https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108738
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2023-02-09
Ever confirmed|0 |1
Known to fail| |10.4.0
Status|UNCONFIRMED |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Happens at least since GCC 10.
There's a comment already:
/* ??? The following is quadratic since analyze_register_chain
iterates over all refs to look for dual-mode regs. Instead this
should be done separately for all regs mentioned in the chain once. */
df_ref ref;
for (ref = DF_INSN_UID_DEFS (insn_uid); ref; ref = DF_REF_NEXT_LOC (ref))
if (!HARD_REGISTER_P (DF_REF_REG (ref)))
analyze_register_chain (candidates, ref);
but the walk also adds to the queue, so it's more interwinded and the suggested
solution isn't the proper. Instead it might be possible to just record
already visited regs.
