LI77105: INEFFICIENT VECTOR CONSTANT GENERATION

XL C/C++ for Blue Gene/Q Fix Pack 12 (May 2015 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 14 (May 2016 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 15 (October 2017 Update) for 12.1
November 2012 Update for XL C/C++ for Blue Gene/Q, V12.1
February 2013 Update for XL C/C++ for Blue Gene/Q, V12.1
May 2013 Update for XL C/C++ for Blue Gene/Q, V12.1
XL C/C++ for Blue Gene/Q Fix Pack 5 (August 2013 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 6 (November 2013 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 7 (February 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 8 (May 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 9 (August 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 10 (November 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 11 (February 2015 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 13 (August 2015 Update) for 12.1

APAR status

• Closed as program error.

Error description

• Inefficient use/access of const vector datatypes in local scope
  as compared to global scope.
  

Local fix

• N/A
  

Problem summary

• PROBLEM DESCRIPTION:
  For local vector variables that are initialized by literals,
  the code generated is inefficient.  It loads and assigns each
  element on the stack, which could be improved by loading the
  whole vector literal once.
  
  USERS AFFECTED:
  User using bracelist initializers to initialize auto variables
  of vector type.
  

Problem conclusion

• Local initialized vector variables are now saved and loaded
  from the contant area/TOC instead of the stack.
  

Temporary fix

Comments

APAR Information

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

  IV21491

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

Fix information

• Fixed component name

  XL C/C++ FOR BG

• Fixed component ID

  5799AG100

Applicable component levels