> I suggest to re-instantiate the canonical type checks for the aggregate type
> case.
OK, thanks, this fixes all the known ICEs so far.
Tested on x86_64-suse-linux, OK for the mainline?
2015-11-03 Eric Botcazou <ebotca...@adacore.com>
* gimple-expr.c (useless_type_conversion_p): Reinstate type canonical
check for aggregate types and beef up comment for mode check.
2015-11-03 Eric Botcazou <ebotca...@adacore.com>
* gnat.dg/discr45.adb: Only compile the test.
--
Eric Botcazou
Index: gimple-expr.c
===================================================================
--- gimple-expr.c (revision 229616)
+++ gimple-expr.c (working copy)
@@ -84,7 +84,15 @@ useless_type_conversion_p (tree outer_ty
if (inner_type == outer_type)
return true;
- /* Changes in machine mode are never useless conversions unless. */
+ /* For aggregate types, if we know the canonical types, compare them. This
+ is important for the remapping of variably-modified types. */
+ if (AGGREGATE_TYPE_P (inner_type)
+ && TYPE_CANONICAL (inner_type)
+ && TYPE_CANONICAL (inner_type) == TYPE_CANONICAL (outer_type))
+ return true;
+
+ /* Changes in machine mode are never useless conversions because the RTL
+ middle-end expects explicit conversions between modes. */
if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type))
return false;
Index: testsuite/gnat.dg/discr45.adb
===================================================================
--- testsuite/gnat.dg/discr45.adb (revision 229630)
+++ testsuite/gnat.dg/discr45.adb (working copy)
@@ -1,4 +1,4 @@
--- { dg-do run }
+-- { dg-do compile }
-- { dg-options "-O2 -gnatws" }
procedure Discr45 is
