Museum

Home

Lab Overview

Retrotechnology Articles

⇒ Online Manual

Media Vault

Software Library

Restoration Projects

Artifacts Sought

BIT(3F)                              BSD                               BIT(3F)



NAME
     bit - and, or, xor, not, rshift, lshift bitwise functions

SYNOPSIS
     (intrinsic) function and (word1, word2)

     (intrinsic) function or (word1, word2)

     (intrinsic) function xor (word1, word2)

     (intrinsic) function not (word)

     (intrinsic) function rshift (word, nbits)

     (intrinsic) function lshift (word, nbits)

DESCRIPTION
     These bitwise functions are built into the compiler and return the data
     type of their argument(s).  Their arguments must be integer or logical
     values.

     The bitwise combinatorial functions return the bitwise "AND" (and), "OR"
     (or), or "exclusive OR" (xor) of two operands.  not returns the bitwise
     complement of its operand.

     lshift, or rshift with a negative nbits, is a logical left shift with no
     end around carry.  rshift, or lshift with a negative nbits, is an
     arithmetic right shift with sign extension.  No test is made for a
     reasonable value of nbits.

     These functions can be used to create a variety of general routines, as
     in the following statement function definitions:

          integer bitset, bitclr, getbit, word, bitnum

          bitset( word, bitnum ) = or(word,lshift(1,bitnum))
          bitclr( word, bitnum ) = and(word,not(lshift(1,bitnum)))
          getbit( word, bitnum ) = and(rshift(word,bitnum),1)

FILES
     These functions are generated in-line by the f77 compiler.

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026