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Diffstat (limited to 'src/Sbitset.h')
| -rw-r--r-- | src/Sbitset.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/src/Sbitset.h b/src/Sbitset.h new file mode 100644 index 00000000..4b4b7508 --- /dev/null +++ b/src/Sbitset.h @@ -0,0 +1,87 @@ +/* A simple, memory-efficient bitset implementation. + + Copyright (C) 2009 Free Software Foundation, Inc. + + This file is part of Bison, the GNU Compiler Compiler. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#ifndef SBITSET_H_ +# define SBITSET_H_ + +typedef char *Sbitset; +typedef size_t Sbitset__Index; + +#define Sbitset__nbytes(NBITS) (((NBITS)+7)/8) +#define Sbitset__byteAddress(SELF, INDEX) (((SELF) + (INDEX)/8)) +#define Sbitset__bit_mask(INDEX) (0x1 << (7 - (INDEX)%8)) +#define Sbitset__last_byte_mask(NBITS) (0xff << (7 - ((NBITS)-1)%8)) + +/* nbits must not be 0. */ +Sbitset Sbitset__new (Sbitset__Index nbits); +Sbitset Sbitset__new_on_obstack (Sbitset__Index nbits, + struct obstack *obstackp); +void Sbitset__delete (Sbitset self); + +#define Sbitset__test(SELF, INDEX) \ + ((*Sbitset__byteAddress ((SELF), (INDEX)) & Sbitset__bit_mask (INDEX)) != 0) + +bool Sbitset__isEmpty (Sbitset self, Sbitset__Index nbits); + +void Sbitset__fprint(Sbitset self, Sbitset__Index nbits, FILE *file); + +#define Sbitset__set(SELF, INDEX) \ +do { \ + *Sbitset__byteAddress ((SELF), (INDEX)) = \ + *Sbitset__byteAddress ((SELF), (INDEX)) | Sbitset__bit_mask (INDEX); \ +} while(0) + +#define Sbitset__reset(SELF, INDEX) \ +do { \ + *Sbitset__byteAddress ((SELF), (INDEX)) = \ + *Sbitset__byteAddress ((SELF), (INDEX)) & ~Sbitset__bit_mask (INDEX); \ +} while(0) + +/* NBITS is the size of the bitset. More than NBITS bits might be reset. */ +#define Sbitset__zero(SELF, NBITS) \ +do { \ + memset (SELF, 0, Sbitset__nbytes (NBITS)); \ +} while(0) + +/* NBITS is the size of the bitset. More than NBITS bits might be set. */ +#define Sbitset__ones(SELF, NBITS) \ +do { \ + memset (SELF, 0xff, Sbitset__nbytes (NBITS)); \ +} while(0) + +/* NBITS is the size of every bitset. More than NBITS bits might be set. */ +#define Sbitset__or(SELF, OTHER1, OTHER2, NBITS) \ +do { \ + char *ptr_self = (SELF); \ + char *ptr_other1 = (OTHER1); \ + char *ptr_other2 = (OTHER2); \ + char *end_self = ptr_self + Sbitset__nbytes (NBITS); \ + for (; ptr_self < end_self; ++ptr_self, ++ptr_other1, ++ptr_other2) \ + *ptr_self = *ptr_other1 | *ptr_other2; \ +} while(0) + +#define SBITSET__FOR_EACH(SELF, NBITS, ITER, INDEX) \ + for ((ITER) = (SELF); (ITER) < (SELF) + Sbitset__nbytes (NBITS); ++(ITER)) \ + if (*(ITER) != 0) \ + for ((INDEX) = ((ITER)-(SELF))*8; \ + (INDEX) < (NBITS) && (SELF)+(INDEX)/8 < (ITER)+1; \ + ++(INDEX)) \ + if (((*ITER) & Sbitset__bit_mask (INDEX)) != 0) + +#endif /* !SBITSET_H_ */ |