[Bug tree-optimization/50178] [4.6 regression] ICE with gfortran -O3, not with gfortran -02

[irar at il dot ibm.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50178

Ira Rosen <irar at il dot ibm.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |irar at il dot ibm.com

--- Comment #5 from Ira Rosen <irar at il dot ibm.com> 2011-09-01 07:01:07 UTC ---
The problem here is that in vectorizable_call we replace the original call with
a dummy stmt and also remove its stmt_vec_info, which causes the segfault when
we try to access it through related pattern stmt. I'm testing the following
patch that updates related pattern stmt to be the dummy stmt:

Index: tree-vect-stmts.c
===================================================================
--- tree-vect-stmts.c   (revision 178373)
+++ tree-vect-stmts.c   (working copy)
@@ -1583,6 +1583,14 @@ vectorizable_call (gimple stmt, gimple_stmt_iterat
   new_stmt = gimple_build_assign (gimple_call_lhs (stmt),
                                  build_zero_cst (type));
   set_vinfo_for_stmt (new_stmt, stmt_info);
+  /* For pattern statements make the related statement to point to
+     NEW_STMT in order to be able to retrieve the original statement
+     information later.  */
+  if (is_pattern_stmt_p (stmt_info))
+    {
+      gimple related = STMT_VINFO_RELATED_STMT (stmt_info);
+      STMT_VINFO_RELATED_STMT (vinfo_for_stmt (related)) = new_stmt;
+    }
   set_vinfo_for_stmt (stmt, NULL);
   STMT_VINFO_STMT (stmt_info) = new_stmt;
   gsi_replace (gsi, new_stmt, false);
@@ -4957,11 +4965,7 @@ vect_transform_stmt (gimple stmt, gimple_stmt_iter
             the stmt_info of ORIG_STMT_IN_PATTERN.  See more details in the
             documentation of vect_pattern_recog.  */
          if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo))
-           {
-             gcc_assert (STMT_VINFO_RELATED_STMT (stmt_vinfo)
-                           == orig_scalar_stmt);
-             STMT_VINFO_VEC_STMT (stmt_vinfo) = vec_stmt;
-           }
+           STMT_VINFO_VEC_STMT (stmt_vinfo) = vec_stmt;
        }
     }


r175074 really fixed this problem since now we don't need to retrieve the
original def stmt.