2012-04-03 Richard Guenther <rguenther@suse.de>

[pf3gnuchains/gcc-fork.git] / gcc / tree-sra.c

diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index e2091e5..d132b6c 100644 (file)
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -1526,10 +1526,12 @@ build_ref_for_offset (location_t loc, tree base, HOST_WIDE_INT offset,
      we can extract more optimistic alignment information
      by looking at the access mode.  That would constrain the
      alignment of base + base_offset which we would need to
-     adjust according to offset.
-     ???  But it is not at all clear that prev_base is an access
-     that was in the IL that way, so be conservative for now.  */
+     adjust according to offset.  */
   align = get_pointer_alignment_1 (base, &misalign);
+  if (misalign == 0
+      && (TREE_CODE (prev_base) == MEM_REF
+         || TREE_CODE (prev_base) == TARGET_MEM_REF))
+    align = MAX (align, TYPE_ALIGN (TREE_TYPE (prev_base)));
   misalign += (double_int_sext (tree_to_double_int (off),
                                TYPE_PRECISION (TREE_TYPE (off))).low
               * BITS_PER_UNIT);
@@ -2172,11 +2174,21 @@ analyze_access_subtree (struct access *root, struct access *parent,
              && (root->grp_scalar_write || root->grp_assignment_write))))
     {
       bool new_integer_type;
-      if (TREE_CODE (root->type) == ENUMERAL_TYPE)
+      /* Always create access replacements that cover the whole access.
+         For integral types this means the precision has to match.
+        Avoid assumptions based on the integral type kind, too.  */
+      if (INTEGRAL_TYPE_P (root->type)
+         && (TREE_CODE (root->type) != INTEGER_TYPE
+             || TYPE_PRECISION (root->type) != root->size)
+         /* But leave bitfield accesses alone.  */
+         && (root->offset % BITS_PER_UNIT) == 0)
        {
          tree rt = root->type;
-         root->type = build_nonstandard_integer_type (TYPE_PRECISION (rt),
+         root->type = build_nonstandard_integer_type (root->size,
                                                       TYPE_UNSIGNED (rt));
+         root->expr = build_ref_for_offset (UNKNOWN_LOCATION,
+                                            root->base, root->offset,
+                                            root->type, NULL, false);
          new_integer_type = true;
        }
       else
@@ -3108,7 +3120,13 @@ sra_modify_assign (gimple *stmt, gimple_stmt_iterator *gsi)
     }
   else
     {
-      if (access_has_children_p (lacc) && access_has_children_p (racc))
+      if (access_has_children_p (lacc)
+         && access_has_children_p (racc)
+         /* When an access represents an unscalarizable region, it usually
+            represents accesses with variable offset and thus must not be used
+            to generate new memory accesses.  */
+         && !lacc->grp_unscalarizable_region
+         && !racc->grp_unscalarizable_region)
        {
          gimple_stmt_iterator orig_gsi = *gsi;
          enum unscalarized_data_handling refreshed;