RFR(M) 8155980: ARM InterpreterMacroAssembler::get_method_counters() should not be saving callee saved registers

[Chris Plummer]

Hello,

Please review the following arm changes. They will be pushed to JDK 10 
only (when it opens).

https://bugs.openjdk.java.net/browse/JDK-8155980
http://cr.openjdk.java.net/~cjplummer/8155980/webrev.02/webrev.hotspot

JDK-8012544 added a bunch of callee register saving to 
InterpreterMacroAssembler::get_method_counters() around the call_VM() 
call. The reason is because there are a couple of callers of 
get_method_counters() that need to have r0 and r3 preserved. 
get_method_counters() should not be responsible for having to save 
callee saved registers. It does not know which ones are in use when it 
is called, so it can't do this efficiently. In fact 2 of the 4 callers 
of get_method_counters() do not need any registers saved. For this 
reason the callee of get_method_counters() should be responsible for 
saving callee registers.

This solution would have been been pretty straight forward, except that 
AARCH64 does not allow SP to go above extended_sp, so when setting up 
extended_sp I needed to make sure there will be room for the 2 registers 
that need to be pushed. extended_sp is mainly based on max_stack() for 
the method, plus an extra slot for jsr292 and exception handling (but 
not both at the same time). So the fix here is mostly about making sure 
there are always at least 2 extra slots for pushing the 2 registers.

Here are the changes:

interp_masm_arm.cpp
   -No longer save/restore registers in get_method_counters():

templateTable_arm.cpp:
   -Save/restore Rdisp and R3_bytecode to stack around calls to 
get_method_counters.

abstractinterpreter__arm.cpp::
   -Properly account for extra 2 slots needed on AARCH64 when creating a 
frame
    in layout_activation()
   -Note I switched to using method->constMethod()->max_stack() because
    method->max_stack() includes Method::extra_stack_entries(), and I 
want to
    account for Method::extra_stack_entries() separately.

templateInterpreterGenerator_arm.cpp:
   -Properly account for extra 2 slots needed on AARCH64 when creating a 
frame
    in generate_normal_entry().

I've tested the following with -Xcomp and with -Xmixed on arm32 and arm64:

   Kitchensink
   vm.mlvm
   :jdk_svc
   :hotspot_runtime
   :hotspot_serviceability
   :hotspot_compiler
   :jdk_lang
   :jdk_util

I also tested the test case from JDK-8012544.

thanks,

Chris