[JSC] Be aggressive with OSR Entry to FTL if the DFG function was only used for OSR Entry itself
https://bugs.webkit.org/show_bug.cgi?id=154575
Patch by Benjamin Poulain <[email protected]> on 2016-02-25
Reviewed by Filip Pizlo.
I noticed that imaging-gaussian-blur spends most of its
samples in DFG code despite executing most of the loop
iterations in FTL.
On this particular test, the main function is only entered
once and have a very heavy loop there. What happens is DFG
starts by compiling the full function in FTL. That takes about
8 to 10 milliseconds during which the DFG code makes very little
progress. The calls to triggerOSREntryNow() try to OSR Enter
for a while then finally start compiling something. By the time
the function is ready, we have wasted a lot of time in DFG code.
What this patch does is set a flag when a DFG function is entered.
If we try to triggerOSREntryNow() and the flag was never set,
we start compiling both the full function and the one for OSR Entry.
- dfg/DFGJITCode.h:
- dfg/DFGJITCompiler.cpp:
(JSC::DFG::JITCompiler::compileEntryExecutionFlag):
(JSC::DFG::JITCompiler::compile):
(JSC::DFG::JITCompiler::compileFunction):
- dfg/DFGJITCompiler.h:
- dfg/DFGOperations.cpp:
- dfg/DFGPlan.cpp:
(JSC::DFG::Plan::Plan): Deleted.
- dfg/DFGPlan.h:
- dfg/DFGTierUpCheckInjectionPhase.cpp:
(JSC::DFG::TierUpCheckInjectionPhase::run):
