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384 lines
10 KiB
NASM
384 lines
10 KiB
NASM
;This file demonstrates many of the differences between NASM version X and NASM
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;version 0.97
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;
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; changed.asm is copyright (C) 1998 John S. Fine
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;
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; It may be redistributed under the same conditions as NASM as described in
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; LICENSE file in the NASM archive
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;_________________________________
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;
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; nasm changed.asm -l changed.lst
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;
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; When assembled without any -d switches, it includes examples which:
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; Work correctly in version X
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; and Work incorrectly and/or display warnings in version 0.97
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; and Do not prevent the generation of output in version 0.97
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;
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; Not all the differences can be seen in the .lst file. I suggest that you use
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; "ndisasm changes" to examine the code actually generated.
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;_________________________________
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;
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; nasm changed.asm -l changed.lst -doldmsg
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;
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; When assembled with -doldmsg, it adds examples which:
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; Work correctly in version X
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; and Generate error messages in version 0.97 and do not generate output
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;_________________________________
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;
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; nasm changed.asm -l changed.lst -doldcrash
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;
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; When assembled with -doldcrash, it adds examples which:
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; Work correctly in version X
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; and Cause NASM to crash in version 0.97
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;_________________________________
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;
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; nasm changed.asm -l changed.lst -dnewmsg
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;
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; When assembled with -dnewmsg, it adds examples which:
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; Generate error messages in version X
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; and Generate wrong output without warning or error message in version 0.97
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;-----------------------------------------------------------------------------
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; Please note that I have reported the name of the person who made the
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; correction based on very limited information. In several cases, I am sure I
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; will identify the wrong author. Please send me any corrections; I don't
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; intend to insult or exclude anyone.
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;-----------------------------------------------------------------------------
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; Bug fixed by Simon in assemble()
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;
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; The following generated "call next" / "call next-1" instead of
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; two copies of "call next"
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;
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times 2 a16 call next
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next:
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;-----------------------------------------------------------------------------
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; Bug fixed by John in parse_line() (and other routines)
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;
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; This used to jmp to prior.1, when it should be here.1
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;
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prior:
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.1:
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here: jmp .1
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.1:
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;-----------------------------------------------------------------------------
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; Bug fixed by John in assemble()
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;
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; Strings used in dq and dt were not zero filled correctly
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;
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dq 'b'
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;-----------------------------------------------------------------------------
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; Bug fixed by Simon in isn_names[]
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;
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; Was not recognised as an instruction
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;
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int01 ; Instead of INT1
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;-----------------------------------------------------------------------------
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; Bug fixed by Jim Hague in ???
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;
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; Forward references were instruction level rather than per operand
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;
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shr word [forwardref],1
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forwardref:
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;-----------------------------------------------------------------------------
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; Bug fixed by John in preproc.c
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;
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; It used to silently discard id characters appended to a multi-line
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; macro parameter (such as the x in %1x below).
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;
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%macro xxx 1
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%1: nop
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%{1}x: jmp %1x
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%endmacro
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xxx yyy
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;-----------------------------------------------------------------------------
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; Bug added by John in preproc.c 0.98-J4, removed by John in 0.98-J5
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;
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; Tested here to make sure it stays removed
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;
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%macro TestElse 1
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%if %1=0
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%elif %1=1
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nop
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%endif
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%endmacro
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TestElse 1
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%ifdef oldmsg
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;***************************************************************
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;
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; The following examples will generate error messages in 0.97 and will generate
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; correct output in the new version.
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;-----------------------------------------------------------------------------
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; Bug fixed by Simon in isns.dat
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;
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; The optional "near" was not permitted on JMP and CALL
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;
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jmp near here
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;-----------------------------------------------------------------------------
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; Feature added by Simon in stdscan()
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;
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; You can now use the numeric value of strings in %assign
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;
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%assign xxx 'ABCD'
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dd xxx
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;-----------------------------------------------------------------------------
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; Feature added by John in add_vectors()
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;
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; Stranger address expressions are now supported as long as they resolve to
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; something valid.
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;
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mov ax, [eax + ebx + ecx - eax]
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;-----------------------------------------------------------------------------
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; Bug fixed by Simon in ???
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;
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; The EQU directive affected local labels in a way that was inconsistent
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; between passes
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;
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.local:
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neither equ $
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jmp .local
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;-----------------------------------------------------------------------------
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; Feature added by Jules in parse_line
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;
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; You can override a size specifier
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;
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%define arg1 dword [bp+4]
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cmp word arg1, 2
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;-----------------------------------------------------------------------------
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; Bug fixed by John in preproc.c
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;
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; You could not use a label on the same line with a macro invocation, if the
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; macro definition began with a preprocessor directive.
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;
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struc mytype
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.long resd 1
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endstruc
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lbl istruc mytype
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at mytype.long, dd 'ABCD'
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iend
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;-----------------------------------------------------------------------------
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; Warning removed by John in preproc.c
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;
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; In order to allow macros that extend the definition of instructions, I
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; disabled the warning on a multi-line macro referencing itself.
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;
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%endif ;NASM 0.97 doesn't handle %0 etc. inside false %if
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%macro push 1-* ;
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%rep %0 ;
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push %1 ;
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%rotate 1 ;
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%endrep ;
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%endmacro ;
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%ifdef oldmsg ;
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push ax,bx
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;-----------------------------------------------------------------------------
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; Warning removed by John in preproc.c
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;
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; To support other types of macros that extend the definition of instructions,
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; I disabled the warning on a multi-line macro called with the wrong number of
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; parameters. PUSH and POP can be extended equally well by either method, but
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; other intruction extensions may need one method or the other, so I made both
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; work.
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;
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; Note that neither of these warnings was really needed, because a later stage
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; of NASM would almost always give an adequate error message if the macro use
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; really was wrong.
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;
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%endif
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%macro pop 2-*
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%rep %0
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pop %1
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%rotate 1
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%endrep
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%endmacro
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%ifdef oldmsg
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pop ax,bx
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%endif
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%ifdef newmsg ;***************************************************************
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;-----------------------------------------------------------------------------
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; Bug fixed by John in parse_line() (and other routines)
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;
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; This invalid code used to assemble without errors
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;
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myself equ myself+1
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jmp myself
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;-----------------------------------------------------------------------------
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; Change made by John in preproc.c
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;
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; In 0.97, an id that appears as a label on a macro invocation was always
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; prepended to the first line of the macro expansion. That caused several
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; bugs, but also could be used in tricks like the arg macro in c16.mac and
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; c32.mac.
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;
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; In version X, an id that appears as a label on a macro invocation will
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; normally be defined as a label for the address at which the macro is
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; invoked, regardless of whether the first line of the macro expansion is
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; something that can take a label. The new token %00 may be used for any
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; of the situations in which the old prepend behavior was doing something
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; tricky but useful. %00 can also be used more than once and in places
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; other than the start of the expansion.
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;
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%endif
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%assign arg_off 0
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%imacro arg 0-1 2 ;arg defined the old way
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equ arg_off
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%assign arg_off %1+arg_off
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%endmacro
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%ifdef newmsg
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arg_example arg
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%endif
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%imacro arg2 0-1 2 ;arg defined the new way
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%00 equ arg_off
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%assign arg_off %1+arg_off
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%endmacro
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%ifdef oldmsg
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arg_example2 arg2
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;-----------------------------------------------------------------------------
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; Change made by Jules and John in INSNS.DAT
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;
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; Various instruction in which the size of an immediate is built-in to the
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; instruction set, now allow you to redundantly specify that size as long
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; as you specify it correctly
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;
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AAD byte 5
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AAM byte 5
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BT bx, byte 3
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BTC cx, byte 4
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BTR dx, byte 5
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BTS si, byte 6
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IN eax, byte 0x40
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INT byte 21h
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OUT byte 70h, ax
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RET word 2
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RETN word 2
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RETF word 4
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; note "ENTER" has not been changed yet.
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;-----------------------------------------------------------------------------
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; Enhancement by hpa in insns.dat et al
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;
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; Simplified adding new instructions, and added some missing instructions
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;
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int03 ; Instead of INT3
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ud1 ; No documented mnemonic for this one
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ud2
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sysenter
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sysexit
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syscall
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sysret
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fxsave [ebx]
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fxrstor [es:ebx+esi*4+0x3000]
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;-----------------------------------------------------------------------------
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; Enhancement by hpa in insns.dat et al
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;
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; Actually make SSE work, and use the -p option to ndisasm to select
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; one of several aliased opcodes
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;
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sqrtps xmm0,[ebx+10] ; SSE opcode
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paddsiw mm0,[ebx+10] ; Cyrix opcode with the same byte seq.
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;-----------------------------------------------------------------------------
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; Enhancement by hpa in preproc.c
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;
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; Support %undef to remoce a single-line macro
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;
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%define TEST_ME 42
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%ifndef TEST_ME
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%error "TEST_ME not defined after %define"
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%endif
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%undef TEST_ME
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%ifdef TEST_ME
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%error "TEST_ME defined after %undef"
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%endif
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;-----------------------------------------------------------------------------
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; Bug fix by hpa in insns.dat
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;
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; PSHUFW and PINSRW weren't handling the implicit sizes correctly; all of
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; the entries below are (or should be) legal
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;
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pshufw mm2, mm1, 3
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pshufw mm3,[ebx],2
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pshufw mm7,[0+edi*8],1
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pshufw mm2, mm1, byte 3
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pshufw mm3,[ebx],byte 2
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pshufw mm7,[0+edi*8],byte 1
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pshufw mm2, mm1, 3
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pshufw mm3, qword [ebx], 2
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pshufw mm7, qword [0+edi*8], 1
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pshufw mm2, mm1, byte 3
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pshufw mm3, qword [ebx], byte 2
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pshufw mm7, qword [0+edi*8], byte 1
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pinsrw mm1, [esi], 1
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pinsrw mm1, word [esi], 1
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pinsrw mm1, [esi], byte 1
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pinsrw mm1, word [esi], byte 1
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%endif ; oldmsg
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%ifdef oldcrash ;*************************************************************
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This_label_is_256_characters_long__There_used_to_be_a_bug_in_stdscan_which_made_it_crash_when_it_did_a_keyword_search_on_any_label_longer_than_255_characters__Now_anything_longer_than_MAX_KEYWORD_is_always_a_symbol__It_will_not_even_try_a_keyword_search___
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;-----------------------------------------------------------------------------
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; Bug fixed by John in preproc.c
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;
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; Builds of NASM that prohibit dereferencing a NULL pointer used to crash if a
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; macro that started with a blank line was invoked with a label
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;
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%macro empty_macro 0
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%endm
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emlabel empty_macro
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jmp emlabel
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;-----------------------------------------------------------------------------
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; Enhancement by Conan Brink in preproc.c
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;
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; Allow %rep to be nested
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;
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%rep 4
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%rep 5
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nop
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%endrep
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%endrep
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%endif
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