PR100281 C++: Fix SImode pointer handling

The problem appears to be triggered by two locations in the front-end
where non-POINTER_SIZE pointers aren't handled right now.

1. An assertion in strip_typedefs is triggered because the alignment
of the types don't match. This in turn is caused by creating the new
type with build_pointer_type instead of taking the type of the
original pointer into account.

2. An assertion in cp_convert_to_pointer is triggered which expects
the target type to always have POINTER_SIZE.

gcc/cp/ChangeLog:

	PR c++/100281
	* cvt.c (cp_convert_to_pointer): Use the size of the target
	pointer type.
	* tree.c (cp_build_reference_type): Call
	cp_build_reference_type_for_mode with VOIDmode.
	(cp_build_reference_type_for_mode): Rename from
	cp_build_reference_type.  Add MODE argument and invoke
	build_reference_type_for_mode.
	(strip_typedefs): Use build_pointer_type_for_mode and
	cp_build_reference_type_for_mode for pointers and references.

gcc/ChangeLog:

	PR c++/100281
	* tree.c (build_reference_type_for_mode)
	(build_pointer_type_for_mode): Pick pointer mode if MODE argument
	is VOIDmode.
	(build_reference_type, build_pointer_type): Invoke
	build_*_type_for_mode with VOIDmode.

gcc/testsuite/ChangeLog:

	PR c++/100281
	* g++.target/s390/pr100281-1.C: New test.
	* g++.target/s390/pr100281-2.C: New test.

1 files changed, 18 insertions, 11 deletions

diff --git a/gcc/tree.c b/gcc/tree.c
index 8afba59..31ac424 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -6792,9 +6792,10 @@ operation_no_trapping_overflow (tree type, enum tree_code code)
    constructed by language-dependent code, not here.)  */
 
 /* Construct, lay out and return the type of pointers to TO_TYPE with
-   mode MODE.  If CAN_ALIAS_ALL is TRUE, indicate this type can
-   reference all of memory. If such a type has already been
-   constructed, reuse it.  */
+   mode MODE.  If MODE is VOIDmode, a pointer mode for the address
+   space of TO_TYPE will be picked.  If CAN_ALIAS_ALL is TRUE,
+   indicate this type can reference all of memory. If such a type has
+   already been constructed, reuse it.  */
 
 tree
 build_pointer_type_for_mode (tree to_type, machine_mode mode,
@@ -6806,6 +6807,12 @@ build_pointer_type_for_mode (tree to_type, machine_mode mode,
   if (to_type == error_mark_node)
     return error_mark_node;
 
+  if (mode == VOIDmode)
+    {
+      addr_space_t as = TYPE_ADDR_SPACE (to_type);
+      mode = targetm.addr_space.pointer_mode (as);
+    }
+
   /* If the pointed-to type has the may_alias attribute set, force
      a TYPE_REF_CAN_ALIAS_ALL pointer to be generated.  */
   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (to_type)))
@@ -6857,10 +6864,7 @@ build_pointer_type_for_mode (tree to_type, machine_mode mode,
 tree
 build_pointer_type (tree to_type)
 {
-  addr_space_t as = to_type == error_mark_node? ADDR_SPACE_GENERIC
-					      : TYPE_ADDR_SPACE (to_type);
-  machine_mode pointer_mode = targetm.addr_space.pointer_mode (as);
-  return build_pointer_type_for_mode (to_type, pointer_mode, false);
+  return build_pointer_type_for_mode (to_type, VOIDmode, false);
 }
 
 /* Same as build_pointer_type_for_mode, but for REFERENCE_TYPE.  */
@@ -6875,6 +6879,12 @@ build_reference_type_for_mode (tree to_type, machine_mode mode,
   if (to_type == error_mark_node)
     return error_mark_node;
 
+  if (mode == VOIDmode)
+    {
+      addr_space_t as = TYPE_ADDR_SPACE (to_type);
+      mode = targetm.addr_space.pointer_mode (as);
+    }
+
   /* If the pointed-to type has the may_alias attribute set, force
      a TYPE_REF_CAN_ALIAS_ALL pointer to be generated.  */
   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (to_type)))
@@ -6926,10 +6936,7 @@ build_reference_type_for_mode (tree to_type, machine_mode mode,
 tree
 build_reference_type (tree to_type)
 {
-  addr_space_t as = to_type == error_mark_node? ADDR_SPACE_GENERIC
-					      : TYPE_ADDR_SPACE (to_type);
-  machine_mode pointer_mode = targetm.addr_space.pointer_mode (as);
-  return build_reference_type_for_mode (to_type, pointer_mode, false);
+  return build_reference_type_for_mode (to_type, VOIDmode, false);
 }
 
 #define MAX_INT_CACHED_PREC \