https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64343
Bug ID: 64343 Summary: [5 Regression] lto compile options Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: lto Assignee: unassigned at gcc dot gnu.org Reporter: Joost.VandeVondele at mat dot ethz.ch somewhere between r218726 and r218773 (1day) code compiled & linked with FCFLAGS = -flto=jobserver -ffree-form -cpp LDFLAGS = $(FCFLAGS) -O3 -funroll-loops -ffast-math -march=native -fuse-linker-plugin -flto=jobserver seems to remain in unoptimized form, while previously they would be optimized at -O3. It does now seem like the compile time flags and not the ld flags control the optimization level of the binary.