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Re: [PATCH 2/2][MSP430] Optimize zero_extend insns and PSImode pointer manipulation
- From: Jozef Lawrynowicz <jozef dot l at mittosystems dot com>
- To: Segher Boessenkool <segher at kernel dot crashing dot org>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 9 Oct 2019 14:42:58 +0100
- Subject: Re: [PATCH 2/2][MSP430] Optimize zero_extend insns and PSImode pointer manipulation
- References: <20191008113450.5b6fa184@jozef-kubuntu> <20191008113957.054ec793@jozef-kubuntu> <20191009084732.GZ9749@gate.crashing.org>
Hi Segher!
On Wed, 9 Oct 2019 03:47:32 -0500
Segher Boessenkool <segher@kernel.crashing.org> wrote:
> Hi Jozef,
>
> On Tue, Oct 08, 2019 at 11:39:57AM +0100, Jozef Lawrynowicz wrote:
> > +;; ------------------------
> > +;; ZERO EXTEND INSTRUCTIONS
> > +;; Byte-writes to registers clear bits 19:8
> > +;; * Byte-writes to memory do not affect bits 15:8
> > +;; Word-writes to registers clear bits 19:16
> > +;; PSImode writes to memory clear bits 16:4 of the second memory word
>
> Should that be 15:4 instead?
Whoops, nice spot. I'll fix that before applying (if it gets approved) rather
than re-submitting.
>
> > +; FIXME many of these should be unnnecessary once combine deals with
> > +; (sign_extend (zero_extend)) or (sign_extend (subreg)) BZ 91865.
>
> I have looked at it some time ago, and it is quite hard :-/ It's not
> forgotten though!
Ok, thanks for the update!
Jozef
>
>
> Segher