Re: [Tinycc-devel] avoid needless register save when storing structures

[grischka]

Thanks Jörg.

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--- grischka

Jörg Mische wrote:
> Hi all,
>
> I found a small bug when storing structures in vstore(): the store is done by a 
> call to memcpy() and the arguments are pushed on vstack. But there remains an 
> unused entry on the stack that is popped after the
> code generation for the call (in gfunc_call()).
>
> This should not be a problem, but gfunc_call() calls save_regs() which searches 
> the vstack for registers that must be preserved during a function call. If the 
> unused entry refers to a register, it is saved to memory, although it will 
> never be used again.
>
> By avoiding the unused entry, the needless code generation can be avoided, too. I pushed 
> a patch on the "mob" branch.
>
> Regards,
> Jörg