Leaked source code of windows server 2003
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title llshr - long shift right;***;llshr.asm - long shift right;; Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.;;Purpose:; define signed long shift right routine ; __allshr;;Revision History:; 11-??-83 HS initial version; 11-30-83 DFW added medium model support; 03-12-84 DFW broke apart; added long model support; 06-01-84 RN modified to use cmacros; 11-28-89 GJF Fixed copyright; 11-19-93 SMK Modified to work on 64 bit integers; 01-17-94 GJF Minor changes to build with NT's masm386.; 07-08-94 GJF Faster, fatter version for NT.; 07-13-94 GJF Further improvements from JonM.;;*******************************************************************************
.xlistinclude cruntime.incinclude mm.inc.list
;***;llshr - long shift right;;Purpose:; Does a signed Long Shift Right ; Shifts a long right any number of bits.;;Entry:; EDX:EAX - long value to be shifted; CL - number of bits to shift by;;Exit:; EDX:EAX - shifted value;;Uses:; CL is destroyed.;;Exceptions:;;*******************************************************************************
CODESEG
_allshr PROC NEAR
;; Handle shifts of 64 bits or more (if shifting 64 bits or more, the result; depends only on the high order bit of edx).; cmp cl,64 jae short RETSIGN
;; Handle shifts of between 0 and 31 bits; cmp cl, 32 jae short MORE32 shrd eax,edx,cl sar edx,cl ret
;; Handle shifts of between 32 and 63 bits;MORE32: mov eax,edx sar edx,31 and cl,31 sar eax,cl ret
;; Return double precision 0 or -1, depending on the sign of edx;RETSIGN: sar edx,31 mov eax,edx ret
_allshr ENDP
end
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