5: #include <petscconf.h>
  6: #include <petscviewer.h>

  8: /*S
  9:      PetscBT - PETSc bitarrays

 11:      Level: advanced

 13:      PetscBTCreate(m,&bt)         - creates a bit array with enough room to hold m values
 14:      PetscBTDestroy(&bt)          - destroys the bit array
 15:      PetscBTMemzero(m,bt)         - zeros the entire bit array (sets all values to false)
 16:      PetscBTSet(bt,index)         - sets a particular entry as true
 17:      PetscBTClear(bt,index)       - sets a particular entry as false
 18:      PetscBTLookup(bt,index)      - returns the value
 19:      PetscBTLookupSet(bt,index)   - returns the value and then sets it true
 20:      PetscBTLookupClear(bt,index) - returns the value and then sets it false
 21:      PetscBTLength(m)             - returns number of bytes in array with m bits
 22:      PetscBTView(m,bt,viewer)     - prints all the entries in a bit array

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

 28: S*/
 29: typedef char* PetscBT;


 32: PETSC_STATIC_INLINE PetscInt PetscBTLength(PetscInt m)
 33: {
 34:   return  m/PETSC_BITS_PER_BYTE+1;
 35: }

 37: PETSC_STATIC_INLINE PetscErrorCode PetscBTMemzero(PetscInt m,PetscBT array)
 38: {
 39:   return PetscMemzero(array,sizeof(char)*((size_t)m/PETSC_BITS_PER_BYTE+1));
 40: }

 42: PETSC_STATIC_INLINE PetscErrorCode PetscBTDestroy(PetscBT *array)
 43: {
 44:   return PetscFree(*array);
 45: }

 47: PETSC_STATIC_INLINE char PetscBTLookup(PetscBT array,PetscInt index)
 48: {
 49:   char      BT_mask,BT_c;
 50:   PetscInt  BT_idx;

 52:  return  (BT_idx        = index/PETSC_BITS_PER_BYTE,
 53:           BT_c          = array[BT_idx],
 54:           BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE),
 55:           (char)(BT_c & BT_mask));
 56: }

 58: PETSC_STATIC_INLINE PetscErrorCode PetscBTView(PetscInt m,const PetscBT bt,PetscViewer viewer)
 59: {
 60:   PetscInt       i;

 63:   if (!viewer) {PetscViewerASCIIGetStdout(PETSC_COMM_SELF,&viewer);}
 64:   PetscViewerASCIIPushSynchronized(viewer);
 65:   for (i=0; i<m; i++) {
 66:     PetscViewerASCIISynchronizedPrintf(viewer,"%D %d\n",i,(int)PetscBTLookup(bt,i));
 67:   }
 68:   PetscViewerFlush(viewer);
 69:   PetscViewerASCIIPopSynchronized(viewer);
 70:   return 0;
 71: }

 73: PETSC_STATIC_INLINE PetscErrorCode PetscBTCreate(PetscInt m,PetscBT *array)
 74: {
 75:   return PetscMalloc1((size_t)m/PETSC_BITS_PER_BYTE+1,array) || PetscBTMemzero(m,*array);
 76: }

 78: PETSC_STATIC_INLINE char PetscBTLookupSet(PetscBT array,PetscInt index)
 79: {
 80:   char      BT_mask,BT_c;
 81:   PetscInt  BT_idx;

 83:   return (BT_idx        = index/PETSC_BITS_PER_BYTE,
 84:           BT_c          = array[BT_idx],
 85:           BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE),
 86:           array[BT_idx] = (char)(BT_c | BT_mask),
 87:           (char)(BT_c & BT_mask));
 88: }

 90: PETSC_STATIC_INLINE PetscErrorCode PetscBTSet(PetscBT array,PetscInt index)
 91: {
 92:   char      BT_mask,BT_c;
 93:   PetscInt  BT_idx;

 95:   BT_idx        = index/PETSC_BITS_PER_BYTE;
 96:   BT_c          = array[BT_idx];
 97:   BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE);
 98:   array[BT_idx] = (char)(BT_c | BT_mask);
 99:   return 0;
100: }

102: PETSC_STATIC_INLINE PetscErrorCode PetscBTNegate(PetscBT array,PetscInt index)
103: {
104:   const PetscInt BT_idx  = index/PETSC_BITS_PER_BYTE;
105:   const char     BT_mask = (char)(1 << index%PETSC_BITS_PER_BYTE);

107:   array[BT_idx] ^= BT_mask;
108:   return 0;
109: }

111: PETSC_STATIC_INLINE char PetscBTLookupClear(PetscBT array,PetscInt index)
112: {
113:   char      BT_mask,BT_c;
114:   PetscInt  BT_idx;

116:   return (BT_idx        = index/PETSC_BITS_PER_BYTE,
117:           BT_c          = array[BT_idx],
118:           BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE),
119:           array[BT_idx] = (char)(BT_c & ~BT_mask),
120:           (char)(BT_c & BT_mask));
121: }

123: PETSC_STATIC_INLINE PetscErrorCode PetscBTClear(PetscBT array,PetscInt index)
124: {
125:   char      BT_mask,BT_c;
126:   PetscInt  BT_idx;

128:   BT_idx        = index/PETSC_BITS_PER_BYTE;
129:   BT_c          = array[BT_idx];
130:   BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE);
131:   array[BT_idx] = (char)(BT_c & ~BT_mask);
132:  return 0;
133: }


136: #endif