On 9/02/2011, at 6:53 AM, Martin Jambor wrote: > > This patch basically disables all intraprocedural devirtualization > simply because that transformation relies on assumptions that no > longer hold true. That leaves only devirtualization within inlining > and IPA-CP but those do not work intraprocedurally (i.e. when the > object is within the same function as the call). And in your > testcase, early inlining puts all virtual calls to main() where the > objects are. > >> >> GCC mainline just before your patch was optimizing the following >> testcase to have no virtual calls. I wonder how this can be fixed >> non-intrusively to qualify for Stage 4. > > I have patches for this and hope I will post them soon (probably only as an > RFC, however). They in fact are in the gcc-patches archives: > http://gcc.gnu.org/ml/gcc-patches/2011-01/msg01033.html and > http://gcc.gnu.org/ml/gcc-patches/2010-12/msg01214.html > > Unfortunately, I am afraid we would need to make a _very_ compelling > case for them to be included at this point.
Martin, Ping. I am about to submit improvements to inlining that take devirtualization opportunities into account and your two above patches help improve devirtualization quite a bit. Do you plan to commit them some time soon? For reference, I'm attaching the patch that adds several new devirtualization testcases. Not optimizing the very simple inline-devirt-1.C is just embarrassing. Thank you, -- Maxim Kuvyrkov CodeSourcery / Mentor Graphics
fsf-gcc-devirt-testcases.patch
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