chore(avm): remove field support for comparators and bitwise ops (#4516)

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

@@ -175,13 +175,6 @@ describe('Field', () => {
     expect(field1.equals(field3)).toBe(false);
   });
 
-  it(`Should check if one Field is less than another correctly`, () => {
-    const field1 = new Field(5);
-    const field2 = new Field(10);
-    expect(field1.lt(field2)).toBe(true);
-    expect(field2.lt(field1)).toBe(false);
-  });
-
   it(`Should convert Field to BigInt correctly`, () => {
     const field = new Field(5);
     expect(field.toBigInt()).toStrictEqual(5n);

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

@@ -11,7 +11,6 @@ export abstract class MemoryValue {
   public abstract div(rhs: MemoryValue): MemoryValue;
 
   public abstract equals(rhs: MemoryValue): boolean;
-  public abstract lt(rhs: MemoryValue): boolean;
 
   // We need this to be able to build an instance of the subclasses.
   public abstract build(n: bigint): MemoryValue;
@@ -32,6 +31,8 @@ export abstract class IntegralValue extends MemoryValue {
   public abstract or(rhs: IntegralValue): IntegralValue;
   public abstract xor(rhs: IntegralValue): IntegralValue;
   public abstract not(): IntegralValue;
+
+  public abstract lt(rhs: MemoryValue): boolean;
 }
 
 // TODO: Optimize calculation of mod, etc. Can only do once per class?
@@ -200,10 +201,6 @@ export class Field extends MemoryValue {
     return this.rep.equals(rhs.rep);
   }
 
-  public lt(rhs: Field): boolean {
-    return this.rep.lt(rhs.rep);
-  }
-
   public toBigInt(): bigint {
     return this.rep.toBigInt();
   }
@@ -284,7 +281,13 @@ export class TaggedMemory {
    */
   public checkTag(tag: TypeTag, offset: number) {
     if (this.getTag(offset) !== tag) {
-      throw new TagCheckError(offset, TypeTag[this.getTag(offset)], TypeTag[tag]);
+      throw TagCheckError.forOffset(offset, TypeTag[this.getTag(offset)], TypeTag[tag]);
+    }
+  }
+
+  public static checkIsIntegralTag(tag: TypeTag) {
+    if (![TypeTag.UINT8, TypeTag.UINT16, TypeTag.UINT32, TypeTag.UINT64, TypeTag.UINT128].includes(tag)) {
+      throw TagCheckError.forTag(TypeTag[tag], 'integral');
     }
   }
 

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

@@ -42,8 +42,16 @@ export class InstructionExecutionError extends AvmExecutionError {
  * Error thrown on failed AVM memory tag check.
  */
 export class TagCheckError extends AvmExecutionError {
-  constructor(offset: number, gotTag: string, expectedTag: string) {
-    super(`Memory offset ${offset} has tag ${gotTag}, expected ${expectedTag}`);
+  public static forOffset(offset: number, gotTag: string, expectedTag: string): TagCheckError {
+    return new TagCheckError(`Tag mismatch at offset ${offset}, got ${gotTag}, expected ${expectedTag}`);
+  }
+
+  public static forTag(gotTag: string, expectedTag: string): TagCheckError {
+    return new TagCheckError(`Tag mismatch, got ${gotTag}, expected ${expectedTag}`);
+  }
+
+  constructor(message: string) {
+    super(message);
     this.name = 'TagCheckError';
   }
 }

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

@@ -110,19 +110,11 @@ describe('Comparators', () => {
       expect(actual).toEqual([new Uint32(0), new Uint32(1), new Uint32(0)]);
     });
 
-    it('Works on field elements', async () => {
-      context.machineState.memory.setSlice(0, [new Field(1), new Field(2), new Field(0)]);
-
-      [
-        new Lt(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 0, /*dstOffset=*/ 10),
-        new Lt(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 1, /*dstOffset=*/ 11),
-        new Lt(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 2, /*dstOffset=*/ 12),
-      ].forEach(i => i.execute(context));
-
-      const actual = context.machineState.memory.getSlice(/*offset=*/ 10, /*size=*/ 4);
-      expect(actual).toEqual([new Field(0), new Field(1), new Field(0)]);
+    it('Does not work on field elements', async () => {
+      await expect(() =>
+        new Lt(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 1, /*dstOffset=*/ 10).execute(context),
+      ).rejects.toThrow(TagCheckError);
     });
-
     it('InTag is checked', async () => {
       context.machineState.memory.setSlice(0, [new Field(1), new Uint32(2), new Uint16(3)]);
 
@@ -174,17 +166,10 @@ describe('Comparators', () => {
       expect(actual).toEqual([new Uint32(1), new Uint32(1), new Uint32(0)]);
     });
 
-    it('Works on field elements', async () => {
-      context.machineState.memory.setSlice(0, [new Field(1), new Field(2), new Field(0)]);
-
-      [
-        new Lte(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 0, /*dstOffset=*/ 10),
-        new Lte(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 1, /*dstOffset=*/ 11),
-        new Lte(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 2, /*dstOffset=*/ 12),
-      ].forEach(i => i.execute(context));
-
-      const actual = context.machineState.memory.getSlice(/*offset=*/ 10, /*size=*/ 4);
-      expect(actual).toEqual([new Field(1), new Field(1), new Field(0)]);
+    it('Does not work on field elements', async () => {
+      await expect(() =>
+        new Lte(/*indirect=*/ 0, TypeTag.FIELD, /*aOffset=*/ 0, /*bOffset=*/ 1, /*dstOffset=*/ 10).execute(context),
+      ).rejects.toThrow(TagCheckError);
     });
 
     it('InTag is checked', async () => {

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

@@ -1,4 +1,5 @@
 import type { AvmContext } from '../avm_context.js';
+import { IntegralValue, TaggedMemory } from '../avm_memory_types.js';
 import { Opcode } from '../serialization/instruction_serialization.js';
 import { ThreeOperandInstruction } from './instruction_impl.js';
 
@@ -34,9 +35,10 @@ export class Lt extends ThreeOperandInstruction {
 
   async execute(context: AvmContext): Promise<void> {
     context.machineState.memory.checkTags(this.inTag, this.aOffset, this.bOffset);
+    TaggedMemory.checkIsIntegralTag(this.inTag);
 
-    const a = context.machineState.memory.get(this.aOffset);
-    const b = context.machineState.memory.get(this.bOffset);
+    const a = context.machineState.memory.getAs<IntegralValue>(this.aOffset);
+    const b = context.machineState.memory.getAs<IntegralValue>(this.bOffset);
 
     // Result will be of the same type as 'a'.
     const dest = a.build(a.lt(b) ? 1n : 0n);
@@ -56,9 +58,10 @@ export class Lte extends ThreeOperandInstruction {
 
   async execute(context: AvmContext): Promise<void> {
     context.machineState.memory.checkTags(this.inTag, this.aOffset, this.bOffset);
+    TaggedMemory.checkIsIntegralTag(this.inTag);
 
-    const a = context.machineState.memory.get(this.aOffset);
-    const b = context.machineState.memory.get(this.bOffset);
+    const a = context.machineState.memory.getAs<IntegralValue>(this.aOffset);
+    const b = context.machineState.memory.getAs<IntegralValue>(this.bOffset);
 
     // Result will be of the same type as 'a'.
     const dest = a.build(a.equals(b) || a.lt(b) ? 1n : 0n);

yellow-paper/docs/public-vm/gen/_InstructionSet.mdx

@@ -576,7 +576,7 @@ Less-than check (a < b)
 - **Category**: Compute - Comparators
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's left input
 	- **bOffset**: memory offset of the operation's right input
@@ -597,7 +597,7 @@ Less-than-or-equals check (a <= b)
 - **Category**: Compute - Comparators
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's left input
 	- **bOffset**: memory offset of the operation's right input
@@ -618,7 +618,7 @@ Bitwise AND (a & b)
 - **Category**: Compute - Bitwise
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's left input
 	- **bOffset**: memory offset of the operation's right input
@@ -639,7 +639,7 @@ Bitwise OR (a | b)
 - **Category**: Compute - Bitwise
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's left input
 	- **bOffset**: memory offset of the operation's right input
@@ -660,7 +660,7 @@ Bitwise XOR (a ^ b)
 - **Category**: Compute - Bitwise
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's left input
 	- **bOffset**: memory offset of the operation's right input
@@ -681,7 +681,7 @@ Bitwise NOT (inversion)
 - **Category**: Compute - Bitwise
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's input
 	- **dstOffset**: memory offset specifying where to store operation's result
@@ -701,7 +701,7 @@ Bitwise leftward shift (a << b)
 - **Category**: Compute - Bitwise
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's left input
 	- **bOffset**: memory offset of the operation's right input
@@ -722,7 +722,7 @@ Bitwise rightward shift (a >> b)
 - **Category**: Compute - Bitwise
 - **Flags**: 
 	- **indirect**: Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.
-	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.
+	- **inTag**: The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with. `field` type is NOT supported for this instruction.
 - **Args**: 
 	- **aOffset**: memory offset of the operation's left input
 	- **bOffset**: memory offset of the operation's right input

yellow-paper/src/preprocess/InstructionSet/InstructionSet.js

@@ -8,6 +8,7 @@ const TOPICS_IN_SECTIONS = [
 ];
 
 const IN_TAG_DESCRIPTION = "The [tag/size](./state-model#tags-and-tagged-memory) to check inputs against and tag the destination with.";
+const IN_TAG_DESCRIPTION_NO_FIELD = IN_TAG_DESCRIPTION + " `field` type is NOT supported for this instruction.";
 const DST_TAG_DESCRIPTION = "The [tag/size](./state-model#tags-and-tagged-memory) to tag the destination with but not to check inputs against.";
 const INDIRECT_FLAG_DESCRIPTION = "Toggles whether each memory-offset argument is an indirect offset. Rightmost bit corresponds to 0th offset arg, etc. Indirect offsets result in memory accesses like `M[M[offset]]` instead of the more standard `M[offset]`.";
 
@@ -113,7 +114,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Comparators",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's left input"},
@@ -132,7 +133,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Comparators",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's left input"},
@@ -151,7 +152,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Bitwise",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's left input"},
@@ -170,7 +171,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Bitwise",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's left input"},
@@ -189,7 +190,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Bitwise",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's left input"},
@@ -208,7 +209,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Bitwise",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's input"},
@@ -226,7 +227,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Bitwise",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's left input"},
@@ -245,7 +246,7 @@ const INSTRUCTION_SET_RAW = [
         "Category": "Compute - Bitwise",
         "Flags": [
             {"name": "indirect", "description": INDIRECT_FLAG_DESCRIPTION},
-            {"name": "inTag", "description": IN_TAG_DESCRIPTION},
+            {"name": "inTag", "description": IN_TAG_DESCRIPTION_NO_FIELD},
         ],
         "Args": [
             {"name": "aOffset", "description": "memory offset of the operation's left input"},