diff options
Diffstat (limited to 'gcc/sbitmap.c')
| -rw-r--r-- | gcc/sbitmap.c | 60 |
1 files changed, 59 insertions, 1 deletions
diff --git a/gcc/sbitmap.c b/gcc/sbitmap.c index 74aa7cd1b4e..74c24c92855 100644 --- a/gcc/sbitmap.c +++ b/gcc/sbitmap.c @@ -1,5 +1,5 @@ /* Simple bitmaps. - Copyright (C) 1999, 2000, 2002 Free Software Foundation, Inc. + Copyright (C) 1999, 2000, 2002, 2003 Free Software Foundation, Inc. This file is part of GCC. @@ -47,6 +47,64 @@ sbitmap_alloc (n_elms) return bmap; } +/* Resize a simple bitmap BMAP to N_ELMS bits. If increasing the + size of BMAP, clear the new bits to zero if the DEF argument + is zero, and set them to one otherwise. */ + +sbitmap +sbitmap_resize (bmap, n_elms, def) + sbitmap bmap; + unsigned int n_elms; + int def; +{ + unsigned int bytes, size, amt; + unsigned int last_bit; + + size = SBITMAP_SET_SIZE (n_elms); + bytes = size * sizeof (SBITMAP_ELT_TYPE); + if (bytes > bmap->bytes) + { + amt = (sizeof (struct simple_bitmap_def) + + bytes - sizeof (SBITMAP_ELT_TYPE)); + bmap = (sbitmap) xrealloc ((PTR) bmap, amt); + } + + if (n_elms > bmap->n_bits) + { + if (def) + { + memset ((PTR) (bmap->elms + bmap->size), -1, bytes - bmap->bytes); + + /* Set the new bits if the original last element. */ + last_bit = bmap->n_bits % SBITMAP_ELT_BITS; + if (last_bit) + bmap->elms[bmap->size - 1] + |= ~((SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit)); + + /* Clear the unused bit in the new last element. */ + last_bit = n_elms % SBITMAP_ELT_BITS; + if (last_bit) + bmap->elms[size - 1] + &= (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit); + } + else + memset ((PTR) (bmap->elms + bmap->size), 0, bytes - bmap->bytes); + } + else if (n_elms < bmap->n_bits) + { + /* Clear the surplus bits in the last word. */ + last_bit = n_elms % SBITMAP_ELT_BITS; + if (last_bit) + bmap->elms[size - 1] + &= (SBITMAP_ELT_TYPE)-1 >> (SBITMAP_ELT_BITS - last_bit); + } + + bmap->n_bits = n_elms; + bmap->size = size; + bmap->bytes = bytes; + return bmap; +} + /* Allocate a vector of N_VECS bitmaps of N_ELMS bits. */ sbitmap * |