#11285: Split objects makes static linking really slow -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: feature request | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.11 (Linking) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by ezyang): Ha! On a quick and dirty test, `-ffunction-sections` is FOUR times worse for compiling `Setup.hs` on `ld.bfd`. However, it is TWO times better with `ld.gold`. (But not using split objects with gold is still the fastest.) {{{ [ezyang@hs01 ezyang]$ rm Setup; time ghc-8.0-nosplitobjs/inplace/bin/ghc- stage2 -no-user-package-db --make Setup.hs -O0 -optl-fuse-ld=gold [1 of 1] Compiling Main ( Setup.hs, Setup.o ) Linking Setup ... real 0m1.429s user 0m1.250s sys 0m0.163s sys 0m0.583s [ezyang@hs01 ezyang]$ rm Setup; time ghc-8.0/usr/bin/ghc -no-user-package- db --make Setup.hs -O0 -optl-fuse-ld=gold Linking Setup ... real 0m2.537s user 0m2.310s sys 0m0.220s [ezyang@hs01 ezyang]$ rm Setup; time ghc-8.0-nosplitobjs/inplace/bin/ghc- stage2 -no-user-package-db --make Setup.hs -O0 Linking Setup ... real 0m11.349s user 0m10.823s sys 0m0.553s [ezyang@hs01 ezyang]$ rm Setup; time ghc-8.0/usr/bin/ghc -no-user-package- db --make Setup.hs -O0 [1 of 1] Compiling Main ( Setup.hs, Setup.o ) Linking Setup ... real 0m3.380s user 0m2.867s sys 0m0.500s }}} I don't think we can generally assume people will be using gold, so switching this on by default probably is unacceptable. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11285#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler