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/GNU Fortran 4

8.143 LEADZ — Number of leading zero bits of an integer

Description:
LEADZ returns the number of leading zero bits of an integer.
Standard:
Fortran 2008 and later
Class:
Elemental function
Syntax:
RESULT = LEADZ(I)
Arguments:
I Shall be of type INTEGER.
Return value:
The type of the return value is the default INTEGER. If all the bits of I are zero, the result value is BIT_SIZE(I).
Example:
PROGRAM test_leadz
  WRITE (*,*) BIT_SIZE(1)  ! prints 32
  WRITE (*,*) LEADZ(1)     ! prints 31
END PROGRAM
See also:
BIT_SIZE, TRAILZ, POPCNT, POPPAR

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Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-4.9.3/gfortran/LEADZ.html