| JDK 26 |
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| 26 b08Fixed |
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I found this during work with the Template Framework JDK-8344942.
[~thartmann] found it was a regression of JDK-8283894, which was my suspicion after tracing it back to code in CompressBitsNode::Value and more specifically bitshuffle_value, on this line:
hi = mask_max_bw < max_bw ? (1L << mask_max_bw) - 1 : src_type->hi_as_long();
Reproduce the result like this:
java -Xbatch -XX:CompileCommand=compileonly,Test::test -XX:+PrintIdeal Test.java
CompileCommand: compileonly Test.test bool compileonly = true
AFTER: print_ideal
0 Root === 0 28 [[ 0 1 3 21 ]] inner
3 Start === 3 0 [[ 3 5 6 7 8 9 ]] #{0:control, 1:abIO, 2:memory, 3:rawptr:BotPTR, 4:return_address}
5 Parm === 3 [[ 28 ]] Control !jvms: Test::test @ bci:-1 (line 26)
6 Parm === 3 [[ 28 ]] I_O !jvms: Test::test @ bci:-1 (line 26)
7 Parm === 3 [[ 28 ]] Memory Memory: @BotPTR *+bot, idx=Bot; !jvms: Test::test @ bci:-1 (line 26)
8 Parm === 3 [[ 28 ]] FramePtr !jvms: Test::test @ bci:-1 (line 26)
9 Parm === 3 [[ 28 ]] ReturnAdr !jvms: Test::test @ bci:-1 (line 26)
21 ConI === 0 [[ 28 ]] #int:min
28 Return === 5 6 7 8 9 returns 21 [[ 0 ]]
Exception in thread "main" java.lang.RuntimeException: Bad value: -2147483648 0
at Test.main(Test.java:36)
We can see from the PrintIdeal, that the Integer.compress has been constant folded to the wrong value.
------------------------------------------------------------- The identical issue exists for long:
./java -Xbatch -XX:CompileCommand=compileonly,TestL::test -XX:+PrintIdeal TestL.java
CompileCommand: compileonly TestL.test bool compileonly = true
AFTER: print_ideal
0 Root === 0 28 [[ 0 1 3 21 ]] inner
3 Start === 3 0 [[ 3 5 6 7 8 9 ]] #{0:control, 1:abIO, 2:memory, 3:rawptr:BotPTR, 4:return_address}
5 Parm === 3 [[ 28 ]] Control !jvms: TestL::test @ bci:-1 (line 7)
6 Parm === 3 [[ 28 ]] I_O !jvms: TestL::test @ bci:-1 (line 7)
7 Parm === 3 [[ 28 ]] Memory Memory: @BotPTR *+bot, idx=Bot; !jvms: TestL::test @ bci:-1 (line 7)
8 Parm === 3 [[ 28 ]] FramePtr !jvms: TestL::test @ bci:-1 (line 7)
9 Parm === 3 [[ 28 ]] ReturnAdr !jvms: TestL::test @ bci:-1 (line 7)
21 ConL === 0 [[ 28 ]] #long:min
28 Return === 5 6 7 8 9 returns 21 [[ 0 ]]
Exception in thread "main" java.lang.RuntimeException: Bad value: -9223372036854775808 0
at TestL.main(TestL.java:17)
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