LI77935: LONG LONG CONSTANT WITH ADDI/ADDIS+RLDIC

XL C/C++ for Linux Fix Pack 8 (October 2015 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

• Code generated to build certain 64-bit long long constants is
  not optimal and does not always need to load from the TOC.
  
  
      ===== TEST CASE =====
  
  extern "C" unsigned long long c0x0000ffffffff0000()
  {
    return 0x0000fffffff0000ULL;
  }
  
  
  Code Generated at -O2:
  
   | 000000                   PDEF   c0x0000ffffffff0000
  3|                          PROC
  5| 000000 ld   E8620008  1  L8       gr3=.+CONSTANT_AREA(gr2,0)
  5| 000004 ld   E8630000  1  L8       gr3=+CONSTANT_AREA(gr3,0)
  6| 000008 bclr 4E800020  1  BA       lr
  

Local fix

Problem summary

• PROBLEM DESCRIPTION:
  To avoid loads from the constant area and to get better
  performance, and a smaller TOC size.
  
  USERS AFFECTED:
  Users who use -q64.
  

Problem conclusion

• The constants are divided into several pieces and generated
  using ADDI and RLDIC.
  

Temporary fix

Comments

APAR Information

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

  IV52918

• 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 IV52918

     UP06/09/13