Regarding this discussion, see also the comments from an LLVM reviewer
at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97827 * — to keep them
at one place, I won't quote the discussion here.
It would be great if this could be solved one way or the other...
Tobias
* for the LLVM side, see also https://reviews.llvm.org/D92052
On 19.11.20 11:12, Richard Sandiford wrote:
Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
On Thu, Nov 19, 2020 at 09:51:41AM +0000, Richard Sandiford wrote:
I think we shouldn't do this except when targetting the (buggy) llvm
assembler.
Specifying section flags just on first .section directive and not others
is correct, there is no point repeating that and GNU as (but I think many
other assemblers) has been supporting it that way forever.
But are there any negative effects with specifying the flags multiple
times for GNU as? If not, then it seems simpler to generate the form
that “all” assemblers accept.
It makes the assembler files unnecessarily larger and harder to read.
It certainly makes them larger, but surely not by an amount that would
cause anyone difficulty in practice. Not sure about harder to read
though. Personally I've never found reading code that happens to be
after the first switch to a section any harder to read than subsequent
switches to the section.
The problem with switching based on what assembler we think people
are using is that we don't always know. It can often be useful to
try something with a different tool for comparison purposes, and that
includes using llvm-mc instead of gas. (Certainly done that myself
a few times, and I know others have.)
I'm not saying we should bend over backwards to support difficult
quirks. But here we're talking about a choice between (a) doing
something that works “everywhere” unconditionally (and keeping things
simple) vs. (b) having both code that takes a shortcut and code that
doesn't take a shortcut and trying to predict which one we should do.
Thanks,
Richard
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