Poor performance with GCC

I am porting a project from x86 to ARM64 and I have been struggling with poor performance for some time. Recently I tested switching from GCC to LLVM. To my surprise, I got a massive performance boost...
performance: single thread looks OK while multi-thread poor .

performance: single thread looks OK while multi-thread ( 8 threads) poor .as compared to linux64. arm machine is with 64-core. it's verified that 8 threads are started. but why is performance much slow...
performance: single thread looks OK while multi-thread poor .

performance: single thread looks OK while multi-thread ( 8 threads) poor .as compared to linux64. arm machine is with 64-core. it's verified that 8 threads are started. but why is performance much slow...
Note 5 - still struggling for performance (GLES2.0, Java app)

For the best part of a year, on and off, I've been trying without success to get some semblance of decent performance out of some of our Android test devices. The Note 5 has been particularly reluctant...
Note 5 - still struggling for performance (GLES2.0, Java app)

For the best part of a year, on and off, I've been trying without success to get some semblance of decent performance out of some of our Android test devices. The Note 5 has been particularly reluctant...