Identity (dataCopy) precompile (#1628)

### Description

This is a follow-up PR for
[PR#1396](#1396)
from @roynalnaruto. After merging in 1396's changes to a fresh fork, the
branch is compared with Scroll's develop head to incorporate latest
patterns on precompile-related development.

### Issue Link

[Aggregating precompile issue
924](#924)

### Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

### Design choices

See
[documentation](https://www.notion.so/scrollzkp/PR-1396-Follow-up-Precompile-Identity-for-Upstream-3624af055d9b4820a0354e9af4fa7918)

---------

Co-authored-by: Rohit Narurkar <[email protected]>
Co-authored-by: Zhang Zhuo <[email protected]>

Author: 3 people

.gitignore

@@ -2,4 +2,5 @@
 *.png
 .DS_Store
 .vscode
-.idea
+.idea
+*.log

bus-mapping/src/circuit_input_builder/execution.rs

@@ -1,8 +1,11 @@
 //! Execution step related module.
 
 use crate::{
-    circuit_input_builder::CallContext, error::ExecError, exec_trace::OperationRef,
+    circuit_input_builder::CallContext,
+    error::{ExecError, OogError},
+    exec_trace::OperationRef,
     operation::RWCounter,
+    precompile::PrecompileCalls,
 };
 use eth_types::{evm_types::OpcodeId, GethExecStep, Word, H256};
 use gadgets::impl_expr;
@@ -60,6 +63,7 @@ impl ExecStep {
         ExecStep {
             exec_state: ExecState::Op(step.op),
             pc: step.pc,
+
             stack_size: step.stack.0.len(),
             memory_size: call_ctx.memory.len(),
             gas_left: step.gas,
@@ -117,13 +121,25 @@ impl ExecStep {
         assert_eq!(memory_size % n_bytes_word, 0);
         memory_size / n_bytes_word
     }
+
+    /// Returns `true` if this is an execution step of Precompile.
+    pub fn is_precompiled(&self) -> bool {
+        matches!(self.exec_state, ExecState::Precompile(_))
+    }
+
+    /// Returns `true` if `error` is oog in precompile calls
+    pub fn is_precompile_oog_err(&self) -> bool {
+        matches!(self.error, Some(ExecError::OutOfGas(OogError::Precompile)))
+    }
 }
 
 /// Execution state
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum ExecState {
     /// EVM Opcode ID
     Op(OpcodeId),
+    /// Precompile call
+    Precompile(PrecompileCalls),
     /// Virtual step Begin Tx
     BeginTx,
     /// Virtual step End Tx
@@ -279,14 +295,14 @@ impl CopyEvent {
     // increase in rw counter from the start of the copy event to step index
     fn rw_counter_increase(&self, step_index: usize) -> u64 {
         let source_rw_increase = match self.src_type {
-            CopyDataType::Bytecode | CopyDataType::TxCalldata => 0,
+            CopyDataType::Bytecode | CopyDataType::TxCalldata | CopyDataType::RlcAcc => 0,
             CopyDataType::Memory => std::cmp::min(
                 u64::try_from(step_index + 1).unwrap() / 2,
                 self.src_addr_end
                     .checked_sub(self.src_addr)
                     .unwrap_or_default(),
             ),
-            CopyDataType::RlcAcc | CopyDataType::TxLog | CopyDataType::Padding => unreachable!(),
+            CopyDataType::TxLog | CopyDataType::Padding => unreachable!(),
         };
         let destination_rw_increase = match self.dst_type {
             CopyDataType::RlcAcc | CopyDataType::Bytecode => 0,