/*! \file
Copyright (c) 2003, The Regents of the University of California, through
Lawrence Berkeley National Laboratory (subject to receipt of any required 
approvals from U.S. Dept. of Energy) 

All rights reserved. 

The source code is distributed under BSD license, see the file License.txt
at the top-level directory.
*/
/*! @file
 * \brief Utilities for parallel symbolic factorization routine
 *
 * <pre>
 * -- Distributed symbolic factorization auxialiary routine  (version 1.0) --
 * Lawrence Berkeley National Lab, Univ. of California Berkeley - July 2003
 * INRIA France - January 2004
 * Laura Grigori
 *
 * November 1, 2007
 * </pre>
 */

#include "superlu_ddefs.h"
#include "psymbfact.h"

static void
copy_mem_int(int_t howmany, int_t* old, int_t* new)
{
  register int_t i;
  for (i = 0; i < howmany; i++) new[i] = old[i];
}


/*! \brief Expand the existing storage to accommodate more fill-ins.
 */
/************************************************************************/
static int_t *expand
/************************************************************************/
(
 int_t prev_len,    /* length used from previous call */
 int_t min_new_len, /* minimum new length to allocate */
 int_t *prev_mem,    /* pointer to the previous memory */
 int_t *p_new_len,      /* length of the new memory allocated */
 int_t len_tcopy_fbeg,  /* size of the memory to be copied to new store 
			     starting from the beginning of the memory */
 int_t len_tcopy_fend,  /* size of the memory to be copied to new store,
			    starting from the end of the memory */
 psymbfact_stat_t *PS
 )
{
  float exp = 2.0;
  float alpha;
  int_t *new_mem;
  int_t new_len, tries, lword, extra, bytes_to_copy;
  
  alpha = exp;
  lword = sizeof(int_t);
  
  new_len = alpha * prev_len;
  if (min_new_len > 0 && new_len < min_new_len)
    new_len = min_new_len;
  
  new_mem = (void *) SUPERLU_MALLOC(new_len * lword);
  PS->allocMem += new_len * lword;
  
  if (new_mem) {
    if (len_tcopy_fbeg != 0)
      copy_mem_int(len_tcopy_fbeg, prev_mem, new_mem);
    if (len_tcopy_fend != 0)  
      copy_mem_int(len_tcopy_fend, &(prev_mem[prev_len-len_tcopy_fend]), 
		   &(new_mem[new_len-len_tcopy_fend]));
  }
  *p_new_len = new_len;
  return new_mem;
  
} /* EXPAND */


/*! \brief
 *
 * <pre>
 * Expand the data structures for L and U during the factorization.
 * Return value:   0 - successful return
 *               > 0 - number of bytes allocated when run out of space
 * </pre>
 */
/************************************************************************/
int_t psymbfact_LUXpandMem
/************************************************************************/
(
 int_t iam,
 int_t n,           /* total number of columns */
 int_t vtxXp,       /* current vertex */
 int_t next,        /* number of elements currently in the factors */
 int_t min_new_len, /* minimum new length to allocate */
 int_t mem_type,    /* which type of memory to expand  */
 int_t rout_type,   /* during which type of factorization */
 int_t free_prev_mem, /* =1 if prev_mem has to be freed */
 Pslu_freeable_t *Pslu_freeable,
 Llu_symbfact_t *Llu_symbfact,  /* modified - global LU data structures */
 vtcsInfo_symbfact_t *VInfo,
 psymbfact_stat_t *PS
 )
{
  int_t  *new_mem, *prev_mem, *xsub;
  /* size of the memory to be copied to new store starting from the 
     beginning/end of the memory */
  int_t xsub_nextLvl;  
  int_t exp, prev_xsub_nextLvl, vtxXp_lid;
  int_t *globToLoc, maxNvtcsPProc, nvtcs_loc;
  int_t fstVtx_nextLvl, fstVtx_nextLvl_lid, vtx_lid, i, j;
  int_t len_tcopy_fbeg, len_tcopy_fend, new_len, prev_len;  

  exp  = 2;
  globToLoc = Pslu_freeable->globToLoc;
  nvtcs_loc = VInfo->nvtcs_loc;
  maxNvtcsPProc  = Pslu_freeable->maxNvtcsPProc;
  fstVtx_nextLvl = VInfo->fstVtx_nextLvl;
  vtxXp_lid      = LOCAL_IND( globToLoc[vtxXp] );
  len_tcopy_fbeg = next;
  if (fstVtx_nextLvl == n)
    fstVtx_nextLvl_lid = nvtcs_loc;
  else
    fstVtx_nextLvl_lid = LOCAL_IND( globToLoc[fstVtx_nextLvl] );  

  if ( mem_type == LSUB ) {
    prev_mem = Llu_symbfact->lsub;
    prev_len = Llu_symbfact->szLsub;
    xsub = Llu_symbfact->xlsub;
    if (rout_type == DOMAIN_SYMB)
      prev_xsub_nextLvl = xsub[vtxXp_lid+1];
    else
      prev_xsub_nextLvl = VInfo->xlsub_nextLvl;
  } else if ( mem_type == USUB ) {
    prev_mem = Llu_symbfact->usub;
    prev_len = Llu_symbfact->szUsub;
    xsub = Llu_symbfact->xusub;
    if (rout_type == DOMAIN_SYMB)
      prev_xsub_nextLvl = xsub[vtxXp_lid+1];
    else
      prev_xsub_nextLvl = VInfo->xusub_nextLvl;
  }
  
  len_tcopy_fend = prev_len - prev_xsub_nextLvl;  
  /* if (rout_type == DNS_UPSEPS || rout_type == DNS_CURSEP)  { - bug corrected on Sept 1st, 2013 - */
  if (rout_type == DNS_UPSEPS) { 
    fstVtx_nextLvl = n;
    fstVtx_nextLvl_lid = nvtcs_loc;
    len_tcopy_fend = 0;
  }
#ifdef TEST_SYMB
  printf ("Pe[" IFMT "] LUXpand mem_t " IFMT " vtxXp " IFMT "\n",
	  iam, mem_type, vtxXp); 
#endif
  new_mem = expand (prev_len, min_new_len, prev_mem,
		    &new_len, len_tcopy_fbeg, len_tcopy_fend, PS);
  if ( !new_mem ) {
    fprintf(stderr, "Pe[" IFMT "] Can't exp MemType " IFMT ": prv_len " IFMT
	    " min_new " IFMT " new_l " IFMT "\n",
	   iam, mem_type, prev_len, min_new_len, new_len);
    return ERROR_RET;
  }
  
  xsub_nextLvl = new_len - len_tcopy_fend;
  
  /* reset xsub information pointing to A data */
  if (fstVtx_nextLvl != n || rout_type == DOMAIN_SYMB) {
    if (rout_type == DOMAIN_SYMB)
      vtx_lid = vtxXp_lid + 1;
    else {
      vtx_lid = fstVtx_nextLvl_lid +1;
    }
    i = xsub_nextLvl + xsub[vtx_lid] - prev_xsub_nextLvl;
    for (; vtx_lid < nvtcs_loc; vtx_lid ++) {
      j = xsub[vtx_lid+1] - xsub[vtx_lid];
      xsub[vtx_lid] = i;
      i += j;
    }
    xsub[vtx_lid] = i;
  }

  if (free_prev_mem) {
    SUPERLU_FREE (prev_mem);
    PS->allocMem -= 0;
  }
  
  if ( mem_type == LSUB ) {
    Llu_symbfact->lsub   = new_mem;
    Llu_symbfact->szLsub = new_len;
    VInfo->xlsub_nextLvl = xsub_nextLvl;
  } else if ( mem_type == USUB ) {
    Llu_symbfact->usub   = new_mem;
    Llu_symbfact->szUsub = new_len;
    VInfo->xusub_nextLvl = xsub_nextLvl;
  }
  
  Llu_symbfact->no_expand ++;
  return SUCCES_RET;
}

/*! \brief
 *
 * <pre>
 * Expand the data structures for L and U during the factorization.
 * Return value: SUCCES_RET - successful return
 *               ERROR_RET - error due to a memory alocation failure
 * </pre>
 */
/************************************************************************/
int_t psymbfact_LUXpand
/************************************************************************/
(
 int_t iam, 
 int_t n,           /* total number of columns */
 int_t fstVtxLvl_loc, /* first vertex in the level to update */
 int_t vtxXp,         /* current vertex */
 int_t *p_next,        /* number of elements currently in the factors */
 int_t min_new_len, /* minimum new length to allocate */
 int_t mem_type,   /* which type of memory to expand  */
 int_t rout_type,  /* during which type of factorization */
 int_t free_prev_mem, /* =1 if free prev_mem memory */
 Pslu_freeable_t *Pslu_freeable, 
 Llu_symbfact_t *Llu_symbfact,  /* modified - global LU data structures */
 vtcsInfo_symbfact_t *VInfo,
 psymbfact_stat_t *PS
 )
{
  int mem_error;
  int_t  *new_mem, *prev_mem, *xsub, sz_prev_mem;
  /* size of the memory to be copied to new store starting from the 
     beginning/end of the memory */
  int_t exp, prev_xsub_nextLvl, vtxXp_lid, xsub_nextLvl;
  int_t *globToLoc, nvtcs_loc, maxNvtcsPProc;
  int_t fstVtx_nextLvl, fstVtx_nextLvl_lid;
  int_t i, j, k, vtx_lid, len_texp, nelts, nel;
  int_t fstVtxLvl_loc_lid, prev_len, next;
  
  exp  = 2;
  next = *p_next;
  globToLoc = Pslu_freeable->globToLoc;
  nvtcs_loc = VInfo->nvtcs_loc;
  maxNvtcsPProc  = Pslu_freeable->maxNvtcsPProc;
  fstVtx_nextLvl = VInfo->fstVtx_nextLvl;
  
  vtxXp_lid = LOCAL_IND( globToLoc[vtxXp] );
  if (fstVtx_nextLvl == n)
    fstVtx_nextLvl_lid = VInfo->nvtcs_loc;
  else
    fstVtx_nextLvl_lid = LOCAL_IND( globToLoc[fstVtx_nextLvl] );  
  if (rout_type == RL_SYMB)
    fstVtxLvl_loc_lid = LOCAL_IND( globToLoc[fstVtxLvl_loc] );

  if ( mem_type == LSUB ) {
    xsub = Llu_symbfact->xlsub;
    prev_mem = Llu_symbfact->lsub;
    prev_xsub_nextLvl = VInfo->xlsub_nextLvl;
    sz_prev_mem = Llu_symbfact->szLsub;
  } else if ( mem_type == USUB ) {
    xsub = Llu_symbfact->xusub;
    prev_mem = Llu_symbfact->usub;
    prev_xsub_nextLvl = VInfo->xusub_nextLvl;
    sz_prev_mem = Llu_symbfact->szUsub;
  }
#ifdef TEST_SYMB
  printf ("Pe[%d] Expand LU mem_t %d vtxXp %d\n", 
	  iam, mem_type, vtxXp); 
#endif
  /* Try to expand the size of xsub in the existing memory */
  if (rout_type == RL_SYMB) {
    len_texp = 0;
    for (vtx_lid = fstVtxLvl_loc_lid; vtx_lid < fstVtx_nextLvl_lid; vtx_lid ++) {
      nelts = xsub[vtx_lid+1] - xsub[vtx_lid];
      if (nelts == 0) nelts = 1;
      nelts = 2 * nelts;
      if (nelts > Llu_symbfact->cntelt_vtcs[vtx_lid])
	nelts = Llu_symbfact->cntelt_vtcs[vtx_lid];
      len_texp += nelts;
    }
/*     len_texp = 2 * (xsub[fstVtx_nextLvl_lid] - xsub[fstVtxLvl_loc_lid]); */
    prev_len = xsub[fstVtxLvl_loc_lid];
    next = prev_len;
  }
  else {
    nelts = xsub[vtxXp_lid+1] - xsub[vtxXp_lid];
    if (nelts == 0) nelts = 1;
    len_texp = xsub[fstVtx_nextLvl_lid] - xsub[vtxXp_lid+1] +
      4 * nelts;
    prev_len = xsub[vtxXp_lid];
  }
  
  if (prev_len + len_texp >= prev_xsub_nextLvl) {
    /* not enough memory */
    min_new_len = prev_len + len_texp + (sz_prev_mem - prev_xsub_nextLvl);
    if ( (mem_error = 
	  psymbfact_LUXpandMem (iam, n, vtxXp, next, min_new_len, 
				mem_type, rout_type, 0, Pslu_freeable, Llu_symbfact,
				VInfo, PS)) )
      return (mem_error);
    if ( mem_type == LSUB ) 
      new_mem = Llu_symbfact->lsub;
    else if ( mem_type == USUB ) 
      new_mem = Llu_symbfact->usub;
  }
  else 
    new_mem = prev_mem;

  if (mem_type == LSUB && PS->estimLSz < (prev_len + len_texp))
    PS->estimLSz = prev_len + len_texp;
  if (mem_type == USUB && PS->estimUSz < (prev_len + len_texp))
    PS->estimUSz = prev_len;

  /* expand the space */
  if (rout_type == LL_SYMB) {
    i = xsub[vtxXp_lid] + len_texp;
    vtx_lid = fstVtx_nextLvl_lid - 1;
    for (; vtx_lid > vtxXp_lid; vtx_lid --) {
      j = xsub[vtx_lid];  
      nel = 0;
      while (j < xsub[vtx_lid+1] && prev_mem[j] != EMPTY) {
	nel ++; j ++;
      }
      j = xsub[vtx_lid] + nel - 1;  
      k = i - (xsub[vtx_lid+1] - xsub[vtx_lid]) + nel - 1;
      if (k+1 < i)  new_mem[k+1] = EMPTY; 
      while (j >= xsub[vtx_lid]) {
	new_mem[k] = prev_mem[j]; k--; j--;
      }
      k = i;
      i -= (xsub[vtx_lid+1] - xsub[vtx_lid]);
      xsub[vtx_lid+1] = k;
    }
    xsub[vtx_lid+1] = i;
    k = *p_next;
    if (k < xsub[vtx_lid+1])
      new_mem[k] = EMPTY;
  }

  if (rout_type == RL_SYMB) {
    *p_next -= xsub[vtxXp_lid];
    i = xsub[fstVtxLvl_loc_lid] + len_texp;
    vtx_lid = fstVtx_nextLvl_lid - 1;
    for (; vtx_lid >= fstVtxLvl_loc_lid; vtx_lid --) {
      nelts = 2 * (xsub[vtx_lid+1] - xsub[vtx_lid]);
      if (nelts == 0) nelts = 2;
      if (nelts > Llu_symbfact->cntelt_vtcs[vtx_lid])
	nelts = Llu_symbfact->cntelt_vtcs[vtx_lid];
      j = xsub[vtx_lid];  
      nel = 0;
      while (j < xsub[vtx_lid+1] && prev_mem[j] != EMPTY) {
	nel ++; j ++;
      }
      j = xsub[vtx_lid] + nel - 1;  
      k = i - nelts + nel - 1;
      if (k+1 < i) new_mem[k+1] = EMPTY; 
      while (j >= xsub[vtx_lid]) {
	new_mem[k] = prev_mem[j]; k--; j--;
      }
      k = i;
      i -= nelts;
      xsub[vtx_lid+1] = k;
    }
    *p_next += xsub[vtxXp_lid];
  }  

  if (free_prev_mem && new_mem != prev_mem)
    SUPERLU_FREE (prev_mem);
  Llu_symbfact->no_expcp ++;
  
  return SUCCES_RET;
}

/*! \brief
 *
 * <pre>
 * Expand the data structures for L and U during the factorization.
 * Return value:   0 - successful return
 *               > 0 - number of bytes allocated when run out of space
 * </pre>
 */
/************************************************************************/
int_t psymbfact_LUXpand_RL
/************************************************************************/
(
 int_t iam, 
 int_t n,           /* total number of columns */
 int_t vtxXp,       /* current vertex */
 int_t next,        /* number of elements currently in the factors */
 int_t len_texp,    /* length to expand */
 int_t mem_type,    /* which type of memory to expand  */
 Pslu_freeable_t *Pslu_freeable, 
 Llu_symbfact_t *Llu_symbfact,  /* modified - global LU data structures */
 vtcsInfo_symbfact_t *VInfo,
 psymbfact_stat_t *PS
 )
{
  int_t  *new_mem, *prev_mem, *xsub, mem_error, sz_prev_mem;
  /* size of the memory to be copied to new store starting from the 
     beginning/end of the memory */
  int_t exp, prev_xsub_nextLvl, vtxXp_lid, xsub_nextLvl;
  int_t *globToLoc, nvtcs_loc, maxNvtcsPProc;
  int_t fstVtx_nextLvl, fstVtx_nextLvl_lid;
  int_t i, j, k, vtx_lid, nel;
  int_t fstVtxLvl_loc_lid, prev_len, min_new_len;

#ifdef TEST_SYMB
  printf ("Pe[%d] Expand LU_RL mem_t %d vtxXp %d\n", 
	  iam, mem_type, vtxXp); 
#endif
  globToLoc = Pslu_freeable->globToLoc;
  nvtcs_loc = VInfo->nvtcs_loc;
  maxNvtcsPProc  = Pslu_freeable->maxNvtcsPProc;
  fstVtx_nextLvl = VInfo->fstVtx_nextLvl;
  
  vtxXp_lid = LOCAL_IND( globToLoc[vtxXp] );
  if (fstVtx_nextLvl == n)
    fstVtx_nextLvl_lid = VInfo->nvtcs_loc;
  else
    fstVtx_nextLvl_lid = LOCAL_IND( globToLoc[fstVtx_nextLvl] );  

  if ( mem_type == LSUB ) {
    xsub = Llu_symbfact->xlsub;
    prev_mem = Llu_symbfact->lsub;
    prev_xsub_nextLvl = VInfo->xlsub_nextLvl;
    sz_prev_mem = Llu_symbfact->szLsub;
  } else if ( mem_type == USUB ) {
    xsub = Llu_symbfact->xusub;
    prev_mem = Llu_symbfact->usub;
    prev_xsub_nextLvl = VInfo->xusub_nextLvl;
    sz_prev_mem = Llu_symbfact->szUsub;
  }
  else ABORT("Tries to expand nonexisting memory type.\n");
  
  /* Try to expand the size of xsub in the existing memory */
  prev_len = xsub[vtxXp_lid];
  
  if (prev_len + len_texp >= prev_xsub_nextLvl) {
    /* not enough memory */
    min_new_len = prev_len + len_texp + (sz_prev_mem - prev_xsub_nextLvl);
    if ( (mem_error = 
	  psymbfact_LUXpandMem (iam, n, vtxXp, next, min_new_len, 
				mem_type, RL_SYMB, 0, Pslu_freeable, Llu_symbfact,
				VInfo, PS)) )
      return (mem_error);
    if ( mem_type == LSUB ) 
      new_mem = Llu_symbfact->lsub;
    else if ( mem_type == USUB ) 
      new_mem = Llu_symbfact->usub;
  }
  else 
    new_mem = prev_mem;

  /* expand the space */
  if (mem_type == LSUB && PS->estimLSz < (prev_len + len_texp))
    PS->estimLSz = prev_len + len_texp;
  if (mem_type == USUB && PS->estimUSz < (prev_len + len_texp))
    PS->estimUSz = prev_len;

  i = xsub[vtxXp_lid] + len_texp;
  vtx_lid = fstVtx_nextLvl_lid - 1;
  for (; vtx_lid > vtxXp_lid; vtx_lid --) {
    j = xsub[vtx_lid];  
    nel = 0;
    while (j < xsub[vtx_lid+1] && prev_mem[j] != EMPTY) {
      nel ++; j++;
    }
    j = xsub[vtx_lid] + nel - 1;  
    k = i - Llu_symbfact->cntelt_vtcs[vtx_lid] + nel - 1;
    if (k+1 < i) 
      new_mem[k+1] = EMPTY; 
    while (j >= xsub[vtx_lid]) {
      new_mem[k] = prev_mem[j];
      k--; j--;
    }
    k = i;
    i -= Llu_symbfact->cntelt_vtcs[vtx_lid];
    xsub[vtx_lid+1] = k;
  }
  xsub[vtx_lid+1] = i;
  k = next;
  if (k < xsub[vtx_lid+1])
    new_mem[k] = EMPTY;
  
  if (new_mem != prev_mem)
    SUPERLU_FREE (prev_mem);
  Llu_symbfact->no_expcp ++;
  
  return SUCCES_RET;
}

/*! \brief
 *
 * <pre>
 * Expand the data structures for L and U pruned during the factorization.
 * Return value: SUCCES_RET - successful return
 *               ERROR_RET - error when run out of space
 * </pre>
 */
/************************************************************************/
int_t psymbfact_prLUXpand
/************************************************************************/
(
 int_t iam, 
 int_t min_new_len, /* minimum new length to allocate */ 
#if 0
 MemType mem_type,  /* which type of memory to expand  */
#else /* Sherry */
 int mem_type,  /* which type of memory to expand  */
#endif
 Llu_symbfact_t *Llu_symbfact, /* modified L/U pruned structures */
 psymbfact_stat_t *PS
 )
{
  int_t *prev_mem, *new_mem;
  int_t prev_len, new_len, len_tcopy_fbeg;
  
  if ( mem_type == LSUB_PR ) {
    prev_len = Llu_symbfact->szLsubPr;
    prev_mem = Llu_symbfact->lsubPr;
    len_tcopy_fbeg = Llu_symbfact->indLsubPr;
  } else if ( mem_type == USUB_PR ) {
    prev_len = Llu_symbfact->szUsubPr;
    prev_mem = Llu_symbfact->usubPr;
    len_tcopy_fbeg = Llu_symbfact->indUsubPr;
  } else ABORT("Tries to expand nonexisting memory type.\n");
  
#ifdef TEST_SYMB
  printf ("Pe[%d] Expand prmem prev_len %d min_new_l %d len_tfbeg %d\n", 
	  iam, prev_len, min_new_len, len_tcopy_fbeg);
#endif
  
  new_mem = expand (prev_len, min_new_len, prev_mem, 
		    &new_len, len_tcopy_fbeg, 0, PS);
  
  if ( !new_mem ) {
    fprintf(stderr, "Can't expand MemType %d: \n", mem_type);
    return (ERROR_RET);
  }
  
  Llu_symbfact->no_expand_pr ++;
  if ( mem_type == LSUB_PR ) {
    Llu_symbfact->lsubPr  = new_mem;
    Llu_symbfact->szLsubPr = new_len;
  } else if ( mem_type == USUB_PR ) {
    Llu_symbfact->usubPr  = new_mem;
    Llu_symbfact->szUsubPr = new_len;
  } else ABORT("Tries to expand nonexisting memory type.\n");
  
  SUPERLU_FREE (prev_mem);

  return SUCCES_RET;
}
