[PATCH 2/2][MSP430] Optimize zero_extend insns and PSImode pointer manipulation

[Segher Boessenkool]

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?

> +; 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!


Segher