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Re: GCSE store motion
> On Wed, 15 May 2002, Roger Sayle wrote:
>
> >
> > > In addition, never, in any RTL dumps of any code, ever, have I seen it
> > > remove a single store.
> >
> > I'd suggest compiling the testcase in the patch below with -O3 on CVS
> > mainline (before store motion was disabled). The test is ill-formed
> > and the duplicate store should be moved, the call to abort() reveals
> > that the optimizer did its job. Feel free to step through with a
> > debuggger to convince yourself that it was GCSE's store motion at
> > work. For example, it doesn't abort compiling with "-O3 -fno-gcse".
> >
> > Seeing is believing.
> Yes, as I mentioned, I misspoke. It now
> removes 2 stores through global store removal during compilation of gcc, and moves
> 3.
Can you, please describe to person who didn't had time to investigate it
in detail why the optimization is not effective and what needs to be done
to fix it? (or point me to mail mentioning it).
I think it would worth comment in the code disabling it.
Honza