Re: Stuff to include in libgccjit 5.2

[Dibyendu Majumdar <mobile@majumdar.org.uk>]

On 1 July 2015 at 01:25, David Malcolm <dmalcolm@redhat.com> wrote:
> Would it be useful to have some kind of error/warning about unused
> rvalues?  (this would almost certainly be for post-5.2 at this point
> though)   Perhaps specifically for gcc_jit_context_new_call, that one
> seems to be a "gotcha".
>
> Something like:
>
>   extern void
>   gcc_jit_context_set_bool_check_for_unused_rvalues (gcc_jit_context *ctxt,
>                                                      int bool_value);
>
> issuing a hard error if enabled and there's an unused rvalue.
>
> (defaulting to off?  or maybe to on, if all valid client code runs OK
> with it on?)
>

Probably. I guess I will now be more careful about checking for this
so hopefully I won't make the same mistake. So you may want to wait
for other users' feedback before adding an API.

>> I will try to implement as many op codes as I can over the weekend and
>> report back in case of issues.
>
> FWIW, the deadline for the GCC 5.2 release candidate is Friday, and I
> need to take Friday off from the computer for family stuff, so
> effectively the only remaining jit things to go into 5.2 will be
> whatever we get into trunk, and backport in the next two days.
>

Ok

> I believe the two most important issues for Ravi are:
>
> * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66546
> ("No way to disable check for unreachable blocks")
> This is fixed in trunk, with a new entrypoint you'll need to call:
>      gcc_jit_context_set_bool_allow_unreachable_blocks
> I anticipate backporting this to gcc-5-branch tomorrow.
>
>
> * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66700
> ("Bogus gimplification of jit code using ptrs to functions", aka the
> "Weird problem" thread)
> I have a patch for this which I anticipate committing to trunk
> and backporting to gcc-5-branch, both tomorrow.
>

Yes these are the must haves. Rest are all nice to have and can wait.

>
> Other issues affecting Ravi:
>
> * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66594
> ("jitted code should use -mtune=native")
> Sadly I don't have a clean fix for this yet, and I don't anticipate
> having one by the 5.2 deadline.  There's a hackish workaround for x86_64
> attached to the bug.
>
>
> * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66628
> ('jit: Provide a way to add arbitrary options to the toplev "command
> line"')
> Fixed in trunk; I anticipate backporting the fix to gcc-5-branch
> tomorrow.   BTW, note that I don't think you can inject "-mtune=native"
> this way.
>
>
> See also:
> https://gcc.gnu.org/bugzilla/showdependencytree.cgi?id=66627&hide_resolved=0
>
> plus various other patches I've already committed that I hope to
> backport.
>
> Did I miss anything important to Ravi?
>

No that's it so far.


Thanks and Regards
Dibyendu