dwarf2out: Stop using wide_int in GC structures

The planned wide_int/widest_int changes to support larger precisions
make wide_int and widest_int unusable in GC structures, because it
has non-trivial destructors (and may point to heap allocated memory).
dwarf2out.{h,cc} is the only user of wide_int in GC structures for val_wide,
but actually doesn't really need much, all those are at one point created
from const wide_int_ref & and never changed afterwards, with just a couple
of methods used on it.

So, this patch replaces use of wide_int there with a new class, dw_wide_int,
which contains just precision, len field and the limbs in trailing array.
Most needed methods are implemented directly, just for the most complicated
cases it temporarily constructs a wide_int_ref from it and calls its methods.

2023-10-12  Jakub Jelinek  <jakub@redhat.com>

	* dwarf2out.h (wide_int_ptr): Remove.
	(dw_wide_int_ptr): New typedef.
	(struct dw_val_node): Change type of val_wide from wide_int_ptr
	to dw_wide_int_ptr.
	(struct dw_wide_int): New type.
	(dw_wide_int::elt): New method.
	(dw_wide_int::operator ==): Likewise.
	* dwarf2out.cc (get_full_len): Change argument type to
	const dw_wide_int & from const wide_int &.  Use CEIL.  Call
	get_precision method instead of calling wi::get_precision.
	(alloc_dw_wide_int): New function.
	(add_AT_wide): Change w argument type to const wide_int_ref &
	from const wide_int &.  Use alloc_dw_wide_int.
	(mem_loc_descriptor, loc_descriptor): Use alloc_dw_wide_int.
	(insert_wide_int): Change val argument type to const wide_int_ref &
	from const wide_int &.
	(add_const_value_attribute): Pass rtx_mode_t temporary directly to
	add_AT_wide instead of using a temporary variable.

1 files changed, 31 insertions, 2 deletions

diff --git a/gcc/dwarf2out.h b/gcc/dwarf2out.h
index 05ae0d7..515ea0b 100644
--- a/gcc/dwarf2out.h
+++ b/gcc/dwarf2out.h
@@ -30,7 +30,7 @@ typedef struct dw_cfi_node *dw_cfi_ref;
 typedef struct dw_loc_descr_node *dw_loc_descr_ref;
 typedef struct dw_loc_list_struct *dw_loc_list_ref;
 typedef struct dw_discr_list_node *dw_discr_list_ref;
-typedef wide_int *wide_int_ptr;
+typedef struct dw_wide_int *dw_wide_int_ptr;
 
 
 /* Call frames are described using a sequence of Call Frame
@@ -252,7 +252,7 @@ struct GTY(()) dw_val_node {
       unsigned HOST_WIDE_INT
 	GTY ((tag ("dw_val_class_unsigned_const"))) val_unsigned;
       double_int GTY ((tag ("dw_val_class_const_double"))) val_double;
-      wide_int_ptr GTY ((tag ("dw_val_class_wide_int"))) val_wide;
+      dw_wide_int_ptr GTY ((tag ("dw_val_class_wide_int"))) val_wide;
       dw_vec_const GTY ((tag ("dw_val_class_vec"))) val_vec;
       struct dw_val_die_union
 	{
@@ -313,6 +313,35 @@ struct GTY(()) dw_discr_list_node {
   int dw_discr_range;
 };
 
+struct GTY((variable_size)) dw_wide_int {
+  unsigned int precision;
+  unsigned int len;
+  HOST_WIDE_INT val[1];
+
+  unsigned int get_precision () const { return precision; }
+  unsigned int get_len () const { return len; }
+  const HOST_WIDE_INT *get_val () const { return val; }
+  inline HOST_WIDE_INT elt (unsigned int) const;
+  inline bool operator == (const dw_wide_int &) const;
+};
+
+inline HOST_WIDE_INT
+dw_wide_int::elt (unsigned int i) const
+{
+  if (i < len)
+    return val[i];
+  wide_int_ref ref = wi::storage_ref (val, len, precision);
+  return wi::sign_mask (ref);
+}
+
+inline bool
+dw_wide_int::operator == (const dw_wide_int &o) const
+{
+  wide_int_ref ref1 = wi::storage_ref (val, len, precision);
+  wide_int_ref ref2 = wi::storage_ref (o.val, o.len, o.precision);
+  return ref1 == ref2;
+}
+
 /* Interface from dwarf2out.cc to dwarf2cfi.cc.  */
 extern struct dw_loc_descr_node *build_cfa_loc
   (dw_cfa_location *, poly_int64);