[PATCH] TableGen InstrMapping Bug fix

[Vedant Kumar via llvm-commits]

> On Nov 22, 2016, at 12:47 PM, Tyler Kenney <tjkenney at us.ibm.com> wrote:
> 
>  
> Vedant,
>  
> I attached an updated .diff with a filecheck regression test. Look good?

Hm, I don't see the diff anywhere. Maybe it got scrubbed?


>  
> I am far from a TableGen expert so I don't think I am the one to clean up emitEnums(), just had the bug fix and wanted to share it.

Fair enough :).

vedant


>  
> Tyler
>  
>  
> ----- Original message -----
> From: Vedant Kumar <vsk at apple.com>
> To: Tyler Kenney/Marlborough/IBM at IBMUS
> Cc: llvm-commits at lists.llvm.org
> Subject: Re: [PATCH] TableGen InstrMapping Bug fix
> Date: Mon, Nov 7, 2016 6:40 PM
>  
> Your fix looks correct but should really have a test.
> 
> We don't have any existing tests which run -gen-instr-info, but it should be
> possible. We'd just need to hit the emitEnums path with an entry that sets
> FieldValues to {a, a, a}.
> 
> Side note: emitEnums() really needs to be cleaned up. It looks like it has
> cubic runtime in the worst case, and it does what looks like a totally
> unnecessary copy to initialize FieldValues.
> 
> best,
> vedant
> 
> > On Nov 2, 2016, at 7:55 AM, Tyler Kenney via llvm-commits <llvm-commits at lists.llvm.org> wrote:
> >
> >  
> >  
> > I believe I've found a bug in CodeGenMapTable.cpp.emitEnums(). I'm developing an out-of-tree backend and I was getting an error on a tablegen header for a duplicate enum value. emitEnums() was not properly deleting duplicate entries, but does with the attached the patch. Apparently none of the in-tree targets have enough InstrMapping's to trigger this bug, but my backend defines many.
> >  
> > I don't think there is a way to provide a test case for this without providing a whole new backend, so hopefully we can agree that it's not necessary. I've confirmed that all default targets still build with this patch applied.
> >  
> > Tyler
> >  
> >  
> >
> > <CodeGenMapTable.diff>_______________________________________________
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>  
>  
>