--- /dev/null
+/*
+ * Copyright (C) 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef DFGExitProfile_h
+#define DFGExitProfile_h
+
+#include <wtf/HashSet.h>
+#include <wtf/OwnPtr.h>
+#include <wtf/Vector.h>
+
+namespace JSC { namespace DFG {
+
+enum ExitKind {
+ ExitKindUnset,
+ BadType, // We exited because a type prediction was wrong.
+ BadCache, // We exited because an inline cache was wrong.
+ Overflow, // We exited because of overflow.
+ NegativeZero, // We exited because we encountered negative zero.
+ InadequateCoverage, // We exited because we ended up in code that didn't have profiling coverage.
+ Uncountable, // We exited for none of the above reasons, and we should not count it. Most uses of this should be viewed as a FIXME.
+};
+
+inline const char* exitKindToString(ExitKind kind)
+{
+ switch (kind) {
+ case ExitKindUnset:
+ return "Unset";
+ case BadType:
+ return "BadType";
+ case BadCache:
+ return "BadCache";
+ case Overflow:
+ return "Overflow";
+ case NegativeZero:
+ return "NegativeZero";
+ case InadequateCoverage:
+ return "InadequateCoverage";
+ default:
+ return "Unknown";
+ }
+}
+
+inline bool exitKindIsCountable(ExitKind kind)
+{
+ switch (kind) {
+ case ExitKindUnset:
+ ASSERT_NOT_REACHED();
+ case BadType:
+ case Uncountable:
+ return false;
+ default:
+ return true;
+ }
+}
+
+class FrequentExitSite {
+public:
+ FrequentExitSite()
+ : m_bytecodeOffset(0) // 0 = empty value
+ , m_kind(ExitKindUnset)
+ {
+ }
+
+ FrequentExitSite(WTF::HashTableDeletedValueType)
+ : m_bytecodeOffset(1) // 1 = deleted value
+ , m_kind(ExitKindUnset)
+ {
+ }
+
+ explicit FrequentExitSite(unsigned bytecodeOffset, ExitKind kind)
+ : m_bytecodeOffset(bytecodeOffset)
+ , m_kind(kind)
+ {
+ ASSERT(exitKindIsCountable(kind));
+ }
+
+ bool operator!() const
+ {
+ return m_kind == ExitKindUnset;
+ }
+
+ bool operator==(const FrequentExitSite& other) const
+ {
+ return m_bytecodeOffset == other.m_bytecodeOffset
+ && m_kind == other.m_kind;
+ }
+
+ unsigned hash() const
+ {
+ return WTF::intHash(m_bytecodeOffset) + m_kind;
+ }
+
+ unsigned bytecodeOffset() const { return m_bytecodeOffset; }
+ ExitKind kind() const { return m_kind; }
+
+ bool isHashTableDeletedValue() const
+ {
+ return m_kind == ExitKindUnset && m_bytecodeOffset;
+ }
+
+private:
+ unsigned m_bytecodeOffset;
+ ExitKind m_kind;
+};
+
+struct FrequentExitSiteHash {
+ static unsigned hash(const FrequentExitSite& key) { return key.hash(); }
+ static bool equal(const FrequentExitSite& a, const FrequentExitSite& b) { return a == b; }
+ static const bool safeToCompareToEmptyOrDeleted = true;
+};
+
+} } // namespace JSC::DFG
+
+namespace WTF {
+
+template<typename T> struct DefaultHash;
+template<> struct DefaultHash<JSC::DFG::FrequentExitSite> {
+ typedef JSC::DFG::FrequentExitSiteHash Hash;
+};
+
+template<typename T> struct HashTraits;
+template<> struct HashTraits<JSC::DFG::FrequentExitSite> : SimpleClassHashTraits<JSC::DFG::FrequentExitSite> { };
+
+} // namespace WTF
+
+namespace JSC { namespace DFG {
+
+class QueryableExitProfile;
+
+class ExitProfile {
+public:
+ ExitProfile();
+ ~ExitProfile();
+
+ // Add a new frequent exit site. Return true if this is a new one, or false
+ // if we already knew about it. This is an O(n) operation, because it errs
+ // on the side of keeping the data structure compact. Also, this will only
+ // be called a fixed number of times per recompilation. Recompilation is
+ // rare to begin with, and implies doing O(n) operations on the CodeBlock
+ // anyway.
+ bool add(const FrequentExitSite&);
+
+private:
+ friend class QueryableExitProfile;
+
+ OwnPtr<Vector<FrequentExitSite> > m_frequentExitSites;
+};
+
+class QueryableExitProfile {
+public:
+ explicit QueryableExitProfile(const ExitProfile&);
+ ~QueryableExitProfile();
+
+ bool hasExitSite(const FrequentExitSite& site) const
+ {
+ return m_frequentExitSites.find(site) != m_frequentExitSites.end();
+ }
+
+ bool hasExitSite(unsigned bytecodeIndex, ExitKind kind) const
+ {
+ return hasExitSite(FrequentExitSite(bytecodeIndex, kind));
+ }
+private:
+ HashSet<FrequentExitSite> m_frequentExitSites;
+};
+
+} } // namespace JSC::DFG
+
+#endif // DFGExitProfile_h
projects / apple / javascriptcore.git / blobdiff