MIPS_R_A1
[BPF_REG_1] = {MIPS_R_A1, MIPS_R_A0},
BIT(MIPS_R_A1) | \
emit(ctx, move, MIPS_R_A1, src);
emit(ctx, addiu, MIPS_R_A1, MIPS_R_T9, off);
emit(ctx, move, MIPS_R_A1, lo(r0));
[BPF_REG_2] = MIPS_R_A1,