[llvm-dev] [LLVM v3.8.0rc3] cmake-2.8.12: Statistics gcc-4.9 VS. clang-3.8

[Joerg Sonnenberger via llvm-dev]

On Thu, Feb 25, 2016 at 05:13:05PM +0100, Sedat Dilek via llvm-dev wrote:
> Build-time increased approx. 1h from 2 to 3 hours when using CMAKE
> instead of CONFIGURE/MAKE (logs deleted for LLVM v3.8.0rc2).
> Building always done with one single parallel-compile-jobs.
> When using CMAKE $COMPILER does not matter, it's approx. 3 hours build-time.

Are you sure that you are actually using equivalent settings? cmake vs
manual Makefiles should have at most a few percent performance impact
for a full build on moderate concurrent load. It should certainly not be
a factor of 2 or 3.

Joerg