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;
; int sprintf (char* buf, const char* Format, ...);
;
; Ullrich von Bassewitz, 1.12.2000
;
.export _sprintf
.import pushax, addysp, decsp4, _vsprintf
.importzp sp, ptr1
.macpack generic
; ----------------------------------------------------------------------------
; Data
.bss
ParamSize: .res 1 ; Number of parameter bytes
; ----------------------------------------------------------------------------
; Code
.code
_sprintf:
sty ParamSize ; Number of param bytes passed in Y
; We have to push buf and format, both in the order they already have on stack.
; To make this somewhat more efficient, we will create space on the stack and
; then do a copy of the complete block instead of pushing each parameter
; separately. Since the size of the arguments passed is the same as the size
; of the fixed arguments, this will allow us to calculate the pointer to the
; fixed size arguments easier (they're just ParamSize bytes away).
jsr decsp4
; Calculate a pointer to the Format argument
lda ParamSize
add sp
sta ptr1
ldx sp+1
bcc @L1
inx
@L1: stx ptr1+1
; Now copy both, buf and format
ldy #4-1
@L2: lda (ptr1),y
sta (sp),y
dey
bpl @L2
; Load va_list (last and __fastcall__ parameter to vsprintf)
lda ptr1
ldx ptr1+1
; Call vsprintf
jsr _vsprintf
; Cleanup the stack. We will return what we got from vsprintf
ldy ParamSize
jmp addysp
|
