diff --git a/include/library/string.hpp b/include/library/string.hpp
index 2f9d1fe2..6b71badd 100644
--- a/include/library/string.hpp
+++ b/include/library/string.hpp
@@ -230,14 +230,33 @@ private:
 regex_results regex(const std::string& regex, const std::string& str, const char* ex = NULL)
 	throw(std::bad_alloc, std::runtime_error);
 
+enum regex_match_mode
+{
+	REGEX_MATCH_REGEX = 0,
+	REGEX_MATCH_LITERIAL = 1,
+	REGEX_MATCH_IWILDCARDS = 2,
+	REGEX_MATCH_IREGEX = 3,
+};
+
 /**
  * Regexp a string and return match result.
  *
  * Parameter regex: The regexp to apply.
  * Parameter str: The string to apply the regexp to.
+ * Parameter mode: Match mode.
+ *	0 => Case-senstive regex (default).
+ *	1 => Case-insensitive regex.
+ *	2 => 
  * Returns: True if matches, false if not.
  */
-bool regex_match(const std::string& regex, const std::string& str) throw(std::bad_alloc, std::runtime_error);
+bool regex_match(const std::string& regex, const std::string& str, enum regex_match_mode mode = REGEX_MATCH_REGEX)
+	throw(std::bad_alloc, std::runtime_error);
+
+/**
+ * Try match a case-insensitive string fragment and return the result.
+ *
+ * \param pattern The pattern to match a
+ */
 
 /**
  * Cast string to bool.
diff --git a/src/library/string.cpp b/src/library/string.cpp
index 78847978..ef592935 100644
--- a/src/library/string.cpp
+++ b/src/library/string.cpp
@@ -119,9 +119,78 @@ regex_results regex(const std::string& regexp, const std::string& str, const cha
 		return regex_results();
 }
 
-bool regex_match(const std::string& regexp, const std::string& str) throw(std::bad_alloc, std::runtime_error)
+bool regex_match(const std::string& regexp, const std::string& str, enum regex_match_mode mode)
+	throw(std::bad_alloc, std::runtime_error)
 {
-	return regex(regexp, str);
+	static threads::lock m;
+	static std::map<std::string, map_pointer<boost::regex>> regexps;
+	static std::map<std::pair<regex_match_mode, std::string> , std::pair<std::string, bool>> transform_cache;
+	std::string _regexp;
+	bool icase = false;
+	std::ostringstream y;
+	{
+		//See if we have cached transform.
+		threads::alock h(m);
+		auto key = std::make_pair(mode, regexp);
+		if(transform_cache.count(key)) {
+			auto entry = transform_cache[key];
+			_regexp = entry.first;
+			icase = entry.second;
+			goto transformed;
+		}
+	}
+	switch(mode) {
+	case REGEX_MATCH_REGEX:
+		icase = false;
+		_regexp = regexp;
+		break;
+	case REGEX_MATCH_IWILDCARDS:
+	case REGEX_MATCH_LITERIAL:
+		for(size_t i = 0; i < regexp.length(); i++)
+			if(regexp[i] == '?' && mode == REGEX_MATCH_IWILDCARDS)
+				y << ".";
+			else if(regexp[i] == '*' && mode == REGEX_MATCH_IWILDCARDS)
+				y << ".*";
+			else if(regexp[i] >= 'A' && regexp[i] <= 'Z')
+				y << regexp[i];
+			else if(regexp[i] >= 'a' && regexp[i] <= 'z')
+				y << regexp[i];
+			else if(regexp[i] >= '0' && regexp[i] <= '9')
+				y << regexp[i];
+			else if((unsigned char)regexp[i] > 127)	//UTF-8.
+				y << regexp[i];
+			else
+				y << "\\" << regexp[i];
+		_regexp = ".*" + y.str() + ".*";
+		icase = true;
+		break;
+	case REGEX_MATCH_IREGEX:
+		icase = true;
+		_regexp = ".*" + regexp + ".*";
+		break;
+	}
+transformed:
+	threads::alock h(m);
+	auto key = std::make_pair(mode, regexp);
+	if(!transform_cache.count(key))
+		transform_cache[key] = std::make_pair(_regexp, icase);
+
+	if(!regexps.count(regexp)) {
+		boost::regex* y = NULL;
+		auto flags = boost::regex::extended & ~boost::regex::collate;
+		flags |= boost::regex::nosubs;
+		if(icase) flags |= boost::regex::icase;
+		try {
+			y = new boost::regex(_regexp, flags);
+			regexps[_regexp] = y;
+		} catch(std::bad_alloc& e) {
+			delete y;
+			throw;
+		} catch(std::exception& e) {
+			throw std::runtime_error(e.what());
+		}
+	}
+	return boost::regex_match(str.begin(), str.end(), *(regexps[_regexp]));
 }
 
 namespace
diff --git a/src/platform/wxwidgets/tracelogger.cpp b/src/platform/wxwidgets/tracelogger.cpp
index fd4af546..c84227f4 100644
--- a/src/platform/wxwidgets/tracelogger.cpp
+++ b/src/platform/wxwidgets/tracelogger.cpp
@@ -845,49 +845,15 @@ namespace
 		static boost::regex regex;
 		if(pattern == "")
 			return false;
-		if(pattern[0] == 'F') {
-			//Substring find.
-			if(pattern != last_find) {
-				std::string tmp = pattern;
-				tmp = tmp.substr(1);
-				regex = boost::regex(tmp, boost::regex_constants::literal |
-					boost::regex_constants::icase);
-				last_find = pattern;
-			}
-		}
-		if(pattern[0] == 'W') {
-			//wildcard find.
-			if(pattern != last_find) {
-				std::ostringstream y;
-				for(size_t i = 1; i < pattern.length(); i++)
-					if(pattern[i] == '?')
-						y << ".";
-					else if(pattern[i] == '*')
-						y << ".*";
-					else if(pattern[i] >= 'A' && pattern[i] <= 'Z')
-						y << pattern[i];
-					else if(pattern[i] >= 'a' && pattern[i] <= 'z')
-						y << pattern[i];
-					else if(pattern[i] >= '0' && pattern[i] <= '9')
-						y << pattern[i];
-					else
-						y << "\\" << pattern[i];
-				std::string tmp = y.str();
-				regex = boost::regex(tmp, boost::regex_constants::extended);
-				last_find = pattern;
-			}
-		}
-		if(pattern[0] == 'R') {
-			//regexp find.
-			if(pattern != last_find) {
-				std::string tmp = pattern;
-				tmp = tmp.substr(1);
-				regex = boost::regex(tmp, boost::regex_constants::extended |
-					boost::regex_constants::icase);
-				last_find = pattern;
-			}
-		}
-		return regex_search(candidate, regex);
+		std::string tmp = pattern;
+		tmp = tmp.substr(1);
+		if(pattern[0] == 'F')
+			return regex_match(tmp, candidate, REGEX_MATCH_LITERIAL);
+		if(pattern[0] == 'W')
+			return regex_match(tmp, candidate, REGEX_MATCH_IWILDCARDS);
+		if(pattern[0] == 'R')
+			return regex_match(tmp, candidate, REGEX_MATCH_IREGEX);
+		return false;
 	}
 
 	void wxwin_tracelog::on_menu(wxCommandEvent& e)
@@ -933,6 +899,15 @@ namespace
 				find_active = false;
 				return;
 			}
+			//Do syntax check.
+			try {
+				find_match(tmp, "");
+			} catch(...) {
+				find_active = false;
+				wxMessageBox(towxstring("Invalid search pattern"), _T("Invalid pattern"),
+					wxICON_EXCLAMATION | wxOK, this);
+				return;
+			}
 			find_string = tmp;
 			find_active = true;
 			find_line = 0;