re PR debug/55579 (SRA doesn't create debug stmts when they would be useful)

2013-01-08  Martin Jambor  <mjambor@suse.cz>

	PR debug/55579
	* tree-sra.c (analyze_access_subtree): Return true also after
	potentially creating a debug-only replacement.

testsuite/
	* gcc.dg/tree-ssa/pr55579.c: New test.

From-SVN: r195015

4 files changed, 42 insertions, 18 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7d9f569..a4c8481 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2013-01-08  Martin Jambor  <mjambor@suse.cz>
+
+	PR debug/55579
+	* tree-sra.c (analyze_access_subtree): Return true also after
+	potentially creating a debug-only replacement.
+
 2013-01-08  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/55890
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a0bdd9e..5d6acaf 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-01-08  Martin Jambor  <mjambor@suse.cz>
+
+	PR debug/55579
+	* gcc.dg/tree-ssa/pr55579.c: New test.
+
 2013-01-08  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* g++.dg/debug/dwarf2/pr54508.C: Allow for more whitespace after
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr55579.c b/gcc/testsuite/gcc.dg/tree-ssa/pr55579.c
new file mode 100644
index 0000000..a4f1825
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr55579.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -g -fdump-tree-esra" } */
+
+struct S { int a; char b; char c; short d; };
+
+int
+foo (int x)
+{
+  struct S s = { x + 1, x + 2, x + 3, x + 4 };
+  char *p = &s.c;
+  return x;
+}
+
+/* { dg-final { scan-tree-dump "Created a debug-only replacement for s" "esra" } } */
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index 9c75393..af5a36e 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -2197,20 +2197,25 @@ analyze_access_subtree (struct access *root, struct access *parent,
     }
   else
     {
-      if (MAY_HAVE_DEBUG_STMTS && allow_replacements
+      if (allow_replacements
 	  && scalar && !root->first_child
 	  && (root->grp_scalar_write || root->grp_assignment_write))
 	{
 	  gcc_checking_assert (!root->grp_scalar_read
 			       && !root->grp_assignment_read);
-	  root->grp_to_be_debug_replaced = 1;
-	  if (dump_file && (dump_flags & TDF_DETAILS))
+	  sth_created = true;
+	  if (MAY_HAVE_DEBUG_STMTS)
 	    {
-	      fprintf (dump_file, "Marking ");
-	      print_generic_expr (dump_file, root->base, 0);
-	      fprintf (dump_file, " offset: %u, size: %u ",
-		       (unsigned) root->offset, (unsigned) root->size);
-	      fprintf (dump_file, " to be replaced with debug statements.\n");
+	      root->grp_to_be_debug_replaced = 1;
+	      if (dump_file && (dump_flags & TDF_DETAILS))
+		{
+		  fprintf (dump_file, "Marking ");
+		  print_generic_expr (dump_file, root->base, 0);
+		  fprintf (dump_file, " offset: %u, size: %u ",
+			   (unsigned) root->offset, (unsigned) root->size);
+		  fprintf (dump_file, " to be replaced with debug "
+			   "statements.\n");
+		}
 	    }
 	}
 
@@ -2220,17 +2225,11 @@ analyze_access_subtree (struct access *root, struct access *parent,
 	root->grp_total_scalarization = 0;
     }
 
-  if (sth_created
-      && (!hole || root->grp_total_scalarization))
-    {
-      root->grp_covered = 1;
-      return true;
-    }
-  if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
+  if (!hole || root->grp_total_scalarization)
+    root->grp_covered = 1;
+  else if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
     root->grp_unscalarized_data = 1; /* not covered and written to */
-  if (sth_created)
-    return true;
-  return false;
+  return sth_created;
 }
 
 /* Analyze all access trees linked by next_grp by the means of