https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111660
--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:765c3b8f82d50961008c214ac2113f35e7532aa9 commit r14-4693-g765c3b8f82d50961008c214ac2113f35e7532aa9 Author: Marek Polacek <pola...@redhat.com> Date: Thu Oct 12 15:58:05 2023 -0400 c++: Fix compile-time-hog in cp_fold_immediate_r [PR111660] My recent patch introducing cp_fold_immediate_r caused exponential compile time with nested COND_EXPRs. The problem is that the COND_EXPR case recursively walks the arms of a COND_EXPR, but after processing both arms it doesn't end the walk; it proceeds to walk the sub-expressions of the outermost COND_EXPR, triggering again walking the arms of the nested COND_EXPR, and so on. This patch brings the compile time down to about 0m0.030s. The ff_fold_immediate flag is unused after this patch but since I'm using it in the P2564 patch, I'm not removing it now. Maybe at_eof can be used instead and then we can remove ff_fold_immediate. PR c++/111660 gcc/cp/ChangeLog: * cp-gimplify.cc (cp_fold_immediate_r) <case COND_EXPR>: Don't handle it here. (cp_fold_r): Handle COND_EXPR here. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/hog1.C: New test. * g++.dg/cpp2a/consteval36.C: New test.
