How many vector register does Mali GPU have?

This blog covers register allocation for the Mali-T860 core: https://community.arm.com/graphics/b/blog/posts/arm-mali-compute-architecture-fundamentals

Summary: you get either 4, 8, or 16 registers per thread, but increasing register count will give you a proportional reduction in thread count. 

In general try to keep programs at 4 or 8 registers; 16 is possible and may not cost too much if your kernel is dominated to a large degree by arithmetic operations, but comes with a sizable performance penalty if it isn't.

HTH, 
Pete

This blog covers register allocation for the Mali-T860 core: https://community.arm.com/graphics/b/blog/posts/arm-mali-compute-architecture-fundamentals

Summary: you get either 4, 8, or 16 registers per thread, but increasing register count will give you a proportional reduction in thread count. 

In general try to keep programs at 4 or 8 registers; 16 is possible and may not cost too much if your kernel is dominated to a large degree by arithmetic operations, but comes with a sizable performance penalty if it isn't.

HTH, 
Pete