Changeset 222871 in webkit for trunk/Source/JavaScriptCore/assembler/ProbeStack.cpp

Timestamp:

Oct 4, 2017, 1:00:01 PM (8 years ago)

Author:

[email protected]

Message:

Add support for using Probe DFG OSR Exit behind a runtime flag.
​https://bugs.webkit.org/show_bug.cgi?id=177844
<rdar://problem/34801425>

Reviewed by Saam Barati.

Source/JavaScriptCore:

This is based on the code originally posted in ​https://bugs.webkit.org/show_bug.cgi?id=175144
(in r221774 and r221832) with some optimizations and bug fixes added. The probe
based DFG OSR Exit is only enabled if Options::useProbeOSRExit() is true. We're
landing this behind an option switch to make it easier to tune performance using
the probe based OSR exit.

• JavaScriptCore.xcodeproj/project.pbxproj:
• assembler/MacroAssembler.cpp:

(JSC::stdFunctionCallback):

• assembler/MacroAssemblerPrinter.cpp:

(JSC::Printer::printCallback):

• assembler/ProbeContext.cpp:

(JSC::Probe::executeProbe):
(JSC::Probe::flushDirtyStackPages):

• assembler/ProbeContext.h:

(JSC::Probe::Context::Context):
(JSC::Probe::Context::arg):

• assembler/ProbeFrame.h: Added.

(JSC::Probe::Frame::Frame):
(JSC::Probe::Frame::argument):
(JSC::Probe::Frame::operand):
(JSC::Probe::Frame::setArgument):
(JSC::Probe::Frame::setOperand):
(JSC::Probe::Frame::get):
(JSC::Probe::Frame::set):

• assembler/ProbeStack.cpp:

(JSC::Probe::Page::lowWatermarkFromVisitingDirtyChunks):
(JSC::Probe::Stack::Stack):
(JSC::Probe::Stack::lowWatermarkFromVisitingDirtyPages):

• assembler/ProbeStack.h:

(JSC::Probe::Stack::Stack):
(JSC::Probe::Stack::lowWatermark):
(JSC::Probe::Stack::set):
(JSC::Probe::Stack::savedStackPointer const):
(JSC::Probe::Stack::setSavedStackPointer):
(JSC::Probe::Stack::newStackPointer const): Deleted.
(JSC::Probe::Stack::setNewStackPointer): Deleted.

• bytecode/ArrayProfile.h:

(JSC::ArrayProfile::observeArrayMode):

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::updateOSRExitCounterAndCheckIfNeedToReoptimize):

• bytecode/CodeBlock.h:

(JSC::CodeBlock::addressOfOSRExitCounter): Deleted.

• bytecode/ExecutionCounter.h:

(JSC::ExecutionCounter::hasCrossedThreshold const):
(JSC::ExecutionCounter::setNewThresholdForOSRExit):

• bytecode/MethodOfGettingAValueProfile.cpp:

(JSC::MethodOfGettingAValueProfile::reportValue):

• bytecode/MethodOfGettingAValueProfile.h:
• dfg/DFGDriver.cpp:

(JSC::DFG::compileImpl):

• dfg/DFGJITCompiler.cpp:

(JSC::DFG::JITCompiler::linkOSRExits):
(JSC::DFG::JITCompiler::link):

• dfg/DFGOSRExit.cpp:

(JSC::DFG::jsValueFor):
(JSC::DFG::restoreCalleeSavesFor):
(JSC::DFG::saveCalleeSavesFor):
(JSC::DFG::restoreCalleeSavesFromVMEntryFrameCalleeSavesBuffer):
(JSC::DFG::copyCalleeSavesToVMEntryFrameCalleeSavesBuffer):
(JSC::DFG::saveOrCopyCalleeSavesFor):
(JSC::DFG::createDirectArgumentsDuringExit):
(JSC::DFG::createClonedArgumentsDuringExit):
(JSC::DFG::emitRestoreArguments):
(JSC::DFG::OSRExit::executeOSRExit):
(JSC::DFG::reifyInlinedCallFrames):
(JSC::DFG::adjustAndJumpToTarget):
(JSC::DFG::printOSRExit):

• dfg/DFGOSRExit.h:

(JSC::DFG::OSRExitState::OSRExitState):

• dfg/DFGThunks.cpp:

(JSC::DFG::osrExitThunkGenerator):

• dfg/DFGThunks.h:
• dfg/DFGVariableEventStream.cpp:

(JSC::DFG::tryToSetConstantRecovery):
(JSC::DFG::VariableEventStream::reconstruct const):
(JSC::DFG::VariableEventStream::tryToSetConstantRecovery const): Deleted.

• dfg/DFGVariableEventStream.h:
• profiler/ProfilerOSRExit.h:

(JSC::Profiler::OSRExit::incCount):

• runtime/JSCJSValue.h:
• runtime/JSCJSValueInlines.h:
• runtime/Options.h:

Tools:

Enable --useProbeOSrExit=true for dfg-eager and ftl-no-cjit-validate-sampling-profiler
test configurations.

• Scripts/run-jsc-stress-tests:

File:

• trunk/Source/JavaScriptCore/assembler/ProbeStack.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/assembler/ProbeStack.cpp

@@ -35 +35 @@
 namespace Probe {
 
+static void* const maxLowWatermark = reinterpret_cast<void*>(std::numeric_limits<uintptr_t>::max());
+
 #if ASAN_ENABLED
 // FIXME: we should consider using the copy function for both ASan and non-ASan builds.
@@ -50 +52 @@
 }
 #else
-#define copyStackPage(dst, src, size) std::memcpy(dst, src, size);
+#define copyStackPage(dst, src, size) std::memcpy(dst, src, size)
 #endif
 
@@ -85 +87 @@
 }
 
+void* Page::lowWatermarkFromVisitingDirtyChunks()
+{
+    uint64_t dirtyBits = m_dirtyBits;
+    size_t offset = 0;
+    while (dirtyBits) {
+        if (dirtyBits & 1)
+            return reinterpret_cast<uint8_t*>(m_baseLogicalAddress) + offset;
+        dirtyBits = dirtyBits >> 1;
+        offset += s_chunkSize;
+    }
+    return maxLowWatermark;
+}
+
 Stack::Stack(Stack&& other)
-    : m_newStackPointer(other.m_newStackPointer)
-    , m_lowWatermark(other.m_lowWatermark)
-    , m_stackBounds(WTFMove(other.m_stackBounds))
+    : m_stackBounds(WTFMove(other.m_stackBounds))
     , m_pages(WTFMove(other.m_pages))
 {
+    m_savedStackPointer = other.m_savedStackPointer;
 #if !ASSERT_DISABLED
     other.m_isValid = false;
@@ -129 +143 @@
 }
 
+void* Stack::lowWatermarkFromVisitingDirtyPages()
+{
+    void* low = maxLowWatermark;
+    for (auto it = m_pages.begin(); it != m_pages.end(); ++it) {
+        Page& page = *it->value;
+        if (!page.hasWritesToFlush() || low < page.baseAddress())
+            continue;
+        low = std::min(low, page.lowWatermarkFromVisitingDirtyChunks());
+    }
+    return low;
+}
+
 } // namespace Probe
 } // namespace JSC