The to-be-attached testcase takes about 10s to compile at '-O0 -fbounds-check', 30s at '-O2 -fbounds-check' while it requires about 300s at '-O1 -fbounds-check'
The time report shows that at -O1 about 80% of the time is in 'tree canonical iv : 244.29 (82%) usr' -- Summary: long time needed in tree canonical iv Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: compile-time-hog Severity: normal Priority: P3 Component: middle-end AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: jv244 at cam dot ac dot uk http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38729