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Re: [PATCH][ARM] pr50193: ICE on a | (b << negative-constant)

From: Richard Earnshaw <rearnsha at arm dot com>
To: Jakub Jelinek <jakub at redhat dot com>
Cc: Andrew Stubbs <andrew dot stubbs at gmail dot com>, "Joseph S. Myers" <joseph at codesourcery dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, "patches at linaro dot org" <patches at linaro dot org>
Date: Wed, 07 Sep 2011 16:12:05 +0100
Subject: Re: [PATCH][ARM] pr50193: ICE on a | (b << negative-constant)
References: <4E5F6B5F.2020207@codesourcery.com> <Pine.LNX.4.64.1109011314530.1849@digraph.polyomino.org.uk> <4E5FA41F.9010201@codesourcery.com> <4E5FA4D5.9050309@codesourcery.com> <20110901155136.GS2687@tyan-ft48-01.lab.bos.redhat.com>

On 01/09/11 16:51, Jakub Jelinek wrote:
> 1) shift by 0 is well defined (though not sure if arm backend
>    supports it)

The canonical form of
	(<any_shift> (x) (const_int 0))

is just

	(x)

So while it's well defined, it's also useless.

References:
- [PATCH][ARM] pr50193: ICE on a | (b << negative-constant)
  - From: Andrew Stubbs
- Re: [PATCH][ARM] pr50193: ICE on a | (b << negative-constant)
  - From: Joseph S. Myers
- Re: [PATCH][ARM] pr50193: ICE on a | (b << negative-constant)
  - From: Andrew Stubbs
- Re: [PATCH][ARM] pr50193: ICE on a | (b << negative-constant)
  - From: Andrew Stubbs
- Re: [PATCH][ARM] pr50193: ICE on a | (b << negative-constant)
  - From: Jakub Jelinek

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