fix: fix bug in sign-extension function (#157)

* Fix bug in sign extension function * fix clippy * fix fmt
zkMIPS · Aug 12, 2024 · 3eae409 · 3eae409
1 parent 51e07f5
commit 3eae409
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Showing 3 changed files with 16 additions and 26 deletions.
diff --git a/emulator/src/memory.rs b/emulator/src/memory.rs
@@ -209,12 +209,9 @@ impl Memory {
             Some(page) => page,
         };
 
-        match self.rtrace.get(&page_index) {
-            None => {
-                self.rtrace.insert(page_index, page.borrow().clone().data);
-            }
-            Some(_) => {}
-        };
+        self.rtrace
+            .entry(page_index)
+            .or_insert_with(|| page.borrow().clone().data);
 
         if level < 2 {
             self.set_hash_trace(page_index, level + 1);
@@ -239,13 +236,12 @@ impl Memory {
                 // lookup in page
                 let page_addr = (addr as usize) & PAGE_ADDR_MASK;
 
-                match self.rtrace.get(&page_index) {
-                    None => {
-                        self.rtrace.insert(page_index, cached_page.data);
-                        self.set_hash_trace(page_index, 0);
-                    }
-                    Some(_) => {}
+                if let std::collections::btree_map::Entry::Vacant(e) = self.rtrace.entry(page_index)
+                {
+                    e.insert(cached_page.data);
+                    self.set_hash_trace(page_index, 0);
                 };
+
                 u32::from_be_bytes(
                     (&cached_page.data[page_addr..page_addr + 4])
                         .try_into()
@@ -291,12 +287,9 @@ impl Memory {
             }
         };
 
-        match self.rtrace.get(&page_index) {
-            None => {
-                self.rtrace.insert(page_index, cached_page.borrow().data);
-                self.set_hash_trace(page_index, 0);
-            }
-            Some(_) => {}
+        if let std::collections::btree_map::Entry::Vacant(e) = self.rtrace.entry(page_index) {
+            e.insert(cached_page.borrow().data);
+            self.set_hash_trace(page_index, 0);
         };
 
         self.wtrace[0].insert(page_index, cached_page.clone());
@@ -346,12 +339,9 @@ impl Memory {
                 Some(page) => page,
             };
 
-            match self.rtrace.get(&page_index) {
-                None => {
-                    self.rtrace.insert(page_index, page.borrow().data);
-                    self.set_hash_trace(page_index, 0);
-                }
-                Some(_) => {}
+            if let std::collections::btree_map::Entry::Vacant(e) = self.rtrace.entry(page_index) {
+                e.insert(page.borrow().data);
+                self.set_hash_trace(page_index, 0);
             };
 
             self.wtrace[0].insert(page_index, page.clone());

diff --git a/emulator/src/state.rs b/emulator/src/state.rs
@@ -1303,7 +1303,7 @@ impl InstrumentedState {
 
 /// se extends the number to 32 bit with sign.
 fn sign_extension(dat: u32, idx: u32) -> u32 {
-    let is_signed = (dat >> (idx - 1)) != 0;
+    let is_signed = ((dat >> (idx - 1)) & 1) != 0;
     let signed = ((1u32 << (32 - idx)) - 1) << idx;
     let mask = (1u32 << idx) - 1;
     if is_signed {

diff --git a/prover/src/witness/operation.rs b/prover/src/witness/operation.rs
@@ -1435,7 +1435,7 @@ pub(crate) fn generate_signext<F: Field>(
     row.general.io_mut().rt_le = bits_le.try_into().unwrap();
 
     let bits = bits as usize;
-    let is_signed = (in0 >> (bits - 1)) != 0;
+    let is_signed = ((in0 >> (bits - 1)) & 0x1) != 0;
     let signed = ((1 << (32 - bits)) - 1) << bits;
     let mask = (1 << bits) - 1;
     let result = if is_signed {