https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110127
Bug ID: 110127
Summary: -fimplicit-constexpr leads to extremely slow and
memory intensive compilation
Product: gcc
Version: 13.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: fiesh at zefix dot tv
Target Milestone: ---
Created attachment 55262
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55262&action=edit
Testcase for slow -fimplicit-constexpr
The attached test case behaves as follows:
% time g++ -std=c++20 -o /dev/null -c u.ii
g++ -std=c++20 -o /dev/null -c u.ii 0.07s user 0.01s system 99% cpu 0.078
total
% time g++ -std=c++20 -o /dev/null -fimplicit-constexpr -c u.ii
g++ -std=c++20 -o /dev/null -fimplicit-constexpr -c u.ii 1637.98s user 41.63s
system 99% cpu 27:59.91 total
The second run also consumes a large amount of memory in the region of 100GB.
I'm a bit stuck on how to reduce this further.
