> Am 10.01.2025 um 22:17 schrieb Jeff Law <jeffreya...@gmail.com>:
>
>
>
>> On 1/10/25 4:41 AM, Richard Biener wrote:
>> The following puts in a hard limit on ext-dce because it might end
>> up requiring memory on the order of the number of basic blocks
>> times the number of pseudo registers. The limiting follows what
>> GCSE based passes do and thus I re-use --param max-gcse-memory here.
>> This doesn't in any way address the implementation issues of the pass,
>> but it reduces the memory-use when compiling the
>> module_first_rk_step_part1.F90 TU from 521.wrf_r from 25GB to 1GB.
>> Bootstrap and regtest running on x86_64-unknown-linux-gnu.
>> I plan to push this later today unless I hear objection.
>> PR rtl-optimization/117467
>> PR rtl-optimization/117934
>> * ext-dce.cc (ext_dce_execute): Do nothing if a memory
>> allocation estimate exceeds what is allowed by
>> --param max-gcse-memory.
> No objections. Thanks for taking care of it. A bit surprised it's this bad,
> though I guess those bitmaps might be dense for pathological cases.
I‘m quite sure there’s something wrong with the pass, in particular how it
treats live (it doesn’t seem to prune based on kills?). But I don’t have time
to investigate nor less to rewrite its ‘dataflow’.
Richard
>
> Jeff
>
