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Re: [tree-ssa] DCE with control dependence again (with numbers, for a change)
- From: Steven Bosscher <s dot bosscher at student dot tudelft dot nl>
- To: law at redhat dot com, "Zack Weinberg" <zack at codesourcery dot com>
- Cc: gcc-patches at gcc dot gnu dot org, aj at suse dot de, pinskia at physics dot uc dot edu
- Date: Sat, 17 Jan 2004 02:42:12 +0100
- Subject: Re: [tree-ssa] DCE with control dependence again (with numbers, for a change)
- References: <200401170034.i0H0YoJq025817@speedy.slc.redhat.com>
On Saturday 17 January 2004 01:34, email@example.com wrote:
> In message <firstname.lastname@example.org>, "Zack Weinberg" writes:
> >The level of testing being asked - and done - for this change is
> >wildly out of proportion to the level of testing being done for other
> >changes going onto the tree-ssa branch.
> That's because we have already been down this design decision before.
> Steven effectively wants to bring back code we threw out about 6 months
> ago because it had some significant compile time performance concerns and
> the increased complexity bought us nearly nothing in terms of generating
> better code.
You are right.
Not that we ever had this code on the tree-ssa branch -- you just
said you had tried it. And clearly my attempts are more successful
than yours given that you claimed (4 months ago) that using control
dependence in DCE would significantly slow down the compiler, and I
have shown that it need not be so. But still you are right. Just
because I have shown the numbers and you have just casted doubt
without the proof that I've been trying to give.
Consider my patch withdrawn.