R8 Processing Error Possibly Due to Right Shift Operator [348499741]

Fixed

Bug

Status Update

No update yet.

Description

qi...@gmail.com

created issue #1

Jun 21, 2024 08:46AM

Versions

r8 version: R8 main (build engineering)
art version: ART version 2.1.0 x86_64
java version: 17.0.10

Description

After processing the testcase source code with R8, we used JADX for decompilation and obtained the following result, which is clearly different in semantics and output from the original source code. Comparing the JADX parsing results with the source code, it is the error that eliminates one assignment of test.a, which may due to redundant store elimination. We also conducted some tests using D8 instead of R8, and no similar issues occurred, so it can be confirmed that the problem lies with R8.

package defpackage;

/* loaded from: classes.dex */
class Test {
    public static void main(String[] strArr) {
        for (int i = 0; i < 10; i++) {
        }
        System.out.println(1);
    }
}

Step to Reproduce

javac -source 8 -target 8 -cp . Test.java
jar cvf classes.jar ./*.class
java -cp r8.jar com.android.tools.r8.R8 --pg-conf proguard.pro --release --output ./ ./classes.jar
env ANDROID_LOG_TAGS=*:f ANDROID_DATA=./ /path/to/art --64 --no-compile -cp ./classes.dex Test > result_1

Expected Result

Actual Result

Testcase Source Code

class Test {
    public static void main(String[] args) {
        int d = 1;
        for (int g = 0; g < 10; g++)
            d = 7;
        d >>>= 32;
        System.out.println(d);
    }
}

classes.dex

792 B

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classes.jar

787 B

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Test.class

454 B

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Comments

sg...@google.com <sg...@google.com> Jun 21, 2024 08:52AM

Reassigned to cl...@google.com.

cl...@google.com <cl...@google.com> #2Jun 21, 2024 11:12AM

It's a bug in SparseConditionalConstantPropagation.

Before

 #65: -1: ConstNumber          v11(32) <-  32 (INT)
    : -1: Ushr                 v12 <- v4, v11(32)
 #66: -1: StaticGet            v13 <- ; field: java.io.PrintStream java.lang.System.out
    : -1: Invoke-Virtual       v13, v12; method: void java.io.PrintStream.println(int)

After

 #65: -1: ConstNumber          v11(0b100000) <-  32 (INT)
    : -1: ConstNumber          v12(1) <-  1 (INT)
 #66: -1: StaticGet            v13 <- ; field: java.io.PrintStream java.lang.System.out
    : -1: Invoke-Virtual       v13, v12(1); method: void java.io.PrintStream.println(int)

Message last modified on Jun 21, 2024 11:12AM

cl...@google.com <cl...@google.com> #3Jun 24, 2024 07:41AM

Should be fixed in https://r8-review.git.corp.google.com/c/r8/+/93845

The code is 3 months old so maybe the need to backport is limited.

ap...@google.com <ap...@google.com> #4Jun 24, 2024 09:23AM

Project: r8
Branch: main

commit af99aef53c3ab244cc2021a7837fe9a018fca696
Author: Clément Béra <clementbera@google.com>
Date: Mon Jun 24 09:11:24 2024

Fix shifts in AbstractCalculator

Bug:

b/348499741

Change-Id: Ief9d63fae9a981d2e9800ccab8d8766abb984184

M src/main/java/com/android/tools/r8/ir/analysis/value/arithmetic/AbstractCalculator.java
M src/main/java/com/android/tools/r8/utils/BitUtils.java
A src/test/java/com/android/tools/r8/ir/ShiftIssueTest.java

https://r8-review.googlesource.com/93845

ap...@google.com <ap...@google.com> #5Jun 24, 2024 03:03PM

Project: r8
Branch: 8.5

commit 9d92041cd97f24d4dcbf3865fd26d76a48b9639e
Author: Clément Béra <clementbera@google.com>
Date: Mon Jun 24 13:35:18 2024

Fix shifts in AbstractCalculator

Bug:

b/348499741

https://r8-review.googlesource.com/93882

ap...@google.com <ap...@google.com> #6Jun 24, 2024 03:03PM

Project: r8
Branch: 8.5

commit 23834c71ef57255063202688dbffdd258ad059b6
Author: Clément Béra <clementbera@google.com>
Date: Mon Jun 24 13:39:23 2024

Version 8.5.28

Bug:

b/348499741

Bug:

b/347739663

Change-Id: I642a3acb69b8f55b6417a4e66a56ec974aa52b47

M src/main/java/com/android/tools/r8/Version.java

https://r8-review.googlesource.com/93883

cl...@google.com <cl...@google.com> #7Jun 25, 2024 05:57AM

Marked as fixed.

This should be fixed in 8.6 and 8.5. The reporter can even wait a few weeks for it to get into studio or manually update r8 version.

an...@google.com <an...@google.com> #8Jul 24, 2024 08:39PM

Thank you for your patience while our engineering team worked to resolve this issue. A fix for this issue is now available in:

Android Studio Koala Feature Drop | 2024.1.2 Beta 2
Android Gradle Plugin 8.6.0-beta02

We encourage you to try the latest update.

If you notice further issues or have questions, please file a new bug report.

Thank you for taking the time to submit feedback — we really appreciate it!

an...@google.com <an...@google.com> #9Aug 9, 2024 12:55AM

The fixes for this issue are now also available in:

Android Studio Koala | 2024.1.1 Patch 2
Android Gradle Plugin 8.5.2

We encourage you to try the latest update.

If you notice further issues or have questions, please file a new bug report.

Issue 348499741

Description

Versions

Description

Step to Reproduce

Expected Result

Actual Result

Testcase Source Code

Issue summary

Comments

sg...@google.com <sg...@google.com> Jun 21, 2024 08:52AM

cl...@google.com <cl...@google.com> #2Jun 21, 2024 11:12AM

cl...@google.com <cl...@google.com> #3Jun 24, 2024 07:41AM

ap...@google.com <ap...@google.com> #4Jun 24, 2024 09:23AM

ap...@google.com <ap...@google.com> #5Jun 24, 2024 03:03PM

ap...@google.com <ap...@google.com> #6Jun 24, 2024 03:03PM

cl...@google.com <cl...@google.com> #7Jun 25, 2024 05:57AM

an...@google.com <an...@google.com> #8Jul 24, 2024 08:39PM

an...@google.com <an...@google.com> #9Aug 9, 2024 12:55AM

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