arch/h8300/lib/moddivsi3.S

   1 #include "libgcc.h"
   2
   3 ; numerator in A0/A1
   4 ; denominator in A2/A3
   5         .global __modsi3
   6 __modsi3:
   7         PUSHP   S2P
   8         bsr     modnorm
   9         bsr     __divsi3
  10         mov.l   er3,er0
  11         bra     exitdiv
  12
  13         .global __umodsi3
  14 __umodsi3:
  15         bsr     __udivsi3:16
  16         mov.l   er3,er0
  17         rts
  18
  19         .global __divsi3
  20 __divsi3:
  21         PUSHP   S2P
  22         bsr     divnorm
  23         bsr     __udivsi3:16
  24
  25         ; examine what the sign should be
  26 exitdiv:
  27         btst    #3,S2L
  28         beq     reti
  29
  30         ; should be -ve
  31         neg.l   A0P
  32
  33 reti:
  34         POPP    S2P
  35         rts
  36
  37 divnorm:
  38         mov.l   A0P,A0P         ; is the numerator -ve
  39         stc     ccr,S2L         ; keep the sign in bit 3 of S2L
  40         bge     postive
  41
  42         neg.l   A0P             ; negate arg
  43
  44 postive:
  45         mov.l   A1P,A1P         ; is the denominator -ve
  46         bge     postive2
  47
  48         neg.l   A1P             ; negate arg
  49         xor.b   #0x08,S2L       ; toggle the result sign
  50
  51 postive2:
  52         rts
  53
  54 ;; Basically the same, except that the sign of the divisor determines
  55 ;; the sign.
  56 modnorm:
  57         mov.l   A0P,A0P         ; is the numerator -ve
  58         stc     ccr,S2L         ; keep the sign in bit 3 of S2L
  59         bge     mpostive
  60
  61         neg.l   A0P             ; negate arg
  62
  63 mpostive:
  64         mov.l   A1P,A1P         ; is the denominator -ve
  65         bge     mpostive2
  66
  67         neg.l   A1P             ; negate arg
  68
  69 mpostive2:
  70         rts
  71
  72         .end