refactor: Optimize private call stack item hash for gate count (#7285)

Fixes #7092.

In particular notice the costs around entrypoints 👀 50% reduction,
cutting away 1 million constraints.

l1-contracts/src/core/libraries/ConstantsGen.sol

@@ -146,17 +146,17 @@ library Constants {
   uint256 internal constant NULLIFIER_LENGTH = 3;
   uint256 internal constant SCOPED_NULLIFIER_LENGTH = 4;
   uint256 internal constant CALLER_CONTEXT_LENGTH = 3;
-  uint256 internal constant PRIVATE_CALL_REQUEST_LENGTH = 6;
-  uint256 internal constant SCOPED_PRIVATE_CALL_REQUEST_LENGTH = 7;
+  uint256 internal constant PRIVATE_CALL_REQUEST_LENGTH = 16;
+  uint256 internal constant SCOPED_PRIVATE_CALL_REQUEST_LENGTH = 17;
   uint256 internal constant ROLLUP_VALIDATION_REQUESTS_LENGTH = 2;
   uint256 internal constant STATE_REFERENCE_LENGTH = 8;
   uint256 internal constant TX_CONTEXT_LENGTH = 9;
   uint256 internal constant TX_REQUEST_LENGTH = 13;
   uint256 internal constant TOTAL_FEES_LENGTH = 1;
   uint256 internal constant HEADER_LENGTH = 23;
-  uint256 internal constant PRIVATE_CIRCUIT_PUBLIC_INPUTS_LENGTH = 393;
+  uint256 internal constant PRIVATE_CIRCUIT_PUBLIC_INPUTS_LENGTH = 433;
   uint256 internal constant PUBLIC_CIRCUIT_PUBLIC_INPUTS_LENGTH = 482;
-  uint256 internal constant PRIVATE_CALL_STACK_ITEM_LENGTH = 396;
+  uint256 internal constant PRIVATE_CALL_STACK_ITEM_LENGTH = 436;
   uint256 internal constant PUBLIC_CONTEXT_INPUTS_LENGTH = 41;
   uint256 internal constant AGGREGATION_OBJECT_LENGTH = 16;
   uint256 internal constant SCOPED_READ_REQUEST_LEN = 3;
@@ -166,8 +166,8 @@ library Constants {
   uint256 internal constant COMBINED_ACCUMULATED_DATA_LENGTH = 333;
   uint256 internal constant COMBINED_CONSTANT_DATA_LENGTH = 40;
   uint256 internal constant CALL_REQUEST_LENGTH = 7;
-  uint256 internal constant PRIVATE_ACCUMULATED_DATA_LENGTH = 1152;
-  uint256 internal constant PRIVATE_KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 2227;
+  uint256 internal constant PRIVATE_ACCUMULATED_DATA_LENGTH = 1232;
+  uint256 internal constant PRIVATE_KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 2307;
   uint256 internal constant PUBLIC_ACCUMULATED_DATA_LENGTH = 983;
   uint256 internal constant PUBLIC_KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 3258;
   uint256 internal constant KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 383;

noir-projects/aztec-nr/aztec/src/context/private_context.nr

@@ -405,7 +405,16 @@ impl PrivateContext {
             caller_context.storage_contract_address = self.inputs.call_context.storage_contract_address;
         }
         self.private_call_requests.push(
-            PrivateCallRequest { hash: item.hash(), caller_context, start_side_effect_counter, end_side_effect_counter }
+            PrivateCallRequest {
+            target: item.contract_address,
+            call_context: item.public_inputs.call_context,
+            function_data: item.function_data,
+            args_hash: item.public_inputs.args_hash,
+            returns_hash: item.public_inputs.returns_hash,
+            caller_context,
+            start_side_effect_counter,
+            end_side_effect_counter
+        }
         );
 
         PackedReturns::new(item.public_inputs.returns_hash)

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/components/private_call_data_validator.nr

@@ -156,8 +156,8 @@ impl PrivateCallDataValidator {
         let caller_contract_address = scoped_call_request.contract_address;
         let request = scoped_call_request.call_request;
 
-        assert_eq(
-            request.hash, call_stack_item.hash(), "calculated private_call_hash does not match provided private_call_hash at the top of the call stack"
+        assert(
+            request.matches_stack_item(call_stack_item), "calculated private_call_hash does not match provided private_call_hash at the top of the call stack"
         );
 
         let call_context = call_stack_item.public_inputs.call_context;

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/private_kernel_inner.nr

@@ -88,9 +88,7 @@ mod tests {
         pub fn execute(&mut self) -> PrivateKernelCircuitPublicInputs {
             let private_call = self.private_call.to_private_call_data();
             // Update the previous_kernel's private_call_stack with the current call_stack_item.
-            let hash = private_call.call_stack_item.hash();
-            let is_delegate_call = private_call.call_stack_item.public_inputs.call_context.is_delegate_call;
-            self.previous_kernel.add_private_call_request(hash, is_delegate_call);
+            self.previous_kernel.add_private_call_from_call_stack_item(private_call.call_stack_item);
             let previous_kernel = self.previous_kernel.to_private_kernel_data();
 
             let kernel = PrivateKernelInnerCircuitPrivateInputs { previous_kernel, private_call };

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/tests/private_call_data_validator_builder/validate_against_call_request.nr

@@ -34,7 +34,7 @@ fn validate_against_call_request_mismatch_hash_fails() {
 
     let mut request = builder.private_call.build_private_call_request();
     // Tweak the hash to be a different value.
-    request.call_request.hash += 1;
+    request.call_request.args_hash += 1;
 
     builder.validate_against_call_request(request);
 }

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/tests/private_kernel_circuit_output_validator_builder/mod.nr

@@ -64,7 +64,7 @@ impl PrivateKernelCircuitOutputValidatorBuilder {
         // Append one private call request for the current call.
         let num_private_call_requests = self.previous_kernel.private_call_requests.len();
         previous_kernel.end.private_call_stack[num_private_call_requests] = ScopedPrivateCallRequest::empty();
-        previous_kernel.end.private_call_stack[num_private_call_requests].call_request.hash = 98765432;
+        previous_kernel.end.private_call_stack[num_private_call_requests].call_request.args_hash = 98765432;
 
         let previous_kernel_array_lengths = PrivateKernelCircuitPublicInputsArrayLengths::new(previous_kernel);
         let private_call = self.private_call.to_private_call_data();

noir-projects/noir-protocol-circuits/crates/private-kernel-lib/src/tests/private_kernel_circuit_public_inputs_composer_builder/mod.nr

@@ -54,7 +54,7 @@ impl PrivateKernelCircuitPublicInputsComposerBuilder {
         let mut previous_kernel = self.previous_kernel.to_private_kernel_circuit_public_inputs();
         let num_private_call_requests = self.previous_kernel.private_call_requests.len();
         previous_kernel.end.private_call_stack[num_private_call_requests] = ScopedPrivateCallRequest::empty();
-        previous_kernel.end.private_call_stack[num_private_call_requests].call_request.hash = 98765432;
+        previous_kernel.end.private_call_stack[num_private_call_requests].call_request.args_hash = 98765432;
 
         let private_call = self.private_call.to_private_call_data();
 

noir-projects/noir-protocol-circuits/crates/types/src/abis/private_call_request.nr

@@ -1,11 +1,19 @@
 use crate::{
-    abis::{caller_context::CallerContext, side_effect::{Ordered, RangeOrdered, Scoped}},
+    abis::{
+    private_call_stack_item::PrivateCallStackItem, call_context::CallContext,
+    function_data::FunctionData, caller_context::CallerContext,
+    side_effect::{Ordered, RangeOrdered, Scoped}
+},
     address::AztecAddress, constants::{PRIVATE_CALL_REQUEST_LENGTH, SCOPED_PRIVATE_CALL_REQUEST_LENGTH},
     traits::{Empty, Serialize, Deserialize}, utils::reader::Reader
 };
 
 struct PrivateCallRequest {
-    hash: Field,
+    target: AztecAddress,
+    call_context: CallContext,
+    function_data: FunctionData,
+    args_hash: Field,
+    returns_hash: Field,
     caller_context: CallerContext,
     start_side_effect_counter: u32,
     end_side_effect_counter: u32,
@@ -28,7 +36,11 @@ impl RangeOrdered for PrivateCallRequest {
 
 impl Eq for PrivateCallRequest {
     fn eq(self, other: PrivateCallRequest) -> bool {
-        (self.hash == other.hash)
+        (self.target == other.target) 
+            & (self.call_context == other.call_context) 
+            & (self.function_data == other.function_data) 
+            & (self.args_hash == other.args_hash) 
+            & (self.returns_hash == other.returns_hash)
             & (self.caller_context == other.caller_context)
             & (self.start_side_effect_counter == other.start_side_effect_counter)
             & (self.end_side_effect_counter == other.end_side_effect_counter)
@@ -38,7 +50,11 @@ impl Eq for PrivateCallRequest {
 impl Empty for PrivateCallRequest {
     fn empty() -> Self {
         PrivateCallRequest {
-            hash: 0,
+            target: AztecAddress::empty(),
+            call_context: CallContext::empty(),
+            function_data: FunctionData::empty(),
+            args_hash: 0,
+            returns_hash: 0,
             caller_context: CallerContext::empty(),
             start_side_effect_counter: 0,
             end_side_effect_counter: 0,
@@ -50,7 +66,11 @@ impl Serialize<PRIVATE_CALL_REQUEST_LENGTH> for PrivateCallRequest {
     fn serialize(self) -> [Field; PRIVATE_CALL_REQUEST_LENGTH] {
         let mut fields: BoundedVec<Field, PRIVATE_CALL_REQUEST_LENGTH> = BoundedVec::new();
 
-        fields.push(self.hash);
+        fields.push(self.target.to_field());
+        fields.extend_from_array(self.call_context.serialize());
+        fields.extend_from_array(self.function_data.serialize());
+        fields.push(self.args_hash);
+        fields.push(self.returns_hash);
         fields.extend_from_array(self.caller_context.serialize());
         fields.push(self.start_side_effect_counter as Field);
         fields.push(self.end_side_effect_counter as Field);
@@ -65,7 +85,11 @@ impl Deserialize<PRIVATE_CALL_REQUEST_LENGTH> for PrivateCallRequest {
     fn deserialize(fields: [Field; PRIVATE_CALL_REQUEST_LENGTH]) -> PrivateCallRequest {
         let mut reader = Reader::new(fields);
         let item = PrivateCallRequest {
-            hash: reader.read(),
+            target: reader.read_struct(AztecAddress::deserialize),
+            call_context: reader.read_struct(CallContext::deserialize),
+            function_data: reader.read_struct(FunctionData::deserialize),
+            args_hash: reader.read(),
+            returns_hash: reader.read(),
             caller_context: reader.read_struct(CallerContext::deserialize),
             start_side_effect_counter: reader.read_u32(),
             end_side_effect_counter: reader.read_u32(),
@@ -79,6 +103,18 @@ impl PrivateCallRequest {
     pub fn scope(self, contract_address: AztecAddress) -> ScopedPrivateCallRequest {
         ScopedPrivateCallRequest { call_request: self, contract_address }
     }
+
+    pub fn matches_stack_item(self, stack_item: PrivateCallStackItem) -> bool {
+        (self.target == stack_item.contract_address)
+            & (self.call_context == stack_item.public_inputs.call_context)
+            & (self.function_data == stack_item.function_data)
+            & (self.args_hash == stack_item.public_inputs.args_hash)
+            & (self.returns_hash == stack_item.public_inputs.returns_hash)
+            & (self.start_side_effect_counter
+                                == stack_item.public_inputs.start_side_effect_counter)
+            & (self.end_side_effect_counter
+                                    == stack_item.public_inputs.end_side_effect_counter)
+    }
 }
 
 struct ScopedPrivateCallRequest {

noir-projects/noir-protocol-circuits/crates/types/src/abis/private_call_stack_item.nr

@@ -85,6 +85,6 @@ fn empty_hash() {
     let hash = item.hash();
 
     // Value from private_call_stack_item.test.ts "computes empty item hash" test
-    let test_data_empty_hash = 0x157022d579f892f06461fb895cdf5550b24329e15e7a41df14f9dad582fa1bc5;
+    let test_data_empty_hash = 0x2dacef1b7e5d66445049df33ac3edad6689d86c83c1f11bb2bdaa4748309fd9f;
     assert_eq(hash, test_data_empty_hash);
 }

noir-projects/noir-protocol-circuits/crates/types/src/abis/private_circuit_public_inputs.nr

@@ -250,6 +250,6 @@ fn empty_hash() {
     let inputs = PrivateCircuitPublicInputs::empty();
     let hash = inputs.hash();
     // Value from private_circuit_public_inputs.test.ts "computes empty item hash" test
-    let test_data_empty_hash = 0x1eb5048b5bdcea5ba66519ecd1cbdb9e18fd957d52830b2bcb309f4ce9bcfbd3;
+    let test_data_empty_hash = 0x25748c9f85233dc2faf9eb73b1d2772d0fcb101075845a4f507baa837dc24f6b;
     assert_eq(hash, test_data_empty_hash);
 }

noir-projects/noir-protocol-circuits/crates/types/src/constants.nr

@@ -197,7 +197,7 @@ global SCOPED_NOTE_HASH_LENGTH = NOTE_HASH_LENGTH + 1;
 global NULLIFIER_LENGTH = 3;
 global SCOPED_NULLIFIER_LENGTH = NULLIFIER_LENGTH + 1;
 global CALLER_CONTEXT_LENGTH = 2 * AZTEC_ADDRESS_LENGTH + 1;
-global PRIVATE_CALL_REQUEST_LENGTH = 3 + CALLER_CONTEXT_LENGTH;
+global PRIVATE_CALL_REQUEST_LENGTH = AZTEC_ADDRESS_LENGTH + CALL_CONTEXT_LENGTH + FUNCTION_DATA_LENGTH + 4 + CALLER_CONTEXT_LENGTH;
 global SCOPED_PRIVATE_CALL_REQUEST_LENGTH = PRIVATE_CALL_REQUEST_LENGTH + AZTEC_ADDRESS_LENGTH;
 global ROLLUP_VALIDATION_REQUESTS_LENGTH = MAX_BLOCK_NUMBER_LENGTH;
 global STATE_REFERENCE_LENGTH: u32 = APPEND_ONLY_TREE_SNAPSHOT_LENGTH + PARTIAL_STATE_REFERENCE_LENGTH;

noir-projects/noir-protocol-circuits/crates/types/src/tests/fixture_builder.nr

@@ -217,7 +217,7 @@ impl FixtureBuilder {
     }
 
     pub fn build_private_call_request(self) -> ScopedPrivateCallRequest {
-        let hash = self.to_private_call_stack_item().hash();
+        let item = self.to_private_call_stack_item();
         let is_delegate_call = self.is_delegate_call;
         let mut caller_context = CallerContext::empty();
         caller_context.is_static_call = self.is_static_call;
@@ -226,7 +226,11 @@ impl FixtureBuilder {
             caller_context.storage_contract_address = self.storage_contract_address;
         };
         PrivateCallRequest {
-            hash,
+            target: item.contract_address,
+            call_context: item.public_inputs.call_context,
+            function_data: item.function_data,
+            args_hash: item.public_inputs.args_hash,
+            returns_hash: item.public_inputs.returns_hash,
             caller_context,
             start_side_effect_counter: self.counter_start,
             end_side_effect_counter: self.counter
@@ -784,7 +788,33 @@ impl FixtureBuilder {
         self.unencrypted_log_preimages_length = preimages_length;
     }
 
-    pub fn add_private_call_request(&mut self, hash: Field, is_delegate_call: bool) {
+    pub fn add_private_call_from_call_stack_item(&mut self, item: PrivateCallStackItem) {
+        let mut caller_context = CallerContext::empty();
+        let is_delegate_call = item.public_inputs.call_context.is_delegate_call;
+        caller_context.is_static_call = self.is_static_call;
+        if is_delegate_call {
+            caller_context.msg_sender = self.msg_sender;
+            caller_context.storage_contract_address = self.storage_contract_address;
+        }
+        let start_counter = item.public_inputs.start_side_effect_counter;
+        let end_counter = item.public_inputs.end_side_effect_counter;
+        self.counter = end_counter + 1;
+
+        self.private_call_requests.push(
+            PrivateCallRequest {
+            target: item.contract_address,
+            call_context: item.public_inputs.call_context,
+            function_data: item.function_data,
+            args_hash: item.public_inputs.args_hash,
+            returns_hash: item.public_inputs.returns_hash,
+            caller_context,
+            start_side_effect_counter: start_counter,
+            end_side_effect_counter: end_counter
+        }.scope(self.contract_address)
+        );
+    }
+
+    pub fn add_private_call_request(&mut self, args_hash: Field, is_delegate_call: bool) {
         let mut caller_context = CallerContext::empty();
         caller_context.is_static_call = self.is_static_call;
         if is_delegate_call {
@@ -794,8 +824,23 @@ impl FixtureBuilder {
         let start_counter = self.next_counter();
         let end_counter = start_counter + 10;
         self.counter = end_counter + 1;
+
+        let target = AztecAddress::empty();
+        let call_context = CallContext::empty();
+        let function_data = FunctionData::empty();
+        let returns_hash = 0;
+
         self.private_call_requests.push(
-            PrivateCallRequest { hash, caller_context, start_side_effect_counter: start_counter, end_side_effect_counter: end_counter }.scope(self.contract_address)
+            PrivateCallRequest {
+            target,
+            call_context,
+            function_data,
+            args_hash,
+            returns_hash,
+            caller_context,
+            start_side_effect_counter: start_counter,
+            end_side_effect_counter: end_counter
+        }.scope(self.contract_address)
         );
     }
 

yarn-project/circuits.js/src/constants.gen.ts

@@ -130,17 +130,17 @@ export const SCOPED_NOTE_HASH_LENGTH = 4;
 export const NULLIFIER_LENGTH = 3;
 export const SCOPED_NULLIFIER_LENGTH = 4;
 export const CALLER_CONTEXT_LENGTH = 3;
-export const PRIVATE_CALL_REQUEST_LENGTH = 6;
-export const SCOPED_PRIVATE_CALL_REQUEST_LENGTH = 7;
+export const PRIVATE_CALL_REQUEST_LENGTH = 16;
+export const SCOPED_PRIVATE_CALL_REQUEST_LENGTH = 17;
 export const ROLLUP_VALIDATION_REQUESTS_LENGTH = 2;
 export const STATE_REFERENCE_LENGTH = 8;
 export const TX_CONTEXT_LENGTH = 9;
 export const TX_REQUEST_LENGTH = 13;
 export const TOTAL_FEES_LENGTH = 1;
 export const HEADER_LENGTH = 23;
-export const PRIVATE_CIRCUIT_PUBLIC_INPUTS_LENGTH = 393;
+export const PRIVATE_CIRCUIT_PUBLIC_INPUTS_LENGTH = 433;
 export const PUBLIC_CIRCUIT_PUBLIC_INPUTS_LENGTH = 482;
-export const PRIVATE_CALL_STACK_ITEM_LENGTH = 396;
+export const PRIVATE_CALL_STACK_ITEM_LENGTH = 436;
 export const PUBLIC_CONTEXT_INPUTS_LENGTH = 41;
 export const AGGREGATION_OBJECT_LENGTH = 16;
 export const SCOPED_READ_REQUEST_LEN = 3;
@@ -150,8 +150,8 @@ export const PUBLIC_DATA_UPDATE_REQUEST_LENGTH = 3;
 export const COMBINED_ACCUMULATED_DATA_LENGTH = 333;
 export const COMBINED_CONSTANT_DATA_LENGTH = 40;
 export const CALL_REQUEST_LENGTH = 7;
-export const PRIVATE_ACCUMULATED_DATA_LENGTH = 1152;
-export const PRIVATE_KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 2227;
+export const PRIVATE_ACCUMULATED_DATA_LENGTH = 1232;
+export const PRIVATE_KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 2307;
 export const PUBLIC_ACCUMULATED_DATA_LENGTH = 983;
 export const PUBLIC_KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 3258;
 export const KERNEL_CIRCUIT_PUBLIC_INPUTS_LENGTH = 383;

yarn-project/circuits.js/src/structs/__snapshots__/private_call_stack_item.test.ts.snap

@@ -1,5 +1,5 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`PrivateCallStackItem computes empty item hash 1`] = `Fr<0x157022d579f892f06461fb895cdf5550b24329e15e7a41df14f9dad582fa1bc5>`;
+exports[`PrivateCallStackItem computes empty item hash 1`] = `Fr<0x2dacef1b7e5d66445049df33ac3edad6689d86c83c1f11bb2bdaa4748309fd9f>`;
 
-exports[`PrivateCallStackItem computes hash 1`] = `Fr<0x029b1573da033e679c68a55e05987602c5e73419c4fdfdd6104e178a9a360834>`;
+exports[`PrivateCallStackItem computes hash 1`] = `Fr<0x17171557d06226fae88f7e2b57e23acd8dd767160e5149965ca0f4bebbdedb06>`;

yarn-project/circuits.js/src/structs/__snapshots__/private_circuit_public_inputs.test.ts.snap

@@ -1,5 +1,5 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`PrivateCircuitPublicInputs computes empty inputs hash 1`] = `Fr<0x1eb5048b5bdcea5ba66519ecd1cbdb9e18fd957d52830b2bcb309f4ce9bcfbd3>`;
+exports[`PrivateCircuitPublicInputs computes empty inputs hash 1`] = `Fr<0x25748c9f85233dc2faf9eb73b1d2772d0fcb101075845a4f507baa837dc24f6b>`;
 
-exports[`PrivateCircuitPublicInputs hash matches snapshot 1`] = `Fr<0x0b02f49b7283dacf553c5cfc0615c979fdd1cd146a1d4e71c78610345a711d22>`;
+exports[`PrivateCircuitPublicInputs hash matches snapshot 1`] = `Fr<0x0d8c2da0c15b53e26d2f612cec5d0ac71ce21fb6e1b00caf3e8aa5a8bb02ad65>`;

yarn-project/circuits.js/src/structs/call_context.ts

@@ -1,10 +1,11 @@
 import { FunctionSelector } from '@aztec/foundation/abi';
 import { AztecAddress } from '@aztec/foundation/aztec-address';
+import { pedersenHash } from '@aztec/foundation/crypto';
 import { Fr } from '@aztec/foundation/fields';
 import { BufferReader, FieldReader, serializeToBuffer, serializeToFields } from '@aztec/foundation/serialize';
 import { type FieldsOf } from '@aztec/foundation/types';
 
-import { CALL_CONTEXT_LENGTH } from '../constants.gen.js';
+import { CALL_CONTEXT_LENGTH, GeneratorIndex } from '../constants.gen.js';
 
 /**
  * Call context.
@@ -125,4 +126,8 @@ export class CallContext {
       callContext.sideEffectCounter === this.sideEffectCounter
     );
   }
+
+  hash(): Fr {
+    return pedersenHash(this.toFields(), GeneratorIndex.CALL_CONTEXT);
+  }
 }

yarn-project/circuits.js/src/structs/function_data.ts

@@ -48,6 +48,15 @@ export class FunctionData {
     return this.selector.isEmpty();
   }
 
+  /**
+   * Returns whether this instance is equal to another.
+   * @param other
+   * @returns
+   */
+  equals(other: FunctionData): boolean {
+    return this.selector.equals(other.selector) && this.isPrivate === other.isPrivate;
+  }
+
   /**
    * Returns a new instance of FunctionData with zero function selector.
    * @param args - Arguments to pass to the constructor.