vfp, neon cycle

부동 소수점 +,-,*는 그래도 1사이클에 끝나지만 /는 10사이클 소요됨.

[링크 : https://developer.arm.com/documentation/ddi0409/f/instruction-timing/instruction-specific-scheduling/vfp-instruction-timing]

[링크 : https://developer.arm.com/documentation/ddi0409/g/Instruction-Timing/Instruction-specific-scheduling/Instruction-timing-tables]

 

VFP에 vector가 들어간다고 해도 NEON 수준의 병렬성은 제공하지 않음

The VFP architecture was intended to support execution of short "vector mode" instructions but these operated on each vector element sequentially and thus did not offer the performance of true single instruction, multiple data (SIMD) vector parallelism.

[링크 : https://en.wikipedia.org/wiki/ARM_architecture#VFP]