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Date: Mon, 20 Apr 2020 04:50:41 -0500
From: Segher Boessenkool <segher@kernel.crashing.org>
To: William Tambe <tambewilliam@gmail.com>
Cc: gcc-help <gcc-help@gcc.gnu.org>
Subject: Re: prevent zero-extension when using a memory load instruction
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Hi!

On Sat, Apr 18, 2020 at 11:12:15AM -0400, William Tambe via Gcc-help wrote:
> In the machine description file, is there a way to tell GCC that a
> memory load instruction already zero-extend such that it does not try
> to apply zero-extension ?

At least on a load-store architecture (like a usual RISC), you get best
results if you make a separate pattern for that, and then let combine
combine the zero_extend with the load.


Segher