Changeset 211642 in webkit for trunk/Source/JavaScriptCore/interpreter/Interpreter.cpp

Timestamp:

Feb 3, 2017, 12:00:53 PM (9 years ago)

Author:

[email protected]

Message:

When OSR entering to the baseline JIT from the LLInt for a ProgramCodeBlock we can skip compiling a lot of the program
​https://bugs.webkit.org/show_bug.cgi?id=167725
<rdar://problem/30339082>

Reviewed by Michael Saboff.

We often want to baseline compile ProgramCode once we hit a loop in the LLInt.
However, some programs execute a non-trivial amount of code before the loop.
This code can never be executed again because ProgramCodeBlocks never run more
than once. We're wasting time and memory by compiling code that is unreachable
from the OSR entry destination. This patch fixes this by only compiling code
that is reachable from the OSR entry destination.

This is a speedup on Kraken/ai-astar for devices with limited CPUs (I've been
testing on devices with 2 CPUs). On ai-astar, we were spending 50-100ms compiling
a huge ProgramCodeBlock in the baseline JIT where the majority of the code
would never execute. If this compilation was kicked off on the main thread,
then we'd be stalled for a long time. If it were started on the baseline JITs
background compilation thread, we'd still waste 50-100ms in that thread, causing
all other baseline compilations to happen on the main thread.

• interpreter/Interpreter.cpp:

(JSC::Interpreter::executeProgram):

• interpreter/Interpreter.h:
• jit/JIT.cpp:

(JSC::JIT::JIT):
(JSC::JIT::privateCompileMainPass):

• jit/JIT.h:

(JSC::JIT::compile):

• jit/JITWorklist.cpp:

(JSC::JITWorklist::Plan::Plan):
(JSC::JITWorklist::Plan::compileNow):
(JSC::JITWorklist::compileLater):
(JSC::JITWorklist::compileNow):

• jit/JITWorklist.h:
• llint/LLIntSlowPaths.cpp:

(JSC::LLInt::jitCompileAndSetHeuristics):
(JSC::LLInt::LLINT_SLOW_PATH_DECL):

• runtime/Completion.cpp:

(JSC::evaluate):

File:

• trunk/Source/JavaScriptCore/interpreter/Interpreter.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/interpreter/Interpreter.cpp

@@ -728 +728 @@
 }
 
-JSValue Interpreter::execute(ProgramExecutable* program, CallFrame* callFrame, JSObject* thisObj)
+JSValue Interpreter::executeProgram(const SourceCode& source, CallFrame* callFrame, JSObject* thisObj)
 {
     JSScope* scope = thisObj->globalObject()->globalScope();
     VM& vm = *scope->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
+
+    ProgramExecutable* program = ProgramExecutable::create(callFrame, source);
+    ASSERT(throwScope.exception() || program);
+    RETURN_IF_EXCEPTION(throwScope, { });
 
     ASSERT(!throwScope.exception());