Changeset 254517 in webkit

Timestamp:

Jan 14, 2020, 10:08:40 AM (7 years ago)

Author:

sbarati@apple.com

Message:

Add an option that enables/disables throwing away baseline JIT code
​https://bugs.webkit.org/show_bug.cgi?id=206244

Reviewed by Robin Morisset.

This option is now set to false as I investigate a perf regression with
the original patch.

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::finalizeUnconditionally):

• runtime/OptionsList.h:

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• bytecode/CodeBlock.cpp (modified) (1 diff)
• runtime/OptionsList.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2020-01-14  Saam Barati  <sbarati@apple.com>
+
+        Add an option that enables/disables throwing away baseline JIT code
+        https://bugs.webkit.org/show_bug.cgi?id=206244
+
+        Reviewed by Robin Morisset.
+
+        This option is now set to false as I investigate a perf regression with
+        the original patch.
+
+        * bytecode/CodeBlock.cpp:
+        (JSC::CodeBlock::finalizeUnconditionally):
+        * runtime/OptionsList.h:
+
 2020-01-13  Darin Adler  <darin@apple.com>
 

trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -1387 +1387 @@
     // If BaselineJIT code is not executing, and an optimized replacement exists, we attempt
     // to discard baseline JIT code and reinstall LLInt code to save JIT memory.
-    if (!Options::forceBaseline() && jitType() == JITType::BaselineJIT && !m_vm->heap.codeBlockSet().isCurrentlyExecuting(this)) {
+    if (!Options::forceBaseline() && Options::enableThrowingAwayBaselineCode() && jitType() == JITType::BaselineJIT && !m_vm->heap.codeBlockSet().isCurrentlyExecuting(this)) {
         if (CodeBlock* optimizedCodeBlock = optimizedReplacement()) {
             if (!optimizedCodeBlock->m_osrExitCounter) {

trunk/Source/JavaScriptCore/runtime/OptionsList.h

@@ -496 +496 @@
     v(Bool, useUnlinkedCodeBlockJettisoning, false, Normal, "If true, UnlinkedCodeBlock can be jettisoned.") \
     v(Unsigned, getByValICMaxNumberOfIdentifiers, 4, Normal, "Number of identifiers we see in the LLInt that could cause us to bail on generating an IC for get_by_val.") \
+    v(Bool, enableThrowingAwayBaselineCode, false, Normal, nullptr) \
 
 enum OptionEquivalence {