which rigisters must pushed into stack when i call asm from c or call c funciton from asm?

hi,i am a newbie to c51,now i am am confused at this question that which rigisters must i push into stack when i call asm from c or call c function from asm,except the registers that i apparent used.be...
which rigisters must pushed into stack when i call asm from c or call c funciton from asm?

hi,i am a newbie to c51,now i am am confused at this question that which rigisters must i push into stack when i call asm from c or call c function from asm,except the registers that i apparent used.be...
Cortex-M3 push instruction execution time difference by number of registers

When i execute "push {r1}", the execution time is 0.028 us. then, when i execute "push {r1,r2}", the execution time is 0.042 us. ... when i execute "push {r1,...,rn}", the execution time is 0.014...
Cortex-M3 push instruction execution time difference by number of registers

When i execute "push {r1}", the execution time is 0.028 us. then, when i execute "push {r1,r2}", the execution time is 0.042 us. ... when i execute "push {r1,...,rn}", the execution time is 0.014...
ARM Compiler 5 emits assembly that overwrites pushed registers on stack

I'm currently developing software for an ARM Cortex-M4 MCU. We rely on a third-party SDK, which is not compatible with ARM compiler 6, therefore we still use ARM compiler 5. I stumbled upon a weird...