gimple-fold.c (fold_gimple_assign): Do not dispatch to fold () on single RHSs.

2015-10-30  Richard Biener  <rguenther@suse.de>

	* gimple-fold.c (fold_gimple_assign): Do not dispatch to
	fold () on single RHSs.  Allow CONSTRUCTORS with trailing
	zeros to be folded to VECTOR_CSTs.
	* tree.c (build_vector_from_ctor): Handle VECTOR_CST elements.
	* fold-const.c (fold): Use build_vector_from_ctor.

From-SVN: r229574

gcc/ChangeLog

+2015-10-30  Richard Biener  <rguenther@suse.de>
+
+	* gimple-fold.c (fold_gimple_assign): Do not dispatch to
+	fold () on single RHSs.  Allow CONSTRUCTORS with trailing
+	zeros to be folded to VECTOR_CSTs.
+	* tree.c (build_vector_from_ctor): Handle VECTOR_CST elements.
+	* fold-const.c (fold): Use build_vector_from_ctor.
+
 2015-10-30  Evandro Menezes  <e.menezes@samsung.com>
 
 	* config/aarch64/aarch64.md (*movhf_aarch64): Change the type of

gcc/fold-const.c

@@ -11968,26 +11968,13 @@ fold (tree expr)
 	if (TREE_CODE (type) != VECTOR_TYPE)
 	  return t;
 
-	tree *vec = XALLOCAVEC (tree, TYPE_VECTOR_SUBPARTS (type));
-	unsigned HOST_WIDE_INT idx, pos = 0;
-	tree value;
-
-	FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), idx, value)
-	  {
-	    if (!CONSTANT_CLASS_P (value))
-	      return t;
-	    if (TREE_CODE (value) == VECTOR_CST)
-	      {
-		for (unsigned i = 0; i < VECTOR_CST_NELTS (value); ++i)
-		  vec[pos++] = VECTOR_CST_ELT (value, i);
-	      }
-	    else
-	      vec[pos++] = value;
-	  }
-	for (; pos < TYPE_VECTOR_SUBPARTS (type); ++pos)
-	  vec[pos] = build_zero_cst (TREE_TYPE (type));
+	unsigned i;
+	tree val;
+	FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
+	  if (! CONSTANT_CLASS_P (val))
+	    return t;
 
-	return build_vector (type, vec);
+	return build_vector_from_ctor (type, CONSTRUCTOR_ELTS (t));
       }
 
     case CONST_DECL:

gcc/gimple-fold.c

@@ -354,8 +354,8 @@ fold_gimple_assign (gimple_stmt_iterator *si)
 		    return val;
 		  }
 	      }
-
 	  }
+
 	else if (TREE_CODE (rhs) == ADDR_EXPR)
 	  {
 	    tree ref = TREE_OPERAND (rhs, 0);
@@ -370,21 +370,29 @@ fold_gimple_assign (gimple_stmt_iterator *si)
 	    else if (TREE_CODE (ref) == MEM_REF
 		     && integer_zerop (TREE_OPERAND (ref, 1)))
 	      result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0));
+
+	    if (result)
+	      {
+		/* Strip away useless type conversions.  Both the
+		   NON_LVALUE_EXPR that may have been added by fold, and
+		   "useless" type conversions that might now be apparent
+		   due to propagation.  */
+		STRIP_USELESS_TYPE_CONVERSION (result);
+
+		if (result != rhs && valid_gimple_rhs_p (result))
+		  return result;
+	      }
 	  }
 
 	else if (TREE_CODE (rhs) == CONSTRUCTOR
-		 && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE
-		 && (CONSTRUCTOR_NELTS (rhs)
-		     == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))))
+		 && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE)
 	  {
 	    /* Fold a constant vector CONSTRUCTOR to VECTOR_CST.  */
 	    unsigned i;
 	    tree val;
 
 	    FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val)
-	      if (TREE_CODE (val) != INTEGER_CST
-		  && TREE_CODE (val) != REAL_CST
-		  && TREE_CODE (val) != FIXED_CST)
+	      if (! CONSTANT_CLASS_P (val))
 		return NULL_TREE;
 
 	    return build_vector_from_ctor (TREE_TYPE (rhs),
@@ -393,21 +401,6 @@ fold_gimple_assign (gimple_stmt_iterator *si)
 
 	else if (DECL_P (rhs))
 	  return get_symbol_constant_value (rhs);
-
-        /* If we couldn't fold the RHS, hand over to the generic
-           fold routines.  */
-        if (result == NULL_TREE)
-          result = fold (rhs);
-
-        /* Strip away useless type conversions.  Both the NON_LVALUE_EXPR
-           that may have been added by fold, and "useless" type
-           conversions that might now be apparent due to propagation.  */
-        STRIP_USELESS_TYPE_CONVERSION (result);
-
-        if (result != rhs && valid_gimple_rhs_p (result))
-	  return result;
-
-	return NULL_TREE;
       }
       break;
 

gcc/tree.c

@@ -1729,13 +1729,19 @@ tree
 build_vector_from_ctor (tree type, vec<constructor_elt, va_gc> *v)
 {
   tree *vec = XALLOCAVEC (tree, TYPE_VECTOR_SUBPARTS (type));
-  unsigned HOST_WIDE_INT idx;
+  unsigned HOST_WIDE_INT idx, pos = 0;
   tree value;
 
   FOR_EACH_CONSTRUCTOR_VALUE (v, idx, value)
-    vec[idx] = value;
+    {
+      if (TREE_CODE (value) == VECTOR_CST)
+	for (unsigned i = 0; i < VECTOR_CST_NELTS (value); ++i)
+	  vec[pos++] = VECTOR_CST_ELT (value, i);
+      else
+	vec[pos++] = value;
+    }
   for (; idx < TYPE_VECTOR_SUBPARTS (type); ++idx)
-    vec[idx] = build_zero_cst (TREE_TYPE (type));
+    vec[pos++] = build_zero_cst (TREE_TYPE (type));
 
   return build_vector (type, vec);
 }