plonky2/evm/src/cpu/dup_swap.rs
2023-12-21 15:59:16 -05:00

367 lines
13 KiB
Rust

use itertools::izip;
use plonky2::field::extension::Extendable;
use plonky2::field::packed::PackedField;
use plonky2::field::types::Field;
use plonky2::hash::hash_types::RichField;
use plonky2::iop::ext_target::ExtensionTarget;
use plonky2::plonk::circuit_builder::CircuitBuilder;
use super::membus::NUM_GP_CHANNELS;
use crate::constraint_consumer::{ConstraintConsumer, RecursiveConstraintConsumer};
use crate::cpu::columns::{CpuColumnsView, MemoryChannelView};
use crate::memory::segments::Segment;
/// Constrain two channels to have equal values.
fn channels_equal_packed<P: PackedField>(
filter: P,
ch_a: &MemoryChannelView<P>,
ch_b: &MemoryChannelView<P>,
yield_constr: &mut ConstraintConsumer<P>,
) {
for (limb_a, limb_b) in izip!(ch_a.value, ch_b.value) {
yield_constr.constraint(filter * (limb_a - limb_b));
}
}
/// Constrain two channels to have equal values.
fn channels_equal_ext_circuit<F: RichField + Extendable<D>, const D: usize>(
builder: &mut CircuitBuilder<F, D>,
filter: ExtensionTarget<D>,
ch_a: &MemoryChannelView<ExtensionTarget<D>>,
ch_b: &MemoryChannelView<ExtensionTarget<D>>,
yield_constr: &mut RecursiveConstraintConsumer<F, D>,
) {
for (limb_a, limb_b) in izip!(ch_a.value, ch_b.value) {
let diff = builder.sub_extension(limb_a, limb_b);
let constr = builder.mul_extension(filter, diff);
yield_constr.constraint(builder, constr);
}
}
/// Set `used`, `is_read`, and address for channel.
///
/// `offset` is the stack index before this instruction is executed, e.g. `0` for the top of the
/// stack.
fn constrain_channel_packed<P: PackedField>(
is_read: bool,
filter: P,
offset: P,
channel: &MemoryChannelView<P>,
lv: &CpuColumnsView<P>,
yield_constr: &mut ConstraintConsumer<P>,
) {
yield_constr.constraint(filter * (channel.used - P::ONES));
yield_constr.constraint(filter * (channel.is_read - P::Scalar::from_bool(is_read)));
yield_constr.constraint(filter * (channel.addr_context - lv.context));
yield_constr.constraint(
filter * (channel.addr_segment - P::Scalar::from_canonical_u64(Segment::Stack as u64)),
);
// Top of the stack is at `addr = lv.stack_len - 1`.
let addr_virtual = lv.stack_len - P::ONES - offset;
yield_constr.constraint(filter * (channel.addr_virtual - addr_virtual));
}
/// Set `used`, `is_read`, and address for channel.
///
/// `offset` is the stack index before this instruction is executed, e.g. `0` for the top of the
/// stack.
fn constrain_channel_ext_circuit<F: RichField + Extendable<D>, const D: usize>(
builder: &mut CircuitBuilder<F, D>,
is_read: bool,
filter: ExtensionTarget<D>,
offset: ExtensionTarget<D>,
channel: &MemoryChannelView<ExtensionTarget<D>>,
lv: &CpuColumnsView<ExtensionTarget<D>>,
yield_constr: &mut RecursiveConstraintConsumer<F, D>,
) {
{
let constr = builder.mul_sub_extension(filter, channel.used, filter);
yield_constr.constraint(builder, constr);
}
{
let constr = if is_read {
builder.mul_sub_extension(filter, channel.is_read, filter)
} else {
builder.mul_extension(filter, channel.is_read)
};
yield_constr.constraint(builder, constr);
}
{
let diff = builder.sub_extension(channel.addr_context, lv.context);
let constr = builder.mul_extension(filter, diff);
yield_constr.constraint(builder, constr);
}
{
let constr = builder.arithmetic_extension(
F::ONE,
-F::from_canonical_u64(Segment::Stack as u64),
filter,
channel.addr_segment,
filter,
);
yield_constr.constraint(builder, constr);
}
// Top of the stack is at `addr = lv.stack_len - 1`.
{
let constr = builder.add_extension(channel.addr_virtual, offset);
let constr = builder.sub_extension(constr, lv.stack_len);
let constr = builder.mul_add_extension(filter, constr, filter);
yield_constr.constraint(builder, constr);
}
}
/// Evaluates constraints for DUP.
fn eval_packed_dup<P: PackedField>(
n: P,
lv: &CpuColumnsView<P>,
nv: &CpuColumnsView<P>,
yield_constr: &mut ConstraintConsumer<P>,
) {
// DUP opcodes have 0 at the 5-th position, while SWAP opcodes have 1.
let filter = lv.op.dup_swap * (P::ONES - lv.opcode_bits[4]);
let write_channel = &lv.mem_channels[1];
let read_channel = &lv.mem_channels[2];
// Constrain the input and top of the stack channels to have the same value.
channels_equal_packed(filter, write_channel, &lv.mem_channels[0], yield_constr);
// Constrain the output channel's addresses, `is_read` and `used` fields.
constrain_channel_packed(false, filter, P::ZEROS, write_channel, lv, yield_constr);
// Constrain the output and top of the stack channels to have the same value.
channels_equal_packed(filter, read_channel, &nv.mem_channels[0], yield_constr);
// Constrain the input channel's addresses, `is_read` and `used` fields.
constrain_channel_packed(true, filter, n, read_channel, lv, yield_constr);
// Constrain nv.stack_len.
yield_constr.constraint_transition(filter * (nv.stack_len - lv.stack_len - P::ONES));
// Disable next top.
yield_constr.constraint(filter * nv.mem_channels[0].used);
// Constrain unused channels.
for i in 3..NUM_GP_CHANNELS {
yield_constr.constraint(filter * lv.mem_channels[i].used);
}
}
/// Circuit version of `eval_packed_dup`.
/// Evaluates constraints for DUP.
fn eval_ext_circuit_dup<F: RichField + Extendable<D>, const D: usize>(
builder: &mut CircuitBuilder<F, D>,
n: ExtensionTarget<D>,
lv: &CpuColumnsView<ExtensionTarget<D>>,
nv: &CpuColumnsView<ExtensionTarget<D>>,
yield_constr: &mut RecursiveConstraintConsumer<F, D>,
) {
let zero = builder.zero_extension();
let one = builder.one_extension();
// DUP opcodes have 0 at the 5-th position, while SWAP opcodes have 1.
let mut filter = builder.sub_extension(one, lv.opcode_bits[4]);
filter = builder.mul_extension(lv.op.dup_swap, filter);
let write_channel = &lv.mem_channels[1];
let read_channel = &lv.mem_channels[2];
// Constrain the input and top of the stack channels to have the same value.
channels_equal_ext_circuit(
builder,
filter,
write_channel,
&lv.mem_channels[0],
yield_constr,
);
// Constrain the output channel's addresses, `is_read` and `used` fields.
constrain_channel_ext_circuit(
builder,
false,
filter,
zero,
write_channel,
lv,
yield_constr,
);
// Constrain the output and top of the stack channels to have the same value.
channels_equal_ext_circuit(
builder,
filter,
read_channel,
&nv.mem_channels[0],
yield_constr,
);
// Constrain the input channel's addresses, `is_read` and `used` fields.
constrain_channel_ext_circuit(builder, true, filter, n, read_channel, lv, yield_constr);
// Constrain nv.stack_len.
{
let diff = builder.sub_extension(nv.stack_len, lv.stack_len);
let constr = builder.mul_sub_extension(filter, diff, filter);
yield_constr.constraint_transition(builder, constr);
}
// Disable next top.
{
let constr = builder.mul_extension(filter, nv.mem_channels[0].used);
yield_constr.constraint(builder, constr);
}
// Constrain unused channels.
for i in 3..NUM_GP_CHANNELS {
let constr = builder.mul_extension(filter, lv.mem_channels[i].used);
yield_constr.constraint(builder, constr);
}
}
/// Evaluates constraints for SWAP.
fn eval_packed_swap<P: PackedField>(
n: P,
lv: &CpuColumnsView<P>,
nv: &CpuColumnsView<P>,
yield_constr: &mut ConstraintConsumer<P>,
) {
let n_plus_one = n + P::ONES;
// DUP opcodes have 0 at the 5-th position, while SWAP opcodes have 1.
let filter = lv.op.dup_swap * lv.opcode_bits[4];
let in1_channel = &lv.mem_channels[0];
let in2_channel = &lv.mem_channels[1];
let out_channel = &lv.mem_channels[2];
// Constrain the first input channel value to be equal to the output channel value.
channels_equal_packed(filter, in1_channel, out_channel, yield_constr);
// We set `is_read`, `used` and the address for the first input. The first input is
// read from the top of the stack, and is therefore not a memory read.
constrain_channel_packed(false, filter, n_plus_one, out_channel, lv, yield_constr);
// Constrain the second input channel value to be equal to the new top of the stack.
channels_equal_packed(filter, in2_channel, &nv.mem_channels[0], yield_constr);
// We set `is_read`, `used` and the address for the second input.
constrain_channel_packed(true, filter, n_plus_one, in2_channel, lv, yield_constr);
// Constrain nv.stack_len.
yield_constr.constraint(filter * (nv.stack_len - lv.stack_len));
// Disable next top.
yield_constr.constraint(filter * nv.mem_channels[0].used);
// Constrain unused channels.
for i in 3..NUM_GP_CHANNELS {
yield_constr.constraint(filter * lv.mem_channels[i].used);
}
}
/// Circuit version of `eval_packed_swap`.
/// Evaluates constraints for SWAP.
fn eval_ext_circuit_swap<F: RichField + Extendable<D>, const D: usize>(
builder: &mut CircuitBuilder<F, D>,
n: ExtensionTarget<D>,
lv: &CpuColumnsView<ExtensionTarget<D>>,
nv: &CpuColumnsView<ExtensionTarget<D>>,
yield_constr: &mut RecursiveConstraintConsumer<F, D>,
) {
let one = builder.one_extension();
let n_plus_one = builder.add_extension(n, one);
// DUP opcodes have 0 at the 5-th position, while SWAP opcodes have 1.
let filter = builder.mul_extension(lv.op.dup_swap, lv.opcode_bits[4]);
let in1_channel = &lv.mem_channels[0];
let in2_channel = &lv.mem_channels[1];
let out_channel = &lv.mem_channels[2];
// Constrain the first input channel value to be equal to the output channel value.
channels_equal_ext_circuit(builder, filter, in1_channel, out_channel, yield_constr);
// We set `is_read`, `used` and the address for the first input. The first input is
// read from the top of the stack, and is therefore not a memory read.
constrain_channel_ext_circuit(
builder,
false,
filter,
n_plus_one,
out_channel,
lv,
yield_constr,
);
// Constrain the second input channel value to be equal to the new top of the stack.
channels_equal_ext_circuit(
builder,
filter,
in2_channel,
&nv.mem_channels[0],
yield_constr,
);
// We set `is_read`, `used` and the address for the second input.
constrain_channel_ext_circuit(
builder,
true,
filter,
n_plus_one,
in2_channel,
lv,
yield_constr,
);
// Constrain nv.stack_len.
let diff = builder.sub_extension(nv.stack_len, lv.stack_len);
let constr = builder.mul_extension(filter, diff);
yield_constr.constraint(builder, constr);
// Disable next top.
{
let constr = builder.mul_extension(filter, nv.mem_channels[0].used);
yield_constr.constraint(builder, constr);
}
// Constrain unused channels.
for i in 3..NUM_GP_CHANNELS {
let constr = builder.mul_extension(filter, lv.mem_channels[i].used);
yield_constr.constraint(builder, constr);
}
}
/// Evaluates the constraints for the DUP and SWAP opcodes.
pub(crate) fn eval_packed<P: PackedField>(
lv: &CpuColumnsView<P>,
nv: &CpuColumnsView<P>,
yield_constr: &mut ConstraintConsumer<P>,
) {
let n = lv.opcode_bits[0]
+ lv.opcode_bits[1] * P::Scalar::from_canonical_u64(2)
+ lv.opcode_bits[2] * P::Scalar::from_canonical_u64(4)
+ lv.opcode_bits[3] * P::Scalar::from_canonical_u64(8);
eval_packed_dup(n, lv, nv, yield_constr);
eval_packed_swap(n, lv, nv, yield_constr);
// For both, disable the partial channel.
yield_constr.constraint(lv.op.dup_swap * lv.partial_channel.used);
}
/// Circuit version of `eval_packed`.
/// Evaluates the constraints for the DUP and SWAP opcodes.
pub(crate) fn eval_ext_circuit<F: RichField + Extendable<D>, const D: usize>(
builder: &mut CircuitBuilder<F, D>,
lv: &CpuColumnsView<ExtensionTarget<D>>,
nv: &CpuColumnsView<ExtensionTarget<D>>,
yield_constr: &mut RecursiveConstraintConsumer<F, D>,
) {
let n = lv.opcode_bits[..4].iter().enumerate().fold(
builder.zero_extension(),
|cumul, (i, &bit)| {
builder.mul_const_add_extension(F::from_canonical_u64(1 << i), bit, cumul)
},
);
eval_ext_circuit_dup(builder, n, lv, nv, yield_constr);
eval_ext_circuit_swap(builder, n, lv, nv, yield_constr);
// For both, disable the partial channel.
{
let constr = builder.mul_extension(lv.op.dup_swap, lv.partial_channel.used);
yield_constr.constraint(builder, constr);
}
}