ARM_R2
[BPF_REG_1] = {ARM_R3, ARM_R2},
if (rm[1] != ARM_R0 || rn[1] != ARM_R2) {
emit(ARM_POP(BIT(ARM_R2) | BIT(ARM_R3)), ctx);
if (rn[1] != ARM_R2) {
emit(ARM_MOV_R(ARM_R2, rn[1]), ctx);
if (rd[1] != ARM_R0 && rd[1] != ARM_R2) {
emit(ARM_POP(BIT(ARM_R2) | BIT(ARM_R3)), ctx);
#define CALLER_MASK (1 << ARM_R0 | 1 << ARM_R1 | 1 << ARM_R2 | 1 << ARM_R3)