[llvm-commits] [PATCH]: PR 12760: Fix incorrect pattern matching of SMMLS instruction

[Tim Northover]

On Tuesday 15 May 2012 23:45:10 Meador Inge wrote:
> > The attached patch fixes this be removing the pattern for 'SMMLS'.  The
> > generated code is now correctly:
> >
> > _f:
> >        smmul   r1, r2, r1
> >        sub     r0, r0, r1
> >        bx      lr
> >
> > OK?
> >
> > (P.S. If it is OK, can someone commit for me?  I don't have write
> > access.)

* The attached patch is obviously functionally correct and tested
* I've convinced myself that SMMLA isn't affected.
* The ISD nodes produced for the "correct" sequence are also horribly
  infeasible to match from TableGen (smul_lohi, SUBC, SUBE nodes producing
  more than one output value) so I think the removal is justified for now.

Committed in r156989.

Thanks for the patch!

Tim.

(who really needs to work out why the list acts as a black hole for
his work address).