* uintp.h (UI_Lt): Declare.

	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Array_Type>: Do the size
	computation in sizetype.
	<E_Array_Subtype>: Use unified handling for all index types.  Do not
	generate MAX_EXPR-based expressions, only COND_EXPR-based ones.  Add
	bypass for PATs.
	(annotate_value): Change test for negative values.
	(validate_size): Apply test for negative values on GNAT nodes.
	(set_rm_size): Likewise.
	* gcc-interface/misc.c (gnat_init): Set unsigned types for sizetypes.
	* gcc-interface/utils.c (rest_of_record_type_compilation): Change test
	for negative values.
	(max_size) <MINUS_EXPR>: Do not reassociate a COND_EXPR on the LHS.
	(builtin_type_for_size): Adjust definition of signed_size_type_node.
	* gcc-interface/utils2.c (compare_arrays): Optimize comparison of
	lengths against zero.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158466 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 7 deletions

diff --git a/gcc/ada/gcc-interface/misc.c b/gcc/ada/gcc-interface/misc.c
index f3e7b1b74827..6923105afa24 100644
--- a/gcc/ada/gcc-interface/misc.c
+++ b/gcc/ada/gcc-interface/misc.c
@@ -391,13 +391,16 @@ gnat_init (void)
   /* Do little here, most of the standard declarations are set up after the
      front-end has been run.  Use the same `char' as C, this doesn't really
      matter since we'll use the explicit `unsigned char' for Character.  */
-  build_common_tree_nodes (flag_signed_char, true);
-
-  /* In Ada, we use a signed type for SIZETYPE.  Use the signed type
-     corresponding to the width of Pmode.  In most cases when ptr_mode
-     and Pmode differ, C will use the width of ptr_mode for SIZETYPE.
-     But we get far better code using the width of Pmode.  */
-  size_type_node = gnat_type_for_mode (Pmode, 0);
+  build_common_tree_nodes (flag_signed_char, false);
+
+  /* In Ada, we use the unsigned type corresponding to the width of Pmode as
+     SIZETYPE.  In most cases when ptr_mode and Pmode differ, C will use the
+     width of ptr_mode for SIZETYPE, but we get better code using the width
+     of Pmode.  Note that, although we manipulate negative offsets for some
+     internal constructs and rely on compile time overflow detection in size
+     computations, using unsigned types for SIZETYPEs is fine since they are
+     treated specially by the middle-end, in particular sign-extended.  */
+  size_type_node = gnat_type_for_mode (Pmode, 1);
   set_sizetype (size_type_node);
   TYPE_NAME (sizetype) = get_identifier ("size_type");