Store the value of PC to Memory address

There should be all fine with these instructions unless as daith noted you are assembling Thumb/2.

"We can also specify the PC as the destination register for the result of normal data processing
operations such as ADD or SUB, but this is generally deprecated or unsupported in Thumb. An
additional type of branch instruction can be implemented using either a load (LDR) with the PC
as the target, load multiple (LDM), or stack-pop (POP) instruction with PC in the list of registers to
be loaded."

On a digression side: if you were on armv8 you won't be able to reference PC directly..

There should be all fine with these instructions unless as daith noted you are assembling Thumb/2.

"We can also specify the PC as the destination register for the result of normal data processing
operations such as ADD or SUB, but this is generally deprecated or unsupported in Thumb. An
additional type of branch instruction can be implemented using either a load (LDR) with the PC
as the target, load multiple (LDM), or stack-pop (POP) instruction with PC in the list of registers to
be loaded."

On a digression side: if you were on armv8 you won't be able to reference PC directly..