[LLVMdev] tot clang/llvm and tot gcc performance comparision

[Duncan Sands]

Hi Evan,

>>> Thanks David. Unfortunately many of us cannot use GPL v3 gcc so it's hard for us
>>> to investigate this. One question, can you tell if gcc is inlining significantly
>>> more than llvm? We have reports that this is one of the issue plaguing eon
>>> performance.
>>
>> are you allowed to look at assembler output by GPL v3 gcc?  If so, maybe someone
>> else can do the compiling for you, and just send you results and assembler?
>
> Looking at assembly is probably ok. What you described sounds like a great improvement but it would be even better is someone can do some in-depth analysis.

it would of course be best if someone without GPL v3 restrictions could analyse
the spec results [*].  If no-one steps forward, I could set up some kind of
build server to which you can submit preprocessed source: it would compile it
using gcc-4.5 and send you back the assembler (or something along those lines).

Ciao,

Duncan.

[*] Presumably Apple management can understand the usefulness of studying the
competition.  Perhaps someone can be appointed as "GPL v3 guy", allowed to poke
at GPL v3 software to some extent.