PropBasic Multiplication

FriedV

@Bean,
either I make a very stupid mistake or there is something wrong
with multiplication in PropBasic?

' ----------------------------------------------------------------------
' File......  MotCntCtrl.pbas
' Author....  fgvissel  25.09.2011
' ======================================================================

' ----- Device Settings ------------------------------------------------
  DEVICE P8X32A, XTAL1, PLL16X
  XIN 6_250_000

  tix           var long      
  tox           var long

PROGRAM Start

Start:
' setup code
watch tix
watch tox
Main:

tix = _FREQ / 1000            'period = 1msec tix = 100.000

tox = tix * 3         '<<<<<<<<<<<<<<<<<<<<<<<< doesn't work?

do
 loop

END

Duane C. Johnson

What does it do?

Bean

Yes, there is a bug that makes the compiler hang-up for awhile at multiply. It will continue and generate the proper code.
The bug has been fixed, but I don't have a new revision ready yet.

Bean

FriedV

Not only does the compiler hang on multiply (not everytime BTW) the result is also wrong.
* 3 -> *1, *2 ok, * 4 ok, *6 -> *2
Fried

Bean

FriedV,
I'll check into it.
The mult should not hang for powers of 2 (2, 4, 8, 16, etc).

The mult result may be incorrect for any constant value with 2 bits set.

For now the workaround is to multiply by a variable. You can use__param1 if you are not using it for a subroutine.

Instead of:

tox = tix * 3 

Use

__param1 = 3
tox = tix * 3

Bean