refactor: use u256 for value type (kkrt-labs#895)

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Time spent on this PR: 0.2d

## Pull request type

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Please check the type of change your PR introduces:

- [ ] Bugfix
- [x] Feature
- [ ] Code style update (formatting, renaming)
- [ ] Refactoring (no functional changes, no api changes)
- [ ] Build related changes
- [ ] Documentation content changes
- [ ] Other (please describe):

## What is the current behavior?

<!-- Please describe the current behavior that you are modifying,
or link to a relevant issue. -->

Resolves kkrt-labs#773 

## What is the new behavior?

<!-- Please describe the behavior or changes that are being added by
this PR. -->

-
-
-

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src/kakarot/instructions/environmental_information.cairo

@@ -102,8 +102,7 @@ namespace EnvironmentalInformation {
         memory: model.Memory*,
         state: model.State*,
     }(evm: model.EVM*) -> model.EVM* {
-        let value = Helpers.to_uint256(evm.message.value);
-        Stack.push(value);
+        Stack.push(evm.message.value);
 
         return evm;
     }

src/kakarot/instructions/system_operations.cairo

@@ -54,7 +54,7 @@ namespace SystemOperations {
         let popped_len = 3 + is_create2;
         let (popped) = Stack.pop_n(3 + is_create2);
 
-        let value = popped[0];
+        let value = popped;
         let offset = popped[1];
         let size = popped[2];
 
@@ -98,7 +98,7 @@ namespace SystemOperations {
         // Check sender balance and nonce
         let sender = State.get_account(evm.message.address.evm);
         let is_nonce_overflow = is_le(Constants.MAX_NONCE + 1, sender.nonce);
-        let (is_balance_overflow) = uint256_lt([sender.balance], value);
+        let (is_balance_overflow) = uint256_lt([sender.balance], [value]);
         let stack_depth_limit = is_le(1024, evm.message.depth);
         if (is_nonce_overflow + is_balance_overflow + stack_depth_limit != 0) {
             Stack.push_uint128(0);
@@ -146,7 +146,7 @@ namespace SystemOperations {
             valid_jumpdests=valid_jumpdests,
             calldata=calldata,
             calldata_len=0,
-            value=value.low + value.high * 2 ** 128,
+            value=value,
             parent=parent,
             address=target_account.address,
             read_only=FALSE,
@@ -161,7 +161,7 @@ namespace SystemOperations {
         let target_account = Account.set_nonce(target_account, 1);
         State.update_account(target_account);
 
-        let transfer = model.Transfer(evm.message.address, target_account.address, value);
+        let transfer = model.Transfer(evm.message.address, target_account.address, [value]);
         let success = State.add_transfer(transfer);
         if (success == 0) {
             Stack.push_uint128(0);
@@ -301,7 +301,7 @@ namespace SystemOperations {
         let (popped) = Stack.pop_n(5);
         let gas_param = popped[0];
         let to = uint256_to_uint160(popped[1]);
-        let value = popped[2];
+        let value = popped + 2 * Uint256.SIZE;
         let args_offset = popped + 3 * Uint256.SIZE;
         let args_size = popped + 4 * Uint256.SIZE;
         let (ret_offset) = Stack.peek(0);
@@ -351,7 +351,7 @@ namespace SystemOperations {
         tempvar gas_stipend = gas + is_value_non_zero * Gas.CALL_STIPEND;
 
         let sender = State.get_account(evm.message.address.evm);
-        let (sender_balance_lt_value) = uint256_lt([sender.balance], value);
+        let (sender_balance_lt_value) = uint256_lt([sender.balance], [value]);
         tempvar is_max_depth_reached = 1 - is_not_zero(
             (Constants.STACK_MAX_DEPTH + 1) - evm.message.depth
         );
@@ -373,11 +373,10 @@ namespace SystemOperations {
             return evm;
         }
 
-        // TODO: fix value
         let child_evm = CallHelper.generic_call(
             evm,
             gas=gas_stipend,
-            value=value.low,
+            value=value,
             to=to,
             code_address=to,
             is_staticcall=FALSE,
@@ -387,7 +386,7 @@ namespace SystemOperations {
             ret_size=ret_size,
         );
 
-        let transfer = model.Transfer(evm.message.address, child_evm.message.address, value);
+        let transfer = model.Transfer(evm.message.address, child_evm.message.address, [value]);
         let success = State.add_transfer(transfer);
         if (success == 0) {
             let (revert_reason_len, revert_reason) = Errors.balanceError();
@@ -447,11 +446,12 @@ namespace SystemOperations {
             return evm;
         }
 
+        tempvar zero = new Uint256(0, 0);
         // Operation
         let child_evm = CallHelper.generic_call(
             evm,
             gas,
-            value=0,
+            value=zero,
             to=to,
             code_address=to,
             is_staticcall=TRUE,
@@ -486,15 +486,12 @@ namespace SystemOperations {
         let (popped) = Stack.pop_n(5);
         let gas_param = popped[0];
         let code_address = uint256_to_uint160(popped[1]);
-        let value = popped[2];
+        let value = popped + 2 * Uint256.SIZE;
         let args_offset = popped + 3 * Uint256.SIZE;
         let args_size = popped + 4 * Uint256.SIZE;
         let (ret_offset) = Stack.peek(0);
         let (ret_size) = Stack.peek(1);
 
-        tempvar is_value_non_zero = is_not_zero(value.low) + is_not_zero(value.high);
-        tempvar is_value_non_zero = is_not_zero(is_value_non_zero);
-
         // Gas
         let memory_expansion_cost = Gas.max_memory_expansion_cost(
             memory.words_len, args_offset, args_size, ret_offset, ret_size
@@ -504,7 +501,8 @@ namespace SystemOperations {
         // TODO
         let access_gas_cost = 0;
 
-        // TODO: fix value when refactoring CALLs for proper gas accounting
+        tempvar is_value_non_zero = is_not_zero(value.low) + is_not_zero(value.high);
+        tempvar is_value_non_zero = is_not_zero(is_value_non_zero);
         let transfer_gas_cost = is_value_non_zero * Gas.CALL_VALUE;
 
         let extra_gas = access_gas_cost + transfer_gas_cost;
@@ -522,7 +520,7 @@ namespace SystemOperations {
         tempvar gas_stipend = gas + is_value_non_zero * Gas.CALL_STIPEND;
 
         let sender = State.get_account(evm.message.address.evm);
-        let (sender_balance_lt_value) = uint256_lt([sender.balance], value);
+        let (sender_balance_lt_value) = uint256_lt([sender.balance], [value]);
         tempvar is_max_depth_reached = 1 - is_not_zero(
             (Constants.STACK_MAX_DEPTH + 1) - evm.message.depth
         );
@@ -547,7 +545,7 @@ namespace SystemOperations {
         let child_evm = CallHelper.generic_call(
             evm,
             gas=gas_stipend,
-            value=value.low,
+            value=value,
             to=evm.message.address.evm,
             code_address=code_address,
             is_staticcall=FALSE,
@@ -733,7 +731,7 @@ namespace CallHelper {
     }(
         evm: model.EVM*,
         gas: felt,
-        value: felt,
+        value: Uint256*,
         to: felt,
         code_address: felt,
         is_staticcall: bool,
@@ -757,7 +755,6 @@ namespace CallHelper {
                 evm_address=code_address,
                 calldata_len=args_size.low,
                 calldata=calldata,
-                value=value,
                 parent=parent,
                 gas_left=gas,
             );

src/kakarot/interfaces/interfaces.cairo

@@ -93,14 +93,14 @@ namespace IKakarot {
         to: felt,
         gas_limit: felt,
         gas_price: felt,
-        value: felt,
+        value: Uint256,
         data_len: felt,
         data: felt*,
     ) -> (return_data_len: felt, return_data: felt*, success: felt, gas_used: felt) {
     }
 
     func eth_send_transaction(
-        to: felt, gas_limit: felt, gas_price: felt, value: felt, data_len: felt, data: felt*
+        to: felt, gas_limit: felt, gas_price: felt, value: Uint256, data_len: felt, data: felt*
     ) -> (return_data_len: felt, return_data: felt*, success: felt, gas_used: felt) {
     }
 }

src/kakarot/interpreter.cairo

@@ -8,6 +8,7 @@ from starkware.cairo.common.bool import FALSE, TRUE
 from starkware.cairo.common.cairo_builtins import HashBuiltin, BitwiseBuiltin
 from starkware.cairo.common.math_cmp import is_le, is_not_zero, is_nn
 from starkware.cairo.lang.compiler.lib.registers import get_fp_and_pc
+from starkware.cairo.common.uint256 import Uint256
 
 // Internal dependencies
 from kakarot.account import Account
@@ -721,7 +722,7 @@ namespace Interpreter {
         bytecode: felt*,
         calldata_len: felt,
         calldata: felt*,
-        value: felt,
+        value: Uint256*,
         gas_limit: felt,
     ) -> (model.EVM*, model.Stack*, model.Memory*, model.State*) {
         alloc_locals;
@@ -782,12 +783,11 @@ namespace Interpreter {
 
         with state {
             // Handle value
-            let amount = Helpers.to_uint256(value);
             let origin_starknet_address = Account.compute_starknet_address(env.origin);
             tempvar origin_address = new model.Address(
                 starknet=origin_starknet_address, evm=env.origin
             );
-            let transfer = model.Transfer(origin_address, address, [amount]);
+            let transfer = model.Transfer(origin_address, address, [value]);
             let success = State.add_transfer(transfer);
 
             // Check collision

src/kakarot/kakarot.cairo

@@ -8,6 +8,7 @@ from starkware.cairo.common.bool import FALSE, TRUE
 from starkware.cairo.common.cairo_builtins import HashBuiltin, BitwiseBuiltin
 from starkware.cairo.common.uint256 import Uint256
 from starkware.starknet.common.syscalls import get_caller_address
+from starkware.cairo.common.registers import get_fp_and_pc
 
 // Local dependencies
 from backend.starknet import Starknet
@@ -130,11 +131,14 @@ func eth_call{
     to: felt,
     gas_limit: felt,
     gas_price: felt,
-    value: felt,
+    value: Uint256,
     data_len: felt,
     data: felt*,
 ) -> (return_data_len: felt, return_data: felt*, success: felt, gas_used: felt) {
-    let (evm, state) = Kakarot.eth_call(origin, to, gas_limit, gas_price, value, data_len, data);
+    alloc_locals;
+    let fp_and_pc = get_fp_and_pc();
+    local __fp__: felt* = fp_and_pc.fp_val;
+    let (evm, state) = Kakarot.eth_call(origin, to, gas_limit, gas_price, &value, data_len, data);
     let gas_used = gas_limit - evm.gas_left;
     return (evm.return_data_len, evm.return_data, 1 - evm.reverted, gas_used);
 }
@@ -155,13 +159,15 @@ func eth_call{
 @external
 func eth_send_transaction{
     syscall_ptr: felt*, pedersen_ptr: HashBuiltin*, range_check_ptr, bitwise_ptr: BitwiseBuiltin*
-}(to: felt, gas_limit: felt, gas_price: felt, value: felt, data_len: felt, data: felt*) -> (
+}(to: felt, gas_limit: felt, gas_price: felt, value: Uint256, data_len: felt, data: felt*) -> (
     return_data_len: felt, return_data: felt*, success: felt, gas_used: felt
 ) {
     alloc_locals;
+    let fp_and_pc = get_fp_and_pc();
+    local __fp__: felt* = fp_and_pc.fp_val;
     let (local starknet_caller_address) = get_caller_address();
     let (local origin) = Kakarot.safe_get_evm_address(starknet_caller_address);
-    let (evm, state) = Kakarot.eth_call(origin, to, gas_limit, gas_price, value, data_len, data);
+    let (evm, state) = Kakarot.eth_call(origin, to, gas_limit, gas_price, &value, data_len, data);
     let gas_used = gas_limit - evm.gas_left;
     let result = (evm.return_data_len, evm.return_data, 1 - evm.reverted, gas_used);
 

src/kakarot/library.cairo

@@ -7,6 +7,7 @@ from starkware.cairo.common.bool import FALSE, TRUE
 from starkware.cairo.common.cairo_builtins import HashBuiltin, BitwiseBuiltin
 from starkware.starknet.common.syscalls import get_caller_address, get_tx_info
 from starkware.cairo.common.math_cmp import is_not_zero
+from starkware.cairo.common.uint256 import Uint256
 
 from backend.starknet import Starknet
 from kakarot.account import Account
@@ -71,7 +72,7 @@ namespace Kakarot {
         to: felt,
         gas_limit: felt,
         gas_price: felt,
-        value: felt,
+        value: Uint256*,
         data_len: felt,
         data: felt*,
     ) -> (model.EVM*, model.State*) {

src/kakarot/model.cairo

@@ -103,7 +103,7 @@ namespace model {
         valid_jumpdests: DictAccess*,
         calldata: felt*,
         calldata_len: felt,
-        value: felt,
+        value: Uint256*,
         parent: Parent*,
         address: Address*,
         read_only: felt,

src/kakarot/precompiles/precompiles.cairo

@@ -9,6 +9,7 @@ from starkware.cairo.common.cairo_builtins import HashBuiltin, BitwiseBuiltin
 from starkware.cairo.common.default_dict import default_dict_new
 from starkware.cairo.common.math_cmp import is_le, is_not_zero
 from starkware.cairo.common.dict_access import DictAccess
+from starkware.cairo.common.uint256 import Uint256
 
 // Internal dependencies
 from kakarot.account import Account
@@ -32,7 +33,6 @@ namespace Precompiles {
     // @param evm_address The precompile evm_address to be executed
     // @param calldata_len The calldata length
     // @param calldata The calldata.
-    // @param value The value.
     // @param parent The calling context.
     // @param gas_left The gas left.
     // @return EVM The initialized execution context.
@@ -45,7 +45,6 @@ namespace Precompiles {
         evm_address: felt,
         calldata_len: felt,
         calldata: felt*,
-        value: felt,
         parent: model.Parent*,
         gas_left: felt,
     ) -> model.EVM* {
@@ -55,14 +54,15 @@ namespace Precompiles {
         // Precompiles don't have an actual Starknet address
         tempvar address = new model.Address(starknet=0, evm=evm_address);
         let (valid_jumdests) = default_dict_new(0);
+        tempvar value = new Uint256(0, 0);
         tempvar message = new model.Message(
             bytecode=cast(0, felt*),
             bytecode_len=0,
             valid_jumpdests_start=valid_jumdests,
             valid_jumpdests=valid_jumdests,
             calldata=cast(0, felt*),
             calldata_len=0,
-            value=0,
+            value=value,
             parent=parent,
             address=address,
             read_only=FALSE,

src/utils/eth_transaction.cairo

@@ -31,7 +31,7 @@ namespace EthTransaction {
         gas_price: felt,
         gas_limit: felt,
         destination: felt,
-        amount: felt,
+        amount: Uint256,
         chain_id: felt,
         payload_len: felt,
         payload: felt*,
@@ -71,8 +71,8 @@ namespace EthTransaction {
         let destination = Helpers.bytes_to_felt(
             sub_items[nonce_idx + 3].data_len, sub_items[nonce_idx + 3].data
         );
-        let amount = Helpers.bytes_to_felt(
-            sub_items[nonce_idx + 4].data_len, sub_items[nonce_idx + 4].data
+        let amount = Helpers.bytes_i_to_uint256(
+            sub_items[nonce_idx + 4].data, sub_items[nonce_idx + 4].data_len
         );
         let payload_len = sub_items[nonce_idx + 5].data_len;
         let payload: felt* = sub_items[nonce_idx + 5].data;
@@ -109,7 +109,7 @@ namespace EthTransaction {
         gas_price: felt,
         gas_limit: felt,
         destination: felt,
-        amount: felt,
+        amount: Uint256,
         chain_id: felt,
         payload_len: felt,
         payload: felt*,
@@ -157,8 +157,8 @@ namespace EthTransaction {
         let destination = Helpers.bytes_to_felt(
             sub_items[gas_price_idx + 2].data_len, sub_items[gas_price_idx + 2].data
         );
-        let amount = Helpers.bytes_to_felt(
-            sub_items[gas_price_idx + 3].data_len, sub_items[gas_price_idx + 3].data
+        let amount = Helpers.bytes_i_to_uint256(
+            sub_items[gas_price_idx + 3].data, sub_items[gas_price_idx + 3].data_len
         );
         let payload_len = sub_items[gas_price_idx + 4].data_len;
         let payload: felt* = sub_items[gas_price_idx + 4].data;
@@ -199,7 +199,7 @@ namespace EthTransaction {
         gas_price: felt,
         gas_limit: felt,
         destination: felt,
-        amount: felt,
+        amount: Uint256,
         chain_id: felt,
         payload_len: felt,
         payload: felt*,