re PR tree-optimization/93210 (Sub-optimal code optimization on struct/combound constexpr (gcc vs. clang))

	PR tree-optimization/93210
	* fold-const.h (native_encode_initializer,
	can_native_interpret_type_p): Declare.
	* fold-const.c (native_encode_string): Fix up handling with off != -1,
	simplify.
	(native_encode_initializer): New function, moved from dwarf2out.c.
	Adjust to native_encode_expr compatible arguments, including dry-run
	and partial extraction modes.  Don't handle STRING_CST.
	(can_native_interpret_type_p): No longer static.
	* gimple-fold.c (fold_ctor_reference): For native_encode_expr, verify
	offset / BITS_PER_UNIT fits into int and don't call it if
	can_native_interpret_type_p fails.  If suboff is NULL and for
	CONSTRUCTOR fold_{,non}array_ctor_reference returns NULL, retry with
	native_encode_initializer.
	(fold_const_aggregate_ref_1): Formatting fix.
	* dwarf2out.c (native_encode_initializer): Moved to fold-const.c.
	(tree_add_const_value_attribute): Adjust caller.

	* gcc.dg/pr93210.c: New test.
	* g++.dg/opt/pr93210.C: New test.

From-SVN: r280141

1 files changed, 1 insertions, 145 deletions

diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index d0dee48..70b3fad 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -20258,150 +20258,6 @@ add_location_or_const_value_attribute (dw_die_ref die, tree decl, bool cache_p)
   return tree_add_const_value_attribute_for_decl (die, decl);
 }
 
-/* Helper function for tree_add_const_value_attribute.  Natively encode
-   initializer INIT into an array.  Return true if successful.  */
-
-static bool
-native_encode_initializer (tree init, unsigned char *array, int size)
-{
-  tree type;
-
-  if (init == NULL_TREE)
-    return false;
-
-  STRIP_NOPS (init);
-  switch (TREE_CODE (init))
-    {
-    case STRING_CST:
-      type = TREE_TYPE (init);
-      if (TREE_CODE (type) == ARRAY_TYPE)
-	{
-	  tree enttype = TREE_TYPE (type);
-	  scalar_int_mode mode;
-
-	  if (!is_int_mode (TYPE_MODE (enttype), &mode)
-	      || GET_MODE_SIZE (mode) != 1)
-	    return false;
-	  if (int_size_in_bytes (type) != size)
-	    return false;
-	  if (size > TREE_STRING_LENGTH (init))
-	    {
-	      memcpy (array, TREE_STRING_POINTER (init),
-		      TREE_STRING_LENGTH (init));
-	      memset (array + TREE_STRING_LENGTH (init),
-		      '\0', size - TREE_STRING_LENGTH (init));
-	    }
-	  else
-	    memcpy (array, TREE_STRING_POINTER (init), size);
-	  return true;
-	}
-      return false;
-    case CONSTRUCTOR:
-      type = TREE_TYPE (init);
-      if (int_size_in_bytes (type) != size)
-	return false;
-      if (TREE_CODE (type) == ARRAY_TYPE)
-	{
-	  HOST_WIDE_INT min_index;
-	  unsigned HOST_WIDE_INT cnt;
-	  int curpos = 0, fieldsize;
-	  constructor_elt *ce;
-
-	  if (TYPE_DOMAIN (type) == NULL_TREE
-	      || !tree_fits_shwi_p (TYPE_MIN_VALUE (TYPE_DOMAIN (type))))
-	    return false;
-
-	  fieldsize = int_size_in_bytes (TREE_TYPE (type));
-	  if (fieldsize <= 0)
-	    return false;
-
-	  min_index = tree_to_shwi (TYPE_MIN_VALUE (TYPE_DOMAIN (type)));
-	  memset (array, '\0', size);
-	  FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (init), cnt, ce)
-	    {
-	      tree val = ce->value;
-	      tree index = ce->index;
-	      int pos = curpos;
-	      if (index && TREE_CODE (index) == RANGE_EXPR)
-		pos = (tree_to_shwi (TREE_OPERAND (index, 0)) - min_index)
-		      * fieldsize;
-	      else if (index)
-		pos = (tree_to_shwi (index) - min_index) * fieldsize;
-
-	      if (val)
-		{
-		  STRIP_NOPS (val);
-		  if (!native_encode_initializer (val, array + pos, fieldsize))
-		    return false;
-		}
-	      curpos = pos + fieldsize;
-	      if (index && TREE_CODE (index) == RANGE_EXPR)
-		{
-		  int count = tree_to_shwi (TREE_OPERAND (index, 1))
-			      - tree_to_shwi (TREE_OPERAND (index, 0));
-		  while (count-- > 0)
-		    {
-		      if (val)
-			memcpy (array + curpos, array + pos, fieldsize);
-		      curpos += fieldsize;
-		    }
-		}
-	      gcc_assert (curpos <= size);
-	    }
-	  return true;
-	}
-      else if (TREE_CODE (type) == RECORD_TYPE
-	       || TREE_CODE (type) == UNION_TYPE)
-	{
-	  tree field = NULL_TREE;
-	  unsigned HOST_WIDE_INT cnt;
-	  constructor_elt *ce;
-
-	  if (int_size_in_bytes (type) != size)
-	    return false;
-
-	  if (TREE_CODE (type) == RECORD_TYPE)
-	    field = TYPE_FIELDS (type);
-
-	  FOR_EACH_VEC_SAFE_ELT (CONSTRUCTOR_ELTS (init), cnt, ce)
-	    {
-	      tree val = ce->value;
-	      int pos, fieldsize;
-
-	      if (ce->index != 0)
-		field = ce->index;
-
-	      if (val)
-		STRIP_NOPS (val);
-
-	      if (field == NULL_TREE || DECL_BIT_FIELD (field))
-		return false;
-
-	      if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
-		  && TYPE_DOMAIN (TREE_TYPE (field))
-		  && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
-		return false;
-	      else if (DECL_SIZE_UNIT (field) == NULL_TREE
-		       || !tree_fits_shwi_p (DECL_SIZE_UNIT (field)))
-		return false;
-	      fieldsize = tree_to_shwi (DECL_SIZE_UNIT (field));
-	      pos = int_byte_position (field);
-	      gcc_assert (pos + fieldsize <= size);
-	      if (val && fieldsize != 0
-		  && !native_encode_initializer (val, array + pos, fieldsize))
-		return false;
-	    }
-	  return true;
-	}
-      return false;
-    case VIEW_CONVERT_EXPR:
-    case NON_LVALUE_EXPR:
-      return native_encode_initializer (TREE_OPERAND (init, 0), array, size);
-    default:
-      return native_encode_expr (init, array, size) == size;
-    }
-}
-
 /* Attach a DW_AT_const_value attribute to DIE. The value of the
    attribute is the const value T.  */
 
@@ -20446,7 +20302,7 @@ tree_add_const_value_attribute (dw_die_ref die, tree t)
 	{
 	  unsigned char *array = ggc_cleared_vec_alloc<unsigned char> (size);
 
-	  if (native_encode_initializer (init, array, size))
+	  if (native_encode_initializer (init, array, size) == size)
 	    {
 	      add_AT_vec (die, DW_AT_const_value, size, 1, array);
 	      return true;