Fix to add_eth

It was creating a new account with the hash of an empty storage trie, when really it should be a pointer to an empty storage trie. We can use 0 as this pointer since `@SEGMENT_TRIE_DATA[0] = 0 = @MPT_NODE_EMPTY`.

Also a couple tweaks that helped me debug, like moving the memory value range checks from the interpreter into `MemoryState`, so they're done in actual witness generation as well as interpreter tests.

evm/src/cpu/kernel/asm/core/transfer.asm

@@ -97,7 +97,7 @@ global add_eth_new_account:
     PUSH 0 %append_to_trie_data // nonce
     %append_to_trie_data // balance
     // stack: addr, new_account_ptr, retdest
-    PUSH @EMPTY_NODE_HASH %append_to_trie_data // storage root
+    PUSH 0 %append_to_trie_data // storage root pointer
     PUSH @EMPTY_STRING_HASH %append_to_trie_data // code hash
     // stack: addr, new_account_ptr, retdest
     %addr_to_state_key

evm/src/cpu/kernel/interpreter.rs

@@ -15,7 +15,7 @@ use crate::generation::prover_input::ProverInputFn;
 use crate::generation::state::GenerationState;
 use crate::generation::GenerationInputs;
 use crate::memory::segments::Segment;
-use crate::witness::memory::{MemoryContextState, MemorySegmentState, MemoryState};
+use crate::witness::memory::{MemoryAddress, MemoryContextState, MemorySegmentState, MemoryState};
 use crate::witness::util::stack_peek;
 
 type F = GoldilocksField;
@@ -25,22 +25,11 @@ const DEFAULT_HALT_OFFSET: usize = 0xdeadbeef;
 
 impl MemoryState {
     fn mload_general(&self, context: usize, segment: Segment, offset: usize) -> U256 {
-        let value = self.contexts[context].segments[segment as usize].get(offset);
-        assert!(
-            value.bits() <= segment.bit_range(),
-            "Value read from memory exceeds expected range of {:?} segment",
-            segment
-        );
-        value
+        self.get(MemoryAddress::new(context, segment, offset))
     }
 
     fn mstore_general(&mut self, context: usize, segment: Segment, offset: usize, value: U256) {
-        assert!(
-            value.bits() <= segment.bit_range(),
-            "Value written to memory exceeds expected range of {:?} segment",
-            segment
-        );
-        self.contexts[context].segments[segment as usize].set(offset, value)
+        self.set(MemoryAddress::new(context, segment, offset), value);
     }
 }
 
@@ -735,13 +724,6 @@ impl<'a> Interpreter<'a> {
         let segment = Segment::all()[self.pop().as_usize()];
         let offset = self.pop().as_usize();
         let value = self.pop();
-        assert!(
-            value.bits() <= segment.bit_range(),
-            "Value {} exceeds {:?} range of {} bits",
-            value,
-            segment,
-            segment.bit_range()
-        );
         self.generation_state
             .memory
             .mstore_general(context, segment, offset, value);

evm/src/witness/memory.rs

@@ -11,7 +11,6 @@ pub enum MemoryChannel {
 use MemoryChannel::{Code, GeneralPurpose};
 
 use crate::memory::segments::Segment;
-use crate::util::u256_saturating_cast_usize;
 
 impl MemoryChannel {
     pub fn index(&self) -> usize {
@@ -42,10 +41,17 @@ impl MemoryAddress {
     }
 
     pub(crate) fn new_u256s(context: U256, segment: U256, virt: U256) -> Self {
+        assert!(context.bits() <= 32, "context too large: {}", context);
+        assert!(
+            segment < Segment::COUNT.into(),
+            "segment too large: {}",
+            segment
+        );
+        assert!(virt.bits() <= 32, "virt too large: {}", virt);
         Self {
-            context: u256_saturating_cast_usize(context),
-            segment: u256_saturating_cast_usize(segment),
-            virt: u256_saturating_cast_usize(virt),
+            context: context.as_usize(),
+            segment: segment.as_usize(),
+            virt: virt.as_usize(),
         }
     }
 
@@ -136,10 +142,27 @@ impl MemoryState {
     }
 
     pub fn get(&self, address: MemoryAddress) -> U256 {
-        self.contexts[address.context].segments[address.segment].get(address.virt)
+        let segment = Segment::all()[address.segment];
+        let val = self.contexts[address.context].segments[address.segment].get(address.virt);
+        assert!(
+            val.bits() <= segment.bit_range(),
+            "Value {} exceeds {:?} range of {} bits",
+            val,
+            segment,
+            segment.bit_range()
+        );
+        val
     }
 
     pub fn set(&mut self, address: MemoryAddress, val: U256) {
+        let segment = Segment::all()[address.segment];
+        assert!(
+            val.bits() <= segment.bit_range(),
+            "Value {} exceeds {:?} range of {} bits",
+            val,
+            segment,
+            segment.bit_range()
+        );
         self.contexts[address.context].segments[address.segment].set(address.virt, val);
     }
 }

evm/src/witness/operation.rs

@@ -190,11 +190,8 @@ pub(crate) fn generate_jump<F: Field>(
 
     state.traces.push_memory(log_in0);
     state.traces.push_cpu(row);
+    // TODO: First check if it's a valid JUMPDEST
     state.registers.program_counter = u256_saturating_cast_usize(dst);
-    log::debug!(
-        "Jumping to {}",
-        KERNEL.offset_name(state.registers.program_counter)
-    );
     // TODO: Set other cols like input0_upper_sum_inv.
     Ok(())
 }
@@ -211,12 +208,8 @@ pub(crate) fn generate_jumpi<F: Field>(
     state.registers.program_counter = if cond.is_zero() {
         state.registers.program_counter + 1
     } else {
-        let dst_usize = u256_saturating_cast_usize(dst);
-        log::debug!(
-            "Jumping to {}",
-            KERNEL.offset_name(state.registers.program_counter)
-        );
-        dst_usize
+        // TODO: First check if it's a valid JUMPDEST
+        u256_saturating_cast_usize(dst)
     };
     // TODO: Set other cols like input0_upper_sum_inv.
     Ok(())

evm/tests/transfer_to_new_addr.rs

@@ -107,8 +107,8 @@ fn test_simple_transfer() -> anyhow::Result<()> {
 }
 
 fn eth_to_wei(eth: U256) -> U256 {
-    // 1 ether = 2^18 wei.
-    eth << 18
+    // 1 ether = 10^18 wei.
+    eth * (U256::from(10u8) << 18)
 }
 
 fn init_logger() {