JDK-8238691 : C2: turn subtype check into macro node
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 15
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2020-02-07
  • Updated: 2023-09-20
  • Resolved: 2020-02-17
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JDK 15
15 b11Fixed
Related Reports
Duplicate :  
JDK-8222075 - C2: Enable loop predication for subtype checks
Relates :  
JDK-8239072 - subtype check macro node causes node budget to be exhausted
Relates :  
JDK-8316533 - C2 compilation fails with assert(verify(phase)) failed: missing Value() optimization
Relates :  
JDK-8299155 - C2: SubTypeCheckNode::verify() should not produce dependencies / oop pool entries
Relates :  
JDK-8253566 - clazz.isAssignableFrom will return false for interface implementors
Relates :  
JDK-8239367 - RunThese30M.java failed due to "assert(false) failed: graph should be schedulable"
Relates :  
JDK-8239565 - sa/ClhsdbJhisto.java failed due to "assert(false) failed: unscheduable graph"
Relates :  
JDK-8239335 - C2: assert((Value(phase) == t) || (t != TypeInt::CC_GT && t != TypeInt::CC_EQ)) failed: missing Value() optimization
Description
This should allow subtype checks that can't be compiled as a simple pointer comparison at parse time to:

- better constant fold
- be candidate for predication and split if
- have a chance of being compiled as a simple pointer comparison if type information improves
Comments
URL: https://hg.openjdk.java.net/jdk/jdk/rev/efc0da4a10a9 User: roland Date: 2020-02-17 09:32:11 +0000
17-02-2020