[PATCH] Fix -fcompare-debug failures caused by vectorizer copying locus from debug stmt (PR debug/50017)

[Jakub Jelinek]

Hi!

If gsi_stmt (*gsi) is a debug stmt, vect_finish_stmt_generation happily
copies over location from the debug stmt, instead of the following non-debug
stmt, which causes -fcompare-debug failures.

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

2011-08-18  Jakub Jelinek  <ja...@redhat.com>

        PR debug/50017
        * tree-vect-stmts.c (vect_finish_stmt_generation): If gsi_stmt (*gsi)
        is a debug stmt, use location of the first non-debug stmt after it.

        * gcc.dg/pr50017.c: New test.

--- gcc/tree-vect-stmts.c.jj    2011-08-18 08:36:00.000000000 +0200
+++ gcc/tree-vect-stmts.c       2011-08-18 09:53:40.000000000 +0200
@@ -1,5 +1,5 @@
 /* Statement Analysis and Transformation for Vectorization
-   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
    Contributed by Dorit Naishlos <do...@il.ibm.com>
    and Ira Rosen <i...@il.ibm.com>
@@ -1419,6 +1419,7 @@ vect_finish_stmt_generation (gimple stmt
   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
   bb_vec_info bb_vinfo = STMT_VINFO_BB_VINFO (stmt_info);
+  gimple_stmt_iterator si;
 
   gcc_assert (gimple_code (stmt) != GIMPLE_LABEL);
 
@@ -1433,7 +1434,13 @@ vect_finish_stmt_generation (gimple stmt
       print_gimple_stmt (vect_dump, vec_stmt, 0, TDF_SLIM);
     }
 
-  gimple_set_location (vec_stmt, gimple_location (gsi_stmt (*gsi)));
+  si = *gsi;
+  if (is_gimple_debug (gsi_stmt (si)))
+    {
+      gsi_next_nondebug (&si);
+      gcc_assert (!gsi_end_p (si));
+    }
+  gimple_set_location (vec_stmt, gimple_location (gsi_stmt (si)));
 }
 
 /* Checks if CALL can be vectorized in type VECTYPE.  Returns
--- gcc/testsuite/gcc.dg/pr50017.c.jj   2011-08-18 09:59:58.000000000 +0200
+++ gcc/testsuite/gcc.dg/pr50017.c      2011-08-18 09:59:19.000000000 +0200
@@ -0,0 +1,20 @@
+/* PR debug/50017 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -fcompare-debug" } */
+
+struct S { int r, i; };
+
+void
+foo (struct S *x, int y)
+{
+  int i;
+  for (i = 1; i < y; i++)
+    {
+      struct S a, b, c;
+      a = x[0];
+      b = x[i];
+      c.r = a.r * b.r - a.i * b.i;
+      c.i = a.r * b.i + a.i * b.r;
+      x[i] = c;
+    }
+}

        Jakub