Source code of Windows XP (NT5)
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title llshl - long shift left;***;llshl.asm - long shift left;; Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.;;Purpose:; define long shift left routine (signed and unsigned are same); __allshl;;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
;***;llshl - long shift left;;Purpose:; Does a Long Shift Left (signed and unsigned are identical); Shifts a long left 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
_allshl PROC NEAR
;; Handle shifts of 64 or more bits (all get 0); cmp cl, 64 jae short RETZERO
;; Handle shifts of between 0 and 31 bits; cmp cl, 32 jae short MORE32 shld edx,eax,cl shl eax,cl ret
;; Handle shifts of between 32 and 63 bits;MORE32: mov edx,eax xor eax,eax and cl,31 shl edx,cl ret
;; return 0 in edx:eax;RETZERO: xor eax,eax xor edx,edx ret
_allshl ENDP
end
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