chore(avm): disable mem gas accounting (#6862)

Calculating complex opcode-dependent gas in the AVM is complex. Disable
for now.

After this PR, the simulator only uses the BaseGasCost table to assign
gas to opcodes (EXCEPT externalCall).

See #6861.

cc: @spalladino.

yarn-project/end-to-end/src/benchmarks/bench_tx_size_fees.test.ts

@@ -72,7 +72,7 @@ describe('benchmarks/tx_size_fees', () => {
       // non-rev: 1 nullifiers, overhead; rev: 2 note hashes, 1 nullifier, 1168 B enc note logs, 0 B enc logs,0 B unenc logs, teardown
       // L2:
       // non-rev: 0; rev: 0
-      200752420n,
+      200072320n,
     ],
     [
       'private fee',
@@ -81,7 +81,7 @@ describe('benchmarks/tx_size_fees', () => {
       // non-rev: 3 nullifiers, overhead; rev: 2 note hashes, 1168 B enc note logs, 0 B enc logs, 0 B unenc logs, teardown
       // L2:
       // non-rev: 0; rev: 0
-      200243972n,
+      200036352n,
     ],
   ] as const)(
     'sends a tx with a fee with %s payment method',

yarn-project/end-to-end/src/e2e_avm_simulator.test.ts

@@ -61,7 +61,7 @@ describe('e2e_avm_simulator', () => {
         const l2GasUsed = simulation.publicOutput!.end.gasUsed.l2Gas! - l2TeardownAllocation;
         // L2 gas used will vary a lot depending on codegen and other factors,
         // so we just set a wide range for it, and check it's not a suspiciously round number.
-        expect(l2GasUsed).toBeGreaterThan(1e3);
+        expect(l2GasUsed).toBeGreaterThan(150);
         expect(l2GasUsed).toBeLessThan(1e6);
         expect(l2GasUsed! % 1000).not.toEqual(0);
       });

yarn-project/end-to-end/src/e2e_fees/private_payments.test.ts

@@ -123,21 +123,21 @@ describe('e2e_fees private_payment', () => {
      * 1160 bytes of logs = 1160 * DA_GAS_PER_BYTE = 1160 * 16 = 5568 DA gas
      * tx overhead of 512 DA gas
      * for a total of 21632 DA gas (without gas used during public execution)
-     * public execution uses 222340 gas
-     * for a total of 243972 gas
+     * public execution uses N gas
+     * for a total of 200036352 gas
      *
      * The default teardown gas allocation at present is
      * 100_000_000 for both DA and L2 gas.
      *
-     * That produces a grand total of 200243972n.
+     * That produces a grand total of 200036352.
      *
      * This will change because we are presently squashing notes/nullifiers across non/revertible during
      * private execution, but we shouldn't.
      *
      * TODO(6583): update this comment properly now that public execution consumes gas
      */
 
-    expect(tx.transactionFee).toEqual(200243972n);
+    expect(tx.transactionFee).toEqual(200036352n);
     await expect(t.getCoinbaseBalance()).resolves.toEqual(InitialSequencerL1Gas + tx.transactionFee!);
     const [feeAmount, refundAmount] = getFeeAndRefund(tx);
 

yarn-project/simulator/src/avm/avm_gas.test.ts

@@ -4,10 +4,10 @@ import { initContext } from './fixtures/index.js';
 import { Add, CalldataCopy, Div, Mul, Set as SetInstruction, Sub } from './opcodes/index.js';
 import { encodeToBytecode } from './serialization/bytecode_serialization.js';
 
-describe('AVM simulator: dynamic gas costs per instruction', () => {
+describe.skip('AVM simulator: dynamic gas costs per instruction', () => {
   it.each([
     // BASE_GAS(10) * 1 + MEMORY_WRITE(100) = 110
-    [new SetInstruction(/*indirect=*/ 0, /*inTag=*/ TypeTag.UINT8, /*value=*/ 1, /*dstOffset=*/ 0), [110, 0, 0]],
+    [new SetInstruction(/*indirect=*/ 0, /*inTag=*/ TypeTag.UINT8, /*value=*/ 1, /*dstOffset=*/ 0), [110, 0]],
     // BASE_GAS(10) * 1 + MEMORY_WRITE(100) = 110
     [new SetInstruction(/*indirect=*/ 0, /*inTag=*/ TypeTag.UINT32, /*value=*/ 1, /*dstOffset=*/ 0), [110]],
     // BASE_GAS(10) * 1 + MEMORY_WRITE(100) = 110

yarn-project/simulator/src/avm/avm_gas.ts

@@ -49,93 +49,86 @@ export const EmptyGas: Gas = {
 /** Dimensions of gas usage: L1, L2, and DA. */
 export const GasDimensions = ['l2Gas', 'daGas'] as const;
 
-/** Null object to represent a gas cost that's dynamic instead of fixed for a given instruction. */
-export const DynamicGasCost = Symbol('DynamicGasCost');
-
-/** Temporary default gas cost. We should eventually remove all usage of this variable in favor of actual gas for each opcode. */
-const TemporaryDefaultGasCost = { l2Gas: 10, daGas: 0 };
+/** Default gas cost for an opcode. */
+const DefaultBaseGasCost: Gas = { l2Gas: 10, daGas: 0 };
 
 /** Base gas costs for each instruction. Additional gas cost may be added on top due to memory or storage accesses, etc. */
-export const GasCosts: Record<Opcode, Gas | typeof DynamicGasCost> = {
-  [Opcode.ADD]: TemporaryDefaultGasCost,
-  [Opcode.SUB]: TemporaryDefaultGasCost,
-  [Opcode.MUL]: TemporaryDefaultGasCost,
-  [Opcode.DIV]: TemporaryDefaultGasCost,
-  [Opcode.FDIV]: TemporaryDefaultGasCost,
-  [Opcode.EQ]: TemporaryDefaultGasCost,
-  [Opcode.LT]: TemporaryDefaultGasCost,
-  [Opcode.LTE]: TemporaryDefaultGasCost,
-  [Opcode.AND]: TemporaryDefaultGasCost,
-  [Opcode.OR]: TemporaryDefaultGasCost,
-  [Opcode.XOR]: TemporaryDefaultGasCost,
-  [Opcode.NOT]: TemporaryDefaultGasCost,
-  [Opcode.SHL]: TemporaryDefaultGasCost,
-  [Opcode.SHR]: TemporaryDefaultGasCost,
-  [Opcode.CAST]: TemporaryDefaultGasCost,
+const BaseGasCosts: Record<Opcode, Gas> = {
+  [Opcode.ADD]: DefaultBaseGasCost,
+  [Opcode.SUB]: DefaultBaseGasCost,
+  [Opcode.MUL]: DefaultBaseGasCost,
+  [Opcode.DIV]: DefaultBaseGasCost,
+  [Opcode.FDIV]: DefaultBaseGasCost,
+  [Opcode.EQ]: DefaultBaseGasCost,
+  [Opcode.LT]: DefaultBaseGasCost,
+  [Opcode.LTE]: DefaultBaseGasCost,
+  [Opcode.AND]: DefaultBaseGasCost,
+  [Opcode.OR]: DefaultBaseGasCost,
+  [Opcode.XOR]: DefaultBaseGasCost,
+  [Opcode.NOT]: DefaultBaseGasCost,
+  [Opcode.SHL]: DefaultBaseGasCost,
+  [Opcode.SHR]: DefaultBaseGasCost,
+  [Opcode.CAST]: DefaultBaseGasCost,
   // Execution environment
-  [Opcode.ADDRESS]: TemporaryDefaultGasCost,
-  [Opcode.STORAGEADDRESS]: TemporaryDefaultGasCost,
-  [Opcode.SENDER]: TemporaryDefaultGasCost,
-  [Opcode.FEEPERL2GAS]: TemporaryDefaultGasCost,
-  [Opcode.FEEPERDAGAS]: TemporaryDefaultGasCost,
-  [Opcode.TRANSACTIONFEE]: TemporaryDefaultGasCost,
-  [Opcode.CONTRACTCALLDEPTH]: TemporaryDefaultGasCost,
-  [Opcode.CHAINID]: TemporaryDefaultGasCost,
-  [Opcode.VERSION]: TemporaryDefaultGasCost,
-  [Opcode.BLOCKNUMBER]: TemporaryDefaultGasCost,
-  [Opcode.TIMESTAMP]: TemporaryDefaultGasCost,
-  [Opcode.COINBASE]: TemporaryDefaultGasCost,
-  [Opcode.BLOCKL2GASLIMIT]: TemporaryDefaultGasCost,
-  [Opcode.BLOCKDAGASLIMIT]: TemporaryDefaultGasCost,
-  [Opcode.CALLDATACOPY]: TemporaryDefaultGasCost,
+  [Opcode.ADDRESS]: DefaultBaseGasCost,
+  [Opcode.STORAGEADDRESS]: DefaultBaseGasCost,
+  [Opcode.SENDER]: DefaultBaseGasCost,
+  [Opcode.FEEPERL2GAS]: DefaultBaseGasCost,
+  [Opcode.FEEPERDAGAS]: DefaultBaseGasCost,
+  [Opcode.TRANSACTIONFEE]: DefaultBaseGasCost,
+  [Opcode.CONTRACTCALLDEPTH]: DefaultBaseGasCost,
+  [Opcode.CHAINID]: DefaultBaseGasCost,
+  [Opcode.VERSION]: DefaultBaseGasCost,
+  [Opcode.BLOCKNUMBER]: DefaultBaseGasCost,
+  [Opcode.TIMESTAMP]: DefaultBaseGasCost,
+  [Opcode.COINBASE]: DefaultBaseGasCost,
+  [Opcode.BLOCKL2GASLIMIT]: DefaultBaseGasCost,
+  [Opcode.BLOCKDAGASLIMIT]: DefaultBaseGasCost,
+  [Opcode.CALLDATACOPY]: DefaultBaseGasCost,
   // Gas
-  [Opcode.L2GASLEFT]: TemporaryDefaultGasCost,
-  [Opcode.DAGASLEFT]: TemporaryDefaultGasCost,
+  [Opcode.L2GASLEFT]: DefaultBaseGasCost,
+  [Opcode.DAGASLEFT]: DefaultBaseGasCost,
   // Control flow
-  [Opcode.JUMP]: TemporaryDefaultGasCost,
-  [Opcode.JUMPI]: TemporaryDefaultGasCost,
-  [Opcode.INTERNALCALL]: TemporaryDefaultGasCost,
-  [Opcode.INTERNALRETURN]: TemporaryDefaultGasCost,
+  [Opcode.JUMP]: DefaultBaseGasCost,
+  [Opcode.JUMPI]: DefaultBaseGasCost,
+  [Opcode.INTERNALCALL]: DefaultBaseGasCost,
+  [Opcode.INTERNALRETURN]: DefaultBaseGasCost,
   // Memory
-  [Opcode.SET]: TemporaryDefaultGasCost,
-  [Opcode.MOV]: TemporaryDefaultGasCost,
-  [Opcode.CMOV]: TemporaryDefaultGasCost,
+  [Opcode.SET]: DefaultBaseGasCost,
+  [Opcode.MOV]: DefaultBaseGasCost,
+  [Opcode.CMOV]: DefaultBaseGasCost,
   // World state
-  [Opcode.SLOAD]: TemporaryDefaultGasCost,
-  [Opcode.SSTORE]: TemporaryDefaultGasCost,
-  [Opcode.NOTEHASHEXISTS]: TemporaryDefaultGasCost,
-  [Opcode.EMITNOTEHASH]: TemporaryDefaultGasCost,
-  [Opcode.NULLIFIEREXISTS]: TemporaryDefaultGasCost,
-  [Opcode.EMITNULLIFIER]: TemporaryDefaultGasCost,
-  [Opcode.L1TOL2MSGEXISTS]: TemporaryDefaultGasCost,
-  [Opcode.HEADERMEMBER]: TemporaryDefaultGasCost,
-  [Opcode.EMITUNENCRYPTEDLOG]: TemporaryDefaultGasCost,
-  [Opcode.SENDL2TOL1MSG]: TemporaryDefaultGasCost,
-  [Opcode.GETCONTRACTINSTANCE]: TemporaryDefaultGasCost,
+  [Opcode.SLOAD]: DefaultBaseGasCost,
+  [Opcode.SSTORE]: DefaultBaseGasCost,
+  [Opcode.NOTEHASHEXISTS]: DefaultBaseGasCost,
+  [Opcode.EMITNOTEHASH]: DefaultBaseGasCost,
+  [Opcode.NULLIFIEREXISTS]: DefaultBaseGasCost,
+  [Opcode.EMITNULLIFIER]: DefaultBaseGasCost,
+  [Opcode.L1TOL2MSGEXISTS]: DefaultBaseGasCost,
+  [Opcode.HEADERMEMBER]: DefaultBaseGasCost,
+  [Opcode.EMITUNENCRYPTEDLOG]: DefaultBaseGasCost,
+  [Opcode.SENDL2TOL1MSG]: DefaultBaseGasCost,
+  [Opcode.GETCONTRACTINSTANCE]: DefaultBaseGasCost,
   // External calls
-  [Opcode.CALL]: TemporaryDefaultGasCost,
-  [Opcode.STATICCALL]: TemporaryDefaultGasCost,
-  [Opcode.DELEGATECALL]: TemporaryDefaultGasCost,
-  [Opcode.RETURN]: TemporaryDefaultGasCost,
-  [Opcode.REVERT]: TemporaryDefaultGasCost,
+  [Opcode.CALL]: DefaultBaseGasCost,
+  [Opcode.STATICCALL]: DefaultBaseGasCost,
+  [Opcode.DELEGATECALL]: DefaultBaseGasCost,
+  [Opcode.RETURN]: DefaultBaseGasCost,
+  [Opcode.REVERT]: DefaultBaseGasCost,
   // Misc
-  [Opcode.DEBUGLOG]: TemporaryDefaultGasCost,
+  [Opcode.DEBUGLOG]: DefaultBaseGasCost,
   // Gadgets
-  [Opcode.KECCAK]: TemporaryDefaultGasCost,
-  [Opcode.POSEIDON2]: TemporaryDefaultGasCost,
-  [Opcode.SHA256]: TemporaryDefaultGasCost, // temp - may be removed, but alot of contracts rely on i: TemporaryDefaultGasCost,
-  [Opcode.PEDERSEN]: TemporaryDefaultGasCost, // temp - may be removed, but alot of contracts rely on i: TemporaryDefaultGasCost,t
+  [Opcode.KECCAK]: DefaultBaseGasCost,
+  [Opcode.POSEIDON2]: DefaultBaseGasCost,
+  [Opcode.SHA256]: DefaultBaseGasCost,
+  [Opcode.PEDERSEN]: DefaultBaseGasCost,
   // Conversions
-  [Opcode.TORADIXLE]: TemporaryDefaultGasCost,
+  [Opcode.TORADIXLE]: DefaultBaseGasCost,
 };
 
-/** Returns the fixed base gas cost for a given opcode, or throws if set to dynamic. */
+/** Returns the fixed base gas cost for a given opcode. */
 export function getBaseGasCost(opcode: Opcode): Gas {
-  const cost = GasCosts[opcode];
-  if (cost === DynamicGasCost) {
-    throw new Error(`Opcode ${Opcode[opcode]} has dynamic gas cost`);
-  }
-  return cost;
+  return BaseGasCosts[opcode];
 }
 
 /** Returns the gas cost associated with the memory operations performed. */

yarn-project/simulator/src/avm/avm_simulator.test.ts

@@ -50,7 +50,7 @@ describe('AVM simulator: injected bytecode', () => {
 
     expect(results.reverted).toBe(false);
     expect(results.output).toEqual([new Fr(3)]);
-    expect(context.machineState.l2GasLeft).toEqual(initialL2GasLeft - 670);
+    expect(context.machineState.l2GasLeft).toEqual(initialL2GasLeft - 30);
   });
 
   it('Should halt if runs out of gas', async () => {

yarn-project/simulator/src/avm/opcodes/arithmetic.ts

@@ -1,6 +1,5 @@
 import type { AvmContext } from '../avm_context.js';
-import { getBaseGasCost, getGasCostForTypeTag, getMemoryGasCost, sumGas } from '../avm_gas.js';
-import { type Field, type MemoryOperations, type MemoryValue, TypeTag } from '../avm_memory_types.js';
+import { type Field, type MemoryValue, TypeTag } from '../avm_memory_types.js';
 import { Opcode, OperandType } from '../serialization/instruction_serialization.js';
 import { Instruction } from './instruction.js';
 import { ThreeOperandInstruction } from './instruction_impl.js';
@@ -23,12 +22,6 @@ export abstract class ThreeOperandArithmeticInstruction extends ThreeOperandInst
     context.machineState.incrementPc();
   }
 
-  protected override gasCost(memoryOps: Partial<MemoryOperations & { indirect: number }>) {
-    const baseGasCost = getGasCostForTypeTag(this.inTag, getBaseGasCost(this.opcode));
-    const memoryGasCost = getMemoryGasCost(memoryOps);
-    return sumGas(baseGasCost, memoryGasCost);
-  }
-
   protected abstract compute(a: MemoryValue, b: MemoryValue): MemoryValue;
 }
 
@@ -101,10 +94,4 @@ export class FieldDiv extends Instruction {
     memory.assert(memoryOperations);
     context.machineState.incrementPc();
   }
-
-  protected override gasCost(memoryOps: Partial<MemoryOperations & { indirect: number }>) {
-    const baseGasCost = getGasCostForTypeTag(TypeTag.FIELD, getBaseGasCost(this.opcode));
-    const memoryGasCost = getMemoryGasCost(memoryOps);
-    return sumGas(baseGasCost, memoryGasCost);
-  }
 }

yarn-project/simulator/src/avm/opcodes/context_getters.test.ts

@@ -25,7 +25,7 @@ describe.each([
     await instruction.execute(context);
 
     const actual = context.machineState.memory.get(0).toNumber();
-    const expected = key === 'l2GasLeft' ? value - 110 : value; // l2gascost decreases when it's executed
+    const expected = key === 'l2GasLeft' ? value - 10 : value; // l2gascost decreases when it's executed
     expect(actual).toEqual(expected);
   });
 });

yarn-project/simulator/src/avm/opcodes/instruction.ts

@@ -1,7 +1,7 @@
 import { strict as assert } from 'assert';
 
 import type { AvmContext } from '../avm_context.js';
-import { getBaseGasCost, getMemoryGasCost, sumGas } from '../avm_gas.js';
+import { getBaseGasCost, sumGas } from '../avm_gas.js';
 import { type MemoryOperations } from '../avm_memory_types.js';
 import { type BufferCursor } from '../serialization/buffer_cursor.js';
 import { Opcode, type OperandType, deserialize, serialize } from '../serialization/instruction_serialization.js';
@@ -67,9 +67,11 @@ export abstract class Instruction {
    * @param memoryOps Memory operations performed by the instruction.
    * @returns Gas cost.
    */
-  protected gasCost(memoryOps: Partial<MemoryOperations & { indirect: number }> = {}) {
+  protected gasCost(_memoryOps: Partial<MemoryOperations & { indirect: number }> = {}) {
     const baseGasCost = getBaseGasCost(this.opcode);
-    const memoryGasCost = getMemoryGasCost(memoryOps);
+    // TODO(https://github.com/AztecProtocol/aztec-packages/issues/6861): reconsider.
+    // const memoryGasCost = getMemoryGasCost(memoryOps);
+    const memoryGasCost = { l2Gas: 0, daGas: 0 };
     return sumGas(baseGasCost, memoryGasCost);
   }
 

yarn-project/simulator/src/avm/opcodes/memory.ts

@@ -1,6 +1,5 @@
 import type { AvmContext } from '../avm_context.js';
-import { getBaseGasCost, getMemoryGasCost, sumGas } from '../avm_gas.js';
-import { Field, type MemoryOperations, TaggedMemory, TypeTag } from '../avm_memory_types.js';
+import { Field, TaggedMemory, TypeTag } from '../avm_memory_types.js';
 import { InstructionExecutionError } from '../errors.js';
 import { BufferCursor } from '../serialization/buffer_cursor.js';
 import { Opcode, OperandType, deserialize, serialize } from '../serialization/instruction_serialization.js';
@@ -216,10 +215,4 @@ export class CalldataCopy extends Instruction {
     memory.assert(memoryOperations);
     context.machineState.incrementPc();
   }
-
-  protected override gasCost(memoryOps: Partial<MemoryOperations & { indirect: number }> = {}) {
-    const baseGasCost = getBaseGasCost(this.opcode);
-    const memoryGasCost = getMemoryGasCost(memoryOps);
-    return sumGas(baseGasCost, memoryGasCost);
-  }
 }

yarn-project/simulator/src/avm/opcodes/storage.ts

@@ -1,8 +1,7 @@
 import { Fr } from '@aztec/foundation/fields';
 
 import type { AvmContext } from '../avm_context.js';
-import { type Gas, getBaseGasCost, getMemoryGasCost, mulGas, sumGas } from '../avm_gas.js';
-import { Field, type MemoryOperations } from '../avm_memory_types.js';
+import { Field } from '../avm_memory_types.js';
 import { StaticCallAlterationError } from '../errors.js';
 import { Opcode, OperandType } from '../serialization/instruction_serialization.js';
 import { Addressing } from './addressing_mode.js';
@@ -26,12 +25,6 @@ abstract class BaseStorageInstruction extends Instruction {
   ) {
     super();
   }
-
-  protected override gasCost(memoryOps: Partial<MemoryOperations & { indirect: number }>): Gas {
-    const baseGasCost = mulGas(getBaseGasCost(this.opcode), this.size);
-    const memoryGasCost = getMemoryGasCost(memoryOps);
-    return sumGas(baseGasCost, memoryGasCost);
-  }
 }
 
 export class SStore extends BaseStorageInstruction {