text: /* Simple bitmaps.
     Copyright (C) 1999, 2000 Free Software Foundation, Inc.
  
  This file is part of GCC.
  
  GCC 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 2, or (at your option) any later
  version.
  
  GCC 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 GCC; see the file COPYING.  If not, write to the Free
  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.  */
  
  #include "config.h"
  #include "system.h"
  #include "rtl.h"
  #include "flags.h"
  #include "hard-reg-set.h"
  #include "basic-block.h"
  
  /* Bitmap manipulation routines.  */
  
  /* Allocate a simple bitmap of N_ELMS bits.  */
  
  sbitmap
  sbitmap_alloc (n_elms)
       unsigned int n_elms;
  {
    unsigned int bytes, size, amt;
    sbitmap bmap;
  
    size = SBITMAP_SET_SIZE (n_elms);
    bytes = size * sizeof (SBITMAP_ELT_TYPE);
    amt = (sizeof (struct simple_bitmap_def)
  	 + bytes - sizeof (SBITMAP_ELT_TYPE));
    bmap = (sbitmap) xmalloc (amt);
    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 *
  sbitmap_vector_alloc (n_vecs, n_elms)
       unsigned int n_vecs, n_elms;
  {
    unsigned int i, bytes, offset, elm_bytes, size, amt, vector_bytes;
    sbitmap *bitmap_vector;
  
    size = SBITMAP_SET_SIZE (n_elms);
    bytes = size * sizeof (SBITMAP_ELT_TYPE);
    elm_bytes = (sizeof (struct simple_bitmap_def)
  	       + bytes - sizeof (SBITMAP_ELT_TYPE));
    vector_bytes = n_vecs * sizeof (sbitmap *);
  
    /* Round up `vector_bytes' to account for the alignment requirements
       of an sbitmap.  One could allocate the vector-table and set of sbitmaps
       separately, but that requires maintaining two pointers or creating
       a cover struct to hold both pointers (so our result is still just
       one pointer).  Neither is a bad idea, but this is simpler for now.  */
    {
      /* Based on DEFAULT_ALIGNMENT computation in obstack.c.  */
      struct { char x; SBITMAP_ELT_TYPE y; } align;
      int alignment = (char *) & align.y - & align.x;
      vector_bytes = (vector_bytes + alignment - 1) & ~ (alignment - 1);
    }
  
    amt = vector_bytes + (n_vecs * elm_bytes);
    bitmap_vector = (sbitmap *) xmalloc (amt);
  
    for (i = 0, offset = vector_bytes; i < n_vecs; i++, offset += elm_bytes)
      {
        sbitmap b = (sbitmap) ((char *) bitmap_vector + offset);
  
        bitmap_vector[i] = b;
        b->n_bits = n_elms;
        b->size = size;
        b->bytes = bytes;
      }
  
    return bitmap_vector;
  }
  
  /* Copy sbitmap SRC to DST.  */
  
  void
  sbitmap_copy (dst, src)
       sbitmap dst, src;
  {
    memcpy (dst->elms, src->elms, sizeof (SBITMAP_ELT_TYPE) * dst->size);
  }
  
  /* Determine if a == b.  */
  int
  sbitmap_equal (a, b)
       sbitmap a, b;
  {
    return !memcmp (a->elms, b->elms, sizeof (SBITMAP_ELT_TYPE) * a->size);
  }
  /* Zero all elements in a bitmap.  */
  
  void
  sbitmap_zero (bmap)
       sbitmap bmap;
  {
    memset ((PTR) bmap->elms, 0, bmap->bytes);
  }
  
  /* Set all elements in a bitmap to ones.  */
  
  void
  sbitmap_ones (bmap)
       sbitmap bmap;
  {
    unsigned int last_bit;
  
    memset ((PTR) bmap->elms, -1, bmap->bytes);
  
    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);
  }
  
  /* Zero a vector of N_VECS bitmaps.  */
  
  void
  sbitmap_vector_zero (bmap, n_vecs)
       sbitmap *bmap;
       unsigned int n_vecs;
  {
    unsigned int i;
  
    for (i = 0; i < n_vecs; i++)
      sbitmap_zero (bmap[i]);
  }
  
  /* Set a vector of N_VECS bitmaps to ones.  */
  
  void
  sbitmap_vector_ones (bmap, n_vecs)
       sbitmap *bmap;
       unsigned int n_vecs;
  {
    unsigned int i;
  
    for (i = 0; i < n_vecs; i++)
      sbitmap_ones (bmap[i]);
  }
  
  /* Set DST to be A union (B - C).
     DST = A | (B & ~C).
     Return non-zero if any change is made.  */
  
  int
  sbitmap_union_of_diff (dst, a, b, c)
       sbitmap dst, a, b, c;
  {
    unsigned int i;
    sbitmap_ptr dstp, ap, bp, cp;
    int changed = 0;
  
    for (dstp = dst->elms, ap = a->elms, bp = b->elms, cp = c->elms, i = 0;
         i < dst->size; i++, dstp++)
      {
        SBITMAP_ELT_TYPE tmp = *ap++ | (*bp++ & ~*cp++);
  
        if (*dstp != tmp)
  	{
  	  changed = 1;
  	  *dstp = tmp;
  	}
      }
  
    return changed;
  }
  
  /* Set bitmap DST to the bitwise negation of the bitmap SRC.  */
  
  void
  sbitmap_not (dst, src)
       sbitmap dst, src;
  {
    unsigned int i;
    sbitmap_ptr dstp, srcp;
  
    for (dstp = dst->elms, srcp = src->elms, i = 0; i < dst->size; i++)
      *dstp++ = ~(*srcp++);
  }
  
  /* Set the bits in DST to be the difference between the bits
     in A and the bits in B. i.e. dst = a & (~b).  */
  
  void
  sbitmap_difference (dst, a, b)
       sbitmap dst, a, b;
  {
    unsigned int i;
    sbitmap_ptr dstp, ap, bp;
    
    for (dstp = dst->elms, ap = a->elms, bp = b->elms, i = 0; i < dst->size; i++)
      *dstp++ = *ap++ & (~*bp++);
  }
  
  /* Set DST to be (A and B).
     Return non-zero if any change is made.  */
  
  int
  sbitmap_a_and_b (dst, a, b)
       sbitmap dst, a, b;
  {
    unsigned int i;
    sbitmap_ptr dstp, ap, bp;
    int changed = 0;
  
    for (dstp = dst->elms, ap = a->elms, bp = b->elms, i = 0; i < dst->size;
         i++, dstp++)
      {
        SBITMAP_ELT_TYPE tmp = *ap++ & *bp++;
  
        if (*dstp != tmp)
  	{
  	  changed = 1;
  	  *dstp = tmp;
  	}
      }
  
    return changed;
  }
  
  /* Set DST to be (A xor B)).
     Return non-zero if any change is made.  */
  
  int
  sbitmap_a_xor_b (dst, a, b)
       sbitmap dst, a, b;
  {
    unsigned int i;
    sbitmap_ptr dstp, ap, bp;
    int changed = 0;
    
    for (dstp = dst->elms, ap = a->elms, bp = b->elms, i = 0; i < dst->size;
         i++, dstp++)
      {
        SBITMAP_ELT_TYPE tmp = *ap++ ^ *bp++;
        
        if (*dstp != tmp)
  	{
  	  changed = 1;
  	  *dstp = tmp;
  	}
      }
    return changed;
  }
  
  /* Set DST to be (A or B)).
     Return non-zero if any change is made.  */
  
  int
  sbitmap_a_or_b (dst, a, b)
       sbitmap dst, a, b;
  {
    unsigned int i;
    sbitmap_ptr dstp, ap, bp;
    int changed = 0;
  
    for (dstp = dst->elms, ap = a->elms, bp = b->elms, i = 0; i < dst->size;
         i++, dstp++)
      {
        SBITMAP_ELT_TYPE tmp = *ap++ | *bp++;
  
        if (*dstp != tmp)
  	{
  	  changed = 1;
  	  *dstp = tmp;
  	}
      }
  
    return changed;
  }
  
  /* Return non-zero if A is a subset of B.  */
  
  int
  sbitmap_a_subset_b_p (a, b)
       sbitmap a, b;
  {
    unsigned int i;
    sbitmap_ptr ap, bp;
  
    for (ap = a->elms, bp = b->elms, i = 0; i < a->size; i++, ap++, bp++)
      if ((*ap | *bp) != *bp)
        return 0;
  
    return 1;
  }
  
  /* Set DST to be (A or (B and C)).
     Return non-zero if any change is made.  */
  
  int
  sbitmap_a_or_b_and_c (dst, a, b, c)
       sbitmap dst, a, b, c;
  {
    unsigned int i;
    sbitmap_ptr dstp, ap, bp, cp;
    int changed = 0;
  
    for (dstp = dst->elms, ap = a->elms, bp = b->elms, cp = c->elms, i = 0;
         i < dst->size; i++, dstp++)
      {
        SBITMAP_ELT_TYPE tmp = *ap++ | (*bp++ & *cp++);
  
        if (*dstp != tmp)
  	{
  	  changed = 1;
  	  *dstp = tmp;
  	}
      }
  
    return changed;
  }
  
  /* Set DST to be (A and (B or C)).
     Return non-zero if any change is made.  */
  
  int
  sbitmap_a_and_b_or_c (dst, a, b, c)
       sbitmap dst, a, b, c;
  {
    unsigned int i;
    sbitmap_ptr dstp, ap, bp, cp;
    int changed = 0;
  
    for (dstp = dst->elms, ap = a->elms, bp = b->elms, cp = c->elms, i = 0;
         i < dst->size; i++, dstp++)
      {
        SBITMAP_ELT_TYPE tmp = *ap++ & (*bp++ | *cp++);
  
        if (*dstp != tmp)
  	{
  	  changed = 1;
  	  *dstp = tmp;
  	}
      }
  
    return changed;
  }
  
  #ifdef IN_GCC
  /* Set the bitmap DST to the intersection of SRC of successors of
     block number BB, using the new flow graph structures.  */
  
  void
  sbitmap_intersection_of_succs (dst, src, bb)
       sbitmap dst;
       sbitmap *src;
       int bb;
  {
    basic_block b = BASIC_BLOCK (bb);
    unsigned int set_size = dst->size;
    edge e;
  
    for (e = b->succ; e != 0; e = e->succ_next)
      {
        if (e->dest == EXIT_BLOCK_PTR)
          continue;
  
        sbitmap_copy (dst, src[e->dest->index]);
        break;
      }
  
    if (e == 0)
      sbitmap_ones (dst);
    else
      for (e = e->succ_next; e != 0; e = e->succ_next)
        {
  	unsigned int i;
  	sbitmap_ptr p, r;
  
  	if (e->dest == EXIT_BLOCK_PTR)
  	  continue;
  
  	p = src[e->dest->index]->elms;
  	r = dst->elms;
  	for (i = 0; i < set_size; i++)
  	  *r++ &= *p++;
        }
  }
  
  /* Set the bitmap DST to the intersection of SRC of predecessors of
     block number BB, using the new flow graph structures.  */
  
  void
  sbitmap_intersection_of_preds (dst, src, bb)
       sbitmap dst;
       sbitmap *src;
       int bb;
  {
    basic_block b = BASIC_BLOCK (bb);
    unsigned int set_size = dst->size;
    edge e;
  
    for (e = b->pred; e != 0; e = e->pred_next)
      {
        if (e->src == ENTRY_BLOCK_PTR)
          continue;
  
        sbitmap_copy (dst, src[e->src->index]);
        break;
      }
  
    if (e == 0)
      sbitmap_ones (dst);
    else
      for (e = e->pred_next; e != 0; e = e->pred_next)
        {
  	unsigned int i;
  	sbitmap_ptr p, r;
  
  	if (e->src == ENTRY_BLOCK_PTR)
  	  continue;
  
  	p = src[e->src->index]->elms;
  	r = dst->elms;
  	for (i = 0; i < set_size; i++)
  	  *r++ &= *p++;
        }
  }
  
  /* Set the bitmap DST to the union of SRC of successors of
     block number BB, using the new flow graph structures.  */
  
  void
  sbitmap_union_of_succs (dst, src, bb)
       sbitmap dst;
       sbitmap *src;
       int bb;
  {
    basic_block b = BASIC_BLOCK (bb);
    unsigned int set_size = dst->size;
    edge e;
  
    for (e = b->succ; e != 0; e = e->succ_next)
      {
        if (e->dest == EXIT_BLOCK_PTR)
          continue;
  
        sbitmap_copy (dst, src[e->dest->index]);
        break;
      }
  
    if (e == 0)
      sbitmap_zero (dst);
    else
      for (e = e->succ_next; e != 0; e = e->succ_next)
        {
  	unsigned int i;
  	sbitmap_ptr p, r;
  
  	if (e->dest == EXIT_BLOCK_PTR)
  	  continue;
  
  	p = src[e->dest->index]->elms;
  	r = dst->elms;
  	for (i = 0; i < set_size; i++)
  	  *r++ |= *p++;
        }
  }
  
  /* Set the bitmap DST to the union of SRC of predecessors of
     block number BB, using the new flow graph structures.  */
  
  void
  sbitmap_union_of_preds (dst, src, bb)
       sbitmap dst;
       sbitmap *src;
       int bb;
  {
    basic_block b = BASIC_BLOCK (bb);
    unsigned int set_size = dst->size;
    edge e;
  
    for (e = b->pred; e != 0; e = e->pred_next)
      {
        if (e->src== ENTRY_BLOCK_PTR)
          continue;
  
        sbitmap_copy (dst, src[e->src->index]);
        break;
      }
  
    if (e == 0)
      sbitmap_zero (dst);
    else
      for (e = e->pred_next; e != 0; e = e->pred_next)
        {
  	unsigned int i;
  	sbitmap_ptr p, r;
  
  	if (e->src == ENTRY_BLOCK_PTR)
  	  continue;
  	
  	p = src[e->src->index]->elms;
  	r = dst->elms;
  	for (i = 0; i < set_size; i++)
  	  *r++ |= *p++;
        }
  }
  #endif
  
  /* Return number of first bit set in the bitmap, -1 if none.  */
  
  int
  sbitmap_first_set_bit (bmap)
       sbitmap bmap;
  {
    unsigned int n;
  
    EXECUTE_IF_SET_IN_SBITMAP (bmap, 0, n, { return n; });
    return -1;
  }
  
  /* Return number of last bit set in the bitmap, -1 if none.  */
  
  int
  sbitmap_last_set_bit (bmap)
       sbitmap bmap;
  {
    int i;
    SBITMAP_ELT_TYPE *ptr = bmap->elms;
  
    for (i = bmap->size - 1; i >= 0; i--)
      {
        SBITMAP_ELT_TYPE word = ptr[i];
  
        if (word != 0)
  	{
  	  unsigned int index = (i + 1) * SBITMAP_ELT_BITS - 1;
  	  SBITMAP_ELT_TYPE mask
  	    = (SBITMAP_ELT_TYPE) 1 << (SBITMAP_ELT_BITS - 1);
  
  	  while (1)
  	    {
  	      if ((word & mask) != 0)
  		return index;
  
  	      mask >>= 1;
  	      index--;
  	    }
  	}
      }
  
    return -1;
  }
  
  void
  dump_sbitmap (file, bmap)
       FILE *file;
       sbitmap bmap;
  {
    unsigned int i, n, j;
    unsigned int set_size = bmap->size;
    unsigned int total_bits = bmap->n_bits;
  
    fprintf (file, "  ");
    for (i = n = 0; i < set_size && n < total_bits; i++)
      for (j = 0; j < SBITMAP_ELT_BITS && n < total_bits; j++, n++)
        {
  	if (n != 0 && n % 10 == 0)
  	  fprintf (file, " ");
  
  	fprintf (file, "%d",
  		 (bmap->elms[i] & ((SBITMAP_ELT_TYPE) 1 << j)) != 0);
        }
  
    fprintf (file, "\n");
  }
  
  void
  debug_sbitmap (bmap)
       sbitmap bmap;
  {
    unsigned int i, pos;
  
    fprintf (stderr, "n_bits = %d, set = {", bmap->n_bits);
  
    for (pos = 30, i = 0; i < bmap->n_bits; i++)
      if (TEST_BIT (bmap, i))
        {
  	if (pos > 70)
  	  {
  	    fprintf (stderr, "\n");
  	    pos = 0;
  	  }
  
  	fprintf (stderr, "%d ", i);
  	pos += 1 + (i >= 10) + (i >= 100);
        }
  
    fprintf (stderr, "}\n");
  }
  
  void
  dump_sbitmap_vector (file, title, subtitle, bmaps, n_maps)
       FILE *file;
       const char *title, *subtitle;
       sbitmap *bmaps;
       int n_maps;
  {
    int bb;
  
    fprintf (file, "%s\n", title);
    for (bb = 0; bb < n_maps; bb++)
      {
        fprintf (file, "%s %d\n", subtitle, bb);
        dump_sbitmap (file, bmaps[bb]);
      }
  
    fprintf (file, "\n");
  }
  