How to link with the GNU gold linker instead of ld in Haskell -

my haskell project spends lots of time in linking dist/build/myapp/myapp ... , in loading shared libraries when executing templatehaskell code.

i suspect because ld slow.

how can improve link times switching gold linker?

link 3x faster gold

since ghc 7.8, can tell ghc , cabal (at run time without having recompile ghc) link gnu gold.

you need in .cabal file:

library:   ghc-options: -optl-fuse-ld=gold   ld-options:  -fuse-ld=gold  executable myexecutable   ghc-options: -optl-fuse-ld=gold   ld-options:  -fuse-ld=gold 

(note might want pass these flags stack/cabal/setup.hs on command line instead of hardcoding them in .cabal file in order not reduce portability of package.)

for me it's 3.5x faster, bringing down total link time of project 150 seconds 40 seconds.

---

update: link 10x faster lld

see https://github.com/nh2/link-with-lld-example full example; key parts:

library   ghc-options: "-pgmp clang" "-pgmc clang" "-pgma clang" "-pgml clang" "-optl-fuse-ld=lld"   ld-options:  -fuse-ld=lld  executable myexecutable   ghc-options: "-pgmp clang" "-pgmc clang" "-pgma clang" "-pgml clang"   ld-options:  -fuse-ld=lld 

comparison of link time final executable link times project:

ld   124 seconds gold  36 seconds lld   11 seconds