merge new circuit builder stuff

src/gadgets/arithmetic_u32.rs

@@ -0,0 +1,67 @@
+use std::collections::BTreeMap;
+use std::marker::PhantomData;
+
+use crate::field::field_types::RichField;
+use crate::field::{extension_field::Extendable, field_types::Field};
+use crate::gates::arithmetic_u32::U32ArithmeticGate;
+use crate::gates::switch::SwitchGate;
+use crate::iop::generator::{GeneratedValues, SimpleGenerator};
+use crate::iop::target::Target;
+use crate::iop::witness::{PartitionWitness, Witness};
+use crate::plonk::circuit_builder::CircuitBuilder;
+use crate::util::bimap::bimap_from_lists;
+
+pub struct U32Target(Target);
+
+impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
+    pub fn add_virtual_u32_target(&self) -> U32Target {
+        U32Target(self.add_virtual_target())
+    }
+
+    pub fn zero_u32(&self) -> U32Target {
+        U32Target(self.zero())
+    }
+
+    pub fn one_u32(&self) -> U32Target {
+        U32Target(self.one())
+    }
+
+    pub fn add_mul_u32(
+        &mut self,
+        x: U32Target,
+        y: U32Target,
+        z: U32Target,
+    ) -> (U32Target, U32Target) {
+        let (gate_index, copy) = match self.current_u32_arithmetic_gate {
+            None => {
+                let gate = U32ArithmeticGate {
+                    _phantom: PhantomData,
+                };
+                let gate_index = self.add_gate(gate.clone(), vec![]);
+                (gate_index, 0)
+            },
+            Some((gate_index, copy) => (gate_index, copy),
+        };
+
+        let output_low = self.add_virtual_u32_target();
+        let output_high = self.add_virtual_u32_target();
+
+        self.connect(Target::wire(gate_index, gate.wire_ith_multiplicand_0(copy)), x);
+        self.connect(Target::wire(gate_index, gate.wire_ith_multiplicand_1(copy)), y);
+        self.connect(Target::wire(gate_index, gate.wire_ith_addend(copy)), z);
+        self.connect(Target::wire(gate_index, gate.wire_ith_output_low_half(copy)), output_low);
+        self.connect(Target::wire(gate_index, gate.wire_ith_output_high_half(copy)), output_high);
+
+        self.current_u32_arithmetic_gate = Some((gate_index, 0));
+
+        (output_low, output_high)
+    }
+
+    pub fn add_u32(&mut self, a: U32Target, b: U32Target) -> (U32Target, U32Target) {
+        self.add_mul_u32(a, self.one_u32(), b)
+    }
+
+    pub fn mul_u32(&mut self, a: U32Target, b: U32Target) -> (U32Target, U32Target) {
+        self.add_mul_u32(a, b, self.zero_u32())
+    }
+}

src/gadgets/mod.rs

@@ -1,5 +1,6 @@
 pub mod arithmetic;
 pub mod arithmetic_extension;
+pub mod arithmetic_u32;
 pub mod hash;
 pub mod insert;
 pub mod interpolation;

src/gadgets/nonnative.rs

@@ -3,6 +3,8 @@ use std::marker::PhantomData;
 
 use crate::field::field_types::RichField;
 use crate::field::{extension_field::Extendable, field_types::Field};
+use crate::gadgets::arithmetic_u32::U32Target;
+use crate::gates::arithmetic_u32::U32ArithmeticGate;
 use crate::gates::switch::SwitchGate;
 use crate::iop::generator::{GeneratedValues, SimpleGenerator};
 use crate::iop::target::Target;
@@ -10,8 +12,6 @@ use crate::iop::witness::{PartitionWitness, Witness};
 use crate::plonk::circuit_builder::CircuitBuilder;
 use crate::util::bimap::bimap_from_lists;
 
-pub struct U32Target(Target);
-
 pub struct NonNativeTarget {
     /// The modulus of the field F' being represented.
     modulus: BigUInt,
@@ -20,18 +20,6 @@ pub struct NonNativeTarget {
 }
 
 impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
-    pub fn add_mul_u32(&mut self, x: U32Target, y: U32Target, z:U32Target) -> (U32Target, U32Target) {
-        
-    }
-
-    pub fn add_u32(&mut self, a: U32Target, b: U32Target) -> (U32Target, U32Target) {
-        
-    }
-
-    pub fn mul_u32(&mut self, a: U32Target, b: U32Target) -> (U32Target, U32Target) {
-        
-    }
-
     pub fn add_nonnative(&mut self, a: NonNativeTarget, b: NonNativeTarget) -> NonNativeTarget {
         let modulus = a.modulus;
         let num_limbs = a.limbs.len();
@@ -41,11 +29,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         let mut combined_limbs = self.add_virtual_targets(num_limbs + 1);
         let mut carry = self.zero();
         for i in 0..num_limbs {
-            let gate = ComparisonGate::new(bits, num_chunks);
-            let gate_index = self.add_gate(gate.clone(), vec![]);
-
-            self.connect(Target::wire(gate_index, gate.wire_first_input()), lhs);
-            self.connect(Target::wire(gate_index, gate.wire_second_input()), rhs);
+            
         }
     }
 
@@ -68,7 +52,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         }
 
         let reduced_limbs = self.reduce(combined_limbs, modulus);
-        
+
         NonNativeTarget {
             modulus,
             limbs: reduced_limbs,

src/gates/arithmetic_u32.rs

@@ -17,7 +17,7 @@ use crate::plonk::vars::{EvaluationTargets, EvaluationVars, EvaluationVarsBase};
 pub const NUM_U32_ARITHMETIC_OPS: usize = 3;
 
 /// A gate to perform a basic mul-add on 32-bit values (we assume they are range-checked beforehand).
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct U32ArithmeticGate<F: RichField + Extendable<D>, const D: usize> {
     _phantom: PhantomData<F>,
 }

src/plonk/circuit_builder.rs

@@ -87,6 +87,9 @@ pub struct CircuitBuilder<F: RichField + Extendable<D>, const D: usize> {
     // of switches
     pub(crate) current_switch_gates: Vec<Option<(SwitchGate<F, D>, usize, usize)>>,
 
+    // The `U32ArithmeticGate` currently being filled (so new u32 arithmetic operations will be added to this gate before creating a new one)
+    pub(crate) current_u32_arithmetic_gate: Option<(usize, usize)>,
+
     /// An available `ConstantGate` instance, if any.
     free_constant: Option<(usize, usize)>,
 }
@@ -109,6 +112,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             free_arithmetic: HashMap::new(),
             free_random_access: HashMap::new(),
             current_switch_gates: Vec::new(),
+            current_u32_arithmetic_gate: None,
             free_constant: None,
         };
         builder.check_config();