perf: current_value use usize

web-infra-dev · Jan 2, 2025 · dd2ace7 · dd2ace7
1 parent 212bbc8
commit dd2ace7
Showing 1 changed file with 8 additions and 11 deletions.
diff --git a/src/decoder.rs b/src/decoder.rs
@@ -36,7 +36,7 @@ pub(crate) struct MappingsDecoder<'a> {
   current_data: [u32; 5],
   current_data_pos: usize,
   // current_value will include a sign bit at bit 0
-  current_value: i64,
+  current_value: usize,
   current_value_pos: usize,
   generated_line: u32,
 }
@@ -103,23 +103,20 @@ impl Iterator for MappingsDecoder<'_> {
         }
       } else if (value & CONTINUATION_BIT) == 0 {
         // last sextet
-        self.current_value |= (value as i64) << self.current_value_pos;
-        let final_value = if (self.current_value & 1) != 0 {
-          -(self.current_value >> 1)
-        } else {
-          self.current_value >> 1
-        };
+        self.current_value |= (value as usize) << self.current_value_pos;
         if self.current_data_pos < 5 {
-          self.current_data[self.current_data_pos] =
-            (self.current_data[self.current_data_pos] as i64 + final_value)
-              as u32;
+          self.current_data[self.current_data_pos] = if (self.current_value & 1) != 0 {
+            self.current_data[self.current_data_pos] as usize - (self.current_value >> 1)
+          } else {
+            self.current_data[self.current_data_pos] as usize + (self.current_value >> 1)
+          } as u32;
         }
         self.current_data_pos += 1;
         self.current_value_pos = 0;
         self.current_value = 0;
       } else {
         self.current_value |=
-          ((value & DATA_MASK) as i64) << self.current_value_pos;
+          ((value & DATA_MASK) as usize) << self.current_value_pos;
         self.current_value_pos += 5;
       }
     }