Function emit_ld_reg

dpdk/lib/bpf/bpf_jit_x86.c:566–591

* emit mov (% ), % * note that for non 64-bit ops, higher bits have to be cleared. */

 * note that for non 64-bit ops, higher bits have to be cleared.
 */
static void
emit_ld_reg(struct bpf_jit_state *st, uint32_t op, uint32_t sreg, uint32_t dreg,
	int32_t ofs)
{
	uint32_t mods, opsz;
	const uint8_t op32 = 0x8B;
	const uint8_t op16[] = {0x0F, 0xB7};
	const uint8_t op8[] = {0x0F, 0xB6};

	emit_rex(st, op, dreg, sreg);

	opsz = BPF_SIZE(op);
	if (opsz == BPF_B)
		emit_bytes(st, op8, sizeof(op8));
	else if (opsz == BPF_H)
		emit_bytes(st, op16, sizeof(op16));
	else
		emit_bytes(st, &op32, sizeof(op32));

	mods = (imm_size(ofs) == 1) ? MOD_IDISP8 : MOD_IDISP32;

	emit_modregrm(st, mods, dreg, sreg);
	if (sreg == RSP || sreg == R12)
		emit_sib(st, SIB_SCALE_1, sreg, sreg);
	emit_imm(st, ofs, imm_size(ofs));
}

/*
 * emit one of: