[Bug fortran/21931] New: problem with fugly-logint flag and evaluating if statements

["mark_l_hansen at yahoo dot com" <gcc-bugzilla@gcc.gnu.org>]

The -fugly-logint flag allows FORTRAN to treat integers as logicals and vice 
versa.  The following example program shows some inconsistencies in how the if 
statements evaluate.  If you change VAR1 to 3,2,1,0,-1 and view the results you 
will see some interesting things.  The best way to see the problem is to view 
the output.  Thanks.  I would appreciate an email if anyone has a solution/fix 
for the problem.  Thanks.

Below is the code----

Makefile:
all:
	g77 -c -g -ff90 -ff90-intrinsics-delete -fugly-logint -fno-automatic 
function.for
	g++ -c -g main.cpp
	g++  -o program main.o function.o -lg2c 

main.cpp:
        #include <iostream>
        #include <vector>
        using namespace std;

        extern "C" {
	        void func_();
        }

        int main()
        {
	        func_();
        	return 0;
        }
function.for:
      SUBROUTINE FUNC
      
      IMPLICIT NONE
*
*  LOCAL DECLARATIONS
*
      INTEGER VAR1, VAR2

      LOGICAL LVAR1, LVAR2, LOG1, LOG2

      EQUIVALENCE
     .  (VAR1, LVAR1)
     ., (VAR2, LVAR2)

*C change VAR1 to 2,-1,0,3 and view results     
      VAR1 =  3;
      VAR2 =  -1;
      LOG1 = .true.
      LOG2 = .true.
      
      WRITE (*,*) "LOG1  = ", LOG1
      WRITE (*,*) "LOG2  = ", LOG2
      WRITE (*,*) "VAR1  = ", VAR1
      WRITE (*,*) "VAR2  = ", VAR2
      WRITE (*,*) "LVAR1 = ", LVAR1
      WRITE (*,*) "LVAR2 = ", LVAR2

      IF(.NOT.((LVAR1 .AND. LVAR2) .AND. (LOG1 .AND. LOG2))) THEN
        WRITE (*,*) "LOGICAL TRUE with LOG2"         
      ELSE
        WRITE (*,*) "LOGICAL FALSE with LOG2"         
      ENDIF
      IF(.NOT.(LVAR1 .AND. LVAR2 .AND. LOG1)) THEN
        WRITE (*,*) "LOGICAL TRUE with LOG1"         
      ELSE
        WRITE (*,*) "LOGICAL FALSE with LOG1"         
      ENDIF
      IF(.NOT.(LVAR1 .AND. LVAR2)) THEN
        WRITE (*,*) "LOGICAL TRUE"         
      ELSE
        WRITE (*,*) "LOGICAL FALSE"         
      ENDIF
*----------------------------------------------------------------------      
      IF(.NOT.(VAR1 .AND. VAR2 .AND. LOG1)) THEN
        WRITE (*,*) "BYTE TRUE with LOG1"         
      ELSE
        WRITE (*,*) "BYTE FALSE with LOG1"         
      ENDIF
      IF(.NOT.(VAR1 .AND. VAR2)) THEN
        WRITE (*,*) "BYTE TRUE"         
      ELSE
        WRITE (*,*) "BYTE FALSE"         
      ENDIF
     
      END

-- 
           Summary: problem with fugly-logint flag and evaluating if
                    statements
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mark_l_hansen at yahoo dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21931