re PR c++/82084 (ICE: constructing wstring with -O3)

2017-09-05  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82084
	* fold-const.c (can_native_encode_string_p): Handle wide characters.

From-SVN: r251711

gcc/ChangeLog

 2017-09-05  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/82084
+	* fold-const.c (can_native_encode_string_p): Handle wide characters.
+
+2017-09-05  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/82102
 	* tree-ssa-pre.c (fini_eliminate): Check if lhs is NULL.
 

gcc/fold-const.c

@@ -7489,10 +7489,11 @@ can_native_encode_string_p (const_tree expr)
 {
   tree type = TREE_TYPE (expr);
 
-  if (TREE_CODE (type) != ARRAY_TYPE
+  /* Wide-char strings are encoded in target byte-order so native
+     encoding them is trivial.  */
+  if (BITS_PER_UNIT != CHAR_BIT
+      || TREE_CODE (type) != ARRAY_TYPE
       || TREE_CODE (TREE_TYPE (type)) != INTEGER_TYPE
-      || (GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (TREE_TYPE (type)))
-	  != BITS_PER_UNIT)
       || !tree_fits_shwi_p (TYPE_SIZE_UNIT (type)))
     return false;
   return true;