[cfe-dev] clang builds chromium

[Nico Weber]

On Thu, Oct 14, 2010 at 2:05 PM, Eric Christopher <echristo at apple.com> wrote:
>
> On Oct 14, 2010, at 1:56 PM, Nico Weber wrote:
>
> 2: This was with a Release+Asserts build of clang r116145, the gcc
>
> that comes with XCode on 10.6 ( i686-apple-darwin10-gcc-4.2.1 (GCC)
>
> 4.2.1 (Apple Inc. build 5664) ), and on a MacBook Pro with 4 GB ram
>
> and 2.5 GHz i5 processor.
>
>
> BTW: Release+Asserts is going to do more internal checking IIRC than the
> gcc on the system FWIW.

I rebuilt clang with --disable-assertions and re-ran this test (but
only twice each):

Building chrome with clang-noasserts in Debug
real	32m59.061s
real	32m16.343s

Building all with clang-noasserts in Debug
real	57m36.865s
real	57m21.031s

Building chrome with clang-noasserts in Release
real	35m5.824s
real	34m56.622s

Building all with clang-noasserts in Release
real	63m56.959s
real	63m47.464s


That's with the same revision of clang and chromium, and on the same hardware.

clang Release is 25% faster than clang Release+Asserts and 130% faster than gcc.

(This improvement seemed too big to me, so I re-ran the test with gcc
another time as well to check if something on my system changed in the
meantime. But I got the same compile times with gcc that I got
originally.)

Nico