• compiler optimization options for ARMv8 GCC compiler on ARM cortex a53 (bare metal application)

    I am using ARMv8 GCC compiler(aarch64-none-elf-gcc) for my bare metal application on ARM cortex a53. I am using neon intrinsics with plain C in my code so I would like to ensure to use all optimization option available for this compiler.

    I tried -mfpu…

  • What is arrangement specifier(.16b,.8b) in ARM assembly language instructions?

    I want to what exactly is arrangement specifier in arm assembly instructions.

    I have gone through ARM TRMs and i think if it is size of Neon register that will be used for computation

    for e.g. TBL Vd.Ta, {Vn.16B,Vn+1.16B }, Vm.Ta

    they mentioned Ta to…

  • I'm not seeing any flush-to-zero (FTZ) effects with NEON intrinsics on an ARM A9, any advice?

    Hi everyone,

    As the title states - I've had issues reproducing flush-to-zero (FTZ) using the NEON intrinsics provided in the 'arm_neon.h' header. For test purposes I'm using an iPhone 6 with an ARMv8-A dual-core ('Twister') CPU.…

  • Memory barrier (DSB, DMB). Does they guarantee writing data on cache to memory?

    Hi Experts,

    I'm reading white paper for ARMv7 and ARMv8.

    but when i reading cache part and memory re-ordering, i have silly questions.....

    Suppose there are below instructions..

     

    Core A:

         STR R0, [Msg]

         STR R1, [Something…

  • No segmentation fault when expected with aligned load and store

    Hi all,

    It is a well known fact that performing an aligned vector load with an unaligned memory address should lead to segmentation fault.

    However, when I do try to run code segment below using the same, i do not see any segmentation fault.

    ---------…

  • A Walk Through the Cortex-A Mobile Roadmap

    Chinese Version中文版

    Introduction

    The ARM Cortex-A mobile application processor product line spans several generations and three main product tiers. Developers and SoC designers experienced with one or more of the newer ARM ARM Processors benefit from an…