8351155: C1/C2: Remove 32-bit x86 specific FP rounding support

[shipilev]

C1 and C2 have support for rounding double/floats, to support awkward rounding modes of x87 FPU. With 32-bit x86 port removed, we can remove those parts. This basically deletes all the code that uses strict_fp_requires_explicit_rounding, which is now universally false for all supported platforms.

For C1, we remove RoundFP op, its associated lir_roundfp and related utility methods that insert these nodes in the graph.

For C2, we remove RoundDouble and RoundFloat nodes (note there is a confusingly named RoundDoubleMode nodes that are not related to this), associated utility methods, AD match rules that reference these nodes (as nops!), and some Ideal-s that are no longer needed.

Additional testing:

• Linux x86_64 server fastdebug, tier1
• Linux x86_64 server fastdebug, all

---

Progress

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Issue

• JDK-8351155: C1/C2: Remove 32-bit x86 specific FP rounding support (Sub-task - P4)

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer) Review applies to 376c5ad8
• Vladimir Ivanov (@iwanowww - Reviewer)

Reviewing

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[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:

8351155: C1/C2: Remove 32-bit x86 specific FP rounding support

Reviewed-by: vlivanov, kvn

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 36 new commits pushed to the master branch:

• 1bd0ce1: 8352918: Shenandoah: Verifier does not deactivate barriers as intended
• dc5c414: 8352762: Use EXACTFMT instead of expanded version where applicable
• 2eeda64: 8325132: CDS: Make sure the ArchiveRelocationMode is always printed in the log
• 50ac24e: 8351593: [JMH] test PhoneCode.Bulk reports NPE exception
• 79824c3: 8352184: Jtreg tests using CommandLineOptionTest.getVMTypeOption() and optionsvalidation.JVMOptionsUtils fail on static JDK
• c50a0a1: 8352508: [Redo] G1: Pinned regions with pinned objects only reachable by native code crash VM
• 89e5c42: 8294954: Remove superfluous ResourceMarks when using LogStream
• 41f3eea: 8352624: Add missing {@code} to PassFailJFrame.Builder.splitUI
• e2cd70a: 8351151: Clean up x86 template interpreter after 32-bit x86 removal
• b990780: 8352393: AIX: Problem list serviceability/attach/AttachAPIv2/StreamingOutputTest.java
• ... and 26 more: https://git.openjdk.org/jdk/compare/ee710fec21c4e886769576c17ad6db2ab91a84b4...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.

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[mlbridge]

Webrevs

• 01: Full - Incremental (88e4589c)
• 00: Full (376c5ad8)

[vnkozlov]

Good.

[iwanowww]

Looks good.

[shipilev]

Need a quick re-review after a minor leftover removal.

[shipilev]

Thanks!

/integrate

[openjdk]

Going to push as commit b73663a.
Since your change was applied there have been 36 commits pushed to the master branch:

• 1bd0ce1: 8352918: Shenandoah: Verifier does not deactivate barriers as intended
• dc5c414: 8352762: Use EXACTFMT instead of expanded version where applicable
• 2eeda64: 8325132: CDS: Make sure the ArchiveRelocationMode is always printed in the log
• 50ac24e: 8351593: [JMH] test PhoneCode.Bulk reports NPE exception
• 79824c3: 8352184: Jtreg tests using CommandLineOptionTest.getVMTypeOption() and optionsvalidation.JVMOptionsUtils fail on static JDK
• c50a0a1: 8352508: [Redo] G1: Pinned regions with pinned objects only reachable by native code crash VM
• 89e5c42: 8294954: Remove superfluous ResourceMarks when using LogStream
• 41f3eea: 8352624: Add missing {@code} to PassFailJFrame.Builder.splitUI
• e2cd70a: 8351151: Clean up x86 template interpreter after 32-bit x86 removal
• b990780: 8352393: AIX: Problem list serviceability/attach/AttachAPIv2/StreamingOutputTest.java
• ... and 26 more: https://git.openjdk.org/jdk/compare/ee710fec21c4e886769576c17ad6db2ab91a84b4...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit b73663a.

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