in this function. */
static VEC(int,heap) *sibcall_epilogue;
\f
-/* In order to evaluate some expressions, such as function calls returning
- structures in memory, we need to temporarily allocate stack locations.
- We record each allocated temporary in the following structure.
-
- Associated with each temporary slot is a nesting level. When we pop up
- one level, all temporaries associated with the previous level are freed.
- Normally, all temporaries are freed after the execution of the statement
- in which they were created. However, if we are inside a ({...}) grouping,
- the result may be in a temporary and hence must be preserved. If the
- result could be in a temporary, we preserve it if we can determine which
- one it is in. If we cannot determine which temporary may contain the
- result, all temporaries are preserved. A temporary is preserved by
- pretending it was allocated at the previous nesting level.
-
- Automatic variables are also assigned temporary slots, at the nesting
- level where they are defined. They are marked a "kept" so that
- free_temp_slots will not free them. */
-
-struct temp_slot GTY(())
-{
- /* Points to next temporary slot. */
- struct temp_slot *next;
- /* Points to previous temporary slot. */
- struct temp_slot *prev;
-
- /* The rtx to used to reference the slot. */
- rtx slot;
- /* The rtx used to represent the address if not the address of the
- slot above. May be an EXPR_LIST if multiple addresses exist. */
- rtx address;
- /* The alignment (in bits) of the slot. */
- unsigned int align;
- /* The size, in units, of the slot. */
- HOST_WIDE_INT size;
- /* The type of the object in the slot, or zero if it doesn't correspond
- to a type. We use this to determine whether a slot can be reused.
- It can be reused if objects of the type of the new slot will always
- conflict with objects of the type of the old slot. */
- tree type;
- /* Nonzero if this temporary is currently in use. */
- char in_use;
- /* Nonzero if this temporary has its address taken. */
- char addr_taken;
- /* Nesting level at which this slot is being used. */
- int level;
- /* Nonzero if this should survive a call to free_temp_slots. */
- int keep;
- /* The offset of the slot from the frame_pointer, including extra space
- for alignment. This info is for combine_temp_slots. */
- HOST_WIDE_INT base_offset;
- /* The size of the slot, including extra space for alignment. This
- info is for combine_temp_slots. */
- HOST_WIDE_INT full_size;
-};
-\f
/* Forward declarations. */
static struct temp_slot *find_temp_slot_from_address (rtx);
return assign_stack_local_1 (mode, size, align, false);
}
\f
+\f
+/* In order to evaluate some expressions, such as function calls returning
+ structures in memory, we need to temporarily allocate stack locations.
+ We record each allocated temporary in the following structure.
+
+ Associated with each temporary slot is a nesting level. When we pop up
+ one level, all temporaries associated with the previous level are freed.
+ Normally, all temporaries are freed after the execution of the statement
+ in which they were created. However, if we are inside a ({...}) grouping,
+ the result may be in a temporary and hence must be preserved. If the
+ result could be in a temporary, we preserve it if we can determine which
+ one it is in. If we cannot determine which temporary may contain the
+ result, all temporaries are preserved. A temporary is preserved by
+ pretending it was allocated at the previous nesting level.
+
+ Automatic variables are also assigned temporary slots, at the nesting
+ level where they are defined. They are marked a "kept" so that
+ free_temp_slots will not free them. */
+
+struct temp_slot GTY(())
+{
+ /* Points to next temporary slot. */
+ struct temp_slot *next;
+ /* Points to previous temporary slot. */
+ struct temp_slot *prev;
+ /* The rtx to used to reference the slot. */
+ rtx slot;
+ /* The alignment (in bits) of the slot. */
+ unsigned int align;
+ /* The size, in units, of the slot. */
+ HOST_WIDE_INT size;
+ /* The type of the object in the slot, or zero if it doesn't correspond
+ to a type. We use this to determine whether a slot can be reused.
+ It can be reused if objects of the type of the new slot will always
+ conflict with objects of the type of the old slot. */
+ tree type;
+ /* Nonzero if this temporary is currently in use. */
+ char in_use;
+ /* Nonzero if this temporary has its address taken. */
+ char addr_taken;
+ /* Nesting level at which this slot is being used. */
+ int level;
+ /* Nonzero if this should survive a call to free_temp_slots. */
+ int keep;
+ /* The offset of the slot from the frame_pointer, including extra space
+ for alignment. This info is for combine_temp_slots. */
+ HOST_WIDE_INT base_offset;
+ /* The size of the slot, including extra space for alignment. This
+ info is for combine_temp_slots. */
+ HOST_WIDE_INT full_size;
+};
+
+/* A table of addresses that represent a stack slot. The table is a mapping
+ from address RTXen to a temp slot. */
+static GTY((param_is(struct temp_slot_address_entry))) htab_t temp_slot_address_table;
+
+/* Entry for the above hash table. */
+struct temp_slot_address_entry GTY(())
+{
+ hashval_t hash;
+ rtx address;
+ struct temp_slot *temp_slot;
+};
+
/* Removes temporary slot TEMP from LIST. */
static void
temp->in_use = 0;
temp->level = -1;
}
+
+/* Compute the hash value for an address -> temp slot mapping.
+ The value is cached on the mapping entry. */
+static hashval_t
+temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
+{
+ int do_not_record = 0;
+ return hash_rtx (t->address, GET_MODE (t->address),
+ &do_not_record, NULL, false);
+}
+
+/* Return the hash value for an address -> temp slot mapping. */
+static hashval_t
+temp_slot_address_hash (const void *p)
+{
+ const struct temp_slot_address_entry *t;
+ t = (const struct temp_slot_address_entry *) p;
+ return t->hash;
+}
+
+/* Compare two address -> temp slot mapping entries. */
+static int
+temp_slot_address_eq (const void *p1, const void *p2)
+{
+ const struct temp_slot_address_entry *t1, *t2;
+ t1 = (const struct temp_slot_address_entry *) p1;
+ t2 = (const struct temp_slot_address_entry *) p2;
+ return exp_equiv_p (t1->address, t2->address, 0, true);
+}
+
+/* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
+static void
+insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
+{
+ void **slot;
+ struct temp_slot_address_entry *t = GGC_NEW (struct temp_slot_address_entry);
+ t->address = address;
+ t->temp_slot = temp_slot;
+ t->hash = temp_slot_address_compute_hash (t);
+ slot = htab_find_slot_with_hash (temp_slot_address_table, t, t->hash, INSERT);
+ *slot = t;
+}
+
+/* Remove an address -> temp slot mapping entry if the temp slot is
+ not in use anymore. Callback for remove_unused_temp_slot_addresses. */
+static int
+remove_unused_temp_slot_addresses_1 (void **slot, void *data ATTRIBUTE_UNUSED)
+{
+ const struct temp_slot_address_entry *t;
+ t = (const struct temp_slot_address_entry *) *slot;
+ if (! t->temp_slot->in_use)
+ *slot = NULL;
+ return 1;
+}
+
+/* Remove all mappings of addresses to unused temp slots. */
+static void
+remove_unused_temp_slot_addresses (void)
+{
+ htab_traverse (temp_slot_address_table,
+ remove_unused_temp_slot_addresses_1,
+ NULL);
+}
+
+/* Find the temp slot corresponding to the object at address X. */
+
+static struct temp_slot *
+find_temp_slot_from_address (rtx x)
+{
+ struct temp_slot *p;
+ struct temp_slot_address_entry tmp, *t;
+
+ /* First try the easy way:
+ See if X exists in the address -> temp slot mapping. */
+ tmp.address = x;
+ tmp.temp_slot = NULL;
+ tmp.hash = temp_slot_address_compute_hash (&tmp);
+ t = (struct temp_slot_address_entry *)
+ htab_find_with_hash (temp_slot_address_table, &tmp, tmp.hash);
+ if (t)
+ return t->temp_slot;
+
+ /* If we have a sum involving a register, see if it points to a temp
+ slot. */
+ if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
+ && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
+ return p;
+ else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
+ && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
+ return p;
+
+ /* Last resort: Address is a virtual stack var address. */
+ if (GET_CODE (x) == PLUS
+ && XEXP (x, 0) == virtual_stack_vars_rtx
+ && GET_CODE (XEXP (x, 1)) == CONST_INT)
+ {
+ int i;
+ for (i = max_slot_level (); i >= 0; i--)
+ for (p = *temp_slots_at_level (i); p; p = p->next)
+ {
+ if (INTVAL (XEXP (x, 1)) >= p->base_offset
+ && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)
+ return p;
+ }
+ }
+
+ return NULL;
+}
\f
/* Allocate a temporary stack slot and record it for possible later
reuse.
p->full_size = best_p->full_size - rounded_size;
p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
p->align = best_p->align;
- p->address = 0;
p->type = best_p->type;
insert_slot_to_list (p, &avail_temp_slots);
p->base_offset = frame_offset_old;
p->full_size = frame_offset - frame_offset_old;
}
- p->address = 0;
selected = p;
}
pp = temp_slots_at_level (p->level);
insert_slot_to_list (p, pp);
+ insert_temp_slot_address (XEXP (p->slot, 0), p);
/* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
}
}
\f
-/* Find the temp slot corresponding to the object at address X. */
-
-static struct temp_slot *
-find_temp_slot_from_address (rtx x)
-{
- struct temp_slot *p;
- rtx next;
- int i;
-
- for (i = max_slot_level (); i >= 0; i--)
- for (p = *temp_slots_at_level (i); p; p = p->next)
- {
- if (XEXP (p->slot, 0) == x
- || p->address == x
- || (GET_CODE (x) == PLUS
- && XEXP (x, 0) == virtual_stack_vars_rtx
- && GET_CODE (XEXP (x, 1)) == CONST_INT
- && INTVAL (XEXP (x, 1)) >= p->base_offset
- && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
- return p;
-
- else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
- for (next = p->address; next; next = XEXP (next, 1))
- if (XEXP (next, 0) == x)
- return p;
- }
-
- /* If we have a sum involving a register, see if it points to a temp
- slot. */
- if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
- && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
- return p;
- else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
- && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
- return p;
-
- return 0;
-}
-
/* Indicate that NEW_RTX is an alternate way of referring to the temp
slot that previously was known by OLD_RTX. */
}
/* Otherwise add an alias for the temp's address. */
- else if (p->address == 0)
- p->address = new_rtx;
- else
- {
- if (GET_CODE (p->address) != EXPR_LIST)
- p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
-
- p->address = gen_rtx_EXPR_LIST (VOIDmode, new_rtx, p->address);
- }
+ insert_temp_slot_address (new_rtx, p);
}
/* If X could be a reference to a temporary slot, mark the fact that its
make_slot_available (p);
}
+ remove_unused_temp_slot_addresses ();
combine_temp_slots ();
}
make_slot_available (p);
}
+ remove_unused_temp_slot_addresses ();
combine_temp_slots ();
temp_slot_level--;
avail_temp_slots = 0;
used_temp_slots = 0;
temp_slot_level = 0;
+
+ /* Set up the table to map addresses to temp slots. */
+ if (! temp_slot_address_table)
+ temp_slot_address_table = htab_create_ggc (32,
+ temp_slot_address_hash,
+ temp_slot_address_eq,
+ NULL);
+ else
+ htab_empty (temp_slot_address_table);
}
\f
/* These routines are responsible for converting virtual register references
prepare_function_start (void)
{
gcc_assert (!crtl->emit.x_last_insn);
+ init_temp_slots ();
init_emit ();
init_varasm_status ();
init_expr ();
OSDN Git Service
