Amiga MA Magazine 1998 #6

home *** CD-ROM | disk | FTP | other *** search

/ Amiga MA Magazine 1998 #6 / amigamamagazinepolishissue1998.iso / coders / macros / macros.asm next >

Wrap

Assembly Source File | 1997-08-07 | 26.9 KB | 913 lines

;************************************************* ;** Macros ** ;** © 1990,93,96 THOR-Software inc. ** ;** Version 1.17 23th July 1996 ** ;**---------------------------------------------** ;** This is a package of useful macros for the ** ;** DevPac assembler ** ;** feel free to strip the comments ** ;** but leave every comments marked with an ** ;** asterisk (*) because they are printed ** ;** as error messages if something's getting ** ;** wrong ** ;************************************************* ;************************************************* ;** Global arguments ** ;**---------------------------------------------** ;** If you define a label named ** ;** SHORTSTACK ** ;** the stack gets only word aligned instead of ** ;** long aligned. ** ;** This takes less stack space, but slows the ** ;** code for the MC'20 and higher processors ** ;** somewhat down. ** ;************************************************* ;************************************************* ;** Some useful macros for modifying the ** ;** condition codes in 6502 style ** ;************************************************* sec Macro ;set carry ori #$01,ccr Endm clc Macro ;clear carry andi #$fe,ccr Endm sez Macro ;set zero ori #$04,ccr Endm clz Macro ;clear zero andi #$fb,ccr Endm sen Macro ;set negative ori #$08,ccr Endm cln Macro ;clear negative andi #$f7,ccr Endm noz Macro ;invert zero eor #$04,ccr EndM sev Macro ;set overflow ori #$02,ccr Endm clv Macro ;clear overflow andi #$fd,ccr Endm clx Macro ;clear X andi #$ef,ccr Endm sex Macro ;set X ori #$10,ccr EndM ;************************************************* ;** the next lines clear internal counters ** ;** do not touch them ** ;************************************************* _sc set 0 ;the stack counter _rc set 0 ;counter for registers _re set 0 ;level counter for registers _fc set 0 ;counter for loops _fe set 0 ;level counter for loops _pc set 0 ;parameter counter for C style functions _pe set 0 ;level counter for C style functions _pm set 0 ;counts removed parameters _bs set 0 ;space taken by global static variables ;************************************************* ;** some macros for stack management ** ;** mainly internal use ** ;** but also register framing ** ;************************************************* ifd __G2 ;this works only for DevPac 2 and better reserve Macro ;reserve room on the stack iflt \1 fail ;(*) argument must be greater than zero mexit endc ifd SHORTSTACK _si\<_sc> set (\1+((\1)&1)) elseif _si\<_sc> set ((\1+3)&-4) endc ifne \1 ifle _si\<_sc>-8 subq.l #_si\<_sc>,a7 elseif lea -_si\<_sc>(a7),a7 endc endc _sc set _sc+1 Endm ;Example: ; reserve 100 ; Reserve 100 bytes of stack space, relative to a7. ; address it with dist(a7), dist is positive ; restore Macro ;restore stack space ifle _sc fail ;(*) illegal nesting mexit endc _sc set _sc-1 ifne _si\<_sc> ifle _si\<_sc>-8 addq.l #_si\<_sc>,a7 elseif lea _si\<_sc>(a7),a7 endc endc EndM ;Example: ; reserve 100 reserve stack space ; .... ; restore restore stack ; ; reserve and restore nest, btw extend Macro ;Extend the memory allocated with "reserve" by n bytes ifle _sc fail mexit ;(*) nest failure: "reserve" missing endc ifd SHORTSTACK _si\<_sc> set (\1+((\1)&1)) elseif _si\<_sc> set ((\1+3)&-4) endc ifle _si\<_sc>-8 subq.l #_si\<_sc>,a7 elseif lea -_si\<_sc>(a7),a7 endc _sh set _sc-1 _si\<_sh> set _si\<_sh>+_si\<_sc> EndM ;Example: ; reserve 100 allocate 100 bytes ; extend 50 allocate another 50 bytes in the same stack frame, so get 150 ; restore give 100+50 bytes back shrink Macro ;shrink the stack space by n bytes, opposide to extend ifle _sc fail ;(*) nest failure: reserve missing mexit endc ifd SHORTSTACK _si\<_sc> set (\1+((\1)&1)) elseif _si\<_sc> set ((\1+3)&-4) endc ifle _si\<_sc>-8 addq.l #_si\<_sc>,a7 elseif lea _si\<_sc>(a7),a7 endc _sh set _sc-1 _si\<_sh> set _si\<_sh>-_si\<_sc> iflt _si\<_sh> fail ;(*) shrink out of range mexit endc EndM ;Example: ; reserve 100 reserve 100 bytes ; extend 50 get another 50 bytes in the same frame ; shrink 75 give 75 bytes back ; restore give the remaining 75 bytes back _lastget Macro ;internal macro for stack relative addressing ifne _sh-_sc _sj set _sj+_si\<_sh> _sh set _sh+1 _lastget endc EndM loadbase Macro ;get base address of a previously loaded stack frame iflt \1 fail ;(*) out of range mexit endc _sh set _sc-\1 iflt _sh fail ;(*) nest failure: reserve missing mexit endc _sj set 0 _lastget lea _sj(a7),\2 EndM ;Example: ; reserve 100 ; reserve 50 ; loadbase 1,a6 load base address of the first stack frame into a6 ; a6 is now relative to the 100 bytes, ; a7 to the 50 bytes ; restore ; restore give everything back saveregs Macro ;save registers to the stack _rc set _rc+1 ;unique id _re set _re+1 ;counts levels _rn\<_re> set _rc ;level->number _ri\<_rc> reg \1 movem.l \1,-(sp) EndM ;Example: ; saveregs d2-d3/a2-a3/a6 ; ; Unlike the usual macros, this call DOES nest! ; ; loadregs Macro ;load macros from the stack ifle _re fail ;(*) nest failure: saveregs missing mexit endc _rt set _rn\<_re> movem.l (sp)+,_ri\<_rt> _re set _re-1 EndM ;Example: ; saveregs d2-d3/a2-a3/a6 ; ... ; saveregs d2-d4 yes, this NESTS! ; ... ; loadregs reload the first set ; ... ; loadregs reload the second set ;************************************************* ;** Automatic loop support ** ;** do/while loops & for/next loops ** ;************************************************* for Macro ;a popular for next loop, counts downwards in words _fc set _fc+1 ;unique id _fe set _fe+1 ;level counter _fn\<_fe> set _fc ;level to number ifc '','\1' ;without parameters bra.\0 ._fi\<_fc>_loop elseif move.\0 \1-1,\2 ;(*) only immediate adressing endc ._fi\<_fc>_do: EndM ;Examples ; for start of the loop, counter already loaded ; zero is a legal counter value, the body isn't ; executed then ; for.s start of the loop, short loop, counter already loaded ; ; for.l #9,d0 start loop, load counter (9 loops here) ; this one gets optimized (one branch less) ; but allows only immediate addressing to ; load the counter register (d0 here) ; next Macro ;end of the loop ifle _fe fail ;(*) nest failure: for missing mexit endc _ft set _fn\<_fe> ._fi\<_ft>_loop: ifc '','\1' fail ;(*) counter register missing mexit endc ifc '','\2' ._fi\<_ft>_cont: dbra \1,._fi\<_ft>_do elseif ;(*) cont invalid with condition db\1 \2,._fi\<_ft>_do endc ._fi\<_ft>_exit: _fe set _fe-1 EndM ;Examples ; next d0 end of a for loop with counter register d0 ; next eq,d0 end of a loop, terminate the loop if eq OR ; counted down to zero ; ;Full example: ; for.l #12,d0 ; clr.l (a0)+ ; next d0 clears 12 adjacent long words ; all labels are generated by the macro set ; ; remember, all this looping stuff NESTS! break Macro ;terminates a for or do loop immediately, jumps behind the final comand ifle _fe fail ;(*) break not in a loop body mexit endc _ft set _fn\<_fe> ifc '','\1' ;without condition bra.\0 ._fi\<_ft>_exit elseif b\1.\0 ._fi\<_ft>_exit endc EndM ;Examples ; for.l #9,d0 ; ... ; break terminate loop now ; ; next d0 ; ; break.s break, short distances ; break.s eq break if the eq flag is set ; cont Macro ;continue with the next iteration ifle _fe fail ;(*) cont not in a loop body mexit endc _ft set _fn\<_fe> ifc '','\1' ;without condition bra.\0 ._fi\<_ft>_cont ;(*) cont impossible with next & condition elseif b\1.\0 ._fi\<_ft>_cont ;(*) cont impossible with next & condition endc EndM ;Examples ; ; for.l #8,d0 ; ... ; cont.s eq next iteration if Z flag is set ; ... ; next d0 end of loop ; reloop Macro ;redo looping ifle _fe fail ;(*) reloop not in a loop body mexit endc _ft set _fn\<_fe> ifc '','\1' ;without condition bra.\0 ._fi\<_ft>_do elseif b\1.\0 ._fi\<_ft>_do endc EndM ;Examples ; ; reloop rerun this iteration ; reloop.s rerun, short jump ; reloop.s cc rerun if the carry flag is cleared ; ; The difference between reloop and cont is that cont starts ; the next iteration of a loop (so, the counter is decremented) ; while reloops reruns the loop again with the old counter ; there is NO difference between reloop and cont for do/while ; style loops do Macro ;start of a loop, execute it at least once _fc set _fc+1 ;increment id _fe set _fe+1 ;level counter _fn\<_fe> set _fc ;level->number ._fi\<_fc>_do: ._fi\<_fc>_cont: EndM repeat Macro ;start a loop, possibly no execution at all _fc set _fc+1 ;increment id _fe set _fe+1 ;level counter _fn\<_fe> set _fc ;level->number bra.\0 ._fi\<_fc>_loop ;jump to the end of the loop ._fi\<_fc>_do: ._fi\<_fc>_cont: EndM while Macro ;end of a loop ifle _fe fail ;(*) nest failure: No loop started mexit endc _ft set _fn\<_fe> ._fi\<_ft>_loop: b\1.\0 ._fi\<_ft>_do ._fi\<_ft>_exit: _fe set _fe-1 EndM loop Macro while.\0 ra EndM ;Examples: ; do start a loop.... ; ... ; while.s eq as long as the Z flag is set, short loop ; ;Full example: Travese an exec style list ; ; lea lh_Head(a2),a0 ;get head node ; do ; move.l (a0),a0 ;get first node ; tst.l (a0) ;test if this is a real node or the end ; break.s eq ;abort if end of list reached ; ; ... ;do something with the node ; loop.s ;continue operation ; ; ; repeat.s ;short jump ; ... ; while.s eq ;quite the same as the first example ; ;but checks the condition first before ; ;the loop is entered. A set Z flag ; ;will never enter the loop ;************************************************* ;** String macros ** ;** implementations of some standard C functions** ;************************************************* smove Macro ;copy one string to another, like strcpy ifne NARG-2 fail ;(*) only two arguments endc ._sm\@: move.b (\1)+,(\2)+ bne.s ._sm\@ EndM ;Examples ; smove a0,a1 ;copy string *a0 to string *a1 ; strlen Macro ;get the length of a string, excluding the NUL ifne NARG-2 fail ;(*) only two arguments mexit endc move.l \1,\2 ._sl\@: tst.b (\1)+ bne.s ._sl\@ sub.l \1,\2 not.l \2 Endm ;Examples ; strlen a0,d0 ;get the length of the string *a0 is ; ;pointing to and store it in d0 ; ;*a0 points afterwards behind the NUL ; ;byte ;************************************************* ;** Calling C style functions with ** ;** arguments on the stack ** ;************************************************* _putarg Macro ;internal use macro, writes one argument ifgt \1 _pm set 1 ;get one parameter ifnc '','\2' ;hier: parameter present ifc '.l','\2' _pm set 2 ;explicit size: longword _pc set _pc+4 endc ifc '.w','\2' _pm set 2 ;explicit size: word _pc set _pc+2 endc ifc '.b','\2' _pm set 2 ;explicit size: byte _pc set _pc+2 ;a byte takes REALLY two bytes of stack! endc ifeq _pm-2 ifc '\3','' fail ;parameter missing mexit endc move\2 \3,-(sp) ;write it to the stack elseif ifne _fl move.l \2,-(sp) ;default long _pc set _pc+4 elseif move.w \2,-(sp) ;default word _pc set _pc+2 endc endc endc _pe set \1-_pm ;now call this stuff recursively ifeq _pm-2 _putarg \<_pe>,\4,\5,\6,\7,\8,\9,\A,\B,\C,\D,\E,\F,\G,\H,\I,\J elseif _putarg \<_pe>,\3,\4,\5,\6,\7,\8,\9,\A,\B,\C,\D,\E,\F,\G,\H,\I,\J endc endc endm bcr Macro ;call a C style function, use BSR _pc set 0 _fl set 0 _putarg 18,\J,\I,\H,\G,\F,\E,\D,\C,\B,\A,\9,\8,\7,\6,\5,\4,\3,\2 bsr.\0 \1 ifne _pc lea _pc(a7),a7 endc EndM jcr Macro ;call a C style function, use JSR _pc set 0 _fl set 0 _putarg 18,\J,\I,\H,\G,\F,\E,\D,\C,\B,\A,\9,\8,\7,\6,\5,\4,\3,\2 jsr \1 ifne _pc lea _pc(a7),a7 endc EndM jtags Macro ;a tag based library call with the tags as arguments _pc set 4 _fl set 1 clr.l -(a7) ;TAG_END _putarg 17,\J,\I,\H,\G,\F,\E,\D,\C,\B,\A,\9,\8,\7,\6,\5,\4,\3 move.l a7,\2 jsr \1 lea _pc(a7),a7 EndM ;Examples: ; jcr Handler,.l,#0,IO(a1) ; call the handler functions with long arguments, ; zero and the contents of IO(a1) ; put these arguments on the stack and free the stack ; afterwards ; ; bcr.s TempFree,.l,a1,a5,.b,#0,.l,ExecBase ; call the TempFree function with long arguments a1,a5 ; one byte argument #0 and a long argument ExecBase ; ; all sizes default to word except for the tag based calls, ; where the size defaults to long. ; types must be given PRIOR to the arguments ;************************************************* ;** More tag call support ** ;** (different style) ** ;************************************************* deftag Macro ;start of a tag call _pc set 4 clr.l -(a7) ;TAG_END EndM tag Macro ;place a tag on the stack move.l \2,-(sp) ;(*) illegal tag data move.l #\1,-(sp) ;(*) illegal tag _pc set _pc+8 EndM itag Macro ;place an indirect tag on the stack move.l \2,-(sp) ;(*) illegal tag data move.l \1,-(sp) ;(*) illegal tag _pc set _pc+8 EndM endtag Macro ;end of a tag call and the call itself move.l a7,\2 jsr \1 lea _pc(a7),a7 endM ;Examples: ; deftag ; tag TAG_Width,#320 ; tag TAG_Height,#200 ; endtag OpenWindwoTagList(a6),a0 ; ; the first paratemter to the tag macro is the type of the ; tag, the second its value. ; The endtag macro takes two arguments as well, the ; tag function and the parameter where the tag list has to ; be provided ; ; The tag call expects an immediate number as its first parameter ; whereas the itag call accepts any legal data, so registers are ; valid here, too. ;************************************************* ;** More macros for C-style functions ** ;** this time the function header itself ** ;************************************************* defarg Macro ;start of the argument description rsreset _sh set 0 _sj set 0 _lastget rs.l 1 ;reserve one long for the PC ifnc '','\1' rs.l \1 ;supply number of saved registers here endc rs.b _sj ;room reserved for auto variables EndM arg Macro ;get the name of one argument ifc '','\0' \1 rs.w 1 elseif \1 rs.\0 1 ifc 'b','\0' rs.b 1 endc endc EndM endarg Macro ;end of the argument list EndM ;Examples for argument descriptions ; saveregs d2-d3/a2 ; defarg 3 start of the arguments, three registers saved ; arg buffer one word, gets the name buffer ; arg.l code one longword ; arg.w len one word ; arg.b char one byte ; endarg ; ; move.l code(a7),d0 get the argument ; ;************************************************* ;** The next one is pretty handy: ** ;** variable definions for assembly language ** ;** in case you run out of registers ** ;** the variables are taken from the stack ** ;** and require the stack macros from above ** ;************************************************* defvar Macro ;start of the variable list rsreset EndM auto Macro ;define one auto (stack) variable, take it from the stack ifc '','\2' \1 rs.\0 1 elseif \1 rs.\0 \2 endc EndM static Macro ;define a static (BSS) variable ifc '','\2' _bc set 1 elseif _bc set \2 endc _bz set 0 ifc 'l','\0' _bs set (_bs+1)&$fffffffe _bz set 4 endc ifc 'w','\0' _bs set (_bs+1)&$fffffffe _bz set 2 endc ifc 'b','\0' _bz set 1 endc ifeq _bz fail ;(*) illegal data size mexit endc \1 =_bs _bs set _bs+(_bc*_bz) EndM extern Macro ;define an external variable xref \1 EndM register Macro ;define a register variable \1 equr \2 EndM endvar Macro ;end of the variable list ._vl\@ rs.b 0 reserve ._vl\@ EndM freevar Macro ;free stack space allocated by variables restore EndM staticspace Macro ds.b _bs ;reserve space for static variables EndM ;should be called only once in the program ;or you're wasting space ;One example definition of a function that uses auto variables ;Foo: ; saveregs d2-d3/a2 save local registers ; defvar start of variable definitions ; auto.w count ;a counter ; auto.l help,4 ;four longs ; auto.b char ;one character ; auto.l inc ;one long ; static.l save ;one static variable ; register.w cinc,d0 ;a register variable ; endvar ;that's it! ; ; move.l d0,inc(a7) ;set the inc-variable ; move.w d1,count(a7) ;set count ; do ; ... ; add.l inc(a7),d2 ;increment d2 ; while.s cc ;as long as no overflow ; ... ; freevar ;free variables ; loadregs ;get registers ; rts ; ; One note: Variable names are (sorry to say that, but such is life) ; GLOBAL to the module. You've to invent some unique names for ; them. A popular choice is to use a shortcut of the procedure name ; and an underscore, like "foo_inc" instead of "inc" endc ;the remaining stuff is valid for all assemblers ;************************************************* ;** longword bit field addressing ** ;** for adress-register indirect ** ;** maybe very special, but I need them ** ;************************************************* btstm Macro ;test one bit in a longword btst #(\1)&$7,(3^((\1)>>3))+\2 Endm bclrm Macro ;clear one bit in a longword bclr #(\1)&$7,(3^((\1)>>3))+\2 Endm bsetm Macro ;set one bit in a longword bset #(\1)&$7,(3^((\1)>>3))+\2 Endm bchgm Macro ;change one bit in a longword bchg #(\1)&$7,(3^((\1)>>3))+\2 Endm bnegm Macro ;like btstm, but returns the inverted result btst #(\1)&$7,(3^((\1)>>3))+\2 noz Endm ;Examples: ; btstm cn_Test,cn_Flags(a5) ; test the bit named "cn_Test" in the long word bit field ; cn_Flags(a5) ; The MSB of byte 0 is bit 31, the LSB of byte 3 is bit 0 ; ;************************************************* ;** List support macros ** ;** partially stolen from exec/nodes.i ** ;************************************************* NewList Macro ;Initialize a list. Much shorter than a function call move.l \1,8(\1) addq.l #4,\1 clr.l (\1) move.l \1,-(\1) endm ;provide an address register as argument that points to the list structure ;The next macros take the same arguments as the exec functions of the ;same names, so mostly *a1 for the node pointer and *a0 for the ;list pointer. There's currently no way of using other registers ;even though the modification would be trivial AddHead Macro ;add node *a1 to the top of list *a0 MOVE.L (A0),D0 MOVE.L A1,(A0) MOVEM.L D0/A0,(A1) MOVE.L D0,A0 MOVE.L A1,4(A0) ENDM AddTail Macro ;add node *a1 at the end of list *a0 ADDQ.L #4,A0 MOVE.L 4(A0),D0 MOVE.L A1,4(A0) EXG D0,A0 MOVEM.L D0/A0,(A1) MOVE.L A1,(A0) ENDM Remove Macro ;remove node *a1 from a list MOVE.L (A1)+,A0 MOVE.L (A1),A1 MOVE.L A0,(A1) MOVE.L A1,4(A0) ENDM RemHead Macro ;remove the head of a list, return ptr in d0 MOVE.L (A0),A1 MOVE.L (A1),D0 BEQ.S .__remhead\@ MOVE.L D0,(A0) EXG.L D0,A1 MOVE.L A0,4(A1) .__remhead\@: ENDM RemTail Macro ;remove the tail of a list, return ptr in d0 MOVE.L 8(A0),A1 MOVE.L 4(A1),D0 BEQ.S .__remtail\@ MOVE.L D0,8(A0) EXG.L D0,A1 MOVE.L A0,(A1) ADDQ.L #4,(A1) .__remtail\@: ENDM InsertAfter Macro ;insert node *a1 behind node *a0, no special cases, *a0 must be a valid node move.l (a0),d0 movem.l d0/a0,(a1) move.l a1,(a0) move.l d0,a0 move.l a1,4(a0) EndM InsertBefore Macro ;insert node *a1 in front of *a0, no special cases, *a0 must be a valid node move.l 4(a0),d0 move.l a1,4(a0) exg.l a0,d0 movem.l d0/a0,(a1) move.l a1,(a0) EndM ;That's all folks!