feat(interpreter): add more helper methods to memory (#794)

* feat(interpreter): add more helper methods to memory * chore: reduce usage of `#[inline(always)]` * docs
bluealloy · Oct 16, 2023 · 2f78eb9 · 2f78eb9
1 parent c593653
commit 2f78eb9
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Showing 11 changed files with 186 additions and 126 deletions.
diff --git a/bins/revme/src/statetest/merkle_trie.rs b/bins/revme/src/statetest/merkle_trie.rs
@@ -33,7 +33,6 @@ struct TrieAccount {
 }
 
 impl TrieAccount {
-    #[inline(always)]
     fn new(acc: &PlainAccount) -> Self {
         Self {
             nonce: acc.info.nonce,

diff --git a/crates/interpreter/src/instructions/i256.rs b/crates/interpreter/src/instructions/i256.rs
@@ -20,7 +20,7 @@ const MIN_NEGATIVE_VALUE: U256 = U256::from_limbs([
 
 const FLIPH_BITMASK_U64: u64 = 0x7FFFFFFFFFFFFFFF;
 
-#[inline(always)]
+#[inline]
 pub fn i256_sign(val: &U256) -> Sign {
     if val.bit(U256::BITS - 1) {
         Sign::Minus
@@ -30,7 +30,7 @@ pub fn i256_sign(val: &U256) -> Sign {
     }
 }
 
-#[inline(always)]
+#[inline]
 pub fn i256_sign_compl(val: &mut U256) -> Sign {
     let sign = i256_sign(val);
     if sign == Sign::Minus {
@@ -39,25 +39,25 @@ pub fn i256_sign_compl(val: &mut U256) -> Sign {
     sign
 }
 
-#[inline(always)]
+#[inline]
 fn u256_remove_sign(val: &mut U256) {
     // SAFETY: U256 does not have any padding bytes
     unsafe {
         val.as_limbs_mut()[3] &= FLIPH_BITMASK_U64;
     }
 }
 
-#[inline(always)]
+#[inline]
 pub fn two_compl_mut(op: &mut U256) {
     *op = two_compl(*op);
 }
 
-#[inline(always)]
+#[inline]
 pub fn two_compl(op: U256) -> U256 {
     op.wrapping_neg()
 }
 
-#[inline(always)]
+#[inline]
 pub fn i256_cmp(first: &U256, second: &U256) -> Ordering {
     let first_sign = i256_sign(first);
     let second_sign = i256_sign(second);
@@ -69,7 +69,7 @@ pub fn i256_cmp(first: &U256, second: &U256) -> Ordering {
     }
 }
 
-#[inline(always)]
+#[inline]
 pub fn i256_div(mut first: U256, mut second: U256) -> U256 {
     let second_sign = i256_sign_compl(&mut second);
     if second_sign == Sign::Zero {
@@ -98,7 +98,7 @@ pub fn i256_div(mut first: U256, mut second: U256) -> U256 {
     }
 }
 
-#[inline(always)]
+#[inline]
 pub fn i256_mod(mut first: U256, mut second: U256) -> U256 {
     let first_sign = i256_sign_compl(&mut first);
     if first_sign == Sign::Zero {

diff --git a/crates/interpreter/src/instructions/memory.rs b/crates/interpreter/src/instructions/memory.rs
@@ -10,16 +10,7 @@ pub fn mload<H: Host>(interpreter: &mut Interpreter<'_>, _host: &mut H) {
     pop!(interpreter, index);
     let index = as_usize_or_fail!(interpreter, index);
     shared_memory_resize!(interpreter, index, 32);
-    push!(
-        interpreter,
-        U256::from_be_bytes::<32>(
-            interpreter
-                .shared_memory
-                .slice(index, 32)
-                .try_into()
-                .unwrap()
-        )
-    );
+    push!(interpreter, interpreter.shared_memory.get_u256(index));
 }
 
 pub fn mstore<H: Host>(interpreter: &mut Interpreter<'_>, _host: &mut H) {

diff --git a/crates/interpreter/src/interpreter.rs b/crates/interpreter/src/interpreter.rs
@@ -96,7 +96,8 @@ impl<'a> Interpreter<'a> {
     /// Returns the current program counter.
     #[inline]
     pub fn program_counter(&self) -> usize {
-        // Safety: this is just subtraction of pointers, it is safe to do.
+        // SAFETY: `instruction_pointer` should be at an offset from the start of the bytecode.
+        // In practice this is always true unless a caller modifies the `instruction_pointer` field manually.
         unsafe {
             self.instruction_pointer
                 .offset_from(self.contract.bytecode.as_ptr()) as usize