Richard Biener <rguent...@suse.de> writes:
> This disables postreload GCSE the same way we disable GCSE/cprop.
> On the PR36262 testcase this removes
>
> load CSE after reload : 129.00 ( 72%) 0.08 ( 5%) 130.50 (
> 72%) 6 kB ( 0%)
>
> With a smaller testcase both PRE and postreload GCSE still run
> and GCSE shows itself roughly 2x the cost of postreload GCSE there
> (still wondering why we have two implementations of the same thing?!)
>
> I've seem postreload CSE pop up a lot on larger testcases while
> PRE turns itself off.
>
> So, does this look reasonable?
>
> Thanks,
> Richard.
>
> 2019-09-02 Richard Biener <rguent...@suse.de>
>
> PR rtl-optimization/36262
> * postreload-gcse.c: Include intl.h and gcse.h.
> (gcse_after_reload_main): Skip pass if gcse_or_cprop_is_too_expensive
> says so.
LGTM. At first I thought:
unsigned int memory_request = (n_basic_blocks_for_fn (cfun)
* SBITMAP_SET_SIZE (max_reg_num ())
* sizeof (SBITMAP_ELT_TYPE));
might be a bad approximation after reload, but it looks like the
sbitmap sizes are O(ninsns), and so it's probably pretty good after all.
Richard
