PI90218: POW(3.0,0.5) LESS ACCURATE IN THE LAST DIGIT vs SQRT()

APAR status

• Closed as Permanent restriction.

Error description

• Using the function pow() to evaluate the square root of 3 gives
  a result different from other functions.  It returns:
     3FFBB67A E8584CAB.
  For a higher degree of accuracy, sqrt() will return:
     3FFBB67A E8584CAA.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of z/OS XL C/C++ programs which call   *
  *                 function pow() and compiled with             *
  *                 float(IEEE).                                 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When users invoke pow() in program which is compiled with
  float(IEEE),pow(3.0,0.5) has 0.1 ulps less accurate than
  sqrt(3.0).The error within 1 ulps is acceptable.
  

Problem conclusion

• This APAR is being closed PRS with concurrence from the
  submitting customers. It means a permanent restriction.
  

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:

Fix information

Applicable component levels