How to express this complicated constraint in md file

[Dmitry Grinberg]

Hi,

I have not been able to find an answer in the ".md" files i've read
through, or the docs, so I wanted to try here.

If we have an instruction on a machine that does "ADD x, y", where
register x is both input and output, in the ".md" file one can express
this easily (referencing it as "0" instead of "r"). But what if sizes
differ? Consider a hypothetical instruction on a 32-bit machine:

WUMUL x, y which will multiply 32-bit register x by 32-bit
register y, and produce a 64-bit result, storing the high bits into
register x and low bits into register y

Despite all the searching, I still do not quite know how to express
this in the ".md" file
Are there more docs I need to read? Is there an obvious solution I am missing?


Thanks,
Dmitry

Re: Could I obtain the forms needed to make a contribution?

[Dmitry Grinberg]

Why not just add "-D__LINE__=LinkerError_LineMacroUsed_DoNotDoThat()" to
CFLAGS?


Best Regards,
Dmitry Grinberg


On Mon, Dec 16, 2019 at 3:51 AM Eric Curtin  wrote:

> I want to add a compiler warning, if it will get accepted. It's a
> -Wlines warning. My employer bans the __LINE__ macro as well as the
> ones warned by the -Wdate-time warning, because there is a consensus
> that the addition of whitespace or comments should not yield different
> binary output for our project. Would this patch get accepted?
>