Imported WebKit commit 3a8c29f35d00659d2ce7a0ccdfa8304f14e82327 (http://svn.webkit.org/repository/webkit/trunk@120813)

New snapshot with Windows build fixes

1 files changed, 231 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/assembler/LinkBuffer.cpp b/Source/JavaScriptCore/assembler/LinkBuffer.cpp
new file mode 100644
index 000000000..58030ba7d
--- /dev/null
+++ b/Source/JavaScriptCore/assembler/LinkBuffer.cpp
@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 2012 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. 
+ */
+
+#include "config.h"
+#include "LinkBuffer.h"
+
+#if ENABLE(ASSEMBLER)
+
+#include "Options.h"
+
+namespace JSC {
+
+LinkBuffer::CodeRef LinkBuffer::finalizeCodeWithoutDisassembly()
+{
+    performFinalization();
+    
+    return CodeRef(m_executableMemory);
+}
+
+LinkBuffer::CodeRef LinkBuffer::finalizeCodeWithDisassembly(const char* format, ...)
+{
+    ASSERT(Options::showDisassembly);
+    
+    CodeRef result = finalizeCodeWithoutDisassembly();
+    
+    dataLog("Generated JIT code for ");
+    va_list argList;
+    va_start(argList, format);
+    WTF::dataLogV(format, argList);
+    va_end(argList);
+    dataLog(":\n");
+    
+    dataLog("    Code at [%p, %p):\n", result.code().executableAddress(), static_cast<char*>(result.code().executableAddress()) + result.size());
+    if (!tryToDisassemble(result.code(), m_size, "    ", WTF::dataFile()))
+        dataLog("        <no disassembly available>");
+    
+    return result;
+}
+
+void LinkBuffer::linkCode(void* ownerUID, JITCompilationEffort effort)
+{
+    ASSERT(!m_code);
+#if !ENABLE(BRANCH_COMPACTION)
+    m_executableMemory = m_assembler->m_assembler.executableCopy(*m_globalData, ownerUID, effort);
+    if (!m_executableMemory)
+        return;
+    m_code = m_executableMemory->start();
+    m_size = m_assembler->m_assembler.codeSize();
+    ASSERT(m_code);
+#else
+    m_initialSize = m_assembler->m_assembler.codeSize();
+    m_executableMemory = m_globalData->executableAllocator.allocate(*m_globalData, m_initialSize, ownerUID, effort);
+    if (!m_executableMemory)
+        return;
+    m_code = (uint8_t*)m_executableMemory->start();
+    ASSERT(m_code);
+    ExecutableAllocator::makeWritable(m_code, m_initialSize);
+    uint8_t* inData = (uint8_t*)m_assembler->unlinkedCode();
+    uint8_t* outData = reinterpret_cast<uint8_t*>(m_code);
+    int readPtr = 0;
+    int writePtr = 0;
+    Vector<LinkRecord>& jumpsToLink = m_assembler->jumpsToLink();
+    unsigned jumpCount = jumpsToLink.size();
+    for (unsigned i = 0; i < jumpCount; ++i) {
+        int offset = readPtr - writePtr;
+        ASSERT(!(offset & 1));
+            
+        // Copy the instructions from the last jump to the current one.
+        size_t regionSize = jumpsToLink[i].from() - readPtr;
+        uint16_t* copySource = reinterpret_cast_ptr<uint16_t*>(inData + readPtr);
+        uint16_t* copyEnd = reinterpret_cast_ptr<uint16_t*>(inData + readPtr + regionSize);
+        uint16_t* copyDst = reinterpret_cast_ptr<uint16_t*>(outData + writePtr);
+        ASSERT(!(regionSize % 2));
+        ASSERT(!(readPtr % 2));
+        ASSERT(!(writePtr % 2));
+        while (copySource != copyEnd)
+            *copyDst++ = *copySource++;
+        m_assembler->recordLinkOffsets(readPtr, jumpsToLink[i].from(), offset);
+        readPtr += regionSize;
+        writePtr += regionSize;
+            
+        // Calculate absolute address of the jump target, in the case of backwards
+        // branches we need to be precise, forward branches we are pessimistic
+        const uint8_t* target;
+        if (jumpsToLink[i].to() >= jumpsToLink[i].from())
+            target = outData + jumpsToLink[i].to() - offset; // Compensate for what we have collapsed so far
+        else
+            target = outData + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
+            
+        JumpLinkType jumpLinkType = m_assembler->computeJumpType(jumpsToLink[i], outData + writePtr, target);
+        // Compact branch if we can...
+        if (m_assembler->canCompact(jumpsToLink[i].type())) {
+            // Step back in the write stream
+            int32_t delta = m_assembler->jumpSizeDelta(jumpsToLink[i].type(), jumpLinkType);
+            if (delta) {
+                writePtr -= delta;
+                m_assembler->recordLinkOffsets(jumpsToLink[i].from() - delta, readPtr, readPtr - writePtr);
+            }
+        }
+        jumpsToLink[i].setFrom(writePtr);
+    }
+    // Copy everything after the last jump
+    memcpy(outData + writePtr, inData + readPtr, m_initialSize - readPtr);
+    m_assembler->recordLinkOffsets(readPtr, m_initialSize, readPtr - writePtr);
+        
+    for (unsigned i = 0; i < jumpCount; ++i) {
+        uint8_t* location = outData + jumpsToLink[i].from();
+        uint8_t* target = outData + jumpsToLink[i].to() - m_assembler->executableOffsetFor(jumpsToLink[i].to());
+        m_assembler->link(jumpsToLink[i], location, target);
+    }
+
+    jumpsToLink.clear();
+    m_size = writePtr + m_initialSize - readPtr;
+    m_executableMemory->shrink(m_size);
+
+#if DUMP_LINK_STATISTICS
+    dumpLinkStatistics(m_code, m_initialSize, m_size);
+#endif
+#if DUMP_CODE
+    dumpCode(m_code, m_size);
+#endif
+#endif
+}
+
+void LinkBuffer::performFinalization()
+{
+#ifndef NDEBUG
+    ASSERT(!m_completed);
+    ASSERT(isValid());
+    m_completed = true;
+#endif
+    
+#if ENABLE(BRANCH_COMPACTION)
+    ExecutableAllocator::makeExecutable(code(), m_initialSize);
+#else
+    ExecutableAllocator::makeExecutable(code(), m_size);
+#endif
+    MacroAssembler::cacheFlush(code(), m_size);
+}
+
+#if DUMP_LINK_STATISTICS
+void LinkBuffer::dumpLinkStatistics(void* code, size_t initializeSize, size_t finalSize)
+{
+    static unsigned linkCount = 0;
+    static unsigned totalInitialSize = 0;
+    static unsigned totalFinalSize = 0;
+    linkCount++;
+    totalInitialSize += initialSize;
+    totalFinalSize += finalSize;
+    dataLog("link %p: orig %u, compact %u (delta %u, %.2f%%)\n", 
+            code, static_cast<unsigned>(initialSize), static_cast<unsigned>(finalSize),
+            static_cast<unsigned>(initialSize - finalSize),
+            100.0 * (initialSize - finalSize) / initialSize);
+    dataLog("\ttotal %u: orig %u, compact %u (delta %u, %.2f%%)\n", 
+            linkCount, totalInitialSize, totalFinalSize, totalInitialSize - totalFinalSize,
+            100.0 * (totalInitialSize - totalFinalSize) / totalInitialSize);
+}
+#endif
+
+#if DUMP_CODE
+void LinkBuffer::dumpCode(void* code, size_t size)
+{
+#if CPU(ARM_THUMB2)
+    // Dump the generated code in an asm file format that can be assembled and then disassembled
+    // for debugging purposes. For example, save this output as jit.s:
+    //   gcc -arch armv7 -c jit.s
+    //   otool -tv jit.o
+    static unsigned codeCount = 0;
+    unsigned short* tcode = static_cast<unsigned short*>(code);
+    size_t tsize = size / sizeof(short);
+    char nameBuf[128];
+    snprintf(nameBuf, sizeof(nameBuf), "_jsc_jit%u", codeCount++);
+    dataLog("\t.syntax unified\n"
+            "\t.section\t__TEXT,__text,regular,pure_instructions\n"
+            "\t.globl\t%s\n"
+            "\t.align 2\n"
+            "\t.code 16\n"
+            "\t.thumb_func\t%s\n"
+            "# %p\n"
+            "%s:\n", nameBuf, nameBuf, code, nameBuf);
+        
+    for (unsigned i = 0; i < tsize; i++)
+        dataLog("\t.short\t0x%x\n", tcode[i]);
+#elif CPU(ARM_TRADITIONAL)
+    //   gcc -c jit.s
+    //   objdump -D jit.o
+    static unsigned codeCount = 0;
+    unsigned int* tcode = static_cast<unsigned int*>(code);
+    size_t tsize = size / sizeof(unsigned int);
+    char nameBuf[128];
+    snprintf(nameBuf, sizeof(nameBuf), "_jsc_jit%u", codeCount++);
+    dataLog("\t.globl\t%s\n"
+            "\t.align 4\n"
+            "\t.code 32\n"
+            "\t.text\n"
+            "# %p\n"
+            "%s:\n", nameBuf, code, nameBuf);
+
+    for (unsigned i = 0; i < tsize; i++)
+        dataLog("\t.long\t0x%x\n", tcode[i]);
+#endif
+}
+#endif
+
+} // namespace JSC
+
+#endif // ENABLE(ASSEMBLER)
+
+