Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!csri.toronto.edu!laredo
From: laredo@csri.toronto.edu (Jim Alain Laredo)
Newsgroups: comp.lang.fortran
Subject: Fortran to C translator question.
Message-ID: <1989Aug1.105428.18152@jarvis.csri.toronto.edu>
Date: 1 Aug 89 14:54:29 GMT
Organization: University of Toronto, CSRI
Lines: 41

To those of you that have used any of the Fortran to C translators,
please, tell me what the expected results for this small routine are

	SUBROUTINE X(A,M)
	INTEGER M
	DOUBLE PRECISION A(M,*)

	INTEGER I,J

    DO 20 I=1,M
        DO 10 J=I+1,M
             A(I,J) = A(I,J)+1
10      CONTINUE
20  CONTINUE

According to the FOR_C brochure (from COBALT BLUE) the coordinates
of the matrices are inverted to solve the problem of the memory
distribution, Fortran places the matrices column-wise as oppossed to C
that does it row-wise. Therefore a reference in Fortran to A(i,j)
should be translated into C as A[M*j+i].
	Also, I would like to know if the translator modifies the loops,
note that in the first loop , DO 20 I=1,M, both values have to be
be decremented, while in the second, DO 10 J=I+1,M, only the absolute
value M, should be decremented to fit into the C matrix definitions.

	If the translator is good, I would expect the following code or 
at least something similar.

	void X(A,M)
	int	M;
	double A[];
	{
		int	i,j;
		for(i=0;i<=M-1;i++)
         	for(j=i+1;j<=M-1;j++)
	              A[j*M+i] = A[j*M+i]+1;
	}

	thanks for your help,
	Jim Laredo
	laredo@csri.toronto.edu