xref: /petsc/include/petscbt.h (revision 8cc058d9cd56c1ccb3be12a47760ddfc446aaffc)
1 
2 #if !defined(__PETSCBT_H)
3 #define __PETSCBT_H
4 
5 #include <petscconf.h>
6 #include <petscviewer.h>
7 
8 /*S
9      PetscBT - PETSc bitarrays
10 
11      Level: advanced
12 
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      PetscBTLength(m)           - returns number of bytes in array with m bits
21      PetscBTView(m,bt,viewer)   - prints all the entries in a bit array
22 
23     We do not currently check error flags on PetscBTSet(), PetscBTClear(), PetscBTLookup(),
24     PetcBTLookupSet(), PetscBTLength() cause error checking would cost hundreds more cycles then
25     the operation.
26 
27 S*/
28 typedef char* PetscBT;
29 
30 
31 PETSC_STATIC_INLINE PetscInt  PetscBTLength(PetscInt m)
32 {
33   return  ((m)/PETSC_BITS_PER_BYTE+1);
34 }
35 
36 PETSC_STATIC_INLINE PetscErrorCode PetscBTMemzero(PetscInt m,PetscBT array)
37 {
38   return PetscMemzero(array,sizeof(char)*((m)/PETSC_BITS_PER_BYTE+1));
39 }
40 
41 PETSC_STATIC_INLINE PetscErrorCode PetscBTDestroy(PetscBT *array)
42 {
43   return PetscFree(*array);
44 }
45 
46 PETSC_STATIC_INLINE char PetscBTLookup(PetscBT array,PetscInt index)
47 {
48   char      BT_mask,BT_c;
49   PetscInt  BT_idx;
50 
51  return  (BT_idx        = (index)/PETSC_BITS_PER_BYTE,
52           BT_c          = array[BT_idx],
53           BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE),
54           BT_c & BT_mask);
55 }
56 
57 PETSC_STATIC_INLINE PetscErrorCode PetscBTView(PetscInt m,const PetscBT bt,PetscViewer viewer)
58 {
59   PetscInt       i;
60   PetscErrorCode ierr;
61 
62   ierr = PetscViewerASCIIGetStdout(PETSC_COMM_SELF,&viewer);CHKERRQ(ierr);
63   ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr);
64   for (i=0; i<m; i++) {
65     ierr = PetscViewerASCIISynchronizedPrintf(viewer,"%D %d\n",i,PetscBTLookup(bt,i));CHKERRQ(ierr);
66   }
67   ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
68   ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr);
69   return 0;
70 }
71 
72 PETSC_STATIC_INLINE PetscErrorCode PetscBTCreate(PetscInt m,PetscBT *array)
73 {
74   return (PetscMalloc(((m)/PETSC_BITS_PER_BYTE+1)*sizeof(char),array) || PetscBTMemzero(m,*array));
75 }
76 
77 PETSC_STATIC_INLINE char PetscBTLookupSet(PetscBT array,PetscInt index)
78 {
79   char      BT_mask,BT_c;
80   PetscInt  BT_idx;
81 
82   return (BT_idx        = (index)/PETSC_BITS_PER_BYTE,
83           BT_c          = array[BT_idx],
84           BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE),
85           array[BT_idx] = BT_c | BT_mask,
86           BT_c & BT_mask);
87 }
88 
89 PETSC_STATIC_INLINE PetscErrorCode PetscBTSet(PetscBT array,PetscInt index)
90 {
91   char      BT_mask,BT_c;
92   PetscInt  BT_idx;
93 
94   BT_idx        = (index)/PETSC_BITS_PER_BYTE;
95   BT_c          = array[BT_idx];
96   BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE);
97   array[BT_idx] = BT_c | BT_mask;
98   return 0;
99 }
100 
101 PETSC_STATIC_INLINE PetscErrorCode PetscBTClear(PetscBT array,PetscInt index)
102 {
103   char      BT_mask,BT_c;
104   PetscInt  BT_idx;
105 
106   BT_idx        = (index)/PETSC_BITS_PER_BYTE;
107   BT_c          = array[BT_idx];
108   BT_mask       = (char)1 << ((index)%PETSC_BITS_PER_BYTE);
109   array[BT_idx] = BT_c & (~BT_mask);
110  return 0;
111 }
112 
113 
114 #endif
115