Hi!
On Tue, Oct 10, 2023 at 09:30:31AM +0000, Richard Biener wrote:
> On Mon, 9 Oct 2023, Jakub Jelinek wrote:
> > > This makes wide_int unusable in GC structures, so for dwarf2out
> > > which was the only place which needed it there is a new rwide_int type
> > > (restricted wide_int) which supports only up to RWIDE_INT_MAX_ELTS limbs
> > > inline and is trivially copyable (dwarf2out should never deal with large
> > > _BitInt constants, those should have been lowered earlier).
> >
> > As discussed on IRC, the dwarf2out.{h,cc} needs are actually quite limited,
> > it just needs to allocate new GC structures val_wide points to (constructed
> > from some const wide_int_ref &) and needs to call operator==,
> > get_precision, elt, get_len and get_val methods on it.
> > Even trailing_wide_int would be overkill for that, the following just adds
> > a new struct with precision/len and trailing val array members and
> > implements the needed methods (only 2 of them using wide_int_ref constructed
> > from those).
> >
> > Incremental patch, so far compile time tested only:
>
> LGTM, wonder if we can push this separately as prerequesite?
Here it is as a separate independent patch. Even without the
wide_int changing patch it should save some memory, by not always
allocating room for 9 limbs, but say just the 2/3 or how many we actually
need. And, another advantage is that if we really need it at some point,
it could support even more than 9 limbs if it is created from a wide_int_ref
with get_len () > 9.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2023-10-10 Jakub Jelinek <ja...@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.
--- gcc/dwarf2out.h.jj 2023-10-09 14:37:45.890939965 +0200
+++ gcc/dwarf2out.h 2023-10-09 16:46:14.705816928 +0200
@@ -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);
--- gcc/dwarf2out.cc.jj 2023-10-09 14:37:45.894939909 +0200
+++ gcc/dwarf2out.cc 2023-10-09 16:48:24.565014459 +0200
@@ -397,11 +397,9 @@ dump_struct_debug (tree type, enum debug
of the number. */
static unsigned int
-get_full_len (const wide_int &op)
+get_full_len (const dw_wide_int &op)
{
- int prec = wi::get_precision (op);
- return ((prec + HOST_BITS_PER_WIDE_INT - 1)
- / HOST_BITS_PER_WIDE_INT);
+ return CEIL (op.get_precision (), HOST_BITS_PER_WIDE_INT);
}
static bool
@@ -3900,7 +3898,7 @@ static void add_data_member_location_att
struct vlr_context *);
static bool add_const_value_attribute (dw_die_ref, machine_mode, rtx);
static void insert_int (HOST_WIDE_INT, unsigned, unsigned char *);
-static void insert_wide_int (const wide_int &, unsigned char *, int);
+static void insert_wide_int (const wide_int_ref &, unsigned char *, int);
static unsigned insert_float (const_rtx, unsigned char *);
static rtx rtl_for_decl_location (tree);
static bool add_location_or_const_value_attribute (dw_die_ref, tree, bool);
@@ -4594,19 +4592,31 @@ AT_unsigned (dw_attr_node *a)
return a->dw_attr_val.v.val_unsigned;
}
+dw_wide_int *
+alloc_dw_wide_int (const wide_int_ref &w)
+{
+ dw_wide_int *p
+ = (dw_wide_int *) ggc_internal_alloc (sizeof (dw_wide_int)
+ + ((w.get_len () - 1)
+ * sizeof (HOST_WIDE_INT)));
+ p->precision = w.get_precision ();
+ p->len = w.get_len ();
+ memcpy (p->val, w.get_val (), p->len * sizeof (HOST_WIDE_INT));
+ return p;
+}
+
/* Add an unsigned wide integer attribute value to a DIE. */
static inline void
add_AT_wide (dw_die_ref die, enum dwarf_attribute attr_kind,
- const wide_int& w)
+ const wide_int_ref &w)
{
dw_attr_node attr;
attr.dw_attr = attr_kind;
attr.dw_attr_val.val_class = dw_val_class_wide_int;
attr.dw_attr_val.val_entry = NULL;
- attr.dw_attr_val.v.val_wide = ggc_alloc<wide_int> ();
- *attr.dw_attr_val.v.val_wide = w;
+ attr.dw_attr_val.v.val_wide = alloc_dw_wide_int (w);
add_dwarf_attr (die, &attr);
}
@@ -16714,8 +16724,8 @@ mem_loc_descriptor (rtx rtl, machine_mod
mem_loc_result->dw_loc_oprnd1.v.val_die_ref.external = 0;
mem_loc_result->dw_loc_oprnd2.val_class
= dw_val_class_wide_int;
- mem_loc_result->dw_loc_oprnd2.v.val_wide = ggc_alloc<wide_int> ();
- *mem_loc_result->dw_loc_oprnd2.v.val_wide = rtx_mode_t (rtl, mode);
+ mem_loc_result->dw_loc_oprnd2.v.val_wide
+ = alloc_dw_wide_int (rtx_mode_t (rtl, mode));
}
break;
@@ -17288,8 +17298,8 @@ loc_descriptor (rtx rtl, machine_mode mo
loc_result = new_loc_descr (DW_OP_implicit_value,
GET_MODE_SIZE (int_mode), 0);
loc_result->dw_loc_oprnd2.val_class = dw_val_class_wide_int;
- loc_result->dw_loc_oprnd2.v.val_wide = ggc_alloc<wide_int> ();
- *loc_result->dw_loc_oprnd2.v.val_wide = rtx_mode_t (rtl, int_mode);
+ loc_result->dw_loc_oprnd2.v.val_wide
+ = alloc_dw_wide_int (rtx_mode_t (rtl, int_mode));
}
break;
@@ -20189,7 +20199,7 @@ extract_int (const unsigned char *src, u
/* Writes wide_int values to dw_vec_const array. */
static void
-insert_wide_int (const wide_int &val, unsigned char *dest, int elt_size)
+insert_wide_int (const wide_int_ref &val, unsigned char *dest, int elt_size)
{
int i;
@@ -20274,8 +20284,7 @@ add_const_value_attribute (dw_die_ref di
&& (GET_MODE_PRECISION (int_mode)
& (HOST_BITS_PER_WIDE_INT - 1)) == 0)
{
- wide_int w = rtx_mode_t (rtl, int_mode);
- add_AT_wide (die, DW_AT_const_value, w);
+ add_AT_wide (die, DW_AT_const_value, rtx_mode_t (rtl, int_mode));
return true;
}
return false;
Jakub
