IV74001: ARRAY BOUNDS EXCEPTION ON POWER 7 AND Z13 DUE TO AUTOSIMD

APAR status

• Closed as program error.

Error description

• Error Message: j> 11:20:21 Throwable trace:
  j> 11:20:21 java.lang.StringIndexOutOfBoundsException
  j> 11:20:21     at java.lang.String.substring(String.java:1360)
  j> 11:20:21     at
  java.lang.String.subSequence(String.java:1958)
  j> 11:20:21     at
  java.util.regex.Matcher.getSubSequence(Matcher.java:1305)
  j> 11:20:21     at
  java.util.regex.Matcher.group(Matcher.java:552)
  j> 11:20:21     at
  java.util.Formatter$FormatSpecifier.<init>(Formatter.java:2719)
  j> 11:20:21     at
  java.util.Formatter.parse(Formatter.java:2571)
  j> 11:20:21     at
  java.util.Formatter.format(Formatter.java:2512)
  j> 11:20:21     at
  java.util.Formatter.format(Formatter.java:2466)
  j> 11:20:21     at java.lang.String.format(String.java:2283)
  .
  Stack Trace: N/A
  .
  N/A
  

Local fix

• -Xjit:disableAutoSIMD
  

Problem summary

• The auto-SIMD optimization transforms a loop so it can take
  advantage of SIMD instructions to run several loop iterations in
  parallel, and to implement this change, the optimization
  modifies some of the expressions within the loop.  In certain
  loops, there are expressions that appear in multiple locations
  within the loop, and the auto-SIMD optimization erroneously
  modified the expression in such a way that it was changed in
  every location in which it appeared, but the modification was
  intended to occur only in the one location in which it was
  valid.
  The problem can only occur on following platforms:
  Power 7 onwards
  Z13 onwards
  The problem was introduced in Java 8 and has been fixed in Java
  8 SR2.
  

Problem conclusion

• The auto-SIMD optimization was fixed so it modifies expressions
  only in the location in which those modifications are correct.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR1 FP10  (8.0.1.10)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  Service Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R130 PSY

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