Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference

ID 767251
Date 11/07/2023
Public

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LEADZ

Elemental Intrinsic Function (Specific): Returns the number of leading zero bits in an integer.

result = LEADZ (i)

i

(Input) Must be of type integer or logical.

Results

The result type is default integer. The result value is the number of leading zeros in the binary representation of the integer i.

The model for the interpretation of an integer value as a sequence of bits is shown in Model for Bit Data.

Example

Consider the following:

  INTEGER*8 J, TWO
  PARAMETER (TWO=2)
  DO J= -1, 40
    TYPE *, LEADZ(TWO**J)  ! Prints 64 down to 23 (leading zeros)
  ENDDO
  END