RFR: 8244224: Implementation of JEP 381: Remove the Solaris and SPARC Ports (hotspot)

[Kim Barrett]

> On May 4, 2020, at 1:12 AM, Mikael Vidstedt <mikael.vidstedt at oracle.com> wrote:
> 
> 
> Please review this change which implements part of JEP 381:
> 
> JBS: https://bugs.openjdk.java.net/browse/JDK-8244224
> webrev: http://cr.openjdk.java.net/~mikael/webrevs/8244224/webrev.00/hotspot/open/webrev/
> JEP: https://bugs.openjdk.java.net/browse/JDK-8241787

I've only looked at the src/hotspot changes so far. I've not
duplicated comments already made by Stefan.

Looks good, other than a few very minor issues, some of which might
already be covered by planned followup RFEs.

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I think with sparc removal, c1's pack64/unpack64 stuff is no longer
used.  So I think that can be removed from c1_LIR.[ch]pp too.

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src/hotspot/share/opto/generateOptoStub.cpp
 225   // Clear last_Java_pc and (optionally)_flags

The sparc-specific clearing of "flags" is gone.

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src/hotspot/share/runtime/deoptimization.cpp
1086       *((jlong *) check_alignment_get_addr(obj, index, 8)) = (jlong) *((jlong *) &val);

[pre-existing]
The rhs cast to jlong is unnecessary, since it's dereferencing a jlong*.

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src/hotspot/share/runtime/flags/jvmFlagConstraintsCompiler.cpp
 236 JVMFlag::Error CompilerThreadPriorityConstraintFunc(intx value, bool verbose) {
 237   return JVMFlag::SUCCESS;
 238 }

After SOLARIS code removal we no longer need this constraint function.

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src/hotspot/share/runtime/globals.hpp
2392   experimental(size_t, ArrayAllocatorMallocLimit,                           \
2393           (size_t)-1,                                                       \

Combine these lines.

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src/hotspot/share/utilities/dtrace.hpp

Shuold just eliminate all traces of HS_DTRACE_WORKAROUND_TAIL_CALL_BUG.

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