[master] RFR: 8302065: [Lilliput] Cleanups and touch-ups

[Aleksey Shipilev]

On Wed, 8 Feb 2023 11:40:39 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

> Lilliput accumulated a couple of superfluous changes and could need some minor improvements.

Looks good. I cross-referenced in with https://builds.shipilev.net/patch-openjdk-lilliput/ -- and most are clean reversal. A few questions, though.

src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp line 109:

> 107: 
> 108:  private:
> 109: 

Missed a similar cleanup in `macroAssembler_x86.hpp`, I think.

src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp line 815:

> 813:     if (UseFastLocking) {
> 814:       // If the owner is ANONYMOUS, we need to fix it - in the slow-path.
> 815:       testb(Address(tmpReg, OM_OFFSET_NO_MONITOR_VALUE_TAG(owner)), (int32_t) (intptr_t) ANONYMOUS_OWNER);

Sanity question: This would accept the monitor that has the lowest byte equal to `ANONYMOUS_OWNER`. Are we guaranteed that no monitor would ever have the lowest bit as `1`? Probably true, just checking the reason here.

src/hotspot/cpu/x86/vtableStubs_x86_64.cpp line 220:

> 218:   // The emitted code in lookup_interface_method changes when itable_index exceeds 15.
> 219:   // For linux, a very narrow estimate would be 112, but Solaris requires some more space (130).
> 220:   const ptrdiff_t estimate = 137;

Upstream has it as `136`. Do we need `137`?

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Marked as reviewed by shade (Committer).

PR: https://git.openjdk.org/lilliput/pull/73