#

# http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43430

# http://patchwork.ozlabs.org/patch/64010/

#

# patch had to be re-written because it did not apply cleanly

#

# Bug Summary: when compiling FFmpeg with -ftree-vectorizer-verbose

# certain loops are not being vectorized. This is due to the following

# comparison test in gcc/tree-vect-stmts.c:

# 

# if (TREE_TYPE (TREE_OPERAND (cond_expr, 0)) != TREE_TYPE (vectype))

#     return false;

#

# By replacing all the pointer equality comparisons with types_compatible_p

# comparisons, loops can now be vectorized (this is a very simplified

# description of the patch).

#

--- gcc-4.5.2/gcc/tree-vect-stmts.c	2010-11-02 05:12:56.000000000 -0700

+++ gcc-4.5.2/gcc/tree-vect-stmts.c	2013-02-12 15:35:40.852464111 -0800

@@ -4041,16 +4041,18 @@

   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);

   enum machine_mode vec_mode;

   tree def;

-  enum vect_def_type dt;

+  enum vect_def_type dt, dts[4];

   int nunits = TYPE_VECTOR_SUBPARTS (vectype);

   int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;

   enum tree_code code;

+  stmt_vec_info prev_stmt_info = NULL;

+  int j;

   /* FORNOW: unsupported in basic block SLP.  */

   gcc_assert (loop_vinfo);

   gcc_assert (ncopies >= 1);

-  if (ncopies > 1)

+  if (reduc_index && ncopies > 1)

     return false; /* FORNOW */

   if (!STMT_VINFO_RELEVANT_P (stmt_info))

@@ -4137,18 +4139,51 @@

   vec_dest = vect_create_destination_var (scalar_dest, vectype);

   /* Handle cond expr.  */

+

+  for (j = 0; j < ncopies; j++)

+    {

+      gimple new_stmt;

+      if (j == 0)

+	{

+	  gimple gtemp;

   vec_cond_lhs =

-    vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 0), stmt, NULL);

+	      vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 0),

+					    stmt, NULL);

+	  vect_is_simple_use (TREE_OPERAND (cond_expr, 0), loop_vinfo,

+			      NULL, &gtemp, &def, &dts[0]);

   vec_cond_rhs =

-    vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 1), stmt, NULL);

+	      vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 1),

+					    stmt, NULL);

+	  vect_is_simple_use (TREE_OPERAND (cond_expr, 1), loop_vinfo,

+			      NULL, &gtemp, &def, &dts[1]);

   if (reduc_index == 1)

     vec_then_clause = reduc_def;

   else

-    vec_then_clause = vect_get_vec_def_for_operand (then_clause, stmt, NULL);

+	    {

+	      vec_then_clause = vect_get_vec_def_for_operand (then_clause,

+							      stmt, NULL);

+	      vect_is_simple_use (then_clause, loop_vinfo,

+				  NULL, &gtemp, &def, &dts[2]);

+	    }

   if (reduc_index == 2)

     vec_else_clause = reduc_def;

   else

-    vec_else_clause = vect_get_vec_def_for_operand (else_clause, stmt, NULL);

+	    {

+	      vec_else_clause = vect_get_vec_def_for_operand (else_clause,

+							      stmt, NULL);

+	      vect_is_simple_use (else_clause, loop_vinfo,

+				  NULL, &gtemp, &def, &dts[3]);

+	    }

+	}

+      else

+	{

+	  vec_cond_lhs = vect_get_vec_def_for_stmt_copy (dts[0], vec_cond_lhs);

+	  vec_cond_rhs = vect_get_vec_def_for_stmt_copy (dts[1], vec_cond_rhs);

+	  vec_then_clause = vect_get_vec_def_for_stmt_copy (dts[2],

+							    vec_then_clause);

+	  vec_else_clause = vect_get_vec_def_for_stmt_copy (dts[3],

+							    vec_else_clause);

+	}

   /* Arguments are ready. Create the new vector stmt.  */

   vec_compare = build2 (TREE_CODE (cond_expr), vectype,

@@ -4156,10 +4191,17 @@

   vec_cond_expr = build3 (VEC_COND_EXPR, vectype,

 			  vec_compare, vec_then_clause, vec_else_clause);

-  *vec_stmt = gimple_build_assign (vec_dest, vec_cond_expr);

-  new_temp = make_ssa_name (vec_dest, *vec_stmt);

-  gimple_assign_set_lhs (*vec_stmt, new_temp);

-  vect_finish_stmt_generation (stmt, *vec_stmt, gsi);

+      new_stmt = gimple_build_assign (vec_dest, vec_cond_expr);

+      new_temp = make_ssa_name (vec_dest, new_stmt);

+      gimple_assign_set_lhs (new_stmt, new_temp);

+      vect_finish_stmt_generation (stmt, new_stmt, gsi);

+      if (j == 0)

+        STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;

+      else

+        STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;

+

+      prev_stmt_info = vinfo_for_stmt (new_stmt);

+    }

   return true;

 }