KB109877 - BUG: Smallest Negative Integers Cause Error on Input

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The range of integers that can be read in correctly is:

-127 to 127 for INTEGER*1
-32,767 to 32,767 for INTEGER*2
-2,147,483,647 to 2,147,483,647 for INTEGER*4

The problem occurs when trying to read in

-128 for INTEGER*1
-32,768 for INTEGER*2
-2,147,483,648 for INTEGER*4

Sample Code

C Compile options needed: have no effect
C The following code demonstrates the problem:

       integer*1 i
      integer*2 j
      integer*4 k
      open(1,file='test.dat')
      do n=3,5
        write(1,*) -2**((2**n-1)) !write -128, -32768, -2147483648
      end do

      rewind(1)
      read(1,*,iostat=ierr) i
      if(ierr.eq.6100) then
        print*, 'error reading integer*1 was: ',ierr
      end if

      read(1,*,iostat=ierr) j
      if(ierr.eq.6100) then
        print*, 'error reading integer*2 was: ',ierr
      end if

      read(1,*,iostat=ierr) k
      if(ierr.eq.6100) then
        print*, 'error reading integer*4 was: ',ierr
      end if
      pause
      end

BUG: Smallest Negative Integers Cause Error on Input

SYMPTOMS

RESOLUTION

STATUS

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Sample Code

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