[cfe-dev] Using the new clang driver

[Török Edwin]

Hi,

I tested the new clang driver, and I am very pleased with the results.
Nice job!

Here are the results when building ClamAV with a default ./configure
(which sets CFLAGS to -O2 -g),
and running time make -j4 >/dev/null:

gcc-4.3:    real    0m19.615s user  0m53.727s sys   0m5.800s
ccc:           real    0m16.736s user  0m39.726s sys   0m7.596s
clang:       real    0m13.786s user  0m33.142s sys   0m5.136s
llvm-gcc:  real    0m13.046s user    0m32.662s sys   0m5.332s
ccache+gcc: real    0m4.703s  user  0m6.936s  sys  0m3.380s

As you can see clang is now almost as fast llvm-gcc, and definitely
faster than gcc, and the old ccc driver.
I'm a bit surprised that clang isn't faster than llvm-gcc, but I think
most of the time is spent in the optimizers/codegen
and not in parsing (this is a C application, includes are not as huge as
for C++).

Best regards,
--Edwin