Re: [avr-gcc-list] split movhi to 2 movqi

[Georg-Johann Lay]

Ilya Lesokhin schrieb:
> i want to try to do it after the IRA phase, does anyone know if it makes
> sence, and if so, is there a macro which tells me that i'm after that phase?

reload_completed will tell you.

You can use a splitter or a peephole, put neither of them looks
tempting because handling it pre-reload will reduce the register
pressure. Handling post-reload cannot reduce the register pressure.
The high part will still be allocated and not used, but you don't get
that resource back.

To use slit you have to use a combine pattern. Note that combine won't
try mem_volatile_p, so it's useless to try memory_operand in a combine
pattern.