zkevm-docs/4-core.markdown

@@ -669,7 +669,151 @@ fn gen_witness(&self, trace: &GethExecStep, current_state: &mut WitnessExecHelpe
 1. lookup_value约束: copy_padding_lookup_src_id - 0 , padding的src_id为默认值0  
 1. lookup_value约束: copy_padding_lookup_src_pointer - 0 , padding的src_pointer为默认值0  
 1. lookup_value约束: copy_padding_lookup_len* (copy_padding_lookup_dst_pointer - copy_lookup_dst_pointer - copy_lookup_len ), 当真实有padding数据的时候, padding的dst_pointer 与 copy的dst_pointer相差拷贝的代码长度(copy_lookup_len)  
-1. lookup_value约束: copy_padding_lookup_len* (copy_padding_lookup_dst_stamp - copy_code_stamp_start - copy_lookup_len - 1), 当真实有padding数据的时候,padding的dst_stamp与栈中最后一个元素所处的stamp相差真实拷贝的代码长度+1  
+1. lookup_value约束: copy_padding_lookup_len* (copy_padding_lookup_dst_stamp - copy_code_stamp_start - copy_lookup_len - 1), 当真实有padding数据的时候,padding的dst_stamp与栈中最后一个元素所处的stamp相差真实拷贝的代码长度+1   
+可参考如下示例代码:  
+```rust
+   fn get_constraints(
+        &self,
+        config: &ExecutionConfig<F, NUM_STATE_HI_COL, NUM_STATE_LO_COL>,
+        meta: &mut VirtualCells<F>,
+    ) -> Vec<(String, Expression<F>)> {
+        let opcode = meta.query_advice(config.opcode, Rotation::cur());
+        let pc_cur = meta.query_advice(config.pc, Rotation::cur());
+        let call_id = meta.query_advice(config.call_id, Rotation::cur());
+        let pc_next = meta.query_advice(config.pc, Rotation::next());
+        let (
+            copy_lookup_src_type,
+            copy_lookup_src_id,
+            copy_lookup_src_pointer,
+            _,
+            copy_lookup_dst_type,
+            copy_lookup_dst_id,
+            copy_lookup_dst_pointer,
+            copy_lookup_dst_stamp,
+            copy_lookup_len,
+        ) = extract_lookup_expression!(copy, config.get_copy_lookup(meta));
+
+        let (
+            copy_padding_lookup_src_type,
+            copy_padding_lookup_src_id,
+            copy_padding_lookup_src_pointer,
+            _,
+            copy_padding_lookup_dst_type,
+            copy_padding_lookup_dst_id,
+            copy_padding_lookup_dst_pointer,
+            copy_padding_lookup_dst_stamp,
+            copy_padding_lookup_len,
+        ) = extract_lookup_expression!(copy, config.get_copy_padding_lookup(meta));
+
+        let delta = AuxiliaryDelta {
+            state_stamp: STATE_STAMP_DELTA.expr()
+                + copy_lookup_len.clone()
+                + copy_padding_lookup_len.clone(),
+            stack_pointer: STACK_POINTER_DELTA.expr(),
+            ..Default::default()
+        };
+        // auxiliary constraints ...
+
+        // stack constraints ...
+
+
+        // copy lookup constraints
+        constraints.extend([
+            (
+                "etxcodecopy src_type".into(),
+                copy_lookup_len.clone()
+                    * (copy_lookup_src_type.clone() - (copy::Type::Bytecode as u8).expr()),
+            ),
+            (
+                "extcodecopy dst_type".into(),
+                copy_lookup_len.clone()
+                    * (copy_lookup_dst_type.clone() - (copy::Type::Memory as u8).expr()),
+            ),
+            (
+                "extcodecopy dst_id".into(),
+                copy_lookup_len.clone() * (copy_lookup_dst_id.clone() - call_id.clone()),
+            ),
+            (
+                "extcodecopy dst_stamp".into(),
+                copy_lookup_len.clone()
+                    * (copy_lookup_dst_stamp.clone() - copy_code_stamp_start.clone() - 1.expr()),
+            ),
+            (
+                "extcodecopy src_id".into(),
+                copy_lookup_len.clone()
+                    * (copy_lookup_src_id
+                        - copy_operands[0][0].clone() * pow_of_two::<F>(128)
+                        - copy_operands[0][1].clone()),
+            ),
+            (
+                "extcodecopy dst_pointer value_hi = 0".into(),
+                copy_operands[1][0].clone() - 0.expr(),
+            ),
+            (
+                "extcodecopy dst_pointer".into(),
+                copy_lookup_len.clone()
+                    * (copy_lookup_dst_pointer.clone() - copy_operands[1][1].clone()),
+            ),
+            (
+                "extcodecopy src_pointer value_hi = 0".into(),
+                copy_operands[2][0].clone() - 0.expr(),
+            ),
+            (
+                "extcodecopy src_pointer".into(),
+                copy_lookup_len.clone()
+                    * (copy_lookup_src_pointer.clone() - copy_operands[2][1].clone()),
+            ),
+            (
+                "extcodecopy len value_hi = 0".into(),
+                copy_operands[3][0].clone() - 0.expr(),
+            ),
+            (
+                "extcodecopy len".into(),
+                copy_lookup_len.clone() + copy_padding_lookup_len.clone()
+                    - copy_operands[3][1].clone(),
+            ),
+            (
+                "extcodecopy padding src_type".into(),
+                copy_padding_lookup_src_type.clone() - (copy::Type::default() as u8).expr(),
+            ),
+            (
+                "extcodecopy padding dst_type".into(),
+                copy_padding_lookup_len.clone()
+                    * (copy_padding_lookup_dst_type.clone() - (copy::Type::Memory as u8).expr()),
+            ),
+            (
+                "extcodecopy padding src_id".into(),
+                copy_padding_lookup_src_id.clone() - 0.expr(),
+            ),
+            (
+                "extcodecopy padding src_pointer".into(),
+                copy_padding_lookup_src_pointer.clone() - 0.expr(),
+            ),
+            (
+                "extcodecopy padding dst_id".into(),
+                copy_padding_lookup_len.clone()
+                    * (copy_padding_lookup_dst_id.clone() - call_id.clone()),
+            ),
+            (
+                "extcodecopy padding dst_pointer".into(),
+                copy_padding_lookup_len.clone()
+                    * (copy_padding_lookup_dst_pointer.clone()
+                        - copy_lookup_dst_pointer.clone()
+                        - copy_lookup_len.clone()),
+            ),
+            (
+                "extcodecopy padding copy_padding_lookup_dst_stamp".into(),
+                copy_padding_lookup_len.clone()
+                    * (copy_padding_lookup_dst_stamp.clone()
+                        - copy_code_stamp_start.clone()
+                        - copy_lookup_len.clone()
+                        - 1.expr()),
+            ),
+        ]);
+        // pc & opcode constrains ...
+        constraints
+    }
+```
 
 
 ### LookUp约束