assembly - ARM指令含义

Question

 sub     lr,lr,#4
 stmfd   sp!,{lr}
 stmfd   sp!,{r0-r14}^
 mrs     r1,spsr
 stmfd   sp!,{r1}
 bl      irqHandler
 ldmfd   sp!,{r1}
 msr     spsr_cxsf,r1
 ldmfd   sp!,{pc}^
 bl      irqHandler

谁能帮我解决这个“^”的意思 T_T有什么不同

stmfd   sp!,{r0-r14}^

和

stmfd   sp!,{r0-r14}

？？？

Answer 1

来自ARM manual :

^

is an optional suffix. You must not use it in User mode or Systemmode. It has two purposes: If op is LDM and reglist contains the pc(r15), in addition to the normal multiple register transfer, the SPSRis copied into the CPSR. This is for returning from exceptionhandlers. Use this only from exception modes. Otherwise, data istransferred into or out of the User mode registers instead of thecurrent mode registers.