Re: [vec-cmp, patch 4/6] Support vector mask invariants

[Ilya Enkovich <enkovich.gnu@gmail.com>]

On 14 Oct 13:50, Ilya Enkovich wrote:
> 2015-10-14 11:49 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
> > On Tue, Oct 13, 2015 at 4:52 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> >> I don't understand what you mean. vect_get_vec_def_for_operand has two
> >> changes made.
> >> 1. For boolean invariants use build_same_sized_truth_vector_type
> >> instead of get_vectype_for_scalar_type in case statement produces a
> >> boolean vector. This covers cases when we use invariants in
> >> comparison, AND, IOR, XOR.
> >
> > Yes, I understand we need this special-casing to differentiate between
> > the vector type
> > used for boolean-typed loads/stores and the type for boolean typed constants.
> > What happens if we mix them btw, like with
> >
> >   _Bool b = bools[i];
> >   _Bool c = b || d;
> >   ...
> >
> > ?
> 
> Here both statements should get vector of char as a vectype and we
> never go VECTOR_BOOLEAN_TYPE_P way for them
> 
> >
> >> 2. COND_EXPR is an exception because it has built-in boolean vector
> >> result not reflected in its vecinfo. Thus I added additional operand
> >> for vect_get_vec_def_for_operand to directly specify vectype for
> >> vector definition in case it is a loop invariant.
> >> So what do you propose to do with these changes?
> >
> > This is the change I don't like and don't see why we need it.  It works today
> > and the comparison operands should be of appropriate type already?
> 
> Today it works because we always create vector of integer constant.
> With boolean vectors it may be either integer vector or boolean vector
> depending on context. Consider:
> 
> _Bool _1;
> int _2;
> 
> _2 = _1 != 0 ? 0 : 1
> 
> We have two zero constants here requiring different vectypes.
> 
> Ilya
> 
> >
> > Richard.
> >
> >> Thanks,
> >> Ilya

Here is an updated patch version.

Thanks,
Ilya
--
gcc/

2015-10-14  Ilya Enkovich  <enkovich.gnu@gmail.com>

	* expr.c (const_vector_mask_from_tree): New.
	(const_vector_from_tree): Use const_vector_mask_from_tree
	for boolean vectors.
	* tree-vect-stmts.c (vect_init_vector): Support boolean vector
	invariants.
	(vect_get_vec_def_for_operand): Add VECTYPE arg.
	(vectorizable_condition): Directly provide vectype for invariants
	used in comparison.
	* tree-vectorizer.h (vect_get_vec_def_for_operand): Add VECTYPE
	arg.


diff --git a/gcc/expr.c b/gcc/expr.c
index b5ff598..ab25d1a 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -11344,6 +11344,40 @@ try_tablejump (tree index_type, tree index_expr, tree minval, tree range,
   return 1;
 }
 
+/* Return a CONST_VECTOR rtx representing vector mask for
+   a VECTOR_CST of booleans.  */
+static rtx
+const_vector_mask_from_tree (tree exp)
+{
+  rtvec v;
+  unsigned i;
+  int units;
+  tree elt;
+  machine_mode inner, mode;
+
+  mode = TYPE_MODE (TREE_TYPE (exp));
+  units = GET_MODE_NUNITS (mode);
+  inner = GET_MODE_INNER (mode);
+
+  v = rtvec_alloc (units);
+
+  for (i = 0; i < VECTOR_CST_NELTS (exp); ++i)
+    {
+      elt = VECTOR_CST_ELT (exp, i);
+
+      gcc_assert (TREE_CODE (elt) == INTEGER_CST);
+      if (integer_zerop (elt))
+	RTVEC_ELT (v, i) = CONST0_RTX (inner);
+      else if (integer_onep (elt)
+	       || integer_minus_onep (elt))
+	RTVEC_ELT (v, i) = CONSTM1_RTX (inner);
+      else
+	gcc_unreachable ();
+    }
+
+  return gen_rtx_CONST_VECTOR (mode, v);
+}
+
 /* Return a CONST_VECTOR rtx for a VECTOR_CST tree.  */
 static rtx
 const_vector_from_tree (tree exp)
@@ -11359,6 +11393,9 @@ const_vector_from_tree (tree exp)
   if (initializer_zerop (exp))
     return CONST0_RTX (mode);
 
+  if (VECTOR_BOOLEAN_TYPE_P (TREE_TYPE (exp)))
+    return const_vector_mask_from_tree (exp);
+
   units = GET_MODE_NUNITS (mode);
   inner = GET_MODE_INNER (mode);
 
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 6a52895..01168ae 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -1308,7 +1308,22 @@ vect_init_vector (gimple *stmt, tree val, tree type, gimple_stmt_iterator *gsi)
       if (!types_compatible_p (TREE_TYPE (type), TREE_TYPE (val)))
 	{
 	  if (CONSTANT_CLASS_P (val))
-	    val = fold_unary (VIEW_CONVERT_EXPR, TREE_TYPE (type), val);
+	    {
+	      /* Can't use VIEW_CONVERT_EXPR for booleans because
+		 of possibly different sizes of scalar value and
+		 vector element.  */
+	      if (VECTOR_BOOLEAN_TYPE_P (type))
+		{
+		  if (integer_zerop (val))
+		    val = build_int_cst (TREE_TYPE (type), 0);
+		  else if (integer_onep (val))
+		    val = build_int_cst (TREE_TYPE (type), 1);
+		  else
+		    gcc_unreachable ();
+		}
+	      else
+		val = fold_unary (VIEW_CONVERT_EXPR, TREE_TYPE (type), val);
+	    }
 	  else
 	    {
 	      new_temp = make_ssa_name (TREE_TYPE (type));
@@ -1339,16 +1354,19 @@ vect_init_vector (gimple *stmt, tree val, tree type, gimple_stmt_iterator *gsi)
    STMT_VINFO_VEC_STMT of the defining stmt holds the relevant def.
 
    In case OP is an invariant or constant, a new stmt that creates a vector def
-   needs to be introduced.  */
+   needs to be introduced.  VECTYPE may be used to specify a required type for
+   vector invariant.  */
 
 tree
-vect_get_vec_def_for_operand (tree op, gimple *stmt, tree *scalar_def)
+vect_get_vec_def_for_operand (tree op, gimple *stmt, tree *scalar_def,
+			      tree vectype)
 {
   tree vec_oprnd;
   gimple *vec_stmt;
   gimple *def_stmt;
   stmt_vec_info def_stmt_info = NULL;
   stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt);
+  tree stmt_vectype = STMT_VINFO_VECTYPE (stmt_vinfo);
   unsigned int nunits;
   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo);
   tree def;
@@ -1392,7 +1410,14 @@ vect_get_vec_def_for_operand (tree op, gimple *stmt, tree *scalar_def)
     /* Case 1: operand is a constant.  */
     case vect_constant_def:
       {
-	vector_type = get_vectype_for_scalar_type (TREE_TYPE (op));
+	if (vectype)
+	  vector_type = vectype;
+	else if (TREE_CODE (TREE_TYPE (op)) == BOOLEAN_TYPE
+		 && VECTOR_BOOLEAN_TYPE_P (stmt_vectype))
+	  vector_type = build_same_sized_truth_vector_type (stmt_vectype);
+	else
+	  vector_type = get_vectype_for_scalar_type (TREE_TYPE (op));
+
 	gcc_assert (vector_type);
 	nunits = TYPE_VECTOR_SUBPARTS (vector_type);
 
@@ -1410,7 +1435,13 @@ vect_get_vec_def_for_operand (tree op, gimple *stmt, tree *scalar_def)
     /* Case 2: operand is defined outside the loop - loop invariant.  */
     case vect_external_def:
       {
-	vector_type = get_vectype_for_scalar_type (TREE_TYPE (def));
+	if (vectype)
+	  vector_type = vectype;
+	else if (TREE_CODE (TREE_TYPE (op)) == BOOLEAN_TYPE
+		 && VECTOR_BOOLEAN_TYPE_P (stmt_vectype))
+	  vector_type = build_same_sized_truth_vector_type (stmt_vectype);
+	else
+	  vector_type = get_vectype_for_scalar_type (TREE_TYPE (def));
 	gcc_assert (vector_type);
 
 	if (scalar_def)
@@ -7428,13 +7459,13 @@ vectorizable_condition (gimple *stmt, gimple_stmt_iterator *gsi,
 	      gimple *gtemp;
 	      vec_cond_lhs =
 	      vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 0),
-					    stmt, NULL);
+					    stmt, NULL, comp_vectype);
 	      vect_is_simple_use (TREE_OPERAND (cond_expr, 0), stmt,
 				  loop_vinfo, &gtemp, &def, &dts[0]);
 
 	      vec_cond_rhs =
 		vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 1),
-						stmt, NULL);
+					      stmt, NULL, comp_vectype);
 	      vect_is_simple_use (TREE_OPERAND (cond_expr, 1), stmt,
 				  loop_vinfo, &gtemp, &def, &dts[1]);
 	      if (reduc_index == 1)
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index f8d1e97..8eca7be 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -994,7 +994,7 @@ extern unsigned record_stmt_cost (stmt_vector_for_cost *, int,
 extern void vect_finish_stmt_generation (gimple *, gimple *,
                                          gimple_stmt_iterator *);
 extern bool vect_mark_stmts_to_be_vectorized (loop_vec_info);
-extern tree vect_get_vec_def_for_operand (tree, gimple *, tree *);
+extern tree vect_get_vec_def_for_operand (tree, gimple *, tree *, tree = NULL);
 extern tree vect_init_vector (gimple *, tree, tree,
                               gimple_stmt_iterator *);
 extern tree vect_get_vec_def_for_stmt_copy (enum vect_def_type, tree);