A Look At The GCC 9 Performance On Intel Skylake Against GCC 8, LLVM Clang 7/8

First up are some of the NASA NPB tests on the GCC compilers. Due to the NAS Parallel Benchmarks depending upon Fortran code, only the GCC testing was done due to the LLVM FLANG (Fortran) support still being experimental.

The Block Tri-diagonal solver performance saw a slight pullback in performance with the in-development GCC9...

But meanwhile the embarrassingly parallel test saw a surprising 35% performance increase.

While in the other NPB tests, the results were either unchanged with the new GCC or the Scalar Penta-diagonal solver saw a 9% rise in performance.

In the Fortran-based CloverLeaf hydrodynamics benchmark there was a small performance drop out of the current GCC 9 development code.