LI78434: TOO MANY GROUP BREAKING NOPS

XL C/C++ for Linux Fix Pack 2 (February 2015 Update) for 13.1

APAR status

• Closed as program error.

Error description

• Too many group breaking XNOP ori instructions are scheduled into
  the code, resulting in multiple consecutive XNOPs or affecting
  dispatch groups.
  
  
     === EXAMPLE ===
  
  23| 00000C stw      90010070 1 ST4A
   0| 000010 ori      60420000 1 XNOP
   0| 000014 ori      60420000 1 XNOP    ** Multiple ori
   0| 000018 ori      60420000 1 XNOP
   0| 00001C ori      60420000 1 XNOP
   0| 000020 ori      60420000 1 XNOP
  23| 000024 lxvd2x   7C011E98 1 VLQD
  
  
  15| 000058 addi     38600080 1 LI
  14| 00005C stxvd2x  7C410799 1 VSTQD
   0| 000060 ori      60420000 1 XNOP
  15| 000064 stxvd2x  7C611F99 1 VSTQD
   0| 000068 ori      60420000 1 XNOP
  16| 00006C ld       E8010070 1 L8
   0| 000070 ori      60420000 1 XNOP    ** Superfluous ori
  16| 000074 ld       E8610080 1 L8
  17| 000078 addi     38210090 1 AI
  

Local fix

Problem summary

• PROBLEM DESCRIPTION:
  Inefficient scheduling with -qtune=pwr7.
  
  USERS AFFECTED:
  Those using -qtune=pwr7 with -O2 and up.
  

Problem conclusion

• Fixed an instruction scheduling issue that was causing
  inefficient scheduling of XNOP ori instructions.
  

Temporary fix

Comments

APAR Information

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

  IV61672

• 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

• RD10 PSN IV61672

     UP06/09/13