Re: Can I force a word read-modify-write instread of a byte write?

[Ian Lance Taylor <iant at google dot com>]

Rask Ingemann Lambertsen <rask@sygehus.dk> writes:

>    When it comes to a back end solution, one existing target (MT) has an
> option to not generate byte loads and stores, and there was a long thread
> about modifying the ARM back end to generate byte writes such that, at the
> hardware level, they would become a cache line wide read-modify-write
> access. Search the GCC mailing list for this:
> 
> Modifying ARM code generator for elimination of 8bit writes - need help
> 
>    The ARM solution relies on assistance form the hardware, so I suggest you
> look at the MT back end first to see if it does something clever.

There is no doubt that gcc can do this on a per-compilation basis.
It's not particularly difficult if you're familiar with the gcc
backend.

I think it would take quite a bit more work to do it on per-pointer
basis.

Ian