This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Variable Expansion in unroller + Register Pressure Utility
- From: Revital Eres <ERES at il dot ibm dot com>
- To: Vladimir Makarov <vmakarov at redhat dot com>
- Cc: Daniel Berlin <dberlin at dberlin dot org>, stevenb at suse dot de, gcc-patches at gcc dot gnu dot org, mark at codesourcery dot com, Ayal Zaks <ZAKS at il dot ibm dot com>, Mircea Namolaru <NAMOLARU at il dot ibm dot com>, rakdver at atrey dot karlin dot mff dot cuni dot cz
- Date: Wed, 22 Sep 2004 18:05:08 +0200
- Subject: Re: [PATCH] Variable Expansion in unroller + Register Pressure Utility
> Now I see that Revital added function
> estimate_register_pressure with a register as parameter which I don't
> understand. It just returns difference between number of available hard
> registers in class (which the pseudo-register belongs to for register
> pressure estimation purpose) and maximal register pressure in some
> blocks. Even if we are trying to create a pseudo-register in the basic
> blocks, the returned value says nothing because the new pseudo-register
> could be used in some point where the register pressure does not reach
> maximal value. So with my point of view it is not accurate evaluation
> to decide create or not the new pseudo-register.
>
> Vlad
This is why among others it is highly conservative approach.
I can change it to use per-block register pressure check
if you think it is more accurate.
Thanks,
Revital