Update comments, help messages, fix formatting. Add license informati…

…on to gurobi-plugin file.

include/pluto/libpluto.h

@@ -148,16 +148,16 @@ struct plutoOptions{
     /* Read input from a .scop file */
     int readscop;
 
-    /* Use PIP as ilp solver. */
+    /* Use PIP as the ILP solver. */
     int pipsolve;
 
-    /* Use isl as ilp solver. */
+    /* Use isl as the ILP solver. */
     int islsolve;
 
-    /* Use glpk as ilp solver. */
+    /* Use glpk as the ILP solver. */
     int glpk;
 
-    /* Use gurobi as ilp solver. */
+    /* Use gurobi as the ILP solver. */
     int gurobi;
 
     /* Use lp instead of ILP. */

src/framework-dfp.c

@@ -61,7 +61,7 @@ double* pluto_fusion_constraints_feasibility_solve(PlutoConstraints *cst, PlutoM
 #ifdef GUROBI
         sol = pluto_fcg_constraints_lexmin_gurobi(cst, obj);
 #endif
-    } else {
+    }else{
 #ifdef GLPK
         sol = pluto_fcg_constraints_lexmin_glpk(cst, obj);
 #endif

src/gurobi-plugin.c

@@ -1,10 +1,41 @@
+/*
+ * PLUTO: An automatic parallelizer and locality optimizer
+ *
+ * Author: Aravind Acharya
+ *  
+ * This file is part of Pluto.
+ *
+ * Pluto is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * A copy of the GNU General Public Licence can be found in the file
+ * `LICENSE' in the top-level directory of this distribution. 
+ *
+ */
+
+#include <stdio.h>
 #ifdef GUROBI
 #include "constraints.h"
 #include "pluto.h"
 #include <math.h>
 #include <assert.h>
 #include <gurobi_c.h>
 
+/* The file provides an interface to solve Pluto's constraints with Gurobi as 
+ * the (I)LP solver. The file contains routines that creates a (I)LP problem
+ * from Pluto's constraint matrix. The objective for the optimization problem 
+ * is given as a PlutoMatrix. The constraints are solved a non-null solution 
+ * is returned if a solution exists. The choice of solving ILP/LP can be 
+ * given as a command line option to polycc.  */
+
+/* Prints the error message corresponding to the error value passed */
 inline void check_error_gurobi(GRBmodel *lp, int error)
 {
     if(error) {
@@ -16,6 +47,9 @@ inline void check_error_gurobi(GRBmodel *lp, int error)
     }
 }
 
+/* Creates a double array for gurobi objective from the objective matrix.
+ * The input PlutoMatrix should have a single row and the column elements 
+ * correspond to the coefficients of the variables in the objective function. */
 double* get_gurobi_objective_from_pluto_matrix(PlutoMatrix *obj)
 {
     int j;
@@ -69,7 +103,7 @@ void set_gurobi_constraints_from_pluto_constraints (GRBmodel *lp, const PlutoCon
     free(value);
 }
 
-/* Retrives ilp solution from the input glpk problem. 
+/* Retrives ilp solution from the input gurobi problem. 
  * Assumes that the optimal solution exists and has been found*/
 int64* get_ilp_solution_from_gurobi_problem(GRBmodel *lp)
 {
@@ -91,6 +125,8 @@ int64* get_ilp_solution_from_gurobi_problem(GRBmodel *lp)
     return sol;
 }
 
+/* Retrives lp solution from the input gurobi problem. 
+ * Assumes that the optimal solution exists and has been found*/
 double* get_lp_solution_from_gurobi_problem(GRBmodel *lp)
 {
     int num_cols, error, i;
@@ -118,10 +154,12 @@ inline void find_optimal_solution_gurobi(GRBmodel *lp, double tol)
      GRBsetdblparam(GRBgetenv(lp), "IntFeasTol", tol);
 
      GRBoptimize(lp);
-
 }
 
-
+/* Solve the gurobi problem lp. If optimal solution is found, then it returns 0.
+ * The caller can retrive the funtion from the gurobi model object lp. If the 
+ * problem is infeasible then the routine returns 1. If the problem is 
+ * unbounded, program terminates with the corresponding error message. */
 int pluto_constraints_solve_gurobi(GRBmodel *lp, double tol)
 {
     int optim_status;
@@ -258,6 +296,10 @@ GRBmodel *get_scaling_lp_gurobi(double *fpsol, int num_sols, double **val, int *
     return lp;
 }
 
+/* The rational solutions of pluto-lp are scaled on a per connected component basis. 
+ * The following routine returns the maximum scaling factor among the scaling 
+ * factors of each connected component; the largest among the first num_ccs 
+ * elements of the array sol*/
 int64 get_max_scale_factor(double *sol, int num_ccs)
 {
     int i, max;
@@ -374,7 +416,8 @@ int64 *pluto_prog_constraints_lexmin_gurobi(const PlutoConstraints *cst,
 
 }
 
-
+/* The routine is called during the construction of FCG in pluto-lp-dfp. 
+ * It returns a rational solution if the optimal solution exists else it returns NULL. */
 double *pluto_fcg_constraints_lexmin_gurobi(const PlutoConstraints* cst, PlutoMatrix* obj) 
 {
     double *grb_obj, *sol;
@@ -419,6 +462,5 @@ double *pluto_fcg_constraints_lexmin_gurobi(const PlutoConstraints* cst, PlutoMa
         sol = get_lp_solution_from_gurobi_problem(lp);
         return sol;
     }
-
 }
 #endif

src/main.c

@@ -62,7 +62,7 @@ void usage_message(void)
     fprintf(stdout, "       --islsolve [default]      Use ISL as ILP solver (default)\n");
     fprintf(stdout, "       --pipsolve                Use PIP as ILP solver\n");
 #ifdef GLPK
-    fprintf(stdout, "       --glpk                    Use GLPK as ILP solver\n");
+    fprintf(stdout, "       --glpk                    Use GLPK as ILP solver (default in case of pluto-lp and pluto-dfp)\n");
 #endif
 #if defined GLPK || defined GUROBI
     fprintf(stdout, "       --lp                      Solve MIP instead of ILP\n");
@@ -366,10 +366,10 @@ warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\n"
         options->parallel = 1;
     }
 
-#ifdef GLPK
     if (options->gurobi) {
         options->islsolve = 0;
     }
+#ifdef GLPK
     if (options->lp && !(options->glpk || options->gurobi)) {
         printf("[pluto]: LP option available with a LP solver only. Using GLPK for lp solving\n");
         options->glpk = 1;
@@ -392,8 +392,8 @@ warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\n"
 
 #endif
 
-    if(options->dfp && !(options->glpk || options->gurobi)) {
-        printf ("[pluto]: ERROR: DFP framework currently supported with GLPK solver only. Configure Pluto with --enable-glpk \n");
+    if (options->dfp && !(options->glpk || options->gurobi)) {
+        printf ("[pluto]: ERROR: DFP framework is currently supported with GLPK or GUROBI solvers only. Run ./configure --help to for more information on using different solvers with Pluto.\n");
         pluto_options_free(options);
         usage_message();
         return 1;

src/pluto.c

@@ -385,8 +385,7 @@ int64 *pluto_prog_constraints_lexmin(PlutoConstraints *cst, PlutoProg *prog)
             free(val);
             free(index);
         }
-    }
-    else {
+    }else{
         t_start = rtclock(); 
         sol = pluto_constraints_lexmin_pip(newcst, DO_NOT_ALLOW_NEGATIVE_COEFF);
         prog->mipTime += rtclock()-t_start;