d: Force TYPE_MODE of classes and non-POD structs as BLKmode

Without this being forced, the optimizer could still make decisions that
require objects of the non-POD types to need a temporary, which would
result in an ICE during the expand to RTL passes.

gcc/d/ChangeLog:

	PR d/98427
	* types.cc (TypeVisitor::visit (TypeStruct *)): Set TYPE_MODE of all
	non-trivial types as BLKmode.
	(TypeVisitor::visit (TypeClass *)): Likewise.

gcc/testsuite/ChangeLog:

	PR d/98427
	* gdc.dg/pr98427.d: New test.

2 files changed, 31 insertions, 2 deletions

diff --git a/gcc/d/types.cc b/gcc/d/types.cc
index 94aa1f6..acb8c40 100644
--- a/gcc/d/types.cc
+++ b/gcc/d/types.cc
@@ -964,7 +964,10 @@ public:
     if (!t->sym->isPOD ())
       {
 	for (tree tv = t->ctype; tv != NULL_TREE; tv = TYPE_NEXT_VARIANT (tv))
-	  TREE_ADDRESSABLE (tv) = 1;
+	  {
+	    TREE_ADDRESSABLE (tv) = 1;
+	    SET_TYPE_MODE (tv, BLKmode);
+	  }
       }
   }
 
@@ -999,7 +1002,10 @@ public:
 
     /* Classes only live in memory, so always set the TREE_ADDRESSABLE bit.  */
     for (tree tv = basetype; tv != NULL_TREE; tv = TYPE_NEXT_VARIANT (tv))
-      TREE_ADDRESSABLE (tv) = 1;
+      {
+	TREE_ADDRESSABLE (tv) = 1;
+	SET_TYPE_MODE (tv, BLKmode);
+      }
 
     /* Type is final, there are no derivations.  */
     if (t->sym->storage_class & STCfinal)
diff --git a/gcc/testsuite/gdc.dg/pr98427.d b/gcc/testsuite/gdc.dg/pr98427.d
new file mode 100644
index 0000000..225db8b
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/pr98427.d
@@ -0,0 +1,23 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98427
+// { dg-do compile }
+// { dg-options "-O2 -fno-inline" }
+
+@trusted memoizeExpr()
+{
+    struct CodepointSet
+    {
+        struct CowArray
+        {
+            uint *ptr;
+        }
+
+        const CodepointSet binary(U)(U rhs)
+        {
+            return rhs;
+        }
+
+        CowArray array;
+    }
+
+    CodepointSet().binary(CodepointSet());
+}