Only on head of list */
const char *section; /* Section this loclist is relative to */
dw_loc_descr_ref expr;
+ hashval_t hash;
+ bool emitted;
} dw_loc_list_node;
static dw_loc_descr_ref int_loc_descriptor (HOST_WIDE_INT);
{
dw_loc_list_ref curr = list_head;
+ if (list_head->emitted)
+ return;
+ list_head->emitted = true;
+
ASM_OUTPUT_LABEL (asm_out_file, list_head->ll_symbol);
/* Walk the location list, and output each range + expression. */
FOR_EACH_CHILD (die, c, resolve_addr (c));
}
+\f
+/* Helper routines for optimize_location_lists.
+ This pass tries to share identical local lists in .debug_loc
+ section. */
+
+/* Iteratively hash operands of LOC opcode. */
+
+static inline hashval_t
+hash_loc_operands (dw_loc_descr_ref loc, hashval_t hash)
+{
+ dw_val_ref val1 = &loc->dw_loc_oprnd1;
+ dw_val_ref val2 = &loc->dw_loc_oprnd2;
+
+ switch (loc->dw_loc_opc)
+ {
+ case DW_OP_const4u:
+ case DW_OP_const8u:
+ if (loc->dtprel)
+ goto hash_addr;
+ /* FALLTHRU */
+ case DW_OP_const1u:
+ case DW_OP_const1s:
+ case DW_OP_const2u:
+ case DW_OP_const2s:
+ case DW_OP_const4s:
+ case DW_OP_const8s:
+ case DW_OP_constu:
+ case DW_OP_consts:
+ case DW_OP_pick:
+ case DW_OP_plus_uconst:
+ case DW_OP_breg0:
+ case DW_OP_breg1:
+ case DW_OP_breg2:
+ case DW_OP_breg3:
+ case DW_OP_breg4:
+ case DW_OP_breg5:
+ case DW_OP_breg6:
+ case DW_OP_breg7:
+ case DW_OP_breg8:
+ case DW_OP_breg9:
+ case DW_OP_breg10:
+ case DW_OP_breg11:
+ case DW_OP_breg12:
+ case DW_OP_breg13:
+ case DW_OP_breg14:
+ case DW_OP_breg15:
+ case DW_OP_breg16:
+ case DW_OP_breg17:
+ case DW_OP_breg18:
+ case DW_OP_breg19:
+ case DW_OP_breg20:
+ case DW_OP_breg21:
+ case DW_OP_breg22:
+ case DW_OP_breg23:
+ case DW_OP_breg24:
+ case DW_OP_breg25:
+ case DW_OP_breg26:
+ case DW_OP_breg27:
+ case DW_OP_breg28:
+ case DW_OP_breg29:
+ case DW_OP_breg30:
+ case DW_OP_breg31:
+ case DW_OP_regx:
+ case DW_OP_fbreg:
+ case DW_OP_piece:
+ case DW_OP_deref_size:
+ case DW_OP_xderef_size:
+ hash = iterative_hash_object (val1->v.val_int, hash);
+ break;
+ case DW_OP_skip:
+ case DW_OP_bra:
+ {
+ int offset;
+
+ gcc_assert (val1->val_class == dw_val_class_loc);
+ offset = val1->v.val_loc->dw_loc_addr - (loc->dw_loc_addr + 3);
+ hash = iterative_hash_object (offset, hash);
+ }
+ break;
+ case DW_OP_implicit_value:
+ hash = iterative_hash_object (val1->v.val_unsigned, hash);
+ switch (val2->val_class)
+ {
+ case dw_val_class_const:
+ hash = iterative_hash_object (val2->v.val_int, hash);
+ break;
+ case dw_val_class_vec:
+ {
+ unsigned int elt_size = val2->v.val_vec.elt_size;
+ unsigned int len = val2->v.val_vec.length;
+
+ hash = iterative_hash_object (elt_size, hash);
+ hash = iterative_hash_object (len, hash);
+ hash = iterative_hash (val2->v.val_vec.array,
+ len * elt_size, hash);
+ }
+ break;
+ case dw_val_class_const_double:
+ hash = iterative_hash_object (val2->v.val_double.low, hash);
+ hash = iterative_hash_object (val2->v.val_double.high, hash);
+ break;
+ case dw_val_class_addr:
+ hash = iterative_hash_rtx (val2->v.val_addr, hash);
+ break;
+ default:
+ gcc_unreachable ();
+ }
+ break;
+ case DW_OP_bregx:
+ case DW_OP_bit_piece:
+ hash = iterative_hash_object (val1->v.val_int, hash);
+ hash = iterative_hash_object (val2->v.val_int, hash);
+ break;
+ case DW_OP_addr:
+ hash_addr:
+ if (loc->dtprel)
+ {
+ unsigned char dtprel = 0xd1;
+ hash = iterative_hash_object (dtprel, hash);
+ }
+ hash = iterative_hash_rtx (val1->v.val_addr, hash);
+ break;
+ case DW_OP_GNU_implicit_pointer:
+ hash = iterative_hash_object (val2->v.val_int, hash);
+ break;
+
+ default:
+ /* Other codes have no operands. */
+ break;
+ }
+ return hash;
+}
+
+/* Iteratively hash the whole DWARF location expression LOC. */
+static inline hashval_t
+hash_locs (dw_loc_descr_ref loc, hashval_t hash)
+{
+ dw_loc_descr_ref l;
+ bool sizes_computed = false;
+ /* Compute sizes, so that DW_OP_skip/DW_OP_bra can be checksummed. */
+ size_of_locs (loc);
+
+ for (l = loc; l != NULL; l = l->dw_loc_next)
+ {
+ enum dwarf_location_atom opc = l->dw_loc_opc;
+ hash = iterative_hash_object (opc, hash);
+ if ((opc == DW_OP_skip || opc == DW_OP_bra) && !sizes_computed)
+ {
+ size_of_locs (loc);
+ sizes_computed = true;
+ }
+ hash = hash_loc_operands (l, hash);
+ }
+ return hash;
+}
+
+/* Compute hash of the whole location list LIST_HEAD. */
+
+static inline void
+hash_loc_list (dw_loc_list_ref list_head)
+{
+ dw_loc_list_ref curr = list_head;
+ hashval_t hash = 0;
+
+ for (curr = list_head; curr != NULL; curr = curr->dw_loc_next)
+ {
+ hash = iterative_hash (curr->begin, strlen (curr->begin) + 1, hash);
+ hash = iterative_hash (curr->end, strlen (curr->end) + 1, hash);
+ if (curr->section)
+ hash = iterative_hash (curr->section, strlen (curr->section) + 1,
+ hash);
+ hash = hash_locs (curr->expr, hash);
+ }
+ list_head->hash = hash;
+}
+
+/* Return true if X and Y opcodes have the same operands. */
+
+static inline bool
+compare_loc_operands (dw_loc_descr_ref x, dw_loc_descr_ref y)
+{
+ dw_val_ref valx1 = &x->dw_loc_oprnd1;
+ dw_val_ref valx2 = &x->dw_loc_oprnd2;
+ dw_val_ref valy1 = &y->dw_loc_oprnd1;
+ dw_val_ref valy2 = &y->dw_loc_oprnd2;
+
+ switch (x->dw_loc_opc)
+ {
+ case DW_OP_const4u:
+ case DW_OP_const8u:
+ if (x->dtprel)
+ goto hash_addr;
+ /* FALLTHRU */
+ case DW_OP_const1u:
+ case DW_OP_const1s:
+ case DW_OP_const2u:
+ case DW_OP_const2s:
+ case DW_OP_const4s:
+ case DW_OP_const8s:
+ case DW_OP_constu:
+ case DW_OP_consts:
+ case DW_OP_pick:
+ case DW_OP_plus_uconst:
+ case DW_OP_breg0:
+ case DW_OP_breg1:
+ case DW_OP_breg2:
+ case DW_OP_breg3:
+ case DW_OP_breg4:
+ case DW_OP_breg5:
+ case DW_OP_breg6:
+ case DW_OP_breg7:
+ case DW_OP_breg8:
+ case DW_OP_breg9:
+ case DW_OP_breg10:
+ case DW_OP_breg11:
+ case DW_OP_breg12:
+ case DW_OP_breg13:
+ case DW_OP_breg14:
+ case DW_OP_breg15:
+ case DW_OP_breg16:
+ case DW_OP_breg17:
+ case DW_OP_breg18:
+ case DW_OP_breg19:
+ case DW_OP_breg20:
+ case DW_OP_breg21:
+ case DW_OP_breg22:
+ case DW_OP_breg23:
+ case DW_OP_breg24:
+ case DW_OP_breg25:
+ case DW_OP_breg26:
+ case DW_OP_breg27:
+ case DW_OP_breg28:
+ case DW_OP_breg29:
+ case DW_OP_breg30:
+ case DW_OP_breg31:
+ case DW_OP_regx:
+ case DW_OP_fbreg:
+ case DW_OP_piece:
+ case DW_OP_deref_size:
+ case DW_OP_xderef_size:
+ return valx1->v.val_int == valy1->v.val_int;
+ case DW_OP_skip:
+ case DW_OP_bra:
+ gcc_assert (valx1->val_class == dw_val_class_loc
+ && valy1->val_class == dw_val_class_loc
+ && x->dw_loc_addr == y->dw_loc_addr);
+ return valx1->v.val_loc->dw_loc_addr == valy1->v.val_loc->dw_loc_addr;
+ case DW_OP_implicit_value:
+ if (valx1->v.val_unsigned != valy1->v.val_unsigned
+ || valx2->val_class != valy2->val_class)
+ return false;
+ switch (valx2->val_class)
+ {
+ case dw_val_class_const:
+ return valx2->v.val_int == valy2->v.val_int;
+ case dw_val_class_vec:
+ return valx2->v.val_vec.elt_size == valy2->v.val_vec.elt_size
+ && valx2->v.val_vec.length == valy2->v.val_vec.length
+ && memcmp (valx2->v.val_vec.array, valy2->v.val_vec.array,
+ valx2->v.val_vec.elt_size
+ * valx2->v.val_vec.length) == 0;
+ case dw_val_class_const_double:
+ return valx2->v.val_double.low == valy2->v.val_double.low
+ && valx2->v.val_double.high == valy2->v.val_double.high;
+ case dw_val_class_addr:
+ return rtx_equal_p (valx2->v.val_addr, valy2->v.val_addr);
+ default:
+ gcc_unreachable ();
+ }
+ case DW_OP_bregx:
+ case DW_OP_bit_piece:
+ return valx1->v.val_int == valy1->v.val_int
+ && valx2->v.val_int == valy2->v.val_int;
+ case DW_OP_addr:
+ hash_addr:
+ return rtx_equal_p (valx1->v.val_addr, valx2->v.val_addr);
+ case DW_OP_GNU_implicit_pointer:
+ return valx1->val_class == dw_val_class_die_ref
+ && valx1->val_class == valy1->val_class
+ && valx1->v.val_die_ref.die == valy1->v.val_die_ref.die
+ && valx2->v.val_int == valy2->v.val_int;
+ default:
+ /* Other codes have no operands. */
+ return true;
+ }
+}
+
+/* Return true if DWARF location expressions X and Y are the same. */
+
+static inline bool
+compare_locs (dw_loc_descr_ref x, dw_loc_descr_ref y)
+{
+ for (; x != NULL && y != NULL; x = x->dw_loc_next, y = y->dw_loc_next)
+ if (x->dw_loc_opc != y->dw_loc_opc
+ || x->dtprel != y->dtprel
+ || !compare_loc_operands (x, y))
+ break;
+ return x == NULL && y == NULL;
+}
+
+/* Return precomputed hash of location list X. */
+
+static hashval_t
+loc_list_hash (const void *x)
+{
+ return ((const struct dw_loc_list_struct *) x)->hash;
+}
+
+/* Return 1 if location lists X and Y are the same. */
+
+static int
+loc_list_eq (const void *x, const void *y)
+{
+ const struct dw_loc_list_struct *a = (const struct dw_loc_list_struct *) x;
+ const struct dw_loc_list_struct *b = (const struct dw_loc_list_struct *) y;
+ if (a == b)
+ return 1;
+ if (a->hash != b->hash)
+ return 0;
+ for (; a != NULL && b != NULL; a = a->dw_loc_next, b = b->dw_loc_next)
+ if (strcmp (a->begin, b->begin) != 0
+ || strcmp (a->end, b->end) != 0
+ || (a->section == NULL) != (b->section == NULL)
+ || (a->section && strcmp (a->section, b->section) != 0)
+ || !compare_locs (a->expr, b->expr))
+ break;
+ return a == NULL && b == NULL;
+}
+
+/* Recursively optimize location lists referenced from DIE
+ children and share them whenever possible. */
+
+static void
+optimize_location_lists_1 (dw_die_ref die, htab_t htab)
+{
+ dw_die_ref c;
+ dw_attr_ref a;
+ unsigned ix;
+ void **slot;
+
+ FOR_EACH_VEC_ELT (dw_attr_node, die->die_attr, ix, a)
+ if (AT_class (a) == dw_val_class_loc_list)
+ {
+ dw_loc_list_ref list = AT_loc_list (a);
+ /* TODO: perform some optimizations here, before hashing
+ it and storing into the hash table. */
+ hash_loc_list (list);
+ slot = htab_find_slot_with_hash (htab, list, list->hash,
+ INSERT);
+ if (*slot == NULL)
+ *slot = (void *) list;
+ else
+ a->dw_attr_val.v.val_loc_list = (dw_loc_list_ref) *slot;
+ }
+
+ FOR_EACH_CHILD (die, c, optimize_location_lists_1 (c, htab));
+}
+
+/* Optimize location lists referenced from DIE
+ children and share them whenever possible. */
+
+static void
+optimize_location_lists (dw_die_ref die)
+{
+ htab_t htab = htab_create (500, loc_list_hash, loc_list_eq, NULL);
+ optimize_location_lists_1 (die, htab);
+ htab_delete (htab);
+}
+\f
/* Output stuff that dwarf requires at the end of every file,
and generate the DWARF-2 debugging info. */
if (debug_info_level >= DINFO_LEVEL_VERBOSE)
add_AT_macptr (comp_unit_die (), DW_AT_macro_info, macinfo_section_label);
+ if (have_location_lists)
+ optimize_location_lists (die);
+
/* Output all of the compilation units. We put the main one last so that
the offsets are available to output_pubnames. */
for (node = limbo_die_list; node; node = node->next)
projects / thirdparty / gcc.git / commitdiff
