Some benchmark comparison of gcc4.5 and dragonegg (was dragonegg in FSF gcc?)

[Vladimir Makarov]

Chris Lattner wrote:
> On Apr 21, 2010, at 11:11 AM, Vladimir Makarov wrote:
>
>   
>>> This is definitely interesting, but you're also comparing apples and oranges here (for both compile time and performance). Can you get numbers showing GCC -O3 and dragonegg with LTO to get a better comparison?
>>>
>>>  
>>>       
>> Dragonegg does not work with -flto.  It generates assembler code on which gas complaints (a lot of non-assembler code like target data-layout which are not in comments).
>>     
>
> Ok, I didn't know that didn't get wired up.  I'm not familiar with dragonegg, it might require gold with the llvm lto gold plugin or something.
>
>   
>> So I'll do gcc -O3 without -flto.  I don't think it will change average SPECINT2000 rate significantly (although it can change separte benchmark significantly)  but it will make gcc compiler much faster (may be 2 times because I did not use -fwhole-program).  I'll post the results in an hour.
>>     
>
> Sounds good, thanks!  I suspect the gcc build times will improve.
>   
Here the results of SPECINT2000 on x86_64 for dragonegg -O3 vs gcc-4.5 -O3.

dragonegg: -O3 (release build)
gcc4.5: -O3 (--enable-checking=release)

          Compilation Time  SPECINT2000
Dragonegg 122.85user         2572
gcc-4.5   142.76user         2784

  Dragonegg generates about 9% slower code (vs 11% for gcc with
-flto).  Without -flto, gcc4.5 is only 16% slower than dragonegg.