mirror of
https://github.com/cc65/cc65.git
synced 2024-12-23 19:29:37 +00:00
2275e4c2a8
runtime support function. git-svn-id: svn://svn.cc65.org/cc65/trunk@1479 b7a2c559-68d2-44c3-8de9-860c34a00d81
44 lines
1.0 KiB
ArmAsm
44 lines
1.0 KiB
ArmAsm
; divt.s
|
|
;
|
|
; 2002-10-22, Greg King
|
|
;
|
|
; This signed-division function returns both the quotient and the remainder,
|
|
; in this structure:
|
|
;
|
|
; typedef struct {
|
|
; int rem, quot;
|
|
; } div_t;
|
|
;
|
|
; div_t __fastcall__ div (int numer, int denom);
|
|
;
|
|
; Both sides of an assignment-expression must be cast to (long)
|
|
; because cc65 functions can't return structures -- yet. Example:
|
|
;
|
|
; #include <stdlib.h>
|
|
; div_t answer;
|
|
;
|
|
; (long)answer = (long)div(-41, +3);
|
|
; printf("The quotient is %d, and the remainder is %d.\n",
|
|
; answer.quot, answer.rem);
|
|
|
|
.export _div
|
|
|
|
.import tosdivax, negax
|
|
.importzp sreg, ptr1, tmp1
|
|
|
|
_div: jsr tosdivax ; Division-operator does most of the work
|
|
sta sreg ; Quotient is in sreg
|
|
stx sreg+1
|
|
lda ptr1 ; Unsigned remainder is in ptr1
|
|
ldx ptr1+1
|
|
|
|
; Adjust the sign of the remainder.
|
|
; It must be the same as the sign of the dividend.
|
|
;
|
|
bit tmp1 ; Load high-byte of left argument
|
|
bpl Pos ; Jump if sign-of-result is positive
|
|
jmp negax ; Result is negative, adjust the sign
|
|
|
|
Pos: rts
|
|
|