小数部位该为0却不是0 - Fortran Coder

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program Compute

    implicit none

    integer,parameter::M=1,N=2

    real,dimension(:,:),allocatable::C1

    integer i,j,k,m1,n1,a1,a2,ETL(M*N,5)

    real aa(4,4)

    allocate(C1((M+1)*(N+1),(M+1)*(N+1)))

    open(unit=15,file='storett3',access='sequential',action='write')

    open(unit=14,file='storeaa3',access='sequential',action='write')

    data aa/4,2,1,2,2,4,2,1,1,2,4,2,2,1,2,4/

    k=0

    do j=1,M

       do i=1,N

          k=k+1

          ETL(k,1)=k

          m1=mod(i,N)

          if(m1==0) then

             n1=j*(N+1)-1

          else

             n1=(j-1)*(N+1)+m1

          end if

          ETL(k,2)=n1

          ETL(k,3)=n1+1

          ETL(k,4)=n1+N+2

          ETL(k,5)=n1+N+1

        end do

    end do    

    do k=1,M*N

       do i=1,4

          do j=1,4

             a1=ETL(k,i+1)

             a2=ETL(k,j+1)

             C1(a1,a2)=C1(a1,a2)+aa(i,j)

          end do

       end do

    end do

    write(14,"(<4>('',f,''))")((aa(i,j),i=1,4),j=1,4)

    write(15,"(<6>('',f,''))")((C1(i,j),i=1,6),j=1,6)

end

-finit-local-zero
-finit-derived
-finit-integer=n
-finit-real=<zero|inf|-inf|nan|snan>
-finit-logical=<true|false>
-finit-character=n
The -finit-local-zero option instructs the compiler to initialize local INTEGER, REAL, and COMPLEX variables to zero, LOGICAL variables to false, and CHARACTER variables to a string of null bytes. Finer-grained initialization options are provided by the -finit-integer=n, -finit-real=<zero|inf|-inf|nan|snan> (which also initializes the real and imaginary parts of local COMPLEX variables), -finit-logical=<true|false>, and -finit-character=n (where n is an ASCII character value) options. Components of derived type variables will be initialized according to these flags only with -finit-derived. These options do not initialize

allocatable arrays
variables that appear in an EQUIVALENCE statement.
(These limitations may be removed in future releases).

Note that the -finit-real=nan option initializes REAL and COMPLEX variables with a quiet NaN. For a signalling NaN use -finit-real=snan; note, however, that compile-time optimizations may convert them into quiet NaN and that trapping needs to be enabled (e.g. via -ffpe-trap).

Finally, note that enabling any of the -finit-* options will silence warnings that would have been emitted by -Wuninitialized for the affected local variables.