C++ Games Programming/CPPGAMES.ISO/digmid/real/prologue.mac

Text File | 1992-09-25 | 5KB | 269 lines

;; A header macro file that defines a lot of common useful macros when
;; programming in assembly.  Supports conditional assembly for taking
;; advantage of 80286 opcodes.

IS286    equ    0        ;; True if taking advantage of 80286 opcodes.

Macro     SETUPSEGMENT

SEGMENT _TEXT    PARA PUBLIC 'CODE'
    ASSUME    CS:_TEXT

    Endm

;; This macro replaces the LOOP instruction, because the loop instruction
;; is too damned slow on a 386/486
macro    CLOOP LABEL
    dec    cx
    jnz    LABEL
    endm

macro    CLODSB
    mov    al,[ds:si]
    inc    si
    endm

macro    CSTOSB
    mov    [es:di],al
    inc    di
    endm

macro    CLODSW
    mov    ax,[ds:si]
    add    si,2
    endm

macro    CSTOSW
    mov    [es:di],ax
    add    di,2
    endm


macro   ShiftR  REG,TIMES
;; 2 - shift a register right a number of times.
IF      IS286
        shr     REG,TIMES
ELSE
        REPT    TIMES
    shr    REG,1
        ENDM
ENDIF
        endm

macro   ShiftL  REG,TIMES
;; 3 - shift a register left a number of times
IF      IS286
        shl     REG,TIMES
ELSE
        REPT    TIMES
    shl    REG,1
        ENDM
ENDIF
        endm

macro    LSMUL
;; 4 - performs a long signed multiply AX,DX * BX,CX
    LOCAL    @@HOP1,@@HOP2
;; Long signed multiply
;; Long #1: AX,DX
;; Long #2: BX,CX
    push    si
    xchg    si,ax
    xchg    dx,ax
    or    ax,ax
    jz    @@HOP1
    mul    bx
@@HOP1: xchg    cx,ax
    or    ax,ax
    jz    @@HOP2
    mul    si
    add    cx,ax
@@HOP2: xchg    si,ax
    mul    bx
    add    dx,cx
    pop    si
    endm

macro    LongShiftL TIMES
;; 5 - Shift left AX,DX times.
    REPT TIMES
    shl    ax,1
    rcl    dx,1
    ENDM
    endm

macro    LongShiftR TIMES
;; 6 - Shifr right AX,DX times
    REPT TIMES
    sar    dx,1
    rcr    ax,1
    ENDM
    endm

macro    ShiftAL REG,TIMES
;; 7 - shift arithmetic left register, times
IF      IS286
    sal    REG,TIMES
ELSE
        REPT    TIMES
    sal    REG,1
        ENDM
ENDIF
    endm

macro    ShiftAR REG,TIMES
;; 8 - Shifr arithmatic right register, times
IF      IS286
    sar    REG,TIMES
ELSE
        REPT    TIMES
    sar    REG,1
        ENDM
ENDIF
    endm

macro   PushI   VALUE
;; 9 - Push an immediat onto the stack.
;; Push Immediate
IF      IS286
        push    VALUE
ELSE
        mov     ax,VALUE
        push    ax
ENDIF
        endm

macro   PushEA  DATA
;; 10 - Push an effective address onto the stack.
;; Push Effective address
IF      IS286
        push    offset DATA
ELSE
        mov     ax,offset DATA
        push    ax
ENDIF
        endm

macro   PushFar DATA
;; 11 - Push far address (relative to DS) onto the stack.
        push    ds              ; push the segment
        PushEA  DATA            ; push the offset
        endm

macro   PushAll
;; 12 - Push ALL registers onto the stack.
;; Save all registers
IF      IS286
        pusha                   ;; if a 286 machine use the pusha opcode
        push    ds              ;; save segment DS
        push    es              ;; save segment ES
ELSE
        push    ax              ;; if not 286 machine use normal method
        push    bx
        push    cx
        push    dx
        push    si
        push    di
        push    bp
        push    ds
        push    es
ENDIF
        endm

macro   PopAll
;; 13 - Pop all registers off of the stack.
;;; Restore all registers from a push all
IF      IS286
        pop     es
        pop     ds
        popa
ELSE
        pop     es
        pop     ds
        pop     bp
        pop     di
        pop     si
        pop     dx
        pop     cx
        pop     bx
        pop     ax
ENDIF
        endm

macro   DOSTerminate
;; 14 - Terminate back to DOS
    mov    ah,4Ch
        int     21h
        endm

macro   DosTSR  LOC
;; 15 - Terminate and stay resident back to DOS
        lea     dx,[LOC+100h]   ; (End of program plus PSP)
        int     27h             ; Terminate and stay resident.
        endm

macro   Message data
;; 16 - Print a '$' terminated string to the console
    push    ax
        mov     ah,9            ; Function 9 write string
        lea     dx,[data]       ; Get the address of the message
        int     21h             ; Send the message to the screen.
    pop    ax
        endm



macro   PENTER  STORAGE
;; 17 - Enter a procedue with storage space
;; Procedure enter, uses the 286/386 ENTER opcode
IF      IS286
        enter   STORAGE,0       ; nexting level, always zero.
ELSE
        push    bp
        mov     bp,sp
        IF      STORAGE
        sub     sp,STORAGE
        ENDIF
ENDIF
        endm

macro   PLEAVE
;; 18 - Exit a procedure with stack correction.
IF      IS286
        leave
ELSE
        mov     sp,bp
        pop     bp
ENDIF
        endm

macro   PushCREGS
;; 19 - Save registers for C
        push    es
    push    ds   ;The Kernel is responsible for maintaining DS
        push    si
        push    di
        cld
        endm

macro   PopCREGS
;; 20 - Restore registers for C
        pop     di
        pop     si
    pop    ds ;The Kernel is responsible for maintaining DS
        pop     es
        endm

;; Macro used to insert breakpoints in code to invoke the debugger.  Using
;; the macro allows for easier searches to be done on debug invokations.
Macro    DoDebug
    int    3
    endm

Macro    SwapSegs
    push    es
    push    ds
    pop    es
    pop    ds
    endm