; xdefp __RSU8
|
|
; defp __RSU8
|
|
; not implemented
|
|
; endproc __RSU8
|
|
|
|
; Convert single precision float to signed 64-bit integer with rounding
|
|
; Input: [EAX] = 32-bit float
|
|
|
|
; xdefp __RSI8
|
|
; defp __RSI8
|
|
; not implemented
|
|
; endproc __RSI8
|
|
|
|
endmod
|
|
end
|