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Re: [PATCH] PR 62173, re-shuffle insns for RTL loop invariant hoisting

From: Jeff Law <law at redhat dot com>
To: Steven Bosscher <stevenb dot gcc at gmail dot com>, Jiong Wang <wong dot kwongyuan dot tools at gmail dot com>
Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, Kenneth Zadeck <zadeck at naturalbridge dot com>, Richard Biener <richard dot guenther at gmail dot com>, "Bin.Cheng" <amker dot cheng at gmail dot com>, Segher Boessenkool <segher at kernel dot crashing dot org>
Date: Tue, 14 Apr 2015 11:24:49 -0600
Subject: Re: [PATCH] PR 62173, re-shuffle insns for RTL loop invariant hoisting
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On 04/14/2015 10:48 AM, Steven Bosscher wrote:

So I think this stage2/3 binary difference is acceptable?


No, they should be identical. If there's a difference, then there's a
bug - which, it seems, you've already found, too.

RIght.  And so the natural question is how to fix.

At first glance it would seem like having this new code ignoredependencies rising from debug insns would work.

Which then begs the question, what happens to the debug insn -- it'scertainly not going to be correct anymore if the transformation is made.


jeff

Follow-Ups:
- Re: [PATCH] PR 62173, re-shuffle insns for RTL loop invariant hoisting
  - From: Jiong Wang

References:
- Re: [PATCH] PR 62173, re-shuffle insns for RTL loop invariant hoisting
  - From: Jiong Wang
- Re: [PATCH] PR 62173, re-shuffle insns for RTL loop invariant hoisting
  - From: Steven Bosscher

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