Dynamic libraries by default and GHC 7.8

[Simon Marlow]

On 28/11/12 12:48, Ian Lynagh wrote:
> On Wed, Nov 28, 2012 at 09:20:57AM +0000, Simon Marlow wrote:
>>
>> My personal opinion is that we should switch to dynamic-by-default
>> on all x86_64 platforms, and OS X x86. The performance penalty for
>> x86/Linux is too high (30%),
>
> FWIW, if they're able to move from x86 static to x86_64 dynamic then
> there's only a ~15% difference overall:
>
> Run Time
> -1 s.d. -----   -18.7%
> +1 s.d. -----   +60.5%
> Average -----   +14.2%
>
> Mutator Time
> -1 s.d. -----   -29.0%
> +1 s.d. -----   +33.7%
> Average -----   -2.6%
>
> GC Time
> -1 s.d. -----   +22.0%
> +1 s.d. -----   +116.1%
> Average -----   +62.4%

The figures on the wiki are different: x86 static -> x86_64 dynamic has 
+2.3% runtime. What's going on here?

I'm not sure I buy the argument that it's ok to penalise x86/Linux users 
by 30% because they can use x86_64 instead, which is only 15% slower. 
Unlike OS X, Linux users using the 32-bit binaries probably have a 
32-bit Linux installation, which can't run 64-bit binaries (32-bit is 
still the recommended Ubuntu installation for desktops, FWIW).

Cheers,
	Simon