trailz

Date:

06-19-2023

NAME

TRAILZ - Count the number of trailing zero bits in an integer

SYNOPSIS

Fortran Synopsis

INTEGER FUNCTION TRAILZ ( [I=]I )
  INTEGER I

STANDARDS

Fortran 2008

DESCRIPTION

This intrinsic function counts the number of trailing zero bits in i.

Fortran

TRAILZ accepts argument i, which is a logical, integer, real, or Cray pointer value. Argument i cannot be declared as REAL(KIND=16).

TRAILZ is an elemental function. The name of this function cannot be passed as an argument.

RETURN VALUES

Fortran

TRAILZ returns a default integer.

EXAMPLES

The following lines of Fortran code shows the TRAILZ function used with an argument of type integer. The bit pattern of the argument and the value of the result are also given. For simplicity, a 64-bit object is used:

INTEGER (KIND=8) I1, I2
I2 = TRAILZ(I1)

-----------------------------------------------------------------
| 0 | 0 | 0 | 0 | 0 | 1 | 1 | . . . | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
-----------------------------------------------------------------
                                I1

TRAILZ returns 2 for integer variable I2.

SEE ALSO

leadz(3i)