imm8m
add_off = imm8m(off);
BUILD_BUG_ON(imm8m(offsetof(struct bpf_array, ptrs)) < 0);
off = imm8m(offsetof(struct bpf_array, ptrs));
ctx->stack_size = imm8m(STACK_SIZE);
emit(ARM_ADD_I(ARM_SP, ARM_SP, imm8m(24)), ctx); // callee clean
#define imm8m(x) (__builtin_constant_p(x) ? const_imm8m(x) : imm8m(x))
int imm12 = imm8m(val);