Compiling CMSIS-DSP Source for Optimised Speed

I understand that CMSIS can be built using GCC for ARM or ARM Compiler 6.18. Are there any performance differences that I need to be aware of? E.g. would building cmsis-dsp source with ARM Compiler 6.18 produce more optimised code (in terms of speed) compared to GCC for ARM? I am trying to run the code on an Arm-V8R architecture (Cortex-R52).