more util function

zkevm-circuits/src/evm_circuit/util/common_gadget.rs

@@ -697,6 +697,10 @@ impl<F: Field, const IS_SUCCESS_CALL: bool> CommonCallGadget<F, IS_SUCCESS_CALL>
         self.callee_address.expr()
     }
 
+    pub fn callee_address_word(&self) -> Word<Expression<F>> {
+        self.callee_address.to_word()
+    }
+
     pub fn gas_expr(&self) -> Expression<F> {
         from_bytes::expr(&self.gas.limbs[..N_BYTES_GAS])
     }
@@ -844,7 +848,13 @@ pub(crate) struct SstoreGasGadget<F, T> {
 }
 
 impl<F: Field, T: WordExpr<F>> SstoreGasGadget<F, T> {
-    pub(crate) fn construct(cb: &mut EVMConstraintBuilder<F>, is_warm: Cell<F>, value: T, value_prev: T, original_value: T) -> Self {
+    pub(crate) fn construct(
+        cb: &mut EVMConstraintBuilder<F>,
+        is_warm: Cell<F>,
+        value: T,
+        value_prev: T,
+        original_value: T,
+    ) -> Self {
         let value_eq_prev = IsEqualWordGadget::construct(cb, value, value_prev);
         let original_eq_prev = IsEqualWordGadget::construct(cb, original_value, value_prev);
         let original_is_zero = IsZeroWordGadget::construct(cb, original_value);

zkevm-circuits/src/evm_circuit/util/constraint_builder.rs

@@ -754,6 +754,17 @@ impl<'a, F: Field> EVMConstraintBuilder<'a, F> {
         word
     }
 
+    pub(crate) fn tx_context_as_account_address(
+        &mut self,
+        id: Expression<F>,
+        field_tag: TxContextFieldTag,
+        index: Option<Expression<F>>,
+    ) -> AccountAddress<F> {
+        let word = self.query_account_address();
+        self.tx_context_lookup(id, field_tag, index, word.to_word());
+        word
+    }
+
     pub(crate) fn tx_context_lookup(
         &mut self,
         id: Expression<F>,

zkevm-circuits/src/util/word.rs

@@ -258,20 +258,25 @@ impl<F: Field> Word<Expression<F>> {
     }
 
     // No overflow check on lo/hi limbs
-    pub fn add_unchecked(self, rhs: Self) -> Self {
+    pub fn add_unchecked(&self, rhs: Self) -> Self {
         Word::new([
             self.lo().clone() + rhs.lo().clone(),
             self.hi().clone() + rhs.hi().clone(),
         ])
     }
 
     // No underflow check on lo/hi limbs
-    pub fn sub_unchecked(self, rhs: Self) -> Self {
+    pub fn sub_unchecked(&self, rhs: Self) -> Self {
         Word::new([
             self.lo().clone() - rhs.lo().clone(),
             self.hi().clone() - rhs.hi().clone(),
         ])
     }
+
+    // No overflow check
+    pub fn expr_unchecked(&self) -> Expression<F> {
+        self.lo().clone() * (1 << 128).expr() + self.hi().clone()
+    }
 }
 
 impl<F: Field> WordExpr<F> for Word<Expression<F>> {