LI76979: INEFFICIENT VECTOR CONSTANT GENERATION

September 2012 Update for XL C/C++ for Linux, V12.1
April 2013 Update for XL C/C++ for Linux, V12.1
XL C/C++ for Linux Fix Pack 8 (October 2015 Update) for 12.1
December 2012 Update for XL C/C++ for Linux, V12.1
XL C/C++ for Linux Fix Pack 4 (October 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 5 (December 2013 Update) for 12.1
XL C/C++ for Linux Fix Pack 6 (February 2014 Update) for 12.1
XL C/C++ for Linux Fix Pack 7 (May 2014 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 LI

• Fixed component ID

  5725C7300

Applicable component levels

• RC10 PSN IV21491

     UP06/09/13