IJ58249: DBX DISASSEMBLES OPCODES OF THE MD-FORM (E.G. RLDICL) INCORRECTL

APAR status

• Closed as program error.

Error description

• Issue
  =====
  The dbx, when disassembling opcodes of the
  MD-form (e.g. rldicl, rdicr, rldic, rldimi), is printing
  wrong values for mb (or me) if the values
  are greater than or equal to 0x20.
  
  
  Examples
  ========
  
    0x100000840 (main+0x40) 7868c000  rldicl
  r8,r3,0x18,0x0  #      CORRECT
    0x100000844 (main+0x44) 7868c040  rldicl
  r8,r3,0x18,0x1  #      CORRECT
    0x100000848 (main+0x48) 7868c080  rldicl
  r8,r3,0x18,0x2  #      CORRECT
    0x10000084c (main+0x4c) 7868c0c0  rldicl
  r8,r3,0x18,0x3  #      CORRECT
  
    0x1000008c0 (main+0xc0) 7868c020  rldicl
  r8,r3,0x18,0x1  # <=== WRONG! Should be: rldicl
  r8,r3,0x18,0x20
    0x1000008c4 (main+0xc4) 7868c060  rldicl
  r8,r3,0x18,0x1  # <=== WRONG! Should be: rldicl
  r8,r3,0x18,0x21
    0x1000008c8 (main+0xc8) 7868c0a0  rldicl
  r8,r3,0x18,0x3  # <=== WRONG! Should be: rldicl
  r8,r3,0x18,0x22
    0x1000008cc (main+0xcc) 7868c0e0  rldicl
  r8,r3,0x18,0x3  # <=== WRONG! Should be: rldicl
  r8,r3,0x18,0x23
  
  
  Assumption
  ==========
  The handling of mb5 (or me5) is wrong.
  

Local fix

• N/A
  

Problem summary

• DBX disassembles MD-form rotate instructions (rldicl, rldicr,
  rldic, rldimi) incorrectly, displaying wrong mask values when
  the mask field is 32 or greater.
  

Problem conclusion

• Modified libdbx disassembly code to correctly decode the mask
  field for MD-form instructions.
  

Temporary fix

Comments

APAR Information

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

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

  IJ58712

Fix information

• Fixed component name

  AIX V7.2

• Fixed component ID

  5765CD200

Applicable component levels