https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64326
tbsaunde at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |tbsaunde at gcc dot gnu.org --- Comment #3 from tbsaunde at gcc dot gnu.org --- So, in cfghooks.c make_forwarder_block we redirect two edges to point at a bb, both edges have probability 1 (10000) the first edge's src bb has freq 873, and the second 9409. So at least one of those is slightly high, and when we combine them we set the freq for dummy to 10282. Then later we copy that freq of 10282 and assert because that's not a sane frequency. Its not entirely clear to me if make_forwarder_block should handle this case by capping freq at 10000, or if the bug is even earlier when those two initial frequencies are generated.