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Re: fix IA-64 recip approx cse bug

From: Jim Wilson <wilson at tuliptree dot org>
Cc: gcc-patches at gcc dot gnu dot org
Date: Sat, 12 Apr 2008 09:50:18 -0700
Subject: Re: fix IA-64 recip approx cse bug
References: <1206993585.3209.28.camel@localhost.localdomain>

Jim Wilson wrote:

The main problem here is that the recip approx insn uses DIV for the
result, which confuses CSE into thinking that we have an actual divide
result when we don't.  Changing the recip approx pattern to use UNSPEC
instead of DIV solves the problem.

I've now added this same patch to the gcc-4.3 branch. Tested by SuSE. I did a quick cross compiler build just to make sure I didn't break the build when applying the patch.

Jim

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