Actual source code: petscbt.h

  1: /*    

  3:           BT - Bit array objects: used to compactly store logical arrays of variables.

  5:      PetscBTCreate(m,bt)        - creates a bit array with enough room to hold m values
  6:      PetscBTDestroy(bt)         - destroys the bit array
  7:      PetscBTMemzero(m,bt)       - zeros the entire bit array (sets all values to false)
  8:      PetscBTSet(bt,index)       - sets a particular entry as true
  9:      PetscBTClear(bt,index)     - sets a particular entry as false
 10:      PetscBTLookup(bt,index)    - returns the value 
 11:      PetscBTLookupSet(bt,index) - returns the value and then sets it true
 12:      PetscBTLength(m)           - returns number of bytes in array with m bits
 13:      PetscBTView(m,bt,viewer)   - prints all the entries in a bit array

 15:     These routines do not currently have manual pages.

 17:     The are all implemented as macros with the trivial data structure for efficiency.

 19:     These are not thread safe since they use a few global variables.

 21:     We do not currently check error flags on PetscBTSet(), PetscBTClear(), PetscBTLookup(),
 22:     PetcBTLookupSet(), PetscBTLength() cause error checking would cost hundreds more cycles then
 23:     the operation.

 25: */

 30: /*S
 31:      PetscBT - PETSc bitarrays

 33:    Level: advanced

 35:    Notes: the PetscBT routines do not currently have manual pages. See include/petscbt.h for 
 36:           documentation

 38: .seealso:  PetscBTCreate(), PetscBTDestroy(), PetscBTMemzero(), PetscBTSet(), PetscBTClear(),
 39:            PetscBTLookup(), PetscBTLookupSet(), PetscBTLength(), PetscBTView()
 40: S*/
 41: typedef char* PetscBT;


 47: #define PetscBTLength(m)        ((m)/PETSC_BITS_PER_BYTE+1)
 48: #define PetscBTMemzero(m,array) PetscMemzero(array,sizeof(char)*((m)/PETSC_BITS_PER_BYTE+1))
 49: #define PetscBTDestroy(array)   PetscFree(array)

 51: #define PetscBTView(m,bt,viewer) 0; {\
 52:   PetscInt __i; PetscErrorCode _8_ierr; \
 53:   PetscViewer __viewer = viewer; \
 54:   if (!__viewer) __viewer = PETSC_VIEWER_STDOUT_SELF;\
 55:   for (__i=0; __i<m; __i++) { \
 56:     _8_PetscPrintf(((PetscObject)__viewer)->comm,"%D %d\n",__i,PetscBTLookup(bt,__i));CHKERRQ(_8_ierr);\
 57:   }}

 59: #define PetscBTCreate(m,array)  \
 60:   (PetscMalloc(((m)/PETSC_BITS_PER_BYTE+1)*sizeof(char),&(array)) || PetscBTMemzero(m,array))

 62: #define PetscBTLookupSet(array,index) \
 63:   (_BT_idx        = (index)/PETSC_BITS_PER_BYTE, \
 64:    _BT_c          = array[_BT_idx], \
 65:    _BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE), \
 66:    array[_BT_idx] = _BT_c | _BT_mask, \
 67:    _BT_c & _BT_mask)

 69: #define PetscBTSet(array,index)  \
 70:   (_BT_idx        = (index)/PETSC_BITS_PER_BYTE, \
 71:    _BT_c          = array[_BT_idx], \
 72:    _BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE), \
 73:    array[_BT_idx] = _BT_c | _BT_mask,0)

 75: #define PetscBTClear(array,index) \
 76:   (_BT_idx        = (index)/PETSC_BITS_PER_BYTE, \
 77:    _BT_c          = array[_BT_idx], \
 78:    _BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE), \
 79:    array[_BT_idx] = _BT_c & (~_BT_mask),0)

 81: #define PetscBTLookup(array,index) \
 82:   (_BT_idx        = (index)/PETSC_BITS_PER_BYTE, \
 83:    _BT_c          = array[_BT_idx], \
 84:    _BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE), \
 85:    (_BT_c & _BT_mask) != 0)

 88: #endif