[Haskell-cafe] speed: ghc vs gcc
dan.doel at gmail.com
Fri Feb 20 09:39:25 EST 2009
Sorry for replying to myself, but I got suspicious about the 6ms runtime of
the 64-bit C++ code on my machine. So I looked at the assembly and found this:
movabsq $499999999500000000, %rsi
movl $_ZSt4cout, %edi
I'm no assembly guru, but that makes me think that there's no actual
computation going on in the runtime for the 64-bit C++ program, whereas the
32-bit one is clearly doing work on my system, since it takes around 1 second.
Not that I'd be sad if GHC could reduce that whole constant at compile time,
but GCC isn't doing 1 billion adds in 6 (or even 60) milliseconds.
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