Daily bump.

[pf3gnuchains/gcc-fork.git] / gcc / bitmap.c

diff --git a/gcc/bitmap.c b/gcc/bitmap.c
index 1ab977f..97e60de 100644 (file)
--- a/gcc/bitmap.c
+++ b/gcc/bitmap.c
@@ -6,7 +6,7 @@ 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
+Software Foundation; either version 3, or (at your option) any later
 version.
 
 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
@@ -15,9 +15,8 @@ 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, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA.  */
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
 
 #include "config.h"
 #include "system.h"
@@ -120,6 +119,7 @@ register_overhead (bitmap b, int amount)
 /* Global data */
 bitmap_element bitmap_zero_bits;  /* An element of all zero bits.  */
 bitmap_obstack bitmap_default_obstack;    /* The default bitmap obstack.  */
+static int bitmap_default_obstack_depth;
 static GTY((deletable)) bitmap_element *bitmap_ggc_free; /* Freelist of
                                                            GC'd elements.  */
 
@@ -303,7 +303,11 @@ void
 bitmap_obstack_initialize (bitmap_obstack *bit_obstack)
 {
   if (!bit_obstack)
-    bit_obstack = &bitmap_default_obstack;
+    {
+      if (bitmap_default_obstack_depth++)
+       return;
+      bit_obstack = &bitmap_default_obstack;
+    }
 
 #if !defined(__GNUC__) || (__GNUC__ < 2)
 #define __alignof__(type) 0
@@ -324,7 +328,14 @@ void
 bitmap_obstack_release (bitmap_obstack *bit_obstack)
 {
   if (!bit_obstack)
-    bit_obstack = &bitmap_default_obstack;
+    {
+      if (--bitmap_default_obstack_depth)
+       {
+         gcc_assert (bitmap_default_obstack_depth > 0);
+         return;
+       }
+      bit_obstack = &bitmap_default_obstack;
+    }
 
   bit_obstack->elements = NULL;
   bit_obstack->heads = NULL;
@@ -694,6 +705,40 @@ bitmap_count_bits (const_bitmap a)
   return count;
 }
 
+/* Return true if the bitmap has a single bit set.  Otherwise return
+   false.  */
+
+bool
+bitmap_single_bit_set_p (const_bitmap a)
+{
+  unsigned long count = 0;
+  const bitmap_element *elt;
+  unsigned ix;
+
+  if (bitmap_empty_p (a))
+    return false;
+
+  elt = a->first;
+  /* As there are no completely empty bitmap elements, a second one
+     means we have more than one bit set.  */
+  if (elt->next != NULL)
+    return false;
+
+  for (ix = 0; ix != BITMAP_ELEMENT_WORDS; ix++)
+    {
+#if GCC_VERSION >= 3400
+      /* Note that popcountl matches BITMAP_WORD in type, so the actual size
+        of BITMAP_WORD is not material.  */
+      count += __builtin_popcountl (elt->bits[ix]);
+#else
+      count += bitmap_popcount (elt->bits[ix]);
+#endif
+      if (count > 1)
+       return false;
+    }
+
+  return count == 1;
+}
 
 
 /* Return the bit number of the first set bit in the bitmap.  The