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Text File  |  1995-08-29  |  19KB  |  699 lines
  1. ;[]-----------------------------------------------------------------[]
  2. ;|      RULES.ASI  --  Rules & Structures for assembler              |
  3. ;[]-----------------------------------------------------------------[]
  4.  
  5. ;
  6. ;       C/C++ Run Time Library - Version 6.5
  7. ; 
  8. ;       Copyright (c) 1987, 1994 by Borland International
  9. ;       All Rights Reserved.
  10. ; 
  11.  
  12. ;*** First we begin with a few of the major constants of C.
  13.  
  14. false   equ     0       ; Beware !  For incoming parameters, non-false = true.
  15. true    equ     1       ; For results, we generate the proper numbers.
  16.  
  17. lesser  equ    -1       ; Incoming, lesser < 0
  18. equal   equ     0
  19. greater equ     1       ; Incoming, greater > 0
  20.  
  21.         PAGE
  22. ;[]------------------------------------------------------------[]
  23. ;|                                                              |
  24. ;|      Conditional Assembly Directives                         |
  25. ;|                                                              |
  26. ;[]------------------------------------------------------------[]
  27.  
  28. ;memory model aliases, for the convenience of building the library
  29.  
  30. IFDEF           __t__
  31. __TINY__        equ     1
  32. ENDIF
  33.  
  34. IFDEF           __s__
  35. __SMALL__       equ     1
  36. ENDIF
  37.  
  38. IFDEF           __c__
  39. __COMPACT__     equ     1
  40. ENDIF
  41.  
  42. IFDEF           __m__
  43. __MEDIUM__      equ     1
  44. ENDIF
  45.  
  46. IFDEF           __l__
  47. __LARGE__       equ     1
  48. ENDIF
  49.  
  50. IFDEF           __h__
  51. __HUGE__        equ     1
  52. ENDIF
  53.  
  54. IFNDEF __TINY__
  55.     IFNDEF __SMALL__
  56.         IFNDEF __MEDIUM__
  57.             IFNDEF __COMPACT__
  58.                 IFNDEF __LARGE__
  59.                     IFNDEF __HUGE__
  60.                         %OUT  You must supply a model symbol.
  61.                         .ERR
  62.                     ENDIF
  63.                 ENDIF
  64.             ENDIF
  65.         ENDIF
  66.     ENDIF
  67. ENDIF
  68.  
  69. ;bit masks to extract default pointer types from MMODEL (at run-time)
  70. FCODE           equ     8000h
  71. FDATA           equ     4000h
  72.  
  73. IFDEF   __TINY__                ; Small Code - Small Data
  74.         LPROG           equ     false
  75.         LDATA           equ     false
  76.         MMODEL          equ     0
  77.         _DSSTACK_       equ     <>
  78. ENDIF
  79.  
  80. IFDEF   __SMALL__               ; Small Code - Small Data
  81.         LPROG           equ     false
  82.         LDATA           equ     false
  83.         MMODEL          equ     1
  84.         _DSSTACK_       equ     <>
  85. ENDIF
  86.  
  87. IFDEF   __MEDIUM__              ; Large Code - Small Data
  88.         LPROG           equ     true
  89.         LDATA           equ     false
  90.         MMODEL          equ     FCODE+2
  91.         _DSSTACK_       equ     <>
  92. ENDIF
  93.  
  94. IFDEF   __COMPACT__             ; Small Code - Large Data
  95.         LPROG           equ     false
  96.         LDATA           equ     true
  97.         MMODEL          equ     FDATA+3
  98. ENDIF
  99.  
  100. IFDEF   __LARGE__               ; Large Code - Large Data
  101.         LPROG           equ     true
  102.         LDATA           equ     true
  103.         MMODEL          equ     FCODE+FDATA+4
  104. ENDIF
  105.  
  106. IFDEF   __HUGE__                ; Large Code - Large Data
  107.         LPROG           equ     true
  108.         LDATA           equ     true
  109.         MMODEL          equ     FCODE+FDATA+5
  110. ENDIF
  111.  
  112. IF      LPROG
  113.         DIST            equ     FAR
  114. ELSE
  115.         DIST            equ     NEAR
  116. ENDIF
  117.  
  118.         PAGE
  119. ;[]------------------------------------------------------------[]
  120. ;|                                                              |
  121. ;|      Segment Declarations Macros                             |
  122. ;|                                                              |
  123. ;[]------------------------------------------------------------[]
  124.  
  125. Code_Seg@       MACRO           ;; Open a Code Segment
  126. IFDEF __WINDOWS__
  127. _TEXT   SEGMENT WORD PUBLIC 'CODE'
  128. ELSE
  129. _TEXT   SEGMENT BYTE PUBLIC 'CODE'
  130. ENDIF
  131.         ASSUME  CS:_TEXT
  132.                 ENDM
  133.  
  134. Code_EndS@      MACRO           ;; Close a Code Segment
  135. _TEXT   ENDS
  136.                 ENDM
  137.  
  138. Data_Seg@       MACRO           ;; Open a Data Segment  (initialized)
  139. _DATA   SEGMENT WORD PUBLIC 'DATA'
  140.                 ENDM
  141.  
  142. Data_EndS@      MACRO           ;; Close a Data Segment (initialized)
  143. _DATA   ENDS
  144.                 ENDM
  145.  
  146. IFNDEF __HUGE__
  147.     BSS_Seg@        MACRO       ;; Open a Data Segment  (un-initialized)
  148.     _BSS    SEGMENT WORD PUBLIC 'BSS'
  149.             ENDM
  150.  
  151.     BSS_EndS@       MACRO       ;; Close a Data Segment (un-initialized)
  152.     _BSS    ENDS
  153.                     ENDM
  154. ENDIF
  155.  
  156. FarData_Seg@    MACRO           ;; Open a FAR Data Segment
  157. _FARDATA        SEGMENT PARA PUBLIC 'FAR_DATA'
  158.                 ENDM
  159.  
  160. FarData_EndS@   MACRO           ;; Close a FAR Data Segment
  161. _FARDATA        ENDS
  162.                 ENDM
  163.  
  164. FarBSS_Seg@     MACRO           ;; Open a FAR BSS Segment
  165. _FARBSS         SEGMENT PARA PUBLIC 'FAR_BSS'
  166.                 ENDM
  167.  
  168. FarBSS_EndS@    MACRO           ;; Close a FAR BSS Segment
  169. _FARBSS         ENDS
  170.                 ENDM
  171.  
  172. Const_Seg@      MACRO           ;; Open a CONST Segment
  173. _CONST  SEGMENT WORD PUBLIC 'CONST'
  174.                 ENDM
  175.  
  176. Const_EndS@     MACRO           ;; Close a CONST Segment
  177. _CONST  ENDS
  178.                 ENDM
  179.  
  180. Init_Seg@       MACRO           ;; Open a INIT Segment
  181. _INIT_  SEGMENT WORD PUBLIC 'INITDATA'
  182.                 ENDM
  183.  
  184. Init_EndS@      MACRO           ;; Close a INIT Segment
  185. _INIT_  ENDS
  186.                 ENDM
  187.  
  188. Exit_Seg@       MACRO           ;; Open a EXIT Segment
  189. _EXIT_  SEGMENT WORD PUBLIC 'EXITDATA'
  190.                 ENDM
  191.  
  192. Exit_EndS@      MACRO           ;; Close a EXIT Segment
  193. _EXIT_  ENDS
  194.                 ENDM
  195.  
  196. CVT_Seg@        MACRO
  197. _CVTSEG SEGMENT WORD PUBLIC 'DATA'
  198.                 ENDM
  199.  
  200. CVT_EndS@       MACRO
  201. _CVTSEG ENDS
  202.                 ENDM
  203.  
  204. SCN_Seg@        MACRO
  205. _SCNSEG SEGMENT WORD PUBLIC 'DATA'
  206.                 ENDM
  207.  
  208. SCN_EndS@       MACRO
  209. _SCNSEG ENDS
  210.                 ENDM
  211.  
  212. Header@ MACRO
  213. Code_Seg@
  214. Code_EndS@
  215. Data_Seg@
  216. Data_EndS@
  217. BSS_Seg@
  218. BSS_EndS@
  219.         ASSUME  CS:_TEXT, DS:DGROUP
  220.         ENDM
  221.  
  222. ;[]------------------------------------------------------------[]
  223. ;|                                                              |
  224. ;|      Segment Definitions                                     |
  225. ;|                                                              |
  226. ;[]------------------------------------------------------------[]
  227.  
  228. IFDEF __C0__
  229.  
  230. IFDEF __WINDOWS__
  231. _TEXT           SEGMENT WORD PUBLIC 'CODE'
  232.                 ENDS
  233. ELSE
  234. _TEXT           SEGMENT BYTE PUBLIC 'CODE'
  235.                 ENDS
  236. ENDIF
  237.  
  238. _FARDATA        SEGMENT PARA PUBLIC 'FAR_DATA'
  239.                 ENDS
  240.  
  241. _FARBSS         SEGMENT PARA PUBLIC 'FAR_BSS'
  242.                 ENDS
  243.  
  244. IFNDEF __WINDOWS__
  245.   IFNDEF __TINY__
  246.   _OVERLAY_       SEGMENT PARA PUBLIC 'OVRINFO'
  247.                   ENDS
  248.   _1STUB_         SEGMENT PARA PUBLIC 'STUBSEG'
  249.                   ENDS
  250.   ENDIF
  251. ENDIF
  252.  
  253. IFDEF __WINDOWS__
  254. NULL            SEGMENT PARA PUBLIC 'BEGDATA'
  255.                 ENDS
  256. ENDIF
  257.  
  258. _DATA           SEGMENT PARA PUBLIC 'DATA'
  259.                 ENDS
  260.                 ENDS
  261.  
  262. _CONST          SEGMENT WORD PUBLIC 'CONST'
  263.                 ENDS
  264.  
  265. IFDEF __WINDOWS__
  266. _FPSEG          SEGMENT WORD PUBLIC 'DATA'
  267.                 ENDS
  268. ENDIF
  269.  
  270. _CVTSEG         SEGMENT WORD PUBLIC 'DATA'
  271.                 ENDS
  272.  
  273. _SCNSEG         SEGMENT WORD PUBLIC 'DATA'
  274.                 ENDS
  275.  
  276. _INIT_          SEGMENT WORD PUBLIC 'INITDATA'
  277. InitStart       label byte
  278.                 ENDS
  279. _INITEND_       SEGMENT BYTE PUBLIC 'INITDATA'
  280. InitEnd         label byte
  281.                 ENDS
  282.  
  283. _EXIT_          SEGMENT WORD PUBLIC 'EXITDATA'
  284. ExitStart       label byte
  285.                 ENDS
  286. _EXITEND_       SEGMENT BYTE PUBLIC 'EXITDATA'
  287. ExitEnd         label byte
  288.                 ENDS
  289.  
  290. IFNDEF __HUGE__
  291. _BSS          SEGMENT WORD PUBLIC 'BSS'
  292. BeginBSS      label byte
  293.               ENDS
  294. _BSSEND       SEGMENT BYTE PUBLIC 'BSSEND'
  295. EndBSS        label byte
  296.               ENDS
  297. ENDIF
  298.  
  299.  
  300. IFDEF __WINDOWS__
  301.  
  302.   IFDEF  __HUGE__
  303.   DGROUP GROUP NULL,_DATA,_CONST,_FPSEG,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_
  304.   ELSE
  305.   DGROUP GROUP NULL,_DATA,_CONST,_FPSEG,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_,_BSS,_BSSEND
  306.   ENDIF
  307.  
  308. ELSE
  309.  
  310. IFNDEF __NOFLOAT__
  311.   IF LDATA
  312.     IFDEF  __HUGE__
  313.       DGROUP GROUP _DATA,_CONST,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_
  314.     ELSE
  315.       DGROUP GROUP _DATA,_CONST,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_,_BSS,_BSSEND
  316.     ENDIF
  317.   ELSE
  318.     IFDEF __TINY__
  319.       DGROUP GROUP _TEXT,_DATA,_CONST,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_,_BSS,_BSSEND
  320.     ELSE
  321.       DGROUP GROUP _DATA,_CONST,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_,_BSS,_BSSEND
  322.     ENDIF
  323.   ENDIF
  324. ELSE
  325.   IF LDATA
  326.     IFDEF __HUGE__
  327.       DGROUP GROUP _DATA,_CONST,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_
  328.     ELSE
  329.       DGROUP GROUP _DATA,_CONST,_CVTSEG,_SCNSEG,_BSS,_BSSEND
  330.     ENDIF
  331.   ELSE
  332.     IFDEF __TINY__
  333.       DGROUP GROUP _TEXT,_DATA,_CONST,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_,_BSS,_BSSEND
  334.     ELSE
  335.       DGROUP GROUP _DATA,_CONST,_CVTSEG,_SCNSEG,_INIT_,_INITEND_,_EXIT_,_EXITEND_,_BSS,_BSSEND
  336.     ENDIF
  337.   ENDIF
  338. ENDIF ; __NOFLOAT__
  339.  
  340. ENDIF ; __WINDOWS__
  341.  
  342. ELSE
  343.  
  344. Code_Seg@
  345. Code_EndS@
  346. Data_Seg@
  347. Data_EndS@
  348. DGROUP GROUP _DATA
  349.  
  350. ENDIF ; __C0__
  351.  
  352.         PAGE
  353. ;[]------------------------------------------------------------[]
  354. ;|                                                              |
  355. ;|      Old Segment Declarations Macros                         |
  356. ;|                                                              |
  357. ;[]------------------------------------------------------------[]
  358.  
  359.  
  360. CSeg@           MACRO           ;; Open a Code Segment
  361. IFDEF __WINDOWS__
  362. _TEXT   SEGMENT WORD PUBLIC 'CODE'
  363. ELSE
  364. _TEXT   SEGMENT BYTE PUBLIC 'CODE'
  365. ENDIF
  366.         ASSUME  CS:_TEXT
  367.                 ENDM
  368.  
  369. CSegEnd@        MACRO           ;; Close a Code Segment
  370. _TEXT   ENDS
  371.                 ENDM
  372.  
  373. DSeg@           MACRO           ;; Open a Data Segment  (initialized)
  374. _DATA   SEGMENT WORD PUBLIC 'DATA'
  375.                 ENDM
  376.  
  377. DSegEnd@        MACRO           ;; Close a Data Segment (initialized)
  378. _DATA   ENDS
  379.                 ENDM
  380.  
  381. IFDEF __BSS__
  382.     IFNDEF __HUGE__
  383.         BSeg@           MACRO           ;; Open a Data Segment  (un-initialized)
  384.         _BSS    SEGMENT WORD PUBLIC 'BSS'
  385.                 ENDM
  386.  
  387.         BSegEnd@        MACRO           ;; Close a Data Segment (un-initialized)
  388.         _BSS    ENDS
  389.                         ENDM
  390.     ENDIF
  391. ENDIF
  392.  
  393. Header@ MACRO
  394. IFDEF __WINDOWS__
  395. _TEXT   SEGMENT WORD PUBLIC 'CODE'
  396. ELSE
  397. _TEXT   SEGMENT BYTE PUBLIC 'CODE'
  398. ENDIF
  399. _TEXT   ENDS
  400. _DATA   SEGMENT WORD PUBLIC 'DATA'
  401. _DATA   ENDS
  402. IFDEF __BSS__
  403.     IFNDEF  __HUGE__
  404.         _BSS    SEGMENT WORD PUBLIC 'BSS'
  405.         _BSS    ENDS
  406.     ENDIF
  407. ENDIF
  408.  
  409.         ASSUME  CS:_TEXT, DS:DGROUP
  410.         ENDM
  411.  
  412.         PAGE
  413. ;[]------------------------------------------------------------[]
  414. ;|                                                              |
  415. ;|      C Naming Convention Macros                              |
  416. ;|                                                              |
  417. ;[]------------------------------------------------------------[]
  418.  
  419. UNDERSCORE      EQU     1
  420.  
  421. ExtSym@ MACRO   Sym, sType, sName
  422.         IFNB    <sName>
  423.         IFIDN   <sName>, <__PASCAL__>
  424. NAMING      =       0
  425.         ELSE
  426. NAMING      =       UNDERSCORE
  427.         ENDIF
  428.         ENDIF
  429.         IF      NAMING
  430.         EXTRN   _&Sym : sType
  431. Sym&@   equ     _&Sym
  432.         ELSE
  433.         EXTRN   Sym : sType
  434. Sym&@   equ     Sym
  435.         ENDIF
  436.         ENDM
  437.  
  438. PubSym@ MACRO   Sym, Definition, sName
  439.         IFNB    <sName>
  440.         IFIDN   <sName>, <__PASCAL__>
  441. NAMING      =       0
  442.         ELSE
  443. NAMING      =       UNDERSCORE
  444.         ENDIF
  445.         ENDIF
  446.         IF      NAMING
  447.         PUBLIC  _&Sym
  448. _&Sym   Definition
  449. Sym&@   equ     _&Sym
  450.         ELSE
  451.         PUBLIC  Sym
  452. Sym     Definition
  453. Sym&@   equ     Sym
  454.         ENDIF
  455.         ENDM
  456.  
  457. Static@ MACRO   Sym, Definition, sName
  458.         IFNB    <sName>
  459.         IFIDN   <sName>, <__PASCAL__>
  460. NAMING      =       0
  461.         ELSE
  462. NAMING      =       UNDERSCORE
  463.         ENDIF
  464.         ENDIF
  465.         IF      NAMING
  466. _&Sym   Definition
  467. Sym&@   equ     _&Sym
  468.         ELSE
  469. Sym     Definition
  470. Sym&@   equ     Sym
  471.         ENDIF
  472.         ENDM
  473.  
  474.         PAGE
  475. ;[]------------------------------------------------------------[]
  476. ;|                                                              |
  477. ;|      Macros which are Data Size Dependent                    |
  478. ;|                                                              |
  479. ;[]------------------------------------------------------------[]
  480.  
  481. IF      LDATA
  482. DPTR_           equ     DWORD PTR
  483. dPtrSize        equ     4
  484. LES_            equ     LES
  485. ES_             equ     ES:
  486. SS_             equ     SS:
  487. LDS_            equ     LDS
  488.  
  489. pushDS_         MACRO
  490.                 PUSH    DS
  491.                 ENDM
  492.  
  493. popDS_          MACRO
  494.                 POP    DS
  495.                 ENDM
  496.  
  497. PushPtr         MACRO   dPtrOff, dPtrSeg
  498.                 PUSH    dPtrSeg
  499.                 PUSH    dPtrOff
  500.                 ENDM
  501.  
  502.  
  503. dPtr@           MACRO   Sym, VALUE, sName       ;; Static Data pointer
  504. Static@         Sym, <DD        VALUE>, sName
  505.                 ENDM
  506.  
  507. dPtrPub@        MACRO   Sym, VALUE, sName       ;; Global Data Pointer
  508. PubSym@         Sym, <DD        VALUE>, sName
  509.                 ENDM
  510.  
  511. dPtrExt@        MACRO   Sym, sName      ;; External Data Pointer
  512. ExtSym@         Sym, DWORD, sName
  513.                 ENDM
  514. ELSE
  515. DPTR_           equ     WORD PTR
  516. dPtrSize        equ     2
  517. LES_            equ     MOV
  518. ES_             equ     DS:
  519. SS_             equ     DS:
  520. LDS_            equ     MOV
  521.  
  522. pushDS_         MACRO
  523.                 ENDM
  524.  
  525. popDS_          MACRO
  526.                 ENDM
  527.  
  528. PushPtr         MACRO   dPtrOff, dPtrSeg
  529.                 PUSH    dPtrOff
  530.                 ENDM
  531.  
  532. dPtr@           MACRO   Sym, VALUE, sName       ;; Static Data pointer
  533. Static@         Sym, <DW        VALUE>, sName
  534.                 ENDM
  535.  
  536. dPtrPub@        MACRO   Sym, VALUE, sName       ;; Global Data Pointer
  537. PubSym@         Sym, <DW        VALUE>, sName
  538.                 ENDM
  539.  
  540. dPtrExt@        MACRO   Sym, sName      ;; External Data Pointer
  541. ExtSym@         Sym, WORD, sName
  542.                 ENDM
  543. ENDIF
  544.         PAGE
  545. ;[]------------------------------------------------------------[]
  546. ;|                                                              |
  547. ;|      Macros which are Code Size Dependent                    |
  548. ;|                                                              |
  549. ;[]------------------------------------------------------------[]
  550.  
  551. IF      LPROG
  552. CPTR_           equ     DWORD PTR
  553. cPtrSize        equ     4
  554.  
  555. Proc@           MACRO   Sym, sName      ;; Open a Static function
  556. Static@         Sym, <PROC      FAR>, sName
  557.                 ENDM
  558.  
  559. PubProc@        MACRO   Sym, sName      ;; Open a Public function
  560. PubSym@         Sym, <PROC      FAR>, sName
  561.                 ENDM
  562.  
  563. ExtProc@        MACRO   Sym, sName      ;; External Function
  564. ExtSym@         Sym, FAR, sName
  565.                 ENDM
  566.  
  567. cPtr@           MACRO   Sym, VALUE, sName       ;; Static Function pointer
  568. Static@         Sym, <DD        VALUE>, sName
  569.                 ENDM
  570.  
  571. cPtrPub@        MACRO   Sym, VALUE, sName;; Global Function Pointer
  572. PubSym@         Sym, <DD        VALUE>, sName
  573.                 ENDM
  574.  
  575. cPtrExt@        MACRO   Sym, sName      ;; External Function Pointer
  576. ExtSym@         Sym, DWORD, sName
  577.                 ENDM
  578. ELSE
  579. CPTR_           equ     WORD PTR
  580. cPtrSize        equ     2
  581.  
  582. Proc@           MACRO   Sym, sName      ;; Open a Static function
  583. Static@         Sym, <PROC      NEAR>, sName
  584.                 ENDM
  585.  
  586. PubProc@        MACRO   Sym, sName      ;; Open a Public function
  587. PubSym@         Sym, <PROC      NEAR>, sName
  588.                 ENDM
  589.  
  590. ExtProc@        MACRO   Sym, sName      ;; External Function
  591. ExtSym@         Sym, NEAR, sName
  592.                 ENDM
  593.  
  594. cPtr@           MACRO   Sym, VALUE, sName       ;; Static Function pointer
  595. Static@         Sym, <DW        VALUE>, sName
  596.                 ENDM
  597.  
  598. cPtrPub@        MACRO   Sym, VALUE, sName       ;; Global Function Pointer
  599. PubSym@         Sym, <DW        VALUE>, sName
  600.                 ENDM
  601.  
  602. cPtrExt@        MACRO   Sym, sName      ;; External Function Pointer
  603. ExtSym@         Sym, WORD, sName
  604.                 ENDM
  605. ENDIF
  606.  
  607. EndProc@        MACRO   Sym, sName      ;; Close a function
  608. Static@         Sym, ENDP, sName
  609.                 ENDM
  610.  
  611.         PAGE
  612. ;[]------------------------------------------------------------[]
  613. ;|                                                              |
  614. ;|      Miscellaneous Definitions                               |
  615. ;|                                                              |
  616. ;[]------------------------------------------------------------[]
  617.  
  618. ;*** Set up some macros for procedure parameters and export/import
  619.  
  620. nearCall        STRUC
  621. nearBP          dw      ?
  622. nearIP          dw      ?
  623. nearParam       dw      ?
  624. nearCall        ENDS
  625.  
  626. farCall         STRUC
  627. farBP           dw      ?
  628. farCSIP         dd      ?
  629. aParam          dw      ?
  630. farCall         ENDS
  631.  
  632. ;*** Next, we define some convenient structures to access the parts
  633. ;       of larger objects.
  634.  
  635. _twoBytes       STRUC
  636. BY0     db      ?
  637. BY1     db      ?
  638. _twoBytes       ENDS
  639.  
  640. _fourWords      STRUC
  641. W0      dw      ?
  642. W1      dw      ?
  643. W2      dw      ?
  644. W3      dw      ?
  645. _fourWords      ENDS
  646.  
  647. _twoDwords      STRUC
  648. DD0     dd      ?
  649. DD1     dd      ?
  650. _twoDwords      ENDS
  651.  
  652. _aFloat         STRUC
  653. double          dq      ?
  654. _aFloat         ENDS
  655.  
  656. ; How to invoke MSDOS.
  657.  
  658. MSDOS@  MACRO
  659.         int     21h
  660.         ENDM
  661.         PAGE
  662.  
  663. ; The next section concerns the use of registers.  SI and DI are used
  664. ;       for register variables, and must be conserved.
  665.  
  666. ; Registers AX, BX, CX, DX will not be preserved across function calls.
  667.  
  668. ; Firstly, the registers to be conserved through function calls, including
  669. ;       the setup of local variables.
  670.  
  671. link@   MACRO   _si,_di,_ES,locals
  672.         push    bp
  673.         mov     bp, sp
  674.         IFNB    <locals>
  675.                 lea     sp, locals
  676.         ENDIF
  677.         IFNB    <_si>
  678.                 push    si
  679.         ENDIF
  680.         IFNB    <_di>
  681.                 push    di
  682.         ENDIF
  683. ENDM
  684.  
  685. unLink@ MACRO   _si,_di,_ES,locals
  686.         IFNB    <_di>
  687.                 pop     di
  688.         ENDIF
  689.         IFNB    <_si>
  690.                 pop     si
  691.         ENDIF
  692.         IFNB    <locals>
  693.                 mov     sp, bp
  694.         ENDIF
  695.         pop     bp
  696. ENDM
  697.  
  698. .LIST
  699.