Texas Instruments TI-89 - Bcdadd

374
Appendix A: System Routines — Direct Floating Point Operations
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
bcdadd
Declaration:
BCD16
bcdadd
(BCD16
a
, BCD16
b
)
Category(ies):
Direct Floating Point Operations
Description:
Add two TI binary-code decimal floating-point numbers. This routine
performs the same function as the C “+” operator on BCD16 values. This
routine is provided as a convenience for assembly language programs.
Inputs:
a
,
b
— Two BCD16 numbers to add together.
Outputs:
Returns
a
+
b
as a BCD16 number.
Assumptions:
None
Side Effects:
None
Availability:
All versions of the TI
-
89 / TI
-
92 Plus.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: bcdbcd, bcdcmp, bcddiv, bcdlong, bcdmul, bcdneg, bcdsub
Example:
bcdresult = -10
a = -20
b = -30
sum = -40
.
.
.
move.l b(a6),-(sp) ;push b (a 10-byte BCD16 value)
move.l b+4(a6),-(sp)
move.w b+8(a6),-(sp)
move.l a(a6),-(sp) ;push a
move.l a+4(a6),-(sp)
move.w a+8(a6),-(sp)
move.l bcdadd(a2),a0 ;assumes a2 -> jump table
jsr (a0) ;call bcdadd(a, b)
lea 20(sp),sp ;pop parameters
; BCD16 routine value is always at –10(a6)
move.l bcdresult(a6),sum(a6)
move.l bcdresult+4(a6),sum+4(a6)
move.w bcdresult+8(a6),sum+8(a6)