On 07/25/2011 03:56 PM, Alain Toussaint wrote:
> <<<<
>> I've been thinking about compiling LFS with LLVM; any thought or
>> opinion?
>>
>> Alain
>
>      What's LLVM? I'm still trying to get glibc-2.13 in LFS to compile right.
>
> There's some code there that redirects to a file called configparams and I
> don't know where it is.
>>>>>>
>
> A newer compiler than gcc, have a look at www.llvm.org
>
> It compile faster, the resulting code run faster too

Ahh...not exactly. Compile, yes. Runtime, no...according to this 
article, the result was about 23% slower than gcc-4.5 as of march 2010: 
http://www.phoronix.com/scan.php?page=article&item=gcc_llvm_clang

Looking here:
http://blog.vx.sk/archives/25-FreeBSD-Compiler-Benchmark-gcc-base-vs-gcc-ports-vs-clang.html

Looks like it was still lagging in performance by about 10% of gcc-base 
on FBSD in march 2011 (and 20% of opt gcc ports), which is interesting 
being that the size of the resultant files is smaller with clang.

Finally, here is a much more recent one that includes the dragonegg 
plugin for gcc:
http://www.phoronix.com/scan.php?page=article&item=gcc_46_llvm29&num=8
As you can see from the results, LLVM is gaining on GCC in terms of 
runtime performance.

In almost all cases, clang or dragonegg were faster than gcc at compile 
time, but runtime still pretty much belongs to gcc by only a small 
margin (and even that is not universally true). With all that said, 
however, benchmarks have nothing on real use. The only way to know for 
sure is to try it and see.

-- DJ Lucas



-- 
http://linuxfromscratch.org/mailman/listinfo/lfs-chat
FAQ: http://www.linuxfromscratch.org/faq/
Unsubscribe: See the above information page

Reply via email to