tree-flow-inline.h (get_subvar_at): Use binary search.

2007-10-29  Richard Guenther  <rguenther@suse.de>

	* tree-flow-inline.h (get_subvar_at): Use binary search.
	(get_first_overlapping_subvar): New function to binary search
	for the first overlapping subvar.
	* tree-ssa-operands.c (add_vars_for_offset): Strip down to
	just handle adding subvars for a pointed-to subvar.  Optimize
	and use get_first_overlapping_subvar.
	(add_vars_for_bitmap): Fold into single caller.
	(add_virtual_operand): Streamline, inherit add_vars_for_bitmap
	and non pointed-to bits of add_vars_for_offset.

From-SVN: r129727

gcc/ChangeLog

+2007-10-29  Richard Guenther  <rguenther@suse.de>
+
+	* tree-flow-inline.h (get_subvar_at): Use binary search.
+	(get_first_overlapping_subvar): New function to binary search
+	for the first overlapping subvar.
+	* tree-ssa-operands.c (add_vars_for_offset): Strip down to
+	just handle adding subvars for a pointed-to subvar.  Optimize
+	and use get_first_overlapping_subvar.
+	(add_vars_for_bitmap): Fold into single caller.
+	(add_virtual_operand): Streamline, inherit add_vars_for_bitmap
+	and non pointed-to bits of add_vars_for_offset.
+
 2007-10-29  Revital Eres  <eres@il.ibm.com> 
 
 	* modulo-sched.c (sms_schedule): Add DF_UD_CHAIN problem.

gcc/tree-flow-inline.h

@@ -1610,17 +1610,88 @@ static inline tree
 get_subvar_at (tree var, unsigned HOST_WIDE_INT offset)
 {
   subvar_t sv = get_subvars_for_var (var);
-  unsigned int i;
+  int low, high;
+
+  low = 0;
+  high = VEC_length (tree, sv) - 1;
+  while (low <= high)
+    {
+      int mid = (low + high) / 2;
+      tree subvar = VEC_index (tree, sv, mid);
+      if (SFT_OFFSET (subvar) == offset)
+	return subvar;
+      else if (SFT_OFFSET (subvar) < offset)
+	low = mid + 1;
+      else
+	high = mid - 1;
+    }
+
+  return NULL_TREE;
+}
+
+
+/* Return the first subvariable in SV that overlaps [offset, offset + size[.
+   NULL_TREE is returned, if there is no overlapping subvariable, else *I
+   is set to the index in the SV vector of the first overlap.  */
+
+static inline tree
+get_first_overlapping_subvar (subvar_t sv, unsigned HOST_WIDE_INT offset,
+			      unsigned HOST_WIDE_INT size, unsigned int *i)
+{
+  int low = 0;
+  int high = VEC_length (tree, sv) - 1;
+  int mid;
   tree subvar;
 
-  /* ???  Binary search would be possible here.  */
-  for (i = 0; VEC_iterate (tree, sv, i, subvar); ++i)
-    if (SFT_OFFSET (subvar) == offset)
+  if (low > high)
+    return NULL_TREE;
+
+  /* Binary search for offset.  */
+  do
+    {
+      mid = (low + high) / 2;
+      subvar = VEC_index (tree, sv, mid);
+      if (SFT_OFFSET (subvar) == offset)
+	{
+	  *i = mid;
+	  return subvar;
+	}
+      else if (SFT_OFFSET (subvar) < offset)
+	low = mid + 1;
+      else
+	high = mid - 1;
+    }
+  while (low <= high);
+
+  /* As we didn't find a subvar with offset, adjust to return the
+     first overlapping one.  */
+  if (SFT_OFFSET (subvar) < offset
+      && SFT_OFFSET (subvar) + SFT_SIZE (subvar) <= offset)
+    {
+      mid += 1;
+      if ((unsigned)mid >= VEC_length (tree, sv))
+	return NULL_TREE;
+      subvar = VEC_index (tree, sv, mid);
+    }
+  else if (SFT_OFFSET (subvar) > offset
+	   && size <= SFT_OFFSET (subvar) - offset)
+    {
+      mid -= 1;
+      if (mid < 0)
+	return NULL_TREE;
+      subvar = VEC_index (tree, sv, mid);
+    }
+
+  if (overlap_subvar (offset, size, subvar, NULL))
+    {
+      *i = mid;
       return subvar;
+    }
 
   return NULL_TREE;
 }
 
+
 /* Return true if V is a tree that we can have subvars for.
    Normally, this is any aggregate type.  Also complex
    types which are not gimple registers can have subvars.  */

gcc/tree-ssa-operands.c

@@ -1386,89 +1386,46 @@ access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
    This is necessary because foop only actually points to foo's first
    member, so that is all the points-to set contains.  However, an access
    to foop->a may be touching some single SFT if we have created some
-   SFT's for a structure.  If AS_PTO is false, just add VAR to the vops.  */
+   SFT's for a structure.  */
 
 static bool
-add_vars_for_offset (tree full_ref, tree var, HOST_WIDE_INT offset,
-		     HOST_WIDE_INT size, bool is_call_site, bool is_def,
-		     bool as_pto)
+add_vars_for_offset (tree var,
+		     unsigned HOST_WIDE_INT offset, unsigned HOST_WIDE_INT size,
+		     bool is_def, bitmap mpt_vars)
 {
   bool added = false;
+  tree subvar;
   subvar_t sv;
   unsigned int i;
-  tree subvar;
 
+  /* Adjust offset by the pointed-to location.  */
+  offset += SFT_OFFSET (var);
 
-  /* Call-clobbered tags may have non-call-clobbered
-     symbols in their alias sets.  Ignore them if we are
-     adding VOPs for a call site.  */
-  if (is_call_site && !is_call_clobbered (var))
+  /* Add all subvars of var that overlap with the access.
+     Binary search for the first relevant SFT.  */
+  sv = get_subvars_for_var (SFT_PARENT_VAR (var));
+  if (!get_first_overlapping_subvar (sv, offset, size, &i))
     return false;
 
-  /* For SFTs we have to consider all subvariables of the parent var.  */
-  if (TREE_CODE (var) != STRUCT_FIELD_TAG
-      || !as_pto)
+  for (; VEC_iterate (tree, sv, i, subvar); ++i)
     {
-      /* If we do not know the full reference tree or if the access is
-	 unspecified [0, -1], we cannot prune it.  Otherwise try doing
-	 so using access_can_touch_variable.  */
-      if (full_ref
-	  && !(offset == 0 && size == -1)
-	  && !access_can_touch_variable (full_ref, var, offset, size))
-	return false;
-
-      if (is_def)
-	append_vdef (var);
-      else
-	append_vuse (var);
-      return true;
-    }
-
-  sv = get_subvars_for_var (SFT_PARENT_VAR (var));
-  for (i = 0; VEC_iterate (tree, sv, i, subvar); ++i)
-    {
-      /* Once we hit the end of the parts that could touch,
-	 stop looking.  */
-      if (size != -1
-	  && SFT_OFFSET (var) + offset + size <= SFT_OFFSET (subvar))
+      if (size <= SFT_OFFSET (subvar) - offset)
 	break;
-      if (overlap_subvar (SFT_OFFSET (var) + offset, size, subvar, NULL))
+
+      /* Avoid adding a SFT that is contained in the same MPT as the
+	 pointed-to location as this MPT will be added as alias anyway.  */
+      if (!mpt_vars
+	  || !bitmap_bit_p (mpt_vars, DECL_UID (subvar)))
 	{
-	  added = true;
 	  if (is_def)
 	    append_vdef (subvar);
 	  else
 	    append_vuse (subvar);
 	}
+      added = true;
     }
-  return added;
-}
 
-/* Consider all SFTs in ALIASES as points-to location and add virtual
-   operands for the SFT parent var for the access FULL_REF at OFFSET
-   and size SIZE.  IS_CALL_SITE is true if the stmt of the reference is
-   a call.  IS_DEF is true if we should add VDEF virtual operands,
-   otherwise we'll add VUSEs.  *NONE_ADDED is set to false once the first
-   virtual operand was added.  */
-
-static void
-add_vars_for_bitmap (bitmap aliases, tree full_ref,
-		     HOST_WIDE_INT offset, HOST_WIDE_INT size,
-		     bool is_call_site, bool is_def, bool *none_added)
-{
-  bitmap_iterator bi;
-  unsigned int i;
-
-  EXECUTE_IF_SET_IN_BITMAP (aliases, 0, i, bi)
-    {
-      tree al = referenced_var (i);
-
-      gcc_assert (TREE_CODE (al) != MEMORY_PARTITION_TAG);
-
-      if (TREE_CODE (al) == STRUCT_FIELD_TAG)
-	*none_added &= !add_vars_for_offset (full_ref, al, offset, size,
-					     is_call_site, is_def, true);
-    }
+  return added;
 }
 
 /* Add VAR to the virtual operands array.  FLAGS is as in
@@ -1552,11 +1509,49 @@ add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
 	     But only if we start with NMT aliases.  */
 	  if (TREE_CODE (al) == MEMORY_PARTITION_TAG
 	      && TREE_CODE (var) == NAME_MEMORY_TAG)
-	    add_vars_for_bitmap (MPT_SYMBOLS (al), full_ref, offset, size,
-				 is_call_site, flags & opf_def, &none_added);
-	  none_added &= !add_vars_for_offset (full_ref, al, offset, size,
-					      is_call_site, flags & opf_def,
-					      TREE_CODE (var) == NAME_MEMORY_TAG);
+	    {
+	      bitmap_iterator bi;
+	      unsigned int i;
+
+	      EXECUTE_IF_SET_IN_BITMAP (MPT_SYMBOLS (al), 0, i, bi)
+		{
+		  tree ptsft = referenced_var (i);
+
+		  if (TREE_CODE (ptsft) == STRUCT_FIELD_TAG)
+		    none_added &= !add_vars_for_offset (ptsft, offset, size,
+							flags & opf_def,
+							MPT_SYMBOLS (al));
+		}
+	    }
+
+	  /* For SFTs we have to consider all subvariables of the parent var
+	     if it is a potential points-to location.  */
+	  if (TREE_CODE (al) == STRUCT_FIELD_TAG
+	      && TREE_CODE (var) == NAME_MEMORY_TAG)
+	    none_added &= !add_vars_for_offset (al, offset, size,
+					        flags & opf_def, NULL);
+	  else
+	    {
+	      /* Call-clobbered tags may have non-call-clobbered
+		 symbols in their alias sets.  Ignore them if we are
+		 adding VOPs for a call site.  */
+	      if (is_call_site && !is_call_clobbered (al))
+		 continue;
+
+	      /* If we do not know the full reference tree or if the access is
+		 unspecified [0, -1], we cannot prune it.  Otherwise try doing
+		 so using access_can_touch_variable.  */
+	      if (full_ref
+		  && !(offset == 0 && size == -1)
+		  && !access_can_touch_variable (full_ref, al, offset, size))
+		continue;
+
+	      if (flags & opf_def)
+		append_vdef (al);
+	      else
+		append_vuse (al);
+	      none_added = false;
+	    }
 	}
 
       if (flags & opf_def)