8270307: C2: assert(false) failed: bad AD file after JDK-8267687

[y1yang0]

One input of ConvI2L becomes Top, which causes all nodes in the chain becoming Top, but this CMoveLNode does not change, only its input becomes Top.

  Pop  2146  CMoveL  === _  351  1  2149  [[ 2182  2187 ]]   Type:long !orig=810,696,[439],288 !jvms: Test::vMeth @ bci:78 (line 8)
BreakAtNode: _idx=2461 _debug_idx=102702461 orig._idx=2146 orig._debug_idx=92502146
<               < 2146  CMoveL  === _ _  1 _  [[]]   Type:long !orig=810,696,[439],288 !jvms: Test::vMeth @ bci:78 (line 8)
> long           2461  CMoveL  === _  2458  2149  1  [[ 2187  2182 ]]   Type:long !orig=2146,810,696,[439],288 !jvms: Test::vMeth @ bci:78 (line 8)

This CMoveLNode(CMove Binary(.. ..) (Binary .. Con#Top)) can not match any rules in instruction selection phase and finally hits the assert.

---

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Issue

• JDK-8270307: C2: assert(false) failed: bad AD file after JDK-8267687

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Webrevs

• 00: Full (04321dec)

[TobiHartmann]

Since this is targeted for JDK 17, the PR needs to be opened on the JDK 17 repo. Also, you need to request approval https://openjdk.java.net/jeps/3#Fix-Request-Process

[y1yang0]

Thanks Tobias for kind reminder! I do not familiar with JDK release process. I've added a Fix Request: comment on that.