Changeset 82696 in webkit for trunk/Source/JavaScriptCore/parser/Lexer.h

Timestamp:

Apr 1, 2011, 10:36:14 AM (14 years ago)

Author:

Adam Roben

Message:

Maintain the invariant that Lexer::m_current is set to -1 when at the end of the code buffer

Covered by existing tests.

Fixes <​http://webkit.org/b/56699>.

Reviewed by Oliver Hunt.

• parser/Lexer.h:

(JSC::Lexer::setOffset): Copied code from Lexer::shift to update m_current, because
supposedly the idiom that function uses is fast.

File:

• trunk/Source/JavaScriptCore/parser/Lexer.h (modified) (1 diff)

trunk/Source/JavaScriptCore/parser/Lexer.h

@@ -72 +72 @@
             m_error = 0;
             m_code = m_codeStart + offset;
-            m_current = *m_code;
             m_buffer8.resize(0);
             m_buffer16.resize(0);
-            if (UNLIKELY(m_code == m_codeEnd))
-                m_current = -1;
+            // Faster than an if-else sequence
+            m_current = -1;
+            if (LIKELY(m_code < m_codeEnd))
+                m_current = *m_code;
         }
         void setLineNumber(int line)