xref: /petsc/include/petscbt.h (revision 4e278199b78715991f5c71ebbd945c1489263e6c)
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      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
23 
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.
27 
28 S*/
29 typedef char* PetscBT;
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)*((size_t)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   BT_idx        = index/PETSC_BITS_PER_BYTE;
52   BT_c          = array[BT_idx];
53   BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE);
54   return (char)(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   if (!viewer) {ierr = PetscViewerASCIIGetStdout(PETSC_COMM_SELF,&viewer);CHKERRQ(ierr);}
63   ierr = PetscViewerASCIIPushSynchronized(viewer);CHKERRQ(ierr);
64   for (i=0; i<m; i++) {
65     ierr = PetscViewerASCIISynchronizedPrintf(viewer,"%D %d\n",i,(int)PetscBTLookup(bt,i));CHKERRQ(ierr);
66   }
67   ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
68   ierr = PetscViewerASCIIPopSynchronized(viewer);CHKERRQ(ierr);
69   return 0;
70 }
71 
72 PETSC_STATIC_INLINE PetscErrorCode PetscBTCreate(PetscInt m,PetscBT *array)
73 {
74   return PetscMalloc1((size_t)m/PETSC_BITS_PER_BYTE+1,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   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] = (char)(BT_c | BT_mask);
86   return        (char)(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] = (char)(BT_c | BT_mask);
98   return 0;
99 }
100 
101 PETSC_STATIC_INLINE PetscErrorCode PetscBTNegate(PetscBT array,PetscInt index)
102 {
103   const PetscInt BT_idx  = index/PETSC_BITS_PER_BYTE;
104   const char     BT_mask = (char)(1 << index%PETSC_BITS_PER_BYTE);
105 
106   array[BT_idx] ^= BT_mask;
107   return 0;
108 }
109 
110 PETSC_STATIC_INLINE char PetscBTLookupClear(PetscBT array,PetscInt index)
111 {
112   char      BT_mask,BT_c;
113   PetscInt  BT_idx;
114 
115   BT_idx        = index/PETSC_BITS_PER_BYTE;
116   BT_c          = array[BT_idx];
117   BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE);
118   array[BT_idx] = (char)(BT_c & ~BT_mask);
119   return (char)(BT_c & BT_mask);
120 }
121 
122 PETSC_STATIC_INLINE PetscErrorCode PetscBTClear(PetscBT array,PetscInt index)
123 {
124   char      BT_mask,BT_c;
125   PetscInt  BT_idx;
126 
127   BT_idx        = index/PETSC_BITS_PER_BYTE;
128   BT_c          = array[BT_idx];
129   BT_mask       = (char)(1 << index%PETSC_BITS_PER_BYTE);
130   array[BT_idx] = (char)(BT_c & ~BT_mask);
131  return 0;
132 }
133 
134 #endif
135