Re: GCC 3.1 Prerelease

[Mark Mitchell <mark@codesourcery.com>]

--On Sunday, April 21, 2002 01:50:47 PM -0700 Richard Henderson 
<rth@redhat.com> wrote:

> On Sat, Apr 20, 2002 at 05:24:15PM -0700, Mark Mitchell wrote:
>> It sounds like maybe if the front end were to promise that there
>> were no gotos in a particular function, this would improve things,
>> but I'm not sure.
>
> Less severe than that.  No gotos within a specific region.  Or
> more to the point, binding cleanup code with exception regions
> before generating rtl for them rather than after.

OK.

>> Jason, Richard, what do you think about this?  The only practical
>> option, beyond the speedups Richard already implemented, is to
>> revert Jason's correctness patch at this point.
>
> I really dislike the idea of reverting the correctness patch.

Me too.

> The most practical solution for people actually using these
> sorts of template packages is to not nest the expressions
> quite so deeply.

In general, that hoses the performance of those packages.  The point
is to do loop fusion and such using the expression-template magic;
less nesting means less loop fusion means worse performance.  Perhaps,
however, they could avoid using *destructors* in these objects; that's
not necessary in many of the situations I'm familiar with.

I'm inclined just to suffer here, but let's see what Jason thinks.

--
Mark Mitchell                   mark@codesourcery.com
CodeSourcery, LLC               http://www.codesourcery.com