Re: again problems implementing own target

[Michael_fogel <mikfogel at uni-koblenz dot de>]

Jim Wilson wrote:
> Michael_fogel wrote:
> > The failing instruction is a call. The compiler loads every symbol 
> > reference into a register and calls the function using this. In front 
> > of the error this load is missing. In smaller files the compiler uses 
> > the reference, which is the way i want him to do it.
>
> We need more info in order to determine what is wrong.  Some RTL 
> examples would be nice.  Also, a copy of your pattern in your md file 
> that matches call instructions.
>
> Also, in which pass does the load symbol instruction disappear?  If 
> you compile with -da, you will get RTL dumps after each optimization 
> pass. You can look at them to see where problem was introduced.
>
> There does appear to be a problem with your port, but there is also a 
> way to work around it.  If you define NO_FUNCTION_CSE, then gcc will 
> no longer try to optimize function addresses by loading them into 
> pseudos.  See the docs for this macro in the doc/tm.texi file.
Thank you for your help.

After defining the target hook  TARGET_ADDRESS_COST with return 2 the 
compiler was able to compile it.
I took a closer look at the scheduler and found some interesting macros. 
One of them was NO_FUNCTION_CSE. Now I want to define the costs for 
every instruction so gcc can make a better optimization.

Sometimes I should read the documentation more carefully.

In my opinion the compiler ran out of registers and was not able to 
allocate the pseudo register.  In this case the compiler has to spill 
these registers. How is this done in GCC? Is there a way to control it?

Best regards

Michael Fogel