JavaScriptCore/assembler/AssemblerBuffer.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/assembler/AssemblerBuffer.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2008 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 AssemblerBuffer_h
+#define AssemblerBuffer_h
+
+#if ENABLE(ASSEMBLER)
+
+#include "stdint.h"
+#include <string.h>
+#include <jit/ExecutableAllocator.h>
+#include <wtf/Assertions.h>
+#include <wtf/FastMalloc.h>
+
+namespace JSC {
+
+    class AssemblerBuffer {
+        static const int inlineCapacity = 128 - sizeof(char*) - 2 * sizeof(int);
+    public:
+        AssemblerBuffer()
+            : m_buffer(m_inlineBuffer)
+            , m_capacity(inlineCapacity)
+            , m_size(0)
+        {
+            COMPILE_ASSERT(sizeof(AssemblerBuffer) == 128, AssemblerBuffer_should_be_128_bytes);
+        }
+
+        ~AssemblerBuffer()
+        {
+            if (m_buffer != m_inlineBuffer)
+                fastFree(m_buffer);
+        }
+
+        void ensureSpace(int space)
+        {
+            if (m_size > m_capacity - space)
+                grow();
+        }
+
+        bool isAligned(int alignment) const
+        {
+            return !(m_size & (alignment - 1));
+        }
+
+        void putByteUnchecked(int value)
+        {
+            ASSERT(!(m_size > m_capacity - 4));
+            m_buffer[m_size] = value;
+            m_size++;
+        }
+
+        void putByte(int value)
+        {
+            if (m_size > m_capacity - 4)
+                grow();
+            putByteUnchecked(value);
+        }
+
+        void putShortUnchecked(int value)
+        {
+            ASSERT(!(m_size > m_capacity - 4));
+            *reinterpret_cast<short*>(&m_buffer[m_size]) = value;
+            m_size += 2;
+        }
+
+        void putShort(int value)
+        {
+            if (m_size > m_capacity - 4)
+                grow();
+            putShortUnchecked(value);
+        }
+
+        void putIntUnchecked(int value)
+        {
+            ASSERT(!(m_size > m_capacity - 4));
+            *reinterpret_cast<int*>(&m_buffer[m_size]) = value;
+            m_size += 4;
+        }
+
+        void putInt64Unchecked(int64_t value)
+        {
+            ASSERT(!(m_size > m_capacity - 8));
+            *reinterpret_cast<int64_t*>(&m_buffer[m_size]) = value;
+            m_size += 8;
+        }
+
+        void putInt(int value)
+        {
+            if (m_size > m_capacity - 4)
+                grow();
+            putIntUnchecked(value);
+        }
+
+        void* data() const
+        {
+            return m_buffer;
+        }
+
+        int size() const
+        {
+            return m_size;
+        }
+
+        void* executableCopy(ExecutablePool* allocator)
+        {
+            if (!m_size)
+                return 0;
+
+            void* result = allocator->alloc(m_size);
+
+            if (!result)
+                return 0;
+
+            ExecutableAllocator::makeWritable(result, m_size);
+
+            return memcpy(result, m_buffer, m_size);
+        }
+
+    protected:
+        void append(const char* data, int size)
+        {
+            if (m_size > m_capacity - size)
+                grow(size);
+
+            memcpy(m_buffer + m_size, data, size);
+            m_size += size;
+        }
+
+        void grow(int extraCapacity = 0)
+        {
+            m_capacity += m_capacity / 2 + extraCapacity;
+
+            if (m_buffer == m_inlineBuffer) {
+                char* newBuffer = static_cast<char*>(fastMalloc(m_capacity));
+                m_buffer = static_cast<char*>(memcpy(newBuffer, m_buffer, m_size));
+            } else
+                m_buffer = static_cast<char*>(fastRealloc(m_buffer, m_capacity));
+        }
+
+        char m_inlineBuffer[inlineCapacity];
+        char* m_buffer;
+        int m_capacity;
+        int m_size;
+    };
+
+} // namespace JSC
+
+#endif // ENABLE(ASSEMBLER)
+
+#endif // AssemblerBuffer_h