ilucg.h move here from ../../elliptic/

		and update prototypes for remaining code

[sd]ilucg.f77	convert from being Fortran logical functions
		to subroutines, add explicit error return argument


git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinAnalysis/AHFinderDirect/trunk@1073 f88db872-0e4f-0410-b76b-b9085cfa78c5

3 files changed, 81 insertions, 30 deletions

diff --git a/src/sparse-matrix/ilucg/dilucg.f77 b/src/sparse-matrix/ilucg/dilucg.f77
index 7ed9049..411240d 100644
--- a/src/sparse-matrix/ilucg/dilucg.f77
+++ b/src/sparse-matrix/ilucg/dilucg.f77
@@ -1,4 +1,8 @@
-      LOGICAL FUNCTION DILUCG(N,IA,JA,A,B,X,ITEMP,RTEMP,EPS,ITER,IE)
+      SUBROUTINE DILUCG(N,IA,JA,A,
+     $                  B,X,
+     $                  ITEMP,RTEMP,
+     $                  EPS,ITER,
+     $                  ISTATUS,IERROR)
       IMPLICIT DOUBLE PRECISION (A-H,O-Z)
       DIMENSION IA(*),JA(*),A(*),B(*),X(*),ITEMP(*),RTEMP(*)
 C
@@ -26,19 +30,23 @@ C       IS DEEMED TO HAVE OCCURED WHEN THE INFINITY-NORM OF THE
 C       CHANGE IN THE SOLUTION IN ONE ITERATION IS .LE. EPS * THE
 C       INFINITY-NORM OF THE CURRENT SOLUTION.  HOWEVER, IF EPS
 C       .LT. 0.0D0, IT IS INTERNALLY SCALED BY THE MACHINE PRECISION,
-C       SO THAT, FOR EXAMPLE, EPS = -256.0 WILL ALLOW THE LAST TWO
-C       HEXADECIMAL DIGITS OF THE SOLUTION TO BE IN ERROR.
+C       SO THAT, FOR EXAMPLE, EPS = -256.0D0 WILL ALLOW THE LAST 8 BITS
+C       OF THE SOLUTION TO BE IN ERROR.
 C     ITER GIVES THE REQUESTED NUMBER OF ITERATIONS, OR IS 0 FOR "NO LIMIT".
-C     IE IS AN INTEGER VARIABLE.  FOR NORMAL RETURN, IT GIVES
+C     ISTATUS IS AN INTEGER VARIABLE.  FOR NORMAL RETURN, IT GIVES
 C       THE NUMBER OF ITERATIONS DONE (NEGATIVE IS NO CONVERGENCE).
 C       ON ERROR RETURN, THE ROW IN ERROR.
+C     IERROR IS AN INTEGER VARIABLE.  IT IS SET TO 0 FOR A SUCCESSFUL
+C       SOLUTION (REACHED CONVERGENCE CRITERION), OR NEGATIVE FOR AN
+C       ERROR (INCLUDING FAILURE TO CONVERGE WITHIN THE REQUESTED NUMBER
+C       OF ITERATIONS).
 C
-C THE FUNCTION RETURNS .FALSE. IF ALL'S WELL, .TRUE. ON AN ERROR RETURN.
-C
-C (MODIFIED TO RETURN LOGICAL VALUE, J. THORNBURG, 13/MAY/85.)
-C (MODIFIED TO ADD CONVERGENCE CRITERIA, J. THORNBURG, 17/MAY/85.)
-C (MODIFIED CONVERGENCE CRITERIA, J. THORNBURG, 4/AUG/89.)
-C (MODIFIED TO AVOID SKIP RETURNS, J. THORNBURG, 10/SEP/89.)
+C MODIFICATIONS
+C * RETURN LOGICAL VALUE, J. THORNBURG, 13/MAY/85.
+C * ADD CONVERGENCE CRITERIA, J. THORNBURG, 17/MAY/85.
+C * CHANGED CONVERGENCE CRITERIA, J. THORNBURG, 4/AUG/89.
+C * AVOID SKIP RETURNS, J. THORNBURG, 10/SEP/89.
+C * CHANGE FUNCTION BACK TO SUBROUTINE, J. THORNBURG, 2.JUN.2003
 C
 C REFERENCE:
 C     D.S.KERSHAW,"THE INCOMPLETE CHOLESKY-CONJUGATE GRADIENT
@@ -47,7 +55,7 @@ C       J.COMPUT.PHYS. JAN 1978 PP 43-65
 C
       LOGICAL DLU0
       NP=IABS(N)
-      IE=0
+      ISTATUS=0
       IF (NP.EQ.0) GO TO 20
 C CALCULATE INDICES FOR BREAKING UP TEMPORARY ARRAYS.
       N1=NP+1
@@ -66,16 +74,16 @@ C CALCULATE INDICES FOR BREAKING UP TEMPORARY ARRAYS.
       IF (N.LT.0) GO TO 10
 C DO INCOMPLETE LU DECOMPOSITION
       IF (DLU0(NP,IA,JA,A,ITEMP(IC),ITEMP(JC),ITEMP(JCI),RTEMP(IALU),
-     *    ITEMP(ILU),ITEMP(JLU),ITEMP(ID),RTEMP(IR),IE)) GOTO 20
+     *    ITEMP(ILU),ITEMP(JLU),ITEMP(ID),RTEMP(IR),ISTATUS)) GOTO 20
 C AND DO CONJUGATE GRADIENT ITERATIONS
 C CALL MODIFIED TO ADD ADJUSTABLE CONVERGENCE CRITERIA EPS
 C - J. THORNBURG, 17/MAY/85.
 10    CALL DNCG0(NP,IA,JA,A,B,X,ITEMP(ILU),ITEMP(JLU),ITEMP(ID),
      *  RTEMP(IALU),RTEMP(IR),RTEMP(IP),RTEMP(IS1),RTEMP(IS2),
-     *  EPS,ITER,IE)
-      DILUCG = .FALSE.
+     *  EPS,ITER,ISTATUS)
+      IERROR = 0
       RETURN
-20    DILUCG = .TRUE.
+20    IERROR = -1
       RETURN
       END
 
diff --git a/src/sparse-matrix/ilucg/ilucg.h b/src/sparse-matrix/ilucg/ilucg.h
new file mode 100644
index 0000000..9d839c9
--- /dev/null
+++ b/src/sparse-matrix/ilucg/ilucg.h
@@ -0,0 +1,35 @@
+/* ilucg.h -- C/C++ prototypes for [sd]ilucg() routines */
+/* $Header$ */
+
+/*
+ * prerequisites:
+ *	"cctk.h"
+ *	"config.h"	// for "integer" = Fortran integer
+ */
+
+#ifdef __cplusplus
+extern "C"
+       {
+#endif
+
+/*
+ * ***** ILUCG *****
+ */
+void CCTK_FCALL
+  CCTK_FNAME(silucg)(const integer* N,
+		     const integer IA[], const integer JA[], const float A[],
+		     const float B[], float X[],
+		     integer ITEMP[], float RTEMP[],
+		     const float* EPS, const integer* ITER,
+		     integer* ISTATUS, integer* IERROR);
+void CCTK_FCALL
+  CCTK_FNAME(dilucg)(const integer* N,
+		     const integer IA[], const integer JA[], const double A[],
+		     const double B[], double X[],
+		     integer ITEMP[], double RTEMP[],
+		     const double* EPS, const integer* ITER,
+		     integer* ISTATUS, integer* IERROR);
+
+#ifdef __cplusplus
+       }	/* extern "C" */
+#endif
diff --git a/src/sparse-matrix/ilucg/silucg.f77 b/src/sparse-matrix/ilucg/silucg.f77
index 6eaa94b..09610e0 100644
--- a/src/sparse-matrix/ilucg/silucg.f77
+++ b/src/sparse-matrix/ilucg/silucg.f77
@@ -1,4 +1,8 @@
-      LOGICAL FUNCTION SILUCG(N,IA,JA,A,B,X,ITEMP,RTEMP,EPS,ITER,IE)
+      SUBROUTINE SILUCG(N,IA,JA,A,
+     $                  B,X,
+     $                  ITEMP,RTEMP,
+     $                  EPS,ITER,
+     $                  ISTATUS,IERROR)
       IMPLICIT REAL (A-H,O-Z)
       DIMENSION IA(*),JA(*),A(*),B(*),X(*),ITEMP(*),RTEMP(*)
 C
@@ -26,19 +30,23 @@ C       IS DEEMED TO HAVE OCCURED WHEN THE INFINITY-NORM OF THE
 C       CHANGE IN THE SOLUTION IN ONE ITERATION IS .LE. EPS * THE
 C       INFINITY-NORM OF THE CURRENT SOLUTION.  HOWEVER, IF EPS
 C       .LT. 0.0, IT IS INTERNALLY SCALED BY THE MACHINE PRECISION,
-C       SO THAT, FOR EXAMPLE, EPS = -256.0 WILL ALLOW THE LAST TWO
-C       HEXADECIMAL DIGITS OF THE SOLUTION TO BE IN ERROR.
+C       SO THAT, FOR EXAMPLE, EPS = -256.0 WILL ALLOW THE LAST 8 BITS
+C       OF THE SOLUTION TO BE IN ERROR.       
 C     ITER GIVES THE REQUESTED NUMBER OF ITERATIONS, OR IS 0 FOR "NO LIMIT".
-C     IE IS AN INTEGER VARIABLE.  FOR NORMAL RETURN, IT GIVES
+C     ISTATUS IS AN INTEGER VARIABLE.  FOR NORMAL RETURN, IT GIVES
 C       THE NUMBER OF ITERATIONS DONE (NEGATIVE IS NO CONVERGENCE).
 C       ON ERROR RETURN, THE ROW IN ERROR.
+C     IERROR IS AN INTEGER VARIABLE.  IT IS SET TO 0 FOR A SUCCESSFUL
+C       SOLUTION (REACHED CONVERGENCE CRITERION), OR NEGATIVE FOR AN
+C       ERROR (INCLUDING FAILURE TO CONVERGE WITHIN THE REQUESTED NUMBER
+C       OF ITERATIONS).
 C
-C THE FUNCTION RETURNS .FALSE. IF ALL'S WELL, .TRUE. ON AN ERROR RETURN.
-C
-C (MODIFIED TO RETURN LOGICAL VALUE, J. THORNBURG, 13/MAY/85.)
-C (MODIFIED TO ADD CONVERGENCE CRITERIA, J. THORNBURG, 17/MAY/85.)
-C (MODIFIED CONVERGENCE CRITERIA, J. THORNBURG, 4/AUG/89.)
-C (MODIFIED TO AVOID SKIP RETURNS, J. THORNBURG, 10/SEP/89.)
+C MODIFICATIONS
+C * RETURN LOGICAL VALUE, J. THORNBURG, 13/MAY/85.
+C * ADD CONVERGENCE CRITERIA, J. THORNBURG, 17/MAY/85.
+C * CHANGED CONVERGENCE CRITERIA, J. THORNBURG, 4/AUG/89.
+C * AVOID SKIP RETURNS, J. THORNBURG, 10/SEP/89.
+C * CHANGE FUNCTION BACK TO SUBROUTINE, J. THORNBURG, 2.JUN.2003
 C
 C REFERENCE:
 C     D.S.KERSHAW,"THE INCOMPLETE CHOLESKY-CONJUGATE GRADIENT
@@ -47,7 +55,7 @@ C       J.COMPUT.PHYS. JAN 1978 PP 43-65
 C
       LOGICAL SLU0
       NP=IABS(N)
-      IE=0
+      ISTATUS=0
       IF (NP.EQ.0) GO TO 20
 C CALCULATE INDICES FOR BREAKING UP TEMPORARY ARRAYS.
       N1=NP+1
@@ -66,16 +74,16 @@ C CALCULATE INDICES FOR BREAKING UP TEMPORARY ARRAYS.
       IF (N.LT.0) GO TO 10
 C DO INCOMPLETE LU DECOMPOSITION
       IF (SLU0(NP,IA,JA,A,ITEMP(IC),ITEMP(JC),ITEMP(JCI),RTEMP(IALU),
-     *    ITEMP(ILU),ITEMP(JLU),ITEMP(ID),RTEMP(IR),IE)) GOTO 20
+     *    ITEMP(ILU),ITEMP(JLU),ITEMP(ID),RTEMP(IR),ISTATUS)) GOTO 20
 C AND DO CONJUGATE GRADIENT ITERATIONS
 C CALL MODIFIED TO ADD ADJUSTABLE CONVERGENCE CRITERIA EPS
 C - J. THORNBURG, 17/MAY/85.
 10    CALL SNCG0(NP,IA,JA,A,B,X,ITEMP(ILU),ITEMP(JLU),ITEMP(ID),
      *  RTEMP(IALU),RTEMP(IR),RTEMP(IP),RTEMP(IS1),RTEMP(IS2),
-     *  EPS,ITER,IE)
-      SILUCG = .FALSE.
+     *  EPS,ITER,ISTATUS)
+      IERROR = 0
       RETURN
-20    SILUCG = .TRUE.
+20    IERROR = -1
       RETURN
       END