Accelerator Manual (G06.27+, H06.04+, J06.03+)

Preparing Your Program for the Accelerator

Accelerator Manual—527303-003

3-9

Non-Standard Procedure Call or Return RP Values

option for functions where the number of words returned is dependent upon

run-time logic.

Examples

•

The declared size of a function (procedure or subprocedure) return result value in

the Binder region must match the actual return size or the Accelerator generates

incorrect code. The following TAL procedure returns three words implicitly and two

words explicitly.

INT(32) PROC foo; ! Actually returns INT48

BEGIN

INT tag;

INT(32) value;

STACK 1; ! Put value on stack when not defined

?RP=7 ! Lie to TAL, suppress warning

RETURN 2d; ! Defined return value, does not match

! value returned on the stack

END;

•

This shows how the TAL compiler view of the register stack differs from the actual

run-time register stack. The TAL compiler determines that the register stack is

empty after the RP directive, while at run time the hardware knows that a value is

on the stack.

The Accelerator issues Warning 32 for procedure Foo:

Warning 32: The return value sizes derived for the following

procedures conflict with those given in the Binder region:

'FOO'; 3 derived by the Accelerator;

2 given in the Binder region

Acceleration is based on the Binder region; you can override

that value with a ReturnValSize option.

TAL compiler view of register

stack at procedure return

Run-time view of register

stack at procedure return

Value

VST0302.vdd