Leaked source code of windows server 2003
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;***
;
; Copyright (c) 1984-2001, Microsoft Corporation. All rights reserved.
;
;Revision History:
;
;*******************************************************************************
.xlist
include cruntime.inc
include elem87.inc
.list
.const
staticQ One, 03FF0000000000000R
globalW _DEFAULT_CW_in_mem 027fh
globalT _pi_by_2_to_61 0403ec90fdaa22168c235R ; (2**61) * pi
staticQ DblMax, 07fefffffffffffffR
staticQ DblMin, 00010000000000000R
staticQ IeeeAdjO, 0c098000000000000R
staticQ IeeeAdjU, 04098000000000000R
staticQ _infinity, 07ff0000000000000R
staticQ _zero, 00000000000000000R
CODESEG
extrn _startOneArgErrorHandling:near
extrn _startTwoArgErrorHandling:near
;***********************************************************
;
; _twoToTOS
;
;***********************************************************
; Recieves:
; TOS is not NaN
; Retunns:
; 2^TOS
; Note:
; uses 3 entries of FPU stack
_twoToTOS proc
fld st(0) ; duplicate stack top
frndint ; N = round(y)
fsubr st(1), st
fxch
fchs ; g = y - N where abs(g) < 1
f2xm1 ; 2**g - 1
fld1
fadd ; 2**g
fscale ; (2**g) * (2**N) - gives 2**y
fstp st(1)
ret ; pop extra stuff from fp stack
_twoToTOS endp
;***********************************************************
;
; _load_CW
;
;***********************************************************
; receives current control word on stack
; and it's known that it differs from default
; Purpose:
; load default CW, but take precision from current CW (bits 8 and 9)
; Note:
; value of edx is destroyed
;
_load_CW proc
mov edx,[esp+4]
and edx,0300H ; all bits except precision are zero
or edx,DEFAULT_CW_without_precision
mov [esp+6],dx ; use 2 free bytes in stack
fldcw [esp+6]
ret
_load_CW endp
;***********************************************************
;
; _convertTOStoQNaN
;
;***********************************************************
; Recieves:
; TOS is QNaN or SNaN
; eax is high dword of TOS
; Retunns:
; if TOS=QNaN
; eax=DOMAIN_QNAN
; else (TOS=SNaN)
; eax=DOMAIN
; TOS=QNaN
_convertTOStoQNaN proc
test eax, 00080000H ; test weather arg is QNaN or SNaN
jz tosIsSNaN
mov eax,DOMAIN_QNAN ; TOS is QNaN
ret
tosIsSNaN:
fadd [One] ; convert SNaN to QNan
mov eax,DOMAIN ; TOS was SNaN
ret ; _cdecl return
_convertTOStoQNaN endp
;***********************************************************
;
; _fload_withFB
;
;***********************************************************
; Load arg in the fp stack without raising an exception if the argument
; is a signaling NaN
; In other words, when arg is 53-bit SNaN convert it to 64-bit SNaN
;
; edx points to argument (in double precision)
; return value:
; if we have normal number:
; eax=exponent
; Zero flag is 0
; if we have special number:
; eax=high dword
; Zero flag is 1
_fload_withFB proc ; load with feed back
mov eax, [edx+4] ; get exponent field
and eax, 07ff00000h
cmp eax, 07ff00000h ; check for special exponent
je fpload_special
fld qword ptr[edx] ; ZF=0
ret ; _cdecl return
; have special argument (NaN or INF)
fpload_special: ; convert to long double
mov eax,[edx+4] ; high dword of double
sub esp,LDBLSIZE
or eax, 7fff0000h ; preserve sign, set max long double exp
mov [esp+6],eax ; store sign and power
mov eax,[edx+4] ; low dword of double
mov ecx,[edx]
shld eax,ecx,11
shl ecx,11
mov [esp+4],eax
mov [esp],ecx
fld tbyte ptr [esp]
add esp,LDBLSIZE
test eax,0 ; ZF=1
mov eax,[edx+4] ; high dword of double
ret ; _cdecl return
_fload_withFB endp
;***********************************************************
;
; _checkTOS_withFB
;
;***********************************************************
; Test first argument on INTEGER stack and set registers and flags exactly like _fload_withFB
;
; we have on stack : ret_value(4 bytes), arg1(8 bytes)
; return value:
; if we have normal number:
; eax=exponent
; Zero flag is 0
; if we have special number:
; eax=high dword
; Zero flag is 1
_checkTOS_withFB proc
mov eax, [esp+8] ; get high dword
and eax,07ff00000h
cmp eax,07ff00000h ; check for special exponent
; and set ZF
je special_exp
ret ; _cdecl return
special_exp:
mov eax, [esp+8] ; get exponent field
ret ; _cdecl return
_checkTOS_withFB endp
;***********************************************************
;
; _fast_exit
;
;***********************************************************
; called after execution of each math function (sin,cos, ....),
; and if __fastflag!=0
;
_fast_exit proc
cmp word ptr[esp],default_CW
je fast_exit_CW_is_restored
fldcw [esp]
fast_exit_CW_is_restored:
pop edx ; remove saved CW from stack
ret ; _cdecl return
_fast_exit endp
;***********************************************************
;
; _math_exit
;
;***********************************************************
; called after execution of each math function (sin,cos, ....)
; and if __fastflag=0.
; The purpose is to check inexact exception.
; ecx points to function name
; edx function id (for example OP_LOG)
_math_exit proc
mov ax,word ptr[esp]
cmp ax,default_CW
je CW_is_restored ; we assume here that in default CW inexact
; exception is masked
and ax,20h ; test if inexact exception is masked
jz restore_CW
fstsw ax
and ax,20h
jz restore_CW
mov eax,INEXACT
call _startOneArgErrorHandling
pop edx ; remove saved CW from stack
ret
restore_CW:
fldcw [esp]
CW_is_restored:
pop edx ; remove saved CW from stack
ret ; _cdecl return
_math_exit endp
;***********************************************************
;
; _check_overflow_exit
;
;***********************************************************
;
_check_overflow_exit proc
sub esp,DBLSIZE ; prepare place for argument
fst qword ptr[esp]
mov eax,[esp+4] ; eax=high dword
add esp,DBLSIZE
and eax,7ff00000H
jmp _check_overflow_start
_check_overflow_exit endp
;***********************************************************
;
; _check_range_exit
;
;***********************************************************
; called after execution of math functions, which may generate
; overflow/underflow, and if __fastflag=0.
; used in exp() and pow() functions
; The purpose is to check inexact overflow/underflow and inexact exception
; ecx points to function name
; edx function id (for example OP_EXP)
_check_range_exit proc
sub esp,DBLSIZE ; prepare place for argument
fst qword ptr[esp]
mov eax,[esp+4] ; eax=high dword
add esp,DBLSIZE
and eax,7ff00000H
jz haveunderflow
_check_overflow_start label proc
cmp eax,7ff00000H
jz haveoverflow
; check INEXACT(precision) exception
mov ax,word ptr[esp] ; saved CW
cmp ax,default_CW
je CW_is_restored ; we assume here that in default CW inexact
; exception is masked
and ax,20h ; test if inexact exception is masked
jnz restore_CW
fstsw ax
and ax,20h
jz restore_CW
mov eax,INEXACT
have_error:
cmp edx,OP_POW
je have_error_in_pow
call _startOneArgErrorHandling
pop edx ; remove saved CW from stack
ret
have_error_in_pow:
call _startTwoArgErrorHandling
pop edx ; remove saved CW from stack
ret
restore_CW:
fldcw [esp]
CW_is_restored:
pop edx ; remove saved CW from stack
ret ; _cdecl return
; this code is taken from previous version, to receive
; exactly the same result as before. But we may simplify it...
haveunderflow: ; underflow is detected
fld IeeeAdjU
fxch
fscale
fstp st(1)
fld st(0)
fabs
fcomp [DblMin]
fstsw ax
sahf
mov eax,UNDERFLOW
JSAE have_error
fmul [_zero]
jmp short have_error
haveoverflow: ; overflow is detected
fld IeeeAdjO
fxch
fscale
fstp st(1)
fld st(0)
fabs
fcomp [DblMax]
fstsw ax
sahf
mov eax,OVERFLOW
JSBE have_error
fmul [_infinity]
jmp short have_error
_check_range_exit endp
end