[PATCH] Fix up sbitmap bitmap_{and,ior,xor} (PR target/55562)

[Jakub Jelinek]

Hi!

The bitmap unification changes apparently broke at least modulo scheduling,
which used sbitmap_a_and_b_cg functions, which were replaced by bitmap_and.
But, sbitmap_a_and_b_cg asserted dst->popcount is NULL and returned whether
dst sbitmap changed, but bitmap_and returns always false if dst->popcount is
NULL (and only if it is non-NULL returns if the bitmap changed).

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?

Alternatively we could add back separate functions that would return whether 
dest
changed for speed reasons (similarly to the old *_cg ones), and return void
from the normal ones again.  I bet most of the users don't check the return
value of these functions and thus it is useless computation.

2012-12-18  Jakub Jelinek  <ja...@redhat.com>

        PR target/55562
        * sbitmap.c (bitmap_and, bitmap_xor, bitmap_ior): Return whether
        dst sbitmap changed even if it doesn't have popcount.

--- gcc/sbitmap.c.jj    2012-11-02 09:01:54.000000000 +0100
+++ gcc/sbitmap.c       2012-12-18 14:29:13.695299294 +0100
@@ -434,28 +434,26 @@ bitmap_and (sbitmap dst, const_sbitmap a
   const_sbitmap_ptr bp = b->elms;
   bool has_popcount = dst->popcount != NULL;
   unsigned char *popcountp = dst->popcount;
-  bool anychange = false;
+  SBITMAP_ELT_TYPE changed = 0;
 
   for (i = 0; i < n; i++)
     {
       const SBITMAP_ELT_TYPE tmp = *ap++ & *bp++;
+      SBITMAP_ELT_TYPE wordchanged = *dstp ^ tmp;
       if (has_popcount)
        {
-         bool wordchanged = (*dstp ^ tmp) != 0;
          if (wordchanged)
-           {
-             *popcountp = do_popcount (tmp);
-             anychange = true;
-           }
+           *popcountp = do_popcount (tmp);
          popcountp++;
        }
       *dstp++ = tmp;
+      changed |= wordchanged;
     }
 #ifdef BITMAP_DEBUGGING
   if (has_popcount)
     sbitmap_verify_popcount (dst);
 #endif
-  return anychange;
+  return changed != 0;
 }
 
 /* Set DST to be (A xor B)).
@@ -470,28 +468,26 @@ bitmap_xor (sbitmap dst, const_sbitmap a
   const_sbitmap_ptr bp = b->elms;
   bool has_popcount = dst->popcount != NULL;
   unsigned char *popcountp = dst->popcount;
-  bool anychange = false;
+  SBITMAP_ELT_TYPE changed = 0;
 
   for (i = 0; i < n; i++)
     {
       const SBITMAP_ELT_TYPE tmp = *ap++ ^ *bp++;
+      SBITMAP_ELT_TYPE wordchanged = *dstp ^ tmp;
       if (has_popcount)
        {
-         bool wordchanged = (*dstp ^ tmp) != 0;
          if (wordchanged)
-           {
-             *popcountp = do_popcount (tmp);
-             anychange = true;
-           }
+           *popcountp = do_popcount (tmp);
          popcountp++;
        }
       *dstp++ = tmp;
+      changed |= wordchanged;
     }
 #ifdef BITMAP_DEBUGGING
   if (has_popcount)
     sbitmap_verify_popcount (dst);
 #endif
-  return anychange;
+  return changed != 0;
 }
 
 /* Set DST to be (A or B)).
@@ -506,28 +502,26 @@ bitmap_ior (sbitmap dst, const_sbitmap a
   const_sbitmap_ptr bp = b->elms;
   bool has_popcount = dst->popcount != NULL;
   unsigned char *popcountp = dst->popcount;
-  bool anychange = false;
+  SBITMAP_ELT_TYPE changed = 0;
 
   for (i = 0; i < n; i++)
     {
       const SBITMAP_ELT_TYPE tmp = *ap++ | *bp++;
+      SBITMAP_ELT_TYPE wordchanged = *dstp ^ tmp;
       if (has_popcount)
        {
-         bool wordchanged = (*dstp ^ tmp) != 0;
          if (wordchanged)
-           {
-             *popcountp = do_popcount (tmp);
-             anychange = true;
-           }
+           *popcountp = do_popcount (tmp);
          popcountp++;
        }
       *dstp++ = tmp;
+      changed |= wordchanged;
     }
 #ifdef BITMAP_DEBUGGING
   if (has_popcount)
     sbitmap_verify_popcount (dst);
 #endif
-  return anychange;
+  return changed != 0;
 }
 
 /* Return nonzero if A is a subset of B.  */

        Jakub