Getting the instruction stream for a code block should not require two loads
https://bugs.webkit.org/show_bug.cgi?id=79608
Reviewed by Sam Weinig.
Introduced the RefCountedArray class, which contains a single inline pointer
to a ref-counted non-resizeable vector backing store. This satisfies the
requirements of CodeBlock, which desires the ability to share instruction
streams with other CodeBlocks. It also reduces the number of loads required
for getting the instruction stream by one.
This patch also gets rid of the bytecode discarding logic, since we don't
use it anymore and it's unlikely to ever work right with DFG or LLInt. And
I didn't feel like porting dead code to use RefCountedArray.
* GNUmakefile.list.am:
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/CodeBlock.cpp:
(JSC::instructionOffsetForNth):
(JSC::CodeBlock::dump):
(JSC::CodeBlock::CodeBlock):
(JSC::CodeBlock::finalizeUnconditionally):
(JSC::CodeBlock::handlerForBytecodeOffset):
(JSC::CodeBlock::lineNumberForBytecodeOffset):
(JSC::CodeBlock::expressionRangeForBytecodeOffset):
(JSC::CodeBlock::shrinkToFit):
* bytecode/CodeBlock.h:
(CodeBlock):
(JSC::CodeBlock::numberOfInstructions):
(JSC::CodeBlock::instructions):
(JSC::CodeBlock::instructionCount):
(JSC::CodeBlock::valueProfileForBytecodeOffset):
(JSC):
* bytecompiler/BytecodeGenerator.cpp:
(JSC::Label::setLocation):
(JSC):
(JSC::BytecodeGenerator::generate):
(JSC::BytecodeGenerator::newLabel):
* bytecompiler/BytecodeGenerator.h:
(JSC):
(BytecodeGenerator):
(JSC::BytecodeGenerator::instructions):
* bytecompiler/Label.h:
(JSC::Label::Label):
(Label):
* dfg/DFGByteCodeCache.h:
(JSC::DFG::ByteCodeCache::~ByteCodeCache):
(JSC::DFG::ByteCodeCache::get):
* jit/JITExceptions.cpp:
(JSC::genericThrow):
* llint/LowLevelInterpreter32_64.asm:
* runtime/Executable.cpp:
(JSC::EvalExecutable::compileInternal):
(JSC::ProgramExecutable::compileInternal):
(JSC::FunctionExecutable::codeBlockWithBytecodeFor):
(JSC::FunctionExecutable::produceCodeBlockFor):
* wtf/RefCountedArray.h: Added.
(WTF):
(RefCountedArray):
(WTF::RefCountedArray::RefCountedArray):
(WTF::RefCountedArray::operator=):
(WTF::RefCountedArray::~RefCountedArray):
(WTF::RefCountedArray::size):
(WTF::RefCountedArray::data):
(WTF::RefCountedArray::begin):
(WTF::RefCountedArray::end):
(WTF::RefCountedArray::at):
(WTF::RefCountedArray::operator[]):
(Header):
(WTF::RefCountedArray::Header::size):
(WTF::RefCountedArray::Header::payload):
(WTF::RefCountedArray::Header::fromPayload):
* wtf/Platform.h:
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@108943 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm b/Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm
index ba49fe3..2c3aa7d 100644
--- a/Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm
+++ b/Source/JavaScriptCore/llint/LowLevelInterpreter32_64.asm
@@ -443,8 +443,7 @@
codeBlockSetter(t1)
# Set up the PC.
- loadp CodeBlock::m_instructions[t1], t0
- loadp CodeBlock::Instructions::m_instructions + VectorBufferOffset[t0], PC
+ loadp CodeBlock::m_instructions[t1], PC
end
# Expects that CodeBlock is in t1, which is what prologue() leaves behind.
@@ -503,8 +502,7 @@
.continue:
# Reload CodeBlock and PC, since the slow_path clobbered it.
loadp CodeBlock[cfr], t1
- loadp CodeBlock::m_instructions[t1], t0
- loadp CodeBlock::Instructions::m_instructions + VectorBufferOffset[t0], PC
+ loadp CodeBlock::m_instructions[t1], PC
jmp doneLabel
end
