Return 0 if account doesn't exist

evm/src/cpu/kernel/asm/balance.asm

@@ -1,21 +1,23 @@
-%macro balance
-    // stack: address
+global balance:
+    // stack: address, retdest
     %mpt_read_state_trie
-    // stack: account_ptr
+    // stack: account_ptr, retdest
+    DUP1 ISZERO %jumpi(retzero) // If the account pointer is null, return 0.
     %add_const(1)
     // stack: balance_ptr
     %mload_trie_data
-    // stack: balance
-%endmacro
-
-global balance:
-    // stack: address, retdest
-    %balance
     // stack: balance, retdest
     SWAP1 JUMP
 
-%macro selfbalance
-    // stack: (empty)
-    ADDRESS
-    %balance
-%endmacro
+retzero:
+    %stack (account_ptr, retdest) -> (retdest, 0)
+    JUMP
+
+
+global selfbalance:
+    // stack: retdest
+    %address
+    PUSH balance
+    // stack: balance, address, retdest
+    JUMP
+