GCC Status Report (2004-09-13)

[Mark Mitchell]

Jan Hubicka wrote:

>>Jeffrey A Law wrote:
>>
>>    
>>
>>>On Mon, 2004-09-13 at 17:05, Mark Mitchell wrote:
>>>
>>>September 19
>>>
>>>
>>>* General compile-time performance improvements [Weinberg]
>>>
>>>Q. Presumably we can still also attack memory consumption
>>> issues as well.    Right?
>>>
>>>The reason I ask is I have the first in what I expect will
>>>be a series of patches to start reducing memory consumption
>>>and bring more sense to our data structures.
>>>
>>>
>>>      
>>>
>>Yes.  We have a pretty good sense that reducing memory usage correlates 
>>with reducing compile time, and, of course, people do not infinite RAM 
>>anyhow, so this is a resource we should use prudently.  The biggest 
>>caveat is the one you have been raising recently: that touching pages 
>>merely for the purpose of marking memory as free is by no means always a 
>>win.  But, if you can make data structures smaller in the first place, 
>>and just allocate less along the way, that's going to help.
>>
>>So, yes, this is OK -- but please do use your judgement about the 
>>prudence of attempting major overhauls.  The smaller the change (whether 
>>in terms of lines of code or in terms of conceptual complexity) the 
>>better, naturally.
>>    
>>
>
>Thanks.
>Just for a record - we consume roughly 4 times as much memory as 3.4 did
>for common C sources.  Even tought we are down from 7 times we did week
>ago, this is still major regression.
>
I definitely agree.

-- 
Mark Mitchell
CodeSourcery, LLC
(916) 791-8304
mark@codesourcery.com