[jdk17] RFR: 8268362: [REDO] C2 crash when compile negative Arrays.copyOf length after loop

Hui Shi hshi at openjdk.java.net
Tue Jun 15 02:16:08 UTC 2021


This redos PR https://github.com/openjdk/jdk/pull/4238

Some closed tests fail due to original PR, the main reasons are:

8268325/8268345
CastIINode created in AllocateArrayNode::make_ideal_length apply on a negative array length. GVN transform converts these CastIINode to top. This breaks assumptions, eg., array index node type is TypeInt.
8268345
Some CastIINode is created in LoadRange::Ideal, which doesn't apply GVN transform. CastIINode can not be found in GVN hashtable and cause assertion failure.
Based on previous PR #4238, this PR unifies CastIINode processing post AllocateArrayNode::make_ideal_length. Setup type and add into igvn worklist. Avoid apply GVN transform to break different assumptions in parser.

Based on closed test failrue message, two new tests are added

TestNegArrayLengthAsIndex1 : fail in debug build even without previous PR #4238, it loads a negative array length and apply GVN transform (In GraphKit::load_array_length) which covert length to top node. It also assert in Parse::array_addressing.

TestNegArrayLengthAsIndex2 : similar with failrue in https://bugs.openjdk.java.net/browse/JDK-8268301

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Commit messages:
 - 8268362: [REDO] C2 crash when compile negative Arrays.copyOf length after loop

Changes: https://git.openjdk.java.net/jdk17/pull/49/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17&pr=49&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8268362
  Stats: 210 lines in 6 files changed: 208 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk17/pull/49.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/49/head:pull/49

PR: https://git.openjdk.java.net/jdk17/pull/49


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