ldr sp, [sp]
ldr pc, [sp]
ldr sp, [pc]
-ldr sp, [r0, +pc]
str r0, [sp]
-str r0, [pc]
-str pc, [r0]
str sp, [r0]
-str pc, [pc]
str sp, [sp]
-str pc, [sp]
-str sp, [pc]
-str sp, [r0, +pc]
@ R13 as the first operand <Rn> in any add{s}, cmn, cmp, or sub{s} instruction.