Re: get the number of spilling

[Vladimir Makarov <vmakarov at redhat dot com>]

kito wrote:
> Hello everybody:
> I want to count the number of spilling.
> I have try to compile file with -fdump-rtl-ira
> And then use `grep Spilling *.ira | wc -l`
> Does it's right way to get the number of spilling?
>
>   
That is a wrong way to find real spills.   Lines with Spilling is 
actually reported by reload pass and it means only that reload is 
checking constraints for insns (it is not real spills).  Reload pass can 
do several such iterations.  The more hard registers usages, the more 
iterations are usually needed.  Therefore you are getting that lines 
with 'Spilling' have -O1 < -O2 < -O3.
> I am confuse about  the result data because the number of spilling is
> -O1 < -O2 < -O3.
>
> Benchmark : SPEC2000
> target: arm-linux-elf
> gcc version : 4.4.0
>
>                 -O1     -O2     -O3
> 164.zip         1338    1407    3033
> 181.mcf         305     362     603
> 186.crafty      4888    7159    7878
>