8239454: LLIntData : invalid opcode returned for 16 and 32 bit wide instructions

[arun-joseph]

With new bytecode format introduced in Webkit 608.1, the unlinked and linked bytecodes were replaced by narrow (1-byte operand) and wide (4-byte operand) bytecodes. These were extended to narrow, wide16 and wide32 bytecodes in WebKit 609.1. In narrow instructions, each argument of the opcode has a fixed size of 1-byte. The same applies for wide 16 and wide32 with 2-byte and 4-byte, respectively.

In the Low Level Intepreter (LLInt), each opcode has a corresponding ID assigned for narrow, wide16 and wide32 implementation, and the variable numOpcodeIDs is used to denote the total number of opcodes. The narrow opcode IDs are mapped from 0 to (numOpcodeIDs - 1). The next numOpcodeIDs opcode IDs are mapped to wide16 opcodes, and similarly, the next numOpcodeIDs to wide32 opcodes. The same can be found in LowLevelInterpreter.cpp and also in the autogenerated file Bytecodes.h.

Bug: When getOpcodeWide(id) is called in LLIntData.h, the value (id - numOpcodesIDs) is returned.

Fix: It's modified to (id + numOpcodesIDs) in getOpcodeWide16() and (id + numOpcodesIDs*2) in getOpcodeWide32().

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Progress

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Issue

• JDK-8239454: LLIntData : invalid opcode returned for 16 and 32 bit wide instructions

Reviewers

• Guru Hb (ghb - Reviewer)
• Kevin Rushforth (kcr - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jfx pull/115/head:pull/115
$ git checkout pull/115

[bridgekeeper]

👋 Welcome back ajoseph! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request.

[mlbridge]

Webrevs

• 00: Full (eed2043)

[kevinrushforth]

/reviewers 2

[openjdk]

@kevinrushforth
The number of required reviews for this PR is now set to 2 (with at least 1 of role reviewers).

[kevinrushforth]

Fix looks good. Testing looks good.

[openjdk]

@arun-joseph This change now passes all automated pre-integration checks. When the change also fulfills all project specific requirements, type /integrate in a new comment to proceed. After integration, the commit message will be:

8239454: LLIntData : invalid opcode returned for 16 and 32 bit wide instructions

Reviewed-by: ghb, kcr

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[arun-joseph]

/integrate

[openjdk]

@arun-joseph
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[guruhb]

/sponsor

[openjdk]

@guruhb @arun-joseph The following commits have been pushed to master since your change was applied:

• 48ddd80: Merge
• 35a01ca: 8228867: Fix mistakes in FX API docs

Your commit was automatically rebased without conflicts.

Pushed as commit d8e7f85.

[mlbridge]

Mailing list message from Guru Hb on openjfx-dev:

Changeset: d8e7f85
Author: Arun Joseph <ajoseph at openjdk.org>
Committer: Guru Hb <ghb at openjdk.org>
Date: 2020-02-20 05:33:04 +0000
URL: https://git.openjdk.java.net/jfx/commit/d8e7f850

8239454: LLIntData : invalid opcode returned for 16 and 32 bit wide instructions

Reviewed-by: ghb, kcr

! modules/javafx.web/src/main/native/Source/JavaScriptCore/llint/LLIntData.h