re PR tree-optimization/54981 (Different code generated with / without `-g')

2012-10-19  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/54981
	* tree-loop-distribution.c (ssa_name_has_uses_outside_loop_p):
	Do not consider debug stmts as uses.

	* gcc.dg/pr54981.c: New testcase.

From-SVN: r192612

gcc/ChangeLog

+2012-10-19  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/54981
+	* tree-loop-distribution.c (ssa_name_has_uses_outside_loop_p):
+	Do not consider debug stmts as uses.
+
 2012-10-19  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/54976

gcc/testsuite/ChangeLog

+2012-10-19  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/54981
+	* gcc.dg/pr54981.c: New testcase.
+
 2012-10-19  Zhenqiang Chen <zhenqiang.chen@linaro.org>
 
 	PR target/54892

gcc/testsuite/gcc.dg/pr54981.c

+/* { dg-do compile } */
+/* { dg-options "-O -ftree-loop-distribute-patterns -fcompare-debug" } */
+
+extern void bar(unsigned *, char *);
+
+void foo(char *s)
+{
+  unsigned i;
+  char t[2];
+
+  bar(&i, t);
+
+  for (i = 0; i < 2; i++)
+    s[i] = t[i];
+}

gcc/tree-loop-distribution.c

@@ -125,8 +125,12 @@ ssa_name_has_uses_outside_loop_p (tree def, loop_p loop)
   use_operand_p use_p;
 
   FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def)
-    if (loop != loop_containing_stmt (USE_STMT (use_p)))
-      return true;
+    {
+      gimple use_stmt = USE_STMT (use_p);
+      if (!is_gimple_debug (use_stmt)
+	  && loop != loop_containing_stmt (use_stmt))
+	return true;
+    }
 
   return false;
 }