Many function have PIC branches only because they call one of the many functions from JSValue that in turn call JSImmediate::toDouble, which gets NaN for the undefined and null cases. Getting the NaN value involves access to a global, and hence a PIC branch. Changing this to use a function, and one that's not inlined, would make code inside JavaScriptCore faster on Mac OS X. It would make code outside JavaScriptCore slower, because you'd still need a PIC branch just to call the function. Ideas?
Created attachment 101688 [details] The patch ============================================================================= ** TOTAL **: 1.005x as fast 244.5ms +/- 0.3% 243.2ms +/- 0.4% significant =============================================================================
Comment on attachment 101688 [details] The patch Attachment 101688 [details] did not pass mac-ews (mac): Output: http://queues.webkit.org/results/9209880
Fixed in r91555
(In reply to comment #3) > Fixed in r91555 It broke build on Leopard, SnowLeopard, and Windows. SnowLeopard: Ld /Volumes/Big/slave/snowleopard-intel-debug/build/WebKitBuild/Debug/JavaScriptGlue.framework/Versions/A/JavaScriptGlue normal x86_64 cd /Volumes/Big/slave/snowleopard-intel-debug/build/Source/JavaScriptGlue setenv MACOSX_DEPLOYMENT_TARGET 10.6 /Developer/usr/bin/g++-4.2 -arch x86_64 -dynamiclib -L/Volumes/Big/slave/snowleopard-intel-debug/build/WebKitBuild/Debug -F/Volumes/Big/slave/snowleopard-intel-debug/build/WebKitBuild/Debug -filelist /Volumes/Big/slave/snowleopard-intel-debug/build/WebKitBuild/JavaScriptGlue.build/Debug/JavaScriptGlue.build/Objects-normal/x86_64/JavaScriptGlue.LinkFileList -Xlinker --no-demangle -exported_symbols_list JavaScriptGlue.exp -install_name /Volumes/Big/slave/snowleopard-intel-debug/build/WebKitBuild/Debug/JavaScriptGlue.framework/Versions/A/JavaScriptGlue -mmacosx-version-min=10.6 -dead_strip -framework CoreServices -framework JavaScriptCore -single_module -compatibility_version 1 -current_version 535.1 -o /Volumes/Big/slave/snowleopard-intel-debug/build/WebKitBuild/Debug/JavaScriptGlue.framework/Versions/A/JavaScriptGlue Undefined symbols: "__ZNK3JSC7JSValue16toNumberSlowCaseEPNS_9ExecStateE", referenced from: __ZNK3JSC7JSValue8toNumberEPNS_9ExecStateE in JSUtils.o ld: symbol(s) not found Windows: 9>Linking... 9> Creating library C:\cygwin\home\buildbot\slave\win-release\build\WebKitBuild\Release\lib\WebKit.lib and object C:\cygwin\home\buildbot\slave\win-release\build\WebKitBuild\Release\lib\WebKit.exp 9>NPRuntimeObjectMap.obj : error LNK2019: unresolved external symbol "private: double __thiscall JSC::JSValue::toNumberSlowCase(class JSC::ExecState *)const " (?toNumberSlowCase@JSValue@JSC@@ABENPAVExecState@2@@Z) referenced in function "public: double __thiscall JSC::JSValue::toNumber(class JSC::ExecState *)const " (?toNumber@JSValue@JSC@@QBENPAVExecState@2@@Z) 9>WebCore.lib(JSBindingsAllInOne.obj) : error LNK2001: unresolved external symbol "private: double __thiscall JSC::JSValue::toNumberSlowCase(class JSC::ExecState *)const " (?toNumberSlowCase@JSValue@JSC@@ABENPAVExecState@2@@Z) 9>WebCore.lib(DerivedSources.obj) : error LNK2001: unresolved external symbol "private: double __thiscall JSC::JSValue::toNumberSlowCase(class JSC::ExecState *)const " (?toNumberSlowCase@JSValue@JSC@@ABENPAVExecState@2@@Z) 9>WebCore.lib(c_utility.obj) : error LNK2001: unresolved external symbol "private: double __thiscall JSC::JSValue::toNumberSlowCase(class JSC::ExecState *)const " (?toNumberSlowCase@JSValue@JSC@@ABENPAVExecState@2@@Z) 9>C:\cygwin\home\buildbot\slave\win-release\build\WebKitBuild\Release\bin\WebKit.dll : fatal error LNK1120: 1 unresolved externals
It appears that we just need to add __ZNK3JSC7JSValue16toNumberSlowCaseEPNS_9ExecStateE to JavaScriptCore.exp. Will land a fix soon.