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Re: [PATCH] Promoted variable SUBREG optimizations

From: Richard Henderson <rth at redhat dot com>
To: Roger Sayle <roger at eyesopen dot com>
Cc: gcc-patches at gcc dot gnu dot org
Date: Tue, 12 Aug 2003 09:13:19 -0700
Subject: Re: [PATCH] Promoted variable SUBREG optimizations
References: <20030811213003.GE24357@redhat.com> <Pine.LNX.4.44.0308112051510.2835-100000@www.eyesopen.com>

On Mon, Aug 11, 2003 at 09:29:59PM -0600, Roger Sayle wrote:
> Could you explain what goes wrong above?

I just said -- two alternatives don't sign extend the result.

> The comments in rtl.h seem
> to imply that an extended subreg can only be used as a LHS, when the
> required extension gets performed.  [But that might not be relevant].

You mean RHS?  If that's true, that might be correct.  I would like
to see where that LHS DImode is initialized before I believe it.

> I take it that you're happy with the dojump.c
> hunk of the patch...

I didn't read it separately, sorry.

r~

Follow-Ups:
- Re: [PATCH] Promoted variable SUBREG optimizations
  - From: Roger Sayle

References:
- Re: [PATCH] Promoted variable SUBREG optimizations
  - From: Richard Henderson
- Re: [PATCH] Promoted variable SUBREG optimizations
  - From: Roger Sayle

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