RFR (M): 7200001: failed C1 OSR compile doesn't get recompiled with C2

[Christian Thalinger]

On Sep 21, 2012, at 3:47 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:

> Looks good. But we usually keep "if" check and it's body on separate lines for debugging purpose. You put them on one line in compileBroker.cpp and method.cpp.

Ahh, debugging, right.  I wanted to make it more compact but you have a good point.  I'll undo that.

-- Chris

> 
> Thanks,
> Vladimir
> 
> Christian Thalinger wrote:
>> http://cr.openjdk.java.net/~twisti/7200001
>> 7200001: failed C1 OSR compile doesn't get recompiled with C2
>> Reviewed-by:
>> When a C1 OSR compile bails out we don't recompile the method in C2 which it should:
>>   3661    3 %     3       com.oracle.nashorn.scripts.Script$mult::bench @ 21 (143 bytes)   COMPILE SKIPPED: unlinked call site (FIXME needs patching or recompile support) (retry at different tier)
>> The problem is that we only have one flag that indicates a method is not OSR
>> compilable:
>>  JVM_ACC_NOT_OSR_COMPILABLE      = 0x08000000,
>> Unlike for normal compiles where we have a flag for each compiler:
>>  JVM_ACC_NOT_C2_COMPILABLE       = 0x02000000,
>>  JVM_ACC_NOT_C1_COMPILABLE       = 0x04000000,
>> The fix is to set not-OSR-compilable for the current compile level and not any level.  Since this problem occurs very rarely as C1 usually can compile all methods
>> we set a method not-C1-compilable when it's not-C1-OSR-compilable:
>>  void set_not_c1_osr_compilable() { set_not_c1_compilable(); }
>> and wait for C2 to compile it.
>> If this shows a problem in the future we can sacrifice another bit in the flags.
>> src/share/vm/compiler/compileBroker.cpp
>> src/share/vm/compiler/compileBroker.hpp
>> src/share/vm/compiler/compileLog.cpp
>> src/share/vm/oops/method.cpp
>> src/share/vm/oops/method.hpp
>> src/share/vm/runtime/advancedThresholdPolicy.cpp
>> src/share/vm/runtime/compilationPolicy.cpp
>> src/share/vm/runtime/simpleThresholdPolicy.cpp
>> src/share/vm/runtime/vmStructs.cpp
>> src/share/vm/utilities/accessFlags.hpp