# Utility Functions and Routines

This section describes LAPACK utility functions and routines. Summary information about these routines is given in the following table:

LAPACK Utility Routines
Routine Name | Data Types | Description
--- | --- | ---
ilaver |  | Returns the version of the Lapack library.
ilaenv |  | Environmental enquiry function which returns values for tuning algorithmic performance.
iparmq |  | Environmental enquiry function which returns values for tuning algorithmic performance.
ieeeck |  | Checks if the infinity and NaN arithmetic is safe. Called by ilaenv.
lsame |  | Tests two characters for equality regardless of case.
lsamen |  | Tests two character strings for equality regardless of case.
?labad | s, d | Returns the square root of the underflow and overflow thresholds if the exponent-range is very large.
?lamch | s, d | Determines machine parameters for floating-point arithmetic.
?lamc1 | s, d | Called from ?lamc2. Determines machine parameters given by beta, t, rnd, ieee1.
?lamc2 | s, d | Used by ?lamch. Determines machine parameters specified in its arguments list.
?lamc3 | s, d | Called from ?lamc1-?lamc5. Intended to force a and b to be stored prior to doing the addition of a and b.
?lamc4 | s, d | This is a service routine for ?lamc2.
?lamc5 | s, d | Called from ?lamc2. Attempts to compute the largest machine floating-point number, without overflow.
second/dsecnd |  | Return user time for a process.
xerbla |  | Error handling routine called by LAPACK routines.