| /* |
| * 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() || Options::showDFGDisassembly()); |
| |
| CodeRef result = finalizeCodeWithoutDisassembly(); |
| |
| dataLogF("Generated JIT code for "); |
| va_list argList; |
| va_start(argList, format); |
| WTF::dataLogFV(format, argList); |
| va_end(argList); |
| dataLogF(":\n"); |
| |
| dataLogF(" Code at [%p, %p):\n", result.code().executableAddress(), static_cast<char*>(result.code().executableAddress()) + result.size()); |
| disassemble(result.code(), m_size, " ", WTF::dataFile()); |
| |
| 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; |
| dataLogF("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); |
| dataLogF("\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++); |
| dataLogF("\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++) |
| dataLogF("\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++); |
| dataLogF("\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++) |
| dataLogF("\t.long\t0x%x\n", tcode[i]); |
| #endif |
| } |
| #endif |
| |
| } // namespace JSC |
| |
| #endif // ENABLE(ASSEMBLER) |
| |
| |
