IJ24658: MISSING SWITCH/CASE CASE WITH -O3 AND HOT

APAR status

• Closed as program error.

Error description

• When compiling with optimization (-O3 and -qhot), a case
  in a switch/case statement is removed incorrectly.  For example:
  
       switch(value) {
       case 1:
       rc = func(st);
       break;
       case 2:
       rc = func(st);
       break;
       case 4:
       rc = func(st);
       break;
       }
  
  , the '4' case is optimized away, and no code is run if value=4.
  

Local fix

• Reduce optimization level
  

Problem summary

• PROBLEM DESCRIPTION:
  A valid switch/case execution path is incorrectly determined to
  never be used, and is removed during code optimization.
  
  USERS AFFECTED:
  Users compiling code at -O3
  

Problem conclusion

• The bad code optimization was corrected and the switch code is
  now generated correctly.
  

Temporary fix

Comments

APAR Information

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

  LI81222

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

Fix information

• Fixed component name

  XL C/C++ FOR AI

• Fixed component ID

  5725C7200

Applicable component levels