Texas Instruments TI-89 - Bcdcmp

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Appendix A: System Routines — Direct Floating Point Operations
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
bcdcmp
Declaration:
long
bcdcmp
(BCD16
a
, BCD16
b
)
Category(ies):
Direct Floating Point Operations
Description:
Compare two TI binary-code decimal floating-point numbers. This routine is
provided as a convenience for assembly language programs.
Inputs:
a
,
b
— Two BCD16 numbers to compare.
Outputs:
Returns -1 if
a
<
b
,
0 if
a
==
b
1 if
a
>
b
.
Assumptions:
None
Side Effects:
None
Availability:
All versions of the TI
-
89 / TI
-
92 Plus.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: bcdadd, bcdbcd, bcddiv, bcdlong, bcdmul, bcdneg, bcdsub
Example:
a = -20
b = -30
.
.
.
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 bcdcmp(a2),a0 ;assumes a2 -> jump table
jsr (a0) ;call bcdcmp(a, b)
lea 20(sp),sp ;pop parameters
tst.l d0 ;result returned in d0
blt less ;a < b --->
bgt greater ;a > b --->
. ;a == b
.
.