Re: [sdcc-devel] Accessing structure elements through pointer

[Frieder F. <fri...@we...>]

Hi,

Krishnendu Chatterjee schrieb:
> Please suggest me some idea, where I can get rid of this extra code.

you can tweak your 2.5.0 compiler with an additional peephole rule
(see option "--peep-file") like the one below (not tested).

Some remarks:
a) Actually this should be done above the peephole level of SDCC,
   so non-mcs51 ports get this without additional peepholes (and
   it works for mcs51 memory models other than small)
   Please file a feature request at:
   http://sourceforge.net/tracker/?group_id=599&atid=350599

b) Consider upgrading your compiler to a recent snapshot?

c) You are probably aware of this but you might want to
   make use of memory specifiers like __xdata .

-----------------8<-------------------------
// see mail sdcc-devel 2006-06-07
replace{
        mov     a,#%1
        add     a,%3
        mov     %3,a
        clr     a
        addc    a,%4
        mov     %4,a
        mov     a,#%2
        add     a,%3
        mov     %3,a
        clr     a
        addc    a,%4
        mov     %4,a
} by {
        ;       Peephole xxx    removed double add (there should be no need for this peephole)
        mov     a,#(%1+%2)
        add     a,%3
        mov     %3,a
        mov     a,#((%1+%2)>>8)
        addc    a,%4
        mov     %4,a		; carry might differ
} if notVolatile %3 %4
----------------->8-------------------------

Greetings