xref: /petsc/src/ksp/pc/impls/tfs/bitmask.c (revision 4ad8454beace47809662cdae21ee081016eaa39a)

/********************************bit_mask.c************************************

Author: Henry M. Tufo III

e-mail: hmt@cs.brown.edu

snail-mail:
Division of Applied Mathematics
Brown University
Providence, RI 02912

Last Modification:
11.21.97
*********************************bit_mask.c***********************************/
#include <../src/ksp/pc/impls/tfs/tfs.h>

/*********************************bit_mask.c***********************************/
PetscErrorCode PCTFS_bm_to_proc(char *ptr, PetscInt p_mask, PetscInt *msg_list)
{
  PetscInt i, tmp;

  PetscFunctionBegin;
  if (msg_list) {
    /* low to high */
    ptr += (p_mask - 1);
    for (i = p_mask - 1; i >= 0; i--) {
      tmp = BYTE * (p_mask - i - 1);
      if (*ptr & BIT_0) {
        *msg_list = tmp;
        msg_list++;
      }
      if (*ptr & BIT_1) {
        *msg_list = tmp + 1;
        msg_list++;
      }
      if (*ptr & BIT_2) {
        *msg_list = tmp + 2;
        msg_list++;
      }
      if (*ptr & BIT_3) {
        *msg_list = tmp + 3;
        msg_list++;
      }
      if (*ptr & BIT_4) {
        *msg_list = tmp + 4;
        msg_list++;
      }
      if (*ptr & BIT_5) {
        *msg_list = tmp + 5;
        msg_list++;
      }
      if (*ptr & BIT_6) {
        *msg_list = tmp + 6;
        msg_list++;
      }
      if (*ptr & BIT_7) {
        *msg_list = tmp + 7;
        msg_list++;
      }
      ptr--;
    }
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*********************************bit_mask.c***********************************/
PetscInt PCTFS_ct_bits(char *ptr, PetscInt n)
{
  PetscInt i, tmp = 0;

  for (i = 0; i < n; i++) {
    if (*ptr & 128) tmp++;
    if (*ptr & 64) tmp++;
    if (*ptr & 32) tmp++;
    if (*ptr & 16) tmp++;
    if (*ptr & 8) tmp++;
    if (*ptr & 4) tmp++;
    if (*ptr & 2) tmp++;
    if (*ptr & 1) tmp++;
    ptr++;
  }
  return tmp;
}

/*********************************bit_mask.c***********************************/
PetscInt PCTFS_div_ceil(PetscInt numer, PetscInt denom)
{
  if ((numer < 0) || (denom <= 0)) SETERRABORT(PETSC_COMM_SELF, PETSC_ERR_PLIB, "PCTFS_div_ceil() :: numer=%" PetscInt_FMT " ! >=0, denom=%" PetscInt_FMT " ! >0", numer, denom);
  return PetscCeilInt(numer, denom);
}

/*********************************bit_mask.c***********************************/
PetscInt PCTFS_len_bit_mask(PetscInt num_items)
{
  PetscInt rt_val, tmp;

  PetscCheck(num_items >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Value Sent To PCTFS_len_bit_mask() Must be >= 0!");

  rt_val = PetscCeilInt(num_items, BYTE);
  /* make multiple of sizeof PetscInt */
  if ((tmp = rt_val % sizeof(PetscInt))) rt_val += (sizeof(PetscInt) - tmp);
  return rt_val;
}

/*********************************bit_mask.c***********************************/
PetscErrorCode PCTFS_set_bit_mask(PetscInt *bm, PetscInt len, PetscInt val)
{
  PetscInt i, offset;
  char     mask = 1;
  char    *cptr;

  PetscFunctionBegin;
  PetscCheck(PCTFS_len_bit_mask(val) <= len, PETSC_COMM_SELF, PETSC_ERR_PLIB, "The Bit Mask Isn't That Large!");

  cptr = (char *)bm;

  offset = len / sizeof(PetscInt);
  for (i = 0; i < offset; i++) {
    *bm = 0;
    bm++;
  }

  offset = val % BYTE;
  for (i = 0; i < offset; i++) mask <<= 1;

  offset       = len - val / BYTE - 1;
  cptr[offset] = mask;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*********************************bit_mask.c***********************************/
PetscInt PCTFS_len_buf(PetscInt item_size, PetscInt num_items)
{
  PetscInt rt_val, tmp;

  rt_val = item_size * num_items;

  /*  double precision align for now ... consider page later */
  if ((tmp = (rt_val % (PetscInt)sizeof(double)))) rt_val += (sizeof(double) - tmp);
  return rt_val;
}