Dear Dr. Bastoul,

At the university of Ghent, we are starting to look
at automatic optimization of loops to optimize the implementation
in an FPGA. With the advent of your Cloog tool, we think
it becomes possible to use the polyhedral model
for the kind of optimizations we are thinking about, instead of using
optimizations based on transforming abstract syntax trees.

As a first test, we started with the representation of a
wavelet decoder loop kernel in Cloog format. We do this
by starting from a Fortran77-description, parse it
using our FPT compiler and PolyAst-library, and then
generate the Cloog data structures. Then we use
the function cloog_program_dump_cloog to obtain an
ASCII-file representing the code in Cloog-format.

However, when trying to read in the generated file,
we found that the generated file was incorrect, and
I think the cause is in two small bugs in the
function cloog_program_dump_cloog. After I've
corrected them, the generated file seems correct
(i.e. cloog can correctly read the generated file).

I've attached the adapted program.c source file.
I only changed the function cloog_program_dump_cloog,
and now it looks as follows:

void cloog_program_dump_cloog(FILE * foo, CloogProgram * program)
{ int i, j ;
  Matrix * matrix ;
  Polyhedron * polyhedron ;
  CloogLoop * loop ;

  fprintf(foo,
  "# CLooG -> CLooG\n"
  "# This is an automatic dump of an input file from a CloogProgram data\n"
  "# structure. It can be correct ONLY if dumped before loop generation.\n") ;

  /* Language. */
  if (program->language == 'c')
  fprintf(foo,"# Langage: C\n") ;
  else
  fprintf(foo,"# Langage: FORTRAN\n") ;
  fprintf(foo,"%c\n\n",program->language) ;

  /* Context. */
  fprintf(foo,"# Context (%d parameter(s)):\n",program->context->Dimension) ;
  matrix = cloog_domain_domain2matrix(program->context) ;
  cloog_domain_matrix_print(foo,matrix);
  cloog_domain_matrix_free(matrix);
  fprintf(foo,"1 # Parameter name(s)\n") ;
  for (i=0;i<program->names->nb_parameters;i++)
  fprintf(foo,"%s ",program->names->parameters[i]) ;

  /* Statement number. */
  i = 0 ;
  loop = program->loop ;
  while (loop != NULL)
  { i++ ;
    loop = loop->next ;
  }
  fprintf(foo,"\n\n# Statement number:\n%d\n\n",i) ;

  /* Iteration domains. */
  i = 1 ;
  loop = program->loop ;
  while (loop != NULL)
  { /* Name of the domain. */
    fprintf(foo,"# Iteration domain of statement %d.\n",i) ;

    /* Number of polyhedron inside the union of disjoint polyhedra. */
    j = 0 ;
    polyhedron = /* KB 15.05.2005 remove program->, since otherwise
                    the number of polytopes describing the iteration
                    space of the first loop will be printed, instead
                    of the number of polytopes for the current loop. program->*/loop->domain ;
    while (polyhedron != NULL)
    { j++ ;
      polyhedron = polyhedron->next ;
    }
    fprintf(foo,"%d\n",j) ;

    /* The polyhedra themselves. */
    polyhedron = loop->domain ;
    while (polyhedron != NULL)
    { matrix = cloog_domain_domain2matrix(polyhedron) ;
      cloog_domain_matrix_print(foo,matrix);
      cloog_domain_matrix_free(matrix);
      polyhedron = polyhedron->next ;
    }
    /* KB 15.05.2005 : options should be printed once per statement, not once
       per polytope */
      fprintf(foo,"0 0 0 # For future options.\n\n") ;
    i++ ;
    loop = loop->next ;
  }
  fprintf(foo,"\n1 # Iterator name(s)\n") ;
  for (i=0;i<program->names->nb_iterators;i++)
  fprintf(foo,"%s ",program->names->iterators[i]) ;
  fprintf(foo,"\n\n") ;

  /* Scattering functions (none since included inside domains). */
  fprintf(foo,"# No scattering functions.\n0\n\n") ;
}


The two changes are indicated by comments starting with the letters 'KB'.

I'm sending you these changes, so that they can be incorporated in the
next version of cloog, if you find them to be correct.

with kinds regards,

Kristof Beyls

P.S.: I'm currently studying your work about loop chunking, since I'll
need some kind of generalized loop tiling transformation that extends over
multiple loop nests, to get an efficient implementation of the wavelet
code in an FPGA.


-- -------------------------------------------------------------------- Parallel Information Systems Tel: +32(9)2649528 Universiteit Gent Fax: +32(9)2643594 St.-Pietersnieuwstraat 41 E-mail: Kristof.Beyls@elis.ugent.be B-9000 Gent, Belgium http://www.elis.ugent.be/~kbeyls --------------------------------------------------------------------




   /**-------------------------------------------------------------------**
    **                              CLooG                                **
    **-------------------------------------------------------------------**
    **                            program.c                              **
    **-------------------------------------------------------------------**
    **                 First version: october 25th 2001                  **
    **-------------------------------------------------------------------**/


/******************************************************************************
 *               CLooG : the Chunky Loop Generator (experimental)             *
 ******************************************************************************
 *                                                                            *
 * Copyright (C) 2001 Cedric Bastoul                                          *
 *                                                                            *
 * This 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 2 of the License, or (at your option) any later *
 * version.                                                                   *
 *                                                                            *
 * This software 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.                                                          *
 *                                                                            *
 * You should have received a copy of the GNU General Public License along    *
 * with software; if not, write to the Free Software Foundation, Inc.,        *
 * 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA                     *
 *                                                                            *
 * CLooG, the Chunky Loop Generator                                           *
 * Written by Cedric Bastoul, Cedric.Bastoul@inria.fr                         *
 *                                                                            *
 ******************************************************************************/
/* CAUTION: the english used for comments is probably the worst you ever read,
 *          please feel free to correct and improve it !
 */


# include <sys/types.h>
# include <sys/time.h>
# include <sys/resource.h>
# include <stdlib.h>
# include <stdio.h>
# include <string.h>
# include <ctype.h>
# include "../include/cloog/cloog.h"


/******************************************************************************
 *                          Structure display function                        *
 ******************************************************************************/

/* cloog_program_print function:
 * This function prints the content of a CloogProgram structure (program) into a
 * file (foo, possibly stdout).
 */
void cloog_program_print(FILE * foo, CloogProgram * program)
{ fprintf(foo,"Program:\n") ;
  fprintf(foo,"Language %c.\n",program->language) ;
  fprintf(foo,"Scattering dimension number = %d.\n",program->scattdims) ;

  cloog_names_print(foo,program->names) ;
 
  fprintf(foo,"Under the context:\n") ;
  cloog_domain_print(foo,program->context) ;
  fprintf(foo,"\n") ;
  cloog_loop_print(foo,program->loop) ;
}


/* cloog_program_dump_cloog function:
 * This function dumps a CloogProgram structure supposed to be completely
 * filled in a CLooG input file (foo possibly stdout) such as CLooG can
 * rebuild almost exactly the data structure from the input file (the number
 * of scattering functions is lost since they are included inside the
 * iteration domains, this can only lead to a less beautiful pretty printing).
 * 27 june 2003: first version.
 */
void cloog_program_dump_cloog(FILE * foo, CloogProgram * program)
{ int i, j ;
  Matrix * matrix ;
  Polyhedron * polyhedron ;
  CloogLoop * loop ;
  
  fprintf(foo,
  "# CLooG -> CLooG\n"
  "# This is an automatic dump of an input file from a CloogProgram data\n"
  "# structure. It can be correct ONLY if dumped before loop generation.\n") ;

  /* Language. */
  if (program->language == 'c')
  fprintf(foo,"# Langage: C\n") ;
  else
  fprintf(foo,"# Langage: FORTRAN\n") ;
  fprintf(foo,"%c\n\n",program->language) ;

  /* Context. */
  fprintf(foo,"# Context (%d parameter(s)):\n",program->context->Dimension) ;
  matrix = cloog_domain_domain2matrix(program->context) ;
  cloog_domain_matrix_print(foo,matrix);
  cloog_domain_matrix_free(matrix);
  fprintf(foo,"1 # Parameter name(s)\n") ;
  for (i=0;i<program->names->nb_parameters;i++)
  fprintf(foo,"%s ",program->names->parameters[i]) ;

  /* Statement number. */
  i = 0 ;
  loop = program->loop ;
  while (loop != NULL)
  { i++ ;
    loop = loop->next ;
  } 
  fprintf(foo,"\n\n# Statement number:\n%d\n\n",i) ;
   
  /* Iteration domains. */
  i = 1 ;
  loop = program->loop ;
  while (loop != NULL)
  { /* Name of the domain. */
    fprintf(foo,"# Iteration domain of statement %d.\n",i) ;
  
    /* Number of polyhedron inside the union of disjoint polyhedra. */
    j = 0 ;
    polyhedron = /* KB 15.05.2005 remove program->, since otherwise
                    the number of polytopes describing the iteration
                    space of the first loop will be printed, instead
                    of the number of polytopes for the current loop. program->*/loop->domain ;
    while (polyhedron != NULL)
    { j++ ;
      polyhedron = polyhedron->next ;
    } 
    fprintf(foo,"%d\n",j) ;

    /* The polyhedra themselves. */
    polyhedron = loop->domain ;
    while (polyhedron != NULL)
    { matrix = cloog_domain_domain2matrix(polyhedron) ;
      cloog_domain_matrix_print(foo,matrix);
      cloog_domain_matrix_free(matrix);
      polyhedron = polyhedron->next ;
    }
    /* KB 15.05.2005 : options should be printed once per statement, not once
       per polytope */
      fprintf(foo,"0 0 0 # For future options.\n\n") ;
    i++ ;
    loop = loop->next ;
  } 
  fprintf(foo,"\n1 # Iterator name(s)\n") ;
  for (i=0;i<program->names->nb_iterators;i++)
  fprintf(foo,"%s ",program->names->iterators[i]) ;
  fprintf(foo,"\n\n") ;
  
  /* Scattering functions (none since included inside domains). */
  fprintf(foo,"# No scattering functions.\n0\n\n") ;
}


/* cloog_program_dump_loopgen function:
 * This function dumps a CloogProgram structure supposed to be completely
 * filled in a LoopGen input file (foo possibly stdout) such as LoopGen can
 * generate the code for this problem. If the user of CLooG had the bad idea
 * to put the scattering functions directly inside the iteration domains, the
 * time dimension of LoopGen is supposed to be 1.
 * 27 june 2003: first version (should work but do not...).
 */
void cloog_program_dump_loopgen(FILE * foo, CloogProgram * program)
{ int i, j, time ;
  Matrix * matrix ;
  Polyhedron * polyhedron ;
  CloogLoop * loop ;
  
  /* Statement number and time dimensions. */
  i = 0 ;
  loop = program->loop ;
  while (loop != NULL)
  { i++ ;
    loop = loop->next ;
  } 
  if (program->scattdims)
  time = program->scattdims ;
  else
  time = 1 ;
  fprintf(foo,"%d %d 1\n\n",i,time) ;

  fprintf(foo,
  "# CLooG -> LoopGen\n"
  "# This is an automatic dump of an input file from a CloogProgram data\n"
  "# structure. It can be correct ONLY if dumped before loop generation.\n\n") ;

  /* Context. */
  fprintf(foo,"# Context (%d parameter(s)):\n1\n",program->context->Dimension) ;
  matrix = cloog_domain_domain2matrix(program->context) ;
  cloog_domain_matrix_print(foo,matrix);
  cloog_domain_matrix_free(matrix);
  fprintf(foo,"\n") ;
   
  /* Iteration domains. */
  i = 1 ;
  loop = program->loop ;
  while (loop != NULL)
  { /* Number of polyhedron inside the union of disjoint polyhedra. */
    j = 0 ;
    polyhedron = program->loop->domain ;
    while (polyhedron != NULL)
    { j++ ;
      polyhedron = polyhedron->next ;
    } 
    fprintf(foo,"%d\n",j) ;

    /* Name of the domain. */
    fprintf(foo,"# Iteration domain of statement %d.\n",i) ;
    
    /* The polyhedra themselves. */
    polyhedron = loop->domain ;
    while (polyhedron != NULL)
    { matrix = cloog_domain_domain2matrix(polyhedron) ;
      cloog_domain_matrix_print(foo,matrix);
      cloog_domain_matrix_free(matrix);
       polyhedron = polyhedron->next ;
    }
    fprintf(foo,"\n") ;
    i++ ;
    loop = loop->next ;
  } 
}


/* cloog_program_dump_omega function:
 * This function dumps a CloogProgram structure supposed to be completely
 * filled in a OMEGA Calculator file (foo possibly stdout) such as OC can
 * generate the code for this problem. If the user of CLooG had the bad idea
 * to put the scattering functions directly inside the iteration domains, they
 * will be added in the corresponding iteration domain for OMEGA with some
 * equalities, so he need to pray (because OMEGA and equalities are really
 * not friends)...
 * December 7th 2003: first version.
 */
void cloog_program_dump_omega(FILE * foo, CloogProgram * program)
{ int i, j, k, first, nb_iterators, nb_parameters, max_depth=0,
      statement_number ;
  Polyhedron * polyhedron ;
  CloogLoop * loop ;
  Value sign ;
  
  fprintf(foo,
  "# CLooG -> OMEGA\n"
  "# This is an automatic dump of an input file from a CloogProgram data\n"
  "# structure. It can be correct ONLY if dumped before loop generation.\n\n") ;

  nb_parameters = program->context->Dimension ;
  
  /* Context. */
  fprintf(foo,"# Context (%d parameter(s)).\n",nb_parameters) ;
  if (nb_parameters >= 1)
  { fprintf(foo,"Symbolic %s",program->names->parameters[0]) ;
    for (i=1;i<nb_parameters;i++)
    fprintf(foo,", %s",program->names->parameters[i]) ;
    fprintf(foo," ;\n\n") ;
  }

  /* Statements. */
  fprintf(foo,"# Iteration domains:\n") ;
  statement_number = 1 ;
  loop = program->loop ;
  while (loop != NULL)
  { nb_iterators = loop->domain->Dimension - nb_parameters ;
    if (nb_iterators > max_depth)
    max_depth = nb_iterators ;
    
    /* Name of the statement. */
    fprintf(foo,"IS%d0:={",statement_number) ;
  
    /* Dimensions. */
    fprintf(foo,"[") ;
    if (nb_iterators-program->scattdims >= 1)
    { fprintf(foo,"%s",program->names->iterators[program->scattdims]) ;
      for (j=program->scattdims+1;j<nb_iterators;j++)
      fprintf(foo,",%s",program->names->iterators[j]) ;
    }
    fprintf(foo,"]: ") ;
  
    /* Number of polyhedron inside the union of disjoint polyhedra
     * (must be 1 for OMEGA, we just check it).
     */
    j = 0 ;
    polyhedron = program->loop->domain ;
    while (polyhedron != NULL)
    { j++ ;
      polyhedron = polyhedron->next ;
    }
    if (j > 1)
    { fprintf(stderr,"[CLooG]ERROR: the problem cannot be dumped for OMEGA.\n");
      exit(0) ;
    }

    /* The polyhedra themselves. */
    polyhedron = loop->domain ;
    for (j=program->scattdims;j<polyhedron->NbConstraints;j++)
    { first = 1 ;
      
      if (j > program->scattdims)
      fprintf(foo," && ") ;
    
      /* The coefficients of the iterators and the parameters. */
      for (k=1;k<=polyhedron->Dimension;k++)
      if (polyhedron->Constraint[j][k] != 0)
      { if (!first)
        { if (polyhedron->Constraint[j][k] > 0)
          fprintf(foo,"+") ;
        }
	else
        first = 0 ;
	
        if ((polyhedron->Constraint[j][k] != 1) &&
	    (polyhedron->Constraint[j][k] != -1))
        fprintf(foo,VALUE_FMT,polyhedron->Constraint[j][k]) ;
	else
        if (polyhedron->Constraint[j][k] == -1)
        fprintf(foo,"-") ;
	
        if (k<=nb_iterators)
        fprintf(foo,"%s",program->names->iterators[k-1]) ;
        else
        fprintf(foo,"%s",program->names->parameters[k-1-nb_iterators]) ;
      }
      
      /* The constant (k has the good value after the loop). */
      if (polyhedron->Constraint[j][k] != 0)
      { if (!first)
        { if (polyhedron->Constraint[j][k] > 0)
	  fprintf(foo,"+") ;
        }
        fprintf(foo,VALUE_FMT,polyhedron->Constraint[j][k]) ;
      }
      
      /* The (in)equality to 0. */
      if (polyhedron->Constraint[j][0] == 0)
      fprintf(foo,"=0") ;
      else
      fprintf(foo,">=0") ;
    }
    fprintf(foo,"} ;\n") ;
    
    if ((loop = loop->next) != NULL)
    statement_number ++ ;
  }
  
  /* Scattering functions (scheduling for OMEGA). */
  loop = program->loop ;
  if (program->scattdims > 0)
  { statement_number = 1 ;
    loop = program->loop ;
    fprintf(foo,"\n# Schedules:\n") ;
    
    while (loop != NULL)
    { nb_iterators = loop->domain->Dimension - nb_parameters ;
      if (nb_iterators > max_depth)
      max_depth = nb_iterators ;
    
      /* Name of the statement. */
      fprintf(foo,"T%d0:={",statement_number) ;
  
      /* Dimensions. */
      fprintf(foo,"[") ;
      if (nb_iterators-program->scattdims >= 1)
      { fprintf(foo,"%s",program->names->iterators[program->scattdims]) ;
        for (j=program->scattdims+1;j<nb_iterators;j++)
        fprintf(foo,",%s",program->names->iterators[j]) ;
      }
      fprintf(foo,"] -> [") ;
  
      /* The functions themselves. */
      polyhedron = loop->domain ;
      for (j=0;j<program->scattdims;j++)
      { first = 1 ;
      
        if (j > 0)
        fprintf(foo,",") ;
    
        /* We assume that the coefficient of the scattering iterator is 1. */
        if ((polyhedron->Constraint[j][j+1] != 1) &&
            (polyhedron->Constraint[j][j+1] != -1))
        { fprintf(stderr,"[CLooG]ERROR: scattering dimension coefficients must "
                         "be 1 or -1to dump for OMEGA.") ;
          exit(0) ;
        }
      
        /* Depending on the sign of the scattering coefficient, the
	 * coefficient for the scheduling expression.
	 */
	if (polyhedron->Constraint[j][j+1] == 1)
        sign = -1 ;
        else
        sign = 1 ;
      
        /* The coefficients of the iterators and the parameters. */
        for (k=program->scattdims+1;k<=polyhedron->Dimension;k++)
        if (polyhedron->Constraint[j][k] != 0)
        { if (!first)
          { if (sign*polyhedron->Constraint[j][k] > 0)
            fprintf(foo,"+") ;
          }
	  else
          first = 0 ;

          if ((polyhedron->Constraint[j][k] != 1) &&
	      (polyhedron->Constraint[j][k] != -1))
          fprintf(foo,VALUE_FMT,sign*polyhedron->Constraint[j][k]) ;
	  else
          if (sign*polyhedron->Constraint[j][k] == -1)
          fprintf(foo,"-") ;
	
          if (k<=nb_iterators)
          fprintf(foo,"%s",program->names->iterators[k-1]) ;
          else
          fprintf(foo,"%s",program->names->parameters[k-1-nb_iterators]) ;
        }
      
        /* The constant (k has the good value after the loop). */
        if (polyhedron->Constraint[j][k] != 0)
        { if (!first)
          { if (sign*polyhedron->Constraint[j][k] > 0)
	    fprintf(foo,"+") ;
          }
          fprintf(foo,VALUE_FMT,sign*polyhedron->Constraint[j][k]) ;
        }
	else
	{ if (first)
	  fprintf(foo,"0") ;
	}
      }
    
      /* The scheduling expressions 'a la CLooG' end with the original
       * dimensions...
       */
      if (nb_iterators >= 1)
      { for (j=program->scattdims;j<nb_iterators;j++)
        fprintf(foo,",%s",program->names->iterators[j]) ;
      }
    
      /* ...and possibly zeros in order for the scheduling functions to have
       * the same dimension number.
       */
      for (j=nb_iterators;j<max_depth;j++)
      fprintf(foo,",0") ;
    
      fprintf(foo,"]} ;\n") ;
    
      if ((loop = loop->next) != NULL)
      statement_number ++ ;
    }
  }
  
  /* The codegen call. */
  fprintf(foo,"\n# CodeGen call:\n") ;
  fprintf(foo,"codegen %d ",max_depth) ;
  if (statement_number > 0)
  { if (program->scattdims != 0)
    fprintf(foo,"T10:") ;
    fprintf(foo,"IS10") ;
    for (i=1;i<statement_number;i++)
    { fprintf(foo,", ") ;
      if (program->scattdims != 0)
      fprintf(foo,"T%d0:",i+1) ;
      fprintf(foo,"IS%d0",i+1) ;
    }
  }
  fprintf(foo," ;\n") ; 
}


/* cloog_program_pprint function:
 * This function prints the content of a CloogProgram structure (program) into a
 * file (foo, possibly stdout), in a C-like language.
 */
void cloog_program_pprint(foo, program, options)
FILE * foo ;
CloogProgram * program ;
CloogOptions * options ;
{ CloogInfos * infos ;
  
  infos = (CloogInfos *)malloc(sizeof(CloogInfos)) ;
  infos->nb_iterators  = program->names->nb_iterators ;
  infos->nb_parameters = program->names->nb_parameters ;
  infos->iterators     = program->names->iterators ;
  infos->parameters    = program->names->parameters ;
  infos->scattdims     = program->scattdims ;  
  infos->options       = options ;
  /* Allocation for the array of strides, there is a +1 since the statement can
   * be included inside an external loop without iteration domain.
   */ 
  infos->stride        =(Value *)malloc((infos->nb_iterators+1)*sizeof(Value)) ;
	
  if (program->language == 'f')
  infos->language      = LANGUAGE_FORTRAN ;
  else
  infos->language      = LANGUAGE_C ;
 
  if (program->language == 'f')
  fprintf(foo,"! Generated from %s by CLooG v%s %s bits in %.2fs.\n",
          options->name,CLOOG_RELEASE,CLOOG_VERSION,options->time) ;
  else
  fprintf(foo,"/* Generated from %s by CLooG v%s %s bits in %.2fs. */\n",
          options->name,CLOOG_RELEASE,CLOOG_VERSION,options->time) ;
  
  pprint(foo,program->loop,NULL,1,0,infos) ;
  
  free(infos->stride) ;
  free(infos) ;
}


/******************************************************************************
 *                         Memory deallocation function                       *
 ******************************************************************************/


/* cloog_program_free function:
 * This function frees the allocated memory for a CloogProgram structure.
 */
void cloog_program_free(CloogProgram * program)
{ cloog_names_free(program->names) ;
  cloog_loop_free(program->loop) ;
  cloog_domain_free(program->context) ;
  free(program) ;
}


/******************************************************************************
 *                               Reading function                             *
 ******************************************************************************/


/* cloog_program_read function:
 * This function read the informations to put in a CloogProgram structure from
 * a file (foo, possibly stdin). It returns a pointer to a CloogProgram
 * structure containing the read informations.
 * October 25th 2001: first version.
 * September 9th 2002: - the big reading function is now splitted in several
 *                       functions (one per read data structure).
 *                     - adaptation to the new file format with naming.
 */
CloogProgram * cloog_program_read(FILE * foo)
{ int i, nb_statements, nb_parameters, nb_iterators ;
  char s[MAX_STRING], language, ** scat_names, prefix[2]={'c','\0'} ;
  CloogLoop * current, * next ;
  CloogNames * names ;
  CloogDomainList * scattering ;
  CloogProgram * p ;
  
  /* Memory allocation for the CloogProgram structure. */
  p = (CloogProgram *)malloc(sizeof(CloogProgram)) ;
  if (p == NULL) 
  { fprintf(stderr, "[CLooG]ERROR: memory overflow.\n") ;
    exit(1) ;
  }

  /* Memory allocation for the CloogNames structure. */
  names = (CloogNames *)malloc(sizeof(CloogNames)) ;
  if (names == NULL) 
  { fprintf(stderr, "[CLooG]ERROR: memory overflow.\n") ;
    exit(1) ;
  }
  
  /* First of all, we read the language to use. */
  while (fgets(s,MAX_STRING,foo) == 0) ;
  while ((*s=='#'||*s=='\n') || (sscanf(s," %c",&language)<1))
  fgets(s,MAX_STRING,foo) ;
  p->language = language ;

  /* We then read the context data. */
  p->context = cloog_domain_read(foo) ;
  nb_parameters = p->context->Dimension ;
  
  /* Reading of the parameter names. */
  names->nb_parameters = nb_parameters ;
  names->parameters = cloog_names_read(foo,nb_parameters,NULL,FIRST_PARAMETER) ;
      
  /* We read the statement number. */
  while (fgets(s,MAX_STRING,foo) == 0) ;
  while ((*s=='#'||*s=='\n') || (sscanf(s," %d",&nb_statements)<1))
  fgets(s,MAX_STRING,foo) ;

  /*printf("%d ",nb_statements) ;*/

  /* Domains reading for each statement. */
  if (nb_statements > 0)
  { /* Reading of the first domain. */
    p->loop = cloog_loop_read(foo,1,nb_parameters) ;
    if (p->loop->domain != NULL)
    nb_iterators = p->loop->domain->Dimension - nb_parameters ;
    else
    nb_iterators = 0 ;
    
    /* And the same for each next domain. */
    current = p->loop ;
    for (i=2;i<=nb_statements;i++)
    { next = cloog_loop_read(foo,i,nb_parameters) ;
      if (next->domain != NULL)
      if (next->domain->Dimension - nb_parameters > nb_iterators)
      nb_iterators = next->domain->Dimension - nb_parameters ;
      
      current->next = next ;
      current = current->next ;
    }     
    
    /* Reading of the iterator names. */
    names->nb_iterators = nb_iterators ;
    names->iterators = cloog_names_read(foo,nb_iterators,NULL,FIRST_ITERATOR) ;
    p->names = names ;

    /* Reading and puting the scattering data in program structure. */
    scattering = cloog_domain_list_read(foo) ;
    
    if (scattering != NULL)
    { if (cloog_domain_list_quick_same(scattering))
      { fprintf(stderr, "[CLooG]WARNING: some scattering functions are "
                        "similar.\n") ;
      }
      
      p->scattdims = scattering->domain->Dimension - p->loop->domain->Dimension;
      scat_names = cloog_names_read(foo,p->scattdims,prefix,'1') ;
      cloog_program_scatter(p,scattering,scat_names) ;
      cloog_domain_list_free(scattering) ;
      /* Now we can free scat_names since cloog_program_scatter copied it. */
      for (i=0;i<p->scattdims;i++)
      free(scat_names[i]) ; 
      free(scat_names) ; 
    }
    else
    p->scattdims = 0 ;
  }
  else
  { p->loop = NULL ;
    p->names = NULL ;
  }
        
  return(p) ;
}


/******************************************************************************
 *                            Processing functions                            *
 ******************************************************************************/


/* cloog_program_statement_count function:
 * This function returns the number of statements in the whole program. This has
 * nothing to do here, and I don't remember why and when I wrote it, anyway...
 */
int cloog_program_statement_count(CloogLoop * start)
{ int count=0 ;
  CloogLoop * loop ;
  CloogStatement * statement ;

  loop = start ;

  while (loop != NULL)
  { if (loop->inner != NULL)
    count += cloog_program_statement_count(loop->inner) ;
    
    statement = loop->statement ;
    
    while (statement != NULL)
    { count ++ ;
      statement = statement->next ;
    }
    loop = loop->next ;
  }
  
  return count ;
}


/* cloog_program_generate function:
 * This function calls the Quillere algorithm for loop scanning. (see the
 * Quillere paper) and calls the loop simplification function.
 * - depth is the loop depth we want to optimize (guard free as possible),
 *   the first loop depth is 1 and anegative value is the infinity depth.
 * - sep_level is the level number where we want to start loop separation.
 * October 26th 2001: first version. 
 */ 
CloogProgram * cloog_program_generate(program, options)
CloogProgram * program ;
CloogOptions * options ;
{ float time ;
  struct rusage start, end ;
  CloogLoop * loop, * simplified ;

  if ((program->scattdims > options->l) && (options->l > 0))
  fprintf(stderr, "[CLooG]WARNING: -l depth is less than scattering dimension "
                  "number (the generated code may be illegal).\n") ;
  
  if (program->loop == NULL)
  return program ;
  else
  { loop = program->loop ;
    getrusage(RUSAGE_SELF, &start) ;
    
    /* Here we go ! */
    loop = cloog_loop_generate(loop,program->context,1,
                               program->context->Dimension,options) ;
    
    getrusage(RUSAGE_SELF, &end) ;
    /* We calculate the time spent in code generation. */
    time =  (end.ru_utime.tv_usec -  start.ru_utime.tv_usec)/(float)(MEGA) ;
    time += (float)(end.ru_utime.tv_sec - start.ru_utime.tv_sec) ;
    options->time = time ;
    
    if (loop == NULL)
    { program->loop = NULL ;
      return program ;
    }
    else
    { /*cloog_loop_print(stdout,loop) ;*/
      simplified = cloog_loop_simplify(loop,program->context,1,
                                       program->context->Dimension);
      program->loop = simplified ;
      /*program->loop = loop ;*/
      return program ;
    }
  }
}


/* cloog_program_scatter function:
 * This function adds the scattering (scheduling) informations in a program.
 * If names is NULL, this function create names itself such that the i^th
 * name is ci.
 * November 6th 2001: first version. 
 */
void cloog_program_scatter(program, scattering, names)
CloogProgram * program ;
CloogDomainList * scattering ;
char ** names ;
{ int i, scattering_dim, scattering_dim2, new_dim, not_enough_constraints=0 ;
  char ** iterators ;
  CloogLoop * loop ;
  
  if ((program != NULL) && (scattering != NULL))
  { loop = program->loop ;
    
    /* We compute the scattering dimension and check it is >=0. */
    scattering_dim = scattering->domain->Dimension - loop->domain->Dimension ;
    if (scattering_dim <= 0)
    { fprintf(stderr, "[CLooG]ERROR: scattering has not enough dimensions.\n") ;
      exit(1) ;
    }
    if (scattering_dim >= scattering->domain->NbConstraints)
    not_enough_constraints ++ ;
    
    /* We add scattering names in program->iterators. */
    new_dim = program->names->nb_iterators + scattering_dim ;
    iterators = (char **)malloc(new_dim*sizeof(char *)) ;
    if (iterators == NULL) 
    { fprintf(stderr, "[CLooG]ERROR: memory overflow.\n") ;
      exit(1) ;
    }
    for (i=0;i<scattering_dim;i++)
    { iterators[i] = (char *)malloc(MAX_NAME*sizeof(char)) ;
      if (iterators[i] == NULL) 
      { fprintf(stderr, "[CLooG]ERROR: memory overflow.\n") ;
        exit(1) ;
      }
      if (names != NULL)
      strcpy(iterators[i],names[i]) ;
      else 
      sprintf(iterators[i],"c%d",i+1) ;
    }
    for (i=scattering_dim;i<new_dim;i++)
    iterators[i] = program->names->iterators[i-scattering_dim] ;
    free(program->names->iterators) ;
    program->names->iterators = iterators ;

    /* We update nb_iterators. */
    program->names->nb_iterators = new_dim ;
 
    /* Finally we scatter all loops. */
    cloog_loop_scatter(loop,scattering->domain) ;
    loop = loop->next ;
    scattering = scattering->next ;    
    
    while ((loop != NULL) && (scattering != NULL))
    { scattering_dim2 = scattering->domain->Dimension - loop->domain->Dimension;
      if (scattering_dim2 != scattering_dim)
      { fprintf(stderr, "[CLooG]ERROR: "
                        "scattering dimensions are not the same.\n") ;
        exit(1) ;
      }
      if (scattering_dim2 >= scattering->domain->NbConstraints)
      not_enough_constraints ++ ;
      
      cloog_loop_scatter(loop,scattering->domain) ;
      loop = loop->next ;
      scattering = scattering->next ;
    }
    if ((loop != NULL) || (scattering != NULL))
    fprintf(stderr, "[CLooG]WARNING: "
                    "there is not a scattering for each statement.\n");
    
    if (not_enough_constraints)
    fprintf(stderr, "[CLooG]WARNING: not enough constraints for "
                    "%d scattering function(s).\n",not_enough_constraints) ;
  }
}