8292153: x86: Represent Registers as values

[iwanowww]

As of now, Registers of all sorts use pointer-based representation. It's error-prone, because compilers perform implicit conversions between pointers and integral values. Also, it constraints MacroAssembler API where it may introduce ambiguity between overloads.

Proposed change hides pointer representation behind value class.

Pointer-based representation is kept to avoid massive migration of users (from -> to .) and to enable incremental migration on per-platform basis (pointer-based representation is assumed in shared code).

Code quality doesn't suffer (and even slightly improves):
https://godbolt.org/z/d8dGM1eY1

(I noticed one downside: slowdebug builds become slower, because operator-> isn't inlined there. If it becomes a problem, migrating performance-sensitive places from -> to . should solve the problem.)

Testing: hs-tier1 - hs-tier5

PS: a number of cleanups are incorporated. In particular, I decided to expand all macros from register.hpp because IMO they add confusion rather than improve readability.

---

Progress

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Issue

• JDK-8292153: x86: Represent Registers as values

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer)
• Andrew Haley (@theRealAph - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back vlivanov! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@iwanowww The following labels will be automatically applied to this pull request:

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[mlbridge]

Webrevs

• 01: Full - Incremental (478d4bed)
• 00: Full (4cb98cbd)

[theRealAph]

Shade and I were looking at this bug a week or so ago, but agreed to leave it because this patch would find and fix it. Good!

[vnkozlov]

Looks good to me.

[openjdk]

@iwanowww 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:

8292153: x86: Represent Registers as values

Reviewed-by: kvn, aph

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 22 new commits pushed to the master branch:

• ad5f628: 8292140: (fs) Needless instanceof check in RegistryFileTypeDetector
• 2ddf728: 8292026: Remove redundant allocations from DoubleByteEncoder
• 3aaffd6: 8292071: NMT: move MallocHeader to its own header and inline header checks
• 85a6023: Merge
• 4c6d22a: 8288769: Revert unintentional change to deflate.c
• 5fce02e: 8291496: Allocating card table before heap causes underflow asserts in CardTable::addr_for()
• 0def531: 8290889: JDK 19 RDP2 L10n resource files update - msgdrop 10
• 4b03e13: 8285405: add test and check for negative argument to HashMap::newHashMap et al
• 2e0a17c: 8292187: aarch64: Remove duplicate header files
• 36ef4c1: 8291081: Some sun/tools/jstatd/TestJstatd* tests fail with "Not a percentage: 68.31: expected true, was false"
• ... and 12 more: https://git.openjdk.org/jdk/compare/6397d564a5dab07f81bf4c69b116ebfabb2446ba...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.

[iwanowww]

Thanks for the reviews, Vladimir and Andrew.

/integrate

[openjdk]

Going to push as commit 755ecf6.
Since your change was applied there have been 29 commits pushed to the master branch:

• dedc05c: 8291640: java/beans/XMLDecoder/8028054/Task.java should use the 3-arg Class.forName
• 3d20a8b: 8291959: FileFontStrike#initNative does not properly initialize IG Table on Windows
• a28ab7b: 8288568: Reduce runtime of java.security microbenchmarks
• 7ea9ba1: 8292064: Convert java/lang/management/MemoryMXBean shell tests to java version
• fc1d94e: 8292232: AIX build failure by JDK-8290840
• a9bc149: 8292216: Remove modules/packages_unloading_do
• 1c0f0f4: 8292077: G1 nmethod entry barriers don't keep oops alive
• ad5f628: 8292140: (fs) Needless instanceof check in RegistryFileTypeDetector
• 2ddf728: 8292026: Remove redundant allocations from DoubleByteEncoder
• 3aaffd6: 8292071: NMT: move MallocHeader to its own header and inline header checks
• ... and 19 more: https://git.openjdk.org/jdk/compare/6397d564a5dab07f81bf4c69b116ebfabb2446ba...master

Your commit was automatically rebased without conflicts.

[openjdk]

@iwanowww Pushed as commit 755ecf6.

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