8281744: x86: Use short jumps in TIG::set_vtos_entry_points

[shipilev]

Performance in -Xint mode seems to be bottlenecked on the code size, rather than particular instruction hotspots, which means code density is important.

There are forward branches in TemplateInterpreterGenerator::set_vtos_entry_points, which cannot be shortened by MacroAssembler, unless we tell it specifically that the upcoming branch target would be within the 8-bit offset. Which it apparently is in this particular case, because there are just a handful of push-es between the jump and its target. If a jump offset is more than 8 bits, the interpreter would catch fire just about everywhere, since set_vtos_entry_points is used at every bytecode entry. fastdebug builds assert the offset sanity directly.

Current patch improves SPECjvm2008 performance in -Xint mode on Ryzen 7 5700G:

compiler.compiler: +4.1%
compiler.sunflow: +4.7%
compress: +9.9%
crypto.signverify: +5.2%
scimark.fft.large: +9.5%
scimark.fft.small: +10.1%
serial: +7.3%
xml.transform: +7.1%
xml.validation: +3.3%

There are other places in template interpreter where forward jumps can be short, I'll do them separately, since they are riskier and also less important.

Additional testing:

• Linux x86_64 fastdebug, tier1
• Linux x86_32 fastdebug, tier1

---

Progress

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Issue

• JDK-8281744: x86: Use short jumps in TIG::set_vtos_entry_points

Reviewers

• Robbin Ehn (@robehn - Reviewer)
• Coleen Phillimore (@coleenp - Reviewer)

Reviewing

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[mlbridge]

Webrevs

• 00: Full (61a9f11f)

[robehn]

Thanks

[openjdk]

@shipilev This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8281744: x86: Use short jumps in TIG::set_vtos_entry_points

Reviewed-by: rehn, coleenp

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At the time when this comment was updated there had been 37 new commits pushed to the master branch:

• b156462: 8281467: Allow larger OptoLoopAlignment and CodeEntryAlignment
• f33329e: 8016524: [macosx] Bottom line is not visible for JTableHeader
• d4cd8df: 8281634: jdeps: java.lang.InternalError: Missing message: err.invalid.filters
• 1a7b70a: 8269091: javax/sound/sampled/Clip/SetPositionHang.java failed with ArrayIndexOutOfBoundsException: Array index out of range: -4
• 16f649b: 8281678: appcds/dynamicArchive/ArchiveConsistency.java fails after JDK-8279997
• 88fc3bf: 8280473: CI: Support unresolved JVM_CONSTANT_Dynamic constant pool entries
• f07b816: 8280940: gtest os.release_multi_mappings_vm is racy
• 9d0a4c3: 8274238: Inconsistent type for young_list_target_length()
• 2604a88: 8281585: Remove unused imports under test/lib and jtreg/gc
• 534e557: 8256368: Avoid repeated upcalls into Java to re-resolve MH/VH linkers/invokers
• ... and 27 more: https://git.openjdk.java.net/jdk/compare/3a13425bc9088cbb6d95e1a46248d7eba27fb1a6...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[coleenp]

Looks good

[shipilev]

Thanks for reviews!

/integrate

[openjdk]

Going to push as commit 1870465.
Since your change was applied there have been 45 commits pushed to the master branch:

• 2fe0bf6: 8281748: runtime/logging/RedefineClasses.java failed "assert(addr != __null) failed: invariant"
• bc61484: 8280136: Serial: Remove unnecessary use of ExpandHeap_lock
• 2112a9d: 8246033: bin/print_config.js script uses nashorn jjs tool
• 1c12b15: 8281741: [testbug] PrintIdealPhaseTest fails with -Xcomp
• f82866b: 8281555: [macos] Get rid of deprecated Style Masks constants
• 8819f45: 8281722: Removal of PrintIdealLevel
• 622970e: 8281728: Redundant null check in LineNumberInputStream.read
• 11f943d: 8280916: Simplify HotSpot Style Guide editorial changes
• b156462: 8281467: Allow larger OptoLoopAlignment and CodeEntryAlignment
• f33329e: 8016524: [macosx] Bottom line is not visible for JTableHeader
• ... and 35 more: https://git.openjdk.java.net/jdk/compare/3a13425bc9088cbb6d95e1a46248d7eba27fb1a6...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 1870465.

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