More methods of reducing the register pressure

[Vladimir Makarov]

On 19/04/15 01:11 PM, Jeff Law wrote:
> On 04/19/2015 09:28 AM, Ajit Kumar Agarwal wrote:
>> Hello All:
>>
>> To reduce the register pressure, I am proposing the following methods 
>> of reducing the registers.
>>
>> 1. Assigning same registers or sharing same register for the logical 
>> registers having the same value.
>> To determine the logical registers having the same value is the real 
>> challenge. Is there is any way in
>> GCC to determine the logical registers having the same value?
> I believe Vlad looked at this 10+ years ago and it was of marginal/no 
> real benefit.
>
Right, Jeff.  Results of using GVN for building conflict graph was 
described in article:

ftp://ftp.gwdg.de/pub/misc/gcc/summit/2004/Fighting%20Register%20Pressure.pdf