Re: Benchmarking GHC

ketil+haskell:

"Neil Mitchell" writes:

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I want to benchmark GHC vs some other Haskell compilers, what flags should I use?

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[...] I guess the answer is "-O2 -fvia-C"?

I tend to use -O2, but haven't really tested it against plain -O.

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From what I've seen -fvia-C is sometimes faster, sometimes slower, I tend to cross my fingers and hope the compiler uses sensible defaults on the current architecture.

One thing that IME makes a difference is -funbox-strict-fields. It's probably better to use pragmas for this, though. Another thing to consider is garbage collection RTS flags, those can sometimes make a big difference.

All this and more on the under-publicised Performance wiki, http://haskell.org/haskellwiki/Performance -- Don