-fasm vs. -fvia-c

Duncan Coutts duncan.coutts at worc.ox.ac.uk
Tue Jul 25 09:45:50 EDT 2006

On Tue, 2006-07-25 at 14:29 +0100, Joel Reymont wrote:
> On Jul 25, 2006, at 2:09 PM, Duncan Coutts wrote:
> > You can also cut compile times by compiling fewer non-core  
> > libraries and
> > by using -fasm rather than -fvia-C.
> I heard recently that GHC does not generate code that gcc likes and  
> so there's a push to improve asm generation. What stage is that push at?
> Do I cripple my GHC build in any way by using asm as opposed to via-c?

Depending on what processor type you're using, the resulting code will
be slightly slower or slightly faster than -fvia-C. If I recall
correctly, -fasm is slightly slower on x86 and slightly faster on
x86-64. Not sure about ppc.

There's no other major differences. (Though note that it's recommended
that you use -fvia-C with the FFI as that allows double checking of FFI
imports against C header files.)


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