/* Common subexpression elimination library for GNU compiler.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
-GNU CC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
-#include <setjmp.h>
+#include "coretypes.h"
+#include "tm.h"
#include "rtl.h"
#include "tm_p.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "flags.h"
-#include "real.h"
#include "insn-config.h"
#include "recog.h"
#include "function.h"
-#include "expr.h"
+#include "emit-rtl.h"
+#include "diagnostic-core.h"
#include "toplev.h"
#include "output.h"
#include "ggc.h"
-#include "obstack.h"
#include "hashtab.h"
+#include "tree-pass.h"
#include "cselib.h"
+#include "params.h"
+#include "alloc-pool.h"
+#include "target.h"
+#include "bitmap.h"
+
+static bool cselib_record_memory;
+static bool cselib_preserve_constants;
+static int entry_and_rtx_equal_p (const void *, const void *);
+static hashval_t get_value_hash (const void *);
+static struct elt_list *new_elt_list (struct elt_list *, cselib_val *);
+static struct elt_loc_list *new_elt_loc_list (struct elt_loc_list *, rtx);
+static void unchain_one_value (cselib_val *);
+static void unchain_one_elt_list (struct elt_list **);
+static void unchain_one_elt_loc_list (struct elt_loc_list **);
+static int discard_useless_locs (void **, void *);
+static int discard_useless_values (void **, void *);
+static void remove_useless_values (void);
+static unsigned int cselib_hash_rtx (rtx, int);
+static cselib_val *new_cselib_val (unsigned int, enum machine_mode, rtx);
+static void add_mem_for_addr (cselib_val *, cselib_val *, rtx);
+static cselib_val *cselib_lookup_mem (rtx, int);
+static void cselib_invalidate_regno (unsigned int, enum machine_mode);
+static void cselib_invalidate_mem (rtx);
+static void cselib_record_set (rtx, cselib_val *, cselib_val *);
+static void cselib_record_sets (rtx);
+
+struct expand_value_data
+{
+ bitmap regs_active;
+ cselib_expand_callback callback;
+ void *callback_arg;
+ bool dummy;
+};
-static int entry_and_rtx_equal_p PARAMS ((const void *, const void *));
-static unsigned int get_value_hash PARAMS ((const void *));
-static struct elt_list *new_elt_list PARAMS ((struct elt_list *,
- cselib_val *));
-static struct elt_loc_list *new_elt_loc_list PARAMS ((struct elt_loc_list *,
- rtx));
-static void unchain_one_value PARAMS ((cselib_val *));
-static void unchain_one_elt_list PARAMS ((struct elt_list **));
-static void unchain_one_elt_loc_list PARAMS ((struct elt_loc_list **));
-static void clear_table PARAMS ((int));
-static int discard_useless_locs PARAMS ((void **, void *));
-static int discard_useless_values PARAMS ((void **, void *));
-static void remove_useless_values PARAMS ((void));
-static rtx wrap_constant PARAMS ((enum machine_mode, rtx));
-static unsigned int hash_rtx PARAMS ((rtx, enum machine_mode, int));
-static cselib_val *new_cselib_val PARAMS ((unsigned int,
- enum machine_mode));
-static void add_mem_for_addr PARAMS ((cselib_val *, cselib_val *,
- rtx));
-static cselib_val *cselib_lookup_mem PARAMS ((rtx, int));
-static rtx cselib_subst_to_values PARAMS ((rtx));
-static void cselib_invalidate_regno PARAMS ((unsigned int,
- enum machine_mode));
-static int cselib_mem_conflict_p PARAMS ((rtx, rtx));
-static int cselib_invalidate_mem_1 PARAMS ((void **, void *));
-static void cselib_invalidate_mem PARAMS ((rtx));
-static void cselib_invalidate_rtx PARAMS ((rtx, rtx, void *));
-static void cselib_record_set PARAMS ((rtx, cselib_val *,
- cselib_val *));
-static void cselib_record_sets PARAMS ((rtx));
+static rtx cselib_expand_value_rtx_1 (rtx, struct expand_value_data *, int);
/* There are three ways in which cselib can look up an rtx:
- for a REG, the reg_values table (which is indexed by regno) is used
the locations of the entries with the rtx we are looking up. */
/* A table that enables us to look up elts by their value. */
-static htab_t hash_table;
+static htab_t cselib_hash_table;
/* This is a global so we don't have to pass this through every function.
It is used in new_elt_loc_list to set SETTING_INSN. */
static rtx cselib_current_insn;
-/* Every new unknown value gets a unique number. */
-static unsigned int next_unknown_value;
+/* The unique id that the next create value will take. */
+static unsigned int next_uid;
/* The number of registers we had when the varrays were last resized. */
static unsigned int cselib_nregs;
-/* Count values without known locations. Whenever this grows too big, we
- remove these useless values from the table. */
+/* Count values without known locations, or with only locations that
+ wouldn't have been known except for debug insns. Whenever this
+ grows too big, we remove these useless values from the table.
+
+ Counting values with only debug values is a bit tricky. We don't
+ want to increment n_useless_values when we create a value for a
+ debug insn, for this would get n_useless_values out of sync, but we
+ want increment it if all locs in the list that were ever referenced
+ in nondebug insns are removed from the list.
+
+ In the general case, once we do that, we'd have to stop accepting
+ nondebug expressions in the loc list, to avoid having two values
+ equivalent that, without debug insns, would have been made into
+ separate values. However, because debug insns never introduce
+ equivalences themselves (no assignments), the only means for
+ growing loc lists is through nondebug assignments. If the locs
+ also happen to be referenced in debug insns, it will work just fine.
+
+ A consequence of this is that there's at most one debug-only loc in
+ each loc list. If we keep it in the first entry, testing whether
+ we have a debug-only loc list takes O(1).
+
+ Furthermore, since any additional entry in a loc list containing a
+ debug loc would have to come from an assignment (nondebug) that
+ references both the initial debug loc and the newly-equivalent loc,
+ the initial debug loc would be promoted to a nondebug loc, and the
+ loc list would not contain debug locs any more.
+
+ So the only case we have to be careful with in order to keep
+ n_useless_values in sync between debug and nondebug compilations is
+ to avoid incrementing n_useless_values when removing the single loc
+ from a value that turns out to not appear outside debug values. We
+ increment n_useless_debug_values instead, and leave such values
+ alone until, for other reasons, we garbage-collect useless
+ values. */
static int n_useless_values;
+static int n_useless_debug_values;
+
+/* Count values whose locs have been taken exclusively from debug
+ insns for the entire life of the value. */
+static int n_debug_values;
/* Number of useless values before we remove them from the hash table. */
#define MAX_USELESS_VALUES 32
-/* This table maps from register number to values. It does not contain
- pointers to cselib_val structures, but rather elt_lists. The purpose is
- to be able to refer to the same register in different modes. */
-static varray_type reg_values;
-#define REG_VALUES(I) VARRAY_ELT_LIST (reg_values, (I))
+/* This table maps from register number to values. It does not
+ contain pointers to cselib_val structures, but rather elt_lists.
+ The purpose is to be able to refer to the same register in
+ different modes. The first element of the list defines the mode in
+ which the register was set; if the mode is unknown or the value is
+ no longer valid in that mode, ELT will be NULL for the first
+ element. */
+static struct elt_list **reg_values;
+static unsigned int reg_values_size;
+#define REG_VALUES(i) reg_values[i]
+
+/* The largest number of hard regs used by any entry added to the
+ REG_VALUES table. Cleared on each cselib_clear_table() invocation. */
+static unsigned int max_value_regs;
/* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used
- in clear_table() for fast emptying. */
-static varray_type used_regs;
+ in cselib_clear_table() for fast emptying. */
+static unsigned int *used_regs;
+static unsigned int n_used_regs;
/* We pass this to cselib_invalidate_mem to invalidate all of
memory for a non-const call instruction. */
-static rtx callmem;
-
-/* Memory for our structures is allocated from this obstack. */
-static struct obstack cselib_obstack;
-
-/* Used to quickly free all memory. */
-static char *cselib_startobj;
-
-/* Caches for unused structures. */
-static cselib_val *empty_vals;
-static struct elt_list *empty_elt_lists;
-static struct elt_loc_list *empty_elt_loc_lists;
+static GTY(()) rtx callmem;
/* Set by discard_useless_locs if it deleted the last location of any
value. */
static int values_became_useless;
+
+/* Used as stop element of the containing_mem list so we can check
+ presence in the list by checking the next pointer. */
+static cselib_val dummy_val;
+
+/* If non-NULL, value of the eliminated arg_pointer_rtx or frame_pointer_rtx
+ that is constant through the whole function and should never be
+ eliminated. */
+static cselib_val *cfa_base_preserved_val;
+static unsigned int cfa_base_preserved_regno;
+
+/* Used to list all values that contain memory reference.
+ May or may not contain the useless values - the list is compacted
+ each time memory is invalidated. */
+static cselib_val *first_containing_mem = &dummy_val;
+static alloc_pool elt_loc_list_pool, elt_list_pool, cselib_val_pool, value_pool;
+
+/* If nonnull, cselib will call this function before freeing useless
+ VALUEs. A VALUE is deemed useless if its "locs" field is null. */
+void (*cselib_discard_hook) (cselib_val *);
+
+/* If nonnull, cselib will call this function before recording sets or
+ even clobbering outputs of INSN. All the recorded sets will be
+ represented in the array sets[n_sets]. new_val_min can be used to
+ tell whether values present in sets are introduced by this
+ instruction. */
+void (*cselib_record_sets_hook) (rtx insn, struct cselib_set *sets,
+ int n_sets);
+
+#define PRESERVED_VALUE_P(RTX) \
+ (RTL_FLAG_CHECK1("PRESERVED_VALUE_P", (RTX), VALUE)->unchanging)
+
\f
/* Allocate a struct elt_list and fill in its two elements with the
arguments. */
-static struct elt_list *
-new_elt_list (next, elt)
- struct elt_list *next;
- cselib_val *elt;
+static inline struct elt_list *
+new_elt_list (struct elt_list *next, cselib_val *elt)
{
- struct elt_list *el = empty_elt_lists;
-
- if (el)
- empty_elt_lists = el->next;
- else
- el = (struct elt_list *) obstack_alloc (&cselib_obstack,
- sizeof (struct elt_list));
+ struct elt_list *el;
+ el = (struct elt_list *) pool_alloc (elt_list_pool);
el->next = next;
el->elt = elt;
return el;
/* Allocate a struct elt_loc_list and fill in its two elements with the
arguments. */
-static struct elt_loc_list *
-new_elt_loc_list (next, loc)
- struct elt_loc_list *next;
- rtx loc;
+static inline struct elt_loc_list *
+new_elt_loc_list (struct elt_loc_list *next, rtx loc)
{
- struct elt_loc_list *el = empty_elt_loc_lists;
-
- if (el)
- empty_elt_loc_lists = el->next;
- else
- el = (struct elt_loc_list *) obstack_alloc (&cselib_obstack,
- sizeof (struct elt_loc_list));
+ struct elt_loc_list *el;
+ el = (struct elt_loc_list *) pool_alloc (elt_loc_list_pool);
el->next = next;
el->loc = loc;
el->setting_insn = cselib_current_insn;
+ gcc_assert (!next || !next->setting_insn
+ || !DEBUG_INSN_P (next->setting_insn));
+
+ /* If we're creating the first loc in a debug insn context, we've
+ just created a debug value. Count it. */
+ if (!next && cselib_current_insn && DEBUG_INSN_P (cselib_current_insn))
+ n_debug_values++;
+
return el;
}
+/* Promote loc L to a nondebug cselib_current_insn if L is marked as
+ originating from a debug insn, maintaining the debug values
+ count. */
+
+static inline void
+promote_debug_loc (struct elt_loc_list *l)
+{
+ if (l->setting_insn && DEBUG_INSN_P (l->setting_insn)
+ && (!cselib_current_insn || !DEBUG_INSN_P (cselib_current_insn)))
+ {
+ n_debug_values--;
+ l->setting_insn = cselib_current_insn;
+ gcc_assert (!l->next);
+ }
+}
+
/* The elt_list at *PL is no longer needed. Unchain it and free its
storage. */
-static void
-unchain_one_elt_list (pl)
- struct elt_list **pl;
+static inline void
+unchain_one_elt_list (struct elt_list **pl)
{
struct elt_list *l = *pl;
*pl = l->next;
- l->next = empty_elt_lists;
- empty_elt_lists = l;
+ pool_free (elt_list_pool, l);
}
/* Likewise for elt_loc_lists. */
static void
-unchain_one_elt_loc_list (pl)
- struct elt_loc_list **pl;
+unchain_one_elt_loc_list (struct elt_loc_list **pl)
{
struct elt_loc_list *l = *pl;
*pl = l->next;
- l->next = empty_elt_loc_lists;
- empty_elt_loc_lists = l;
+ pool_free (elt_loc_list_pool, l);
}
/* Likewise for cselib_vals. This also frees the addr_list associated with
V. */
static void
-unchain_one_value (v)
- cselib_val *v;
+unchain_one_value (cselib_val *v)
{
while (v->addr_list)
unchain_one_elt_list (&v->addr_list);
- v->u.next_free = empty_vals;
- empty_vals = v;
+ pool_free (cselib_val_pool, v);
}
/* Remove all entries from the hash table. Also used during
- initialization. If CLEAR_ALL isn't set, then only clear the entries
- which are known to have been used. */
+ initialization. */
-static void
-clear_table (clear_all)
- int clear_all;
+void
+cselib_clear_table (void)
+{
+ cselib_reset_table (1);
+}
+
+/* Remove from hash table all VALUEs except constants. */
+
+static int
+preserve_only_constants (void **x, void *info ATTRIBUTE_UNUSED)
+{
+ cselib_val *v = (cselib_val *)*x;
+
+ if (v->locs != NULL
+ && v->locs->next == NULL)
+ {
+ if (CONSTANT_P (v->locs->loc)
+ && (GET_CODE (v->locs->loc) != CONST
+ || !references_value_p (v->locs->loc, 0)))
+ return 1;
+ if (cfa_base_preserved_val)
+ {
+ if (v == cfa_base_preserved_val)
+ return 1;
+ if (GET_CODE (v->locs->loc) == PLUS
+ && CONST_INT_P (XEXP (v->locs->loc, 1))
+ && XEXP (v->locs->loc, 0) == cfa_base_preserved_val->val_rtx)
+ return 1;
+ }
+ }
+
+ htab_clear_slot (cselib_hash_table, x);
+ return 1;
+}
+
+/* Remove all entries from the hash table, arranging for the next
+ value to be numbered NUM. */
+
+void
+cselib_reset_table (unsigned int num)
{
unsigned int i;
- if (clear_all)
- for (i = 0; i < cselib_nregs; i++)
- REG_VALUES (i) = 0;
- else
- for (i = 0; i < VARRAY_ACTIVE_SIZE (used_regs); i++)
- REG_VALUES (VARRAY_UINT (used_regs, i)) = 0;
+ max_value_regs = 0;
- VARRAY_POP_ALL (used_regs);
+ if (cfa_base_preserved_val)
+ {
+ unsigned int regno = cfa_base_preserved_regno;
+ unsigned int new_used_regs = 0;
+ for (i = 0; i < n_used_regs; i++)
+ if (used_regs[i] == regno)
+ {
+ new_used_regs = 1;
+ continue;
+ }
+ else
+ REG_VALUES (used_regs[i]) = 0;
+ gcc_assert (new_used_regs == 1);
+ n_used_regs = new_used_regs;
+ used_regs[0] = regno;
+ max_value_regs
+ = hard_regno_nregs[regno][GET_MODE (cfa_base_preserved_val->locs->loc)];
+ }
+ else
+ {
+ for (i = 0; i < n_used_regs; i++)
+ REG_VALUES (used_regs[i]) = 0;
+ n_used_regs = 0;
+ }
- htab_empty (hash_table);
- obstack_free (&cselib_obstack, cselib_startobj);
+ if (cselib_preserve_constants)
+ htab_traverse (cselib_hash_table, preserve_only_constants, NULL);
+ else
+ htab_empty (cselib_hash_table);
- empty_vals = 0;
- empty_elt_lists = 0;
- empty_elt_loc_lists = 0;
n_useless_values = 0;
+ n_useless_debug_values = 0;
+ n_debug_values = 0;
+
+ next_uid = num;
+
+ first_containing_mem = &dummy_val;
+}
+
+/* Return the number of the next value that will be generated. */
- next_unknown_value = 0;
+unsigned int
+cselib_get_next_uid (void)
+{
+ return next_uid;
}
/* The equality test for our hash table. The first argument ENTRY is a table
CONST of an appropriate mode. */
static int
-entry_and_rtx_equal_p (entry, x_arg)
- const void *entry, *x_arg;
+entry_and_rtx_equal_p (const void *entry, const void *x_arg)
{
struct elt_loc_list *l;
- const cselib_val *v = (const cselib_val *) entry;
- rtx x = (rtx) x_arg;
+ const cselib_val *const v = (const cselib_val *) entry;
+ rtx x = CONST_CAST_RTX ((const_rtx)x_arg);
enum machine_mode mode = GET_MODE (x);
- if (GET_CODE (x) == CONST_INT
- || (mode == VOIDmode && GET_CODE (x) == CONST_DOUBLE))
- abort ();
- if (mode != GET_MODE (v->u.val_rtx))
+ gcc_assert (!CONST_INT_P (x) && GET_CODE (x) != CONST_FIXED
+ && (mode != VOIDmode || GET_CODE (x) != CONST_DOUBLE));
+
+ if (mode != GET_MODE (v->val_rtx))
return 0;
/* Unwrap X if necessary. */
if (GET_CODE (x) == CONST
- && (GET_CODE (XEXP (x, 0)) == CONST_INT
+ && (CONST_INT_P (XEXP (x, 0))
+ || GET_CODE (XEXP (x, 0)) == CONST_FIXED
|| GET_CODE (XEXP (x, 0)) == CONST_DOUBLE))
x = XEXP (x, 0);
-
+
/* We don't guarantee that distinct rtx's have different hash values,
so we need to do a comparison. */
for (l = v->locs; l; l = l->next)
if (rtx_equal_for_cselib_p (l->loc, x))
- return 1;
+ {
+ promote_debug_loc (l);
+ return 1;
+ }
return 0;
}
/* The hash function for our hash table. The value is always computed with
- hash_rtx when adding an element; this function just extracts the hash
- value from a cselib_val structure. */
+ cselib_hash_rtx when adding an element; this function just extracts the
+ hash value from a cselib_val structure. */
-static unsigned int
-get_value_hash (entry)
- const void *entry;
+static hashval_t
+get_value_hash (const void *entry)
{
- const cselib_val *v = (const cselib_val *) entry;
- return v->value;
+ const cselib_val *const v = (const cselib_val *) entry;
+ return v->hash;
}
/* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we
removed. */
int
-references_value_p (x, only_useless)
- rtx x;
- int only_useless;
+references_value_p (const_rtx x, int only_useless)
{
- enum rtx_code code = GET_CODE (x);
+ const enum rtx_code code = GET_CODE (x);
const char *fmt = GET_RTX_FORMAT (code);
int i, j;
htab_traverse. */
static int
-discard_useless_locs (x, info)
- void **x;
- void *info ATTRIBUTE_UNUSED;
+discard_useless_locs (void **x, void *info ATTRIBUTE_UNUSED)
{
cselib_val *v = (cselib_val *)*x;
struct elt_loc_list **p = &v->locs;
- int had_locs = v->locs != 0;
+ bool had_locs = v->locs != NULL;
+ rtx setting_insn = v->locs ? v->locs->setting_insn : NULL;
while (*p)
{
p = &(*p)->next;
}
- if (had_locs && v->locs == 0)
+ if (had_locs && v->locs == 0 && !PRESERVED_VALUE_P (v->val_rtx))
{
- n_useless_values++;
+ if (setting_insn && DEBUG_INSN_P (setting_insn))
+ n_useless_debug_values++;
+ else
+ n_useless_values++;
values_became_useless = 1;
}
return 1;
/* If X is a value with no locations, remove it from the hashtable. */
static int
-discard_useless_values (x, info)
- void **x;
- void *info ATTRIBUTE_UNUSED;
+discard_useless_values (void **x, void *info ATTRIBUTE_UNUSED)
{
cselib_val *v = (cselib_val *)*x;
- if (v->locs == 0)
+ if (v->locs == 0 && !PRESERVED_VALUE_P (v->val_rtx))
{
- htab_clear_slot (hash_table, x);
+ if (cselib_discard_hook)
+ cselib_discard_hook (v);
+
+ CSELIB_VAL_PTR (v->val_rtx) = NULL;
+ htab_clear_slot (cselib_hash_table, x);
unchain_one_value (v);
n_useless_values--;
}
associated with them) from the hash table. */
static void
-remove_useless_values ()
+remove_useless_values (void)
{
+ cselib_val **p, *v;
+
/* First pass: eliminate locations that reference the value. That in
turn can make more values useless. */
do
{
values_became_useless = 0;
- htab_traverse (hash_table, discard_useless_locs, 0);
+ htab_traverse (cselib_hash_table, discard_useless_locs, 0);
}
while (values_became_useless);
/* Second pass: actually remove the values. */
- htab_traverse (hash_table, discard_useless_values, 0);
- if (n_useless_values != 0)
- abort ();
+ p = &first_containing_mem;
+ for (v = *p; v != &dummy_val; v = v->next_containing_mem)
+ if (v->locs)
+ {
+ *p = v;
+ p = &(*p)->next_containing_mem;
+ }
+ *p = &dummy_val;
+
+ n_useless_values += n_useless_debug_values;
+ n_debug_values -= n_useless_debug_values;
+ n_useless_debug_values = 0;
+
+ htab_traverse (cselib_hash_table, discard_useless_values, 0);
+
+ gcc_assert (!n_useless_values);
+}
+
+/* Arrange for a value to not be removed from the hash table even if
+ it becomes useless. */
+
+void
+cselib_preserve_value (cselib_val *v)
+{
+ PRESERVED_VALUE_P (v->val_rtx) = 1;
+}
+
+/* Test whether a value is preserved. */
+
+bool
+cselib_preserved_value_p (cselib_val *v)
+{
+ return PRESERVED_VALUE_P (v->val_rtx);
+}
+
+/* Arrange for a REG value to be assumed constant through the whole function,
+ never invalidated and preserved across cselib_reset_table calls. */
+
+void
+cselib_preserve_cfa_base_value (cselib_val *v, unsigned int regno)
+{
+ if (cselib_preserve_constants
+ && v->locs
+ && REG_P (v->locs->loc))
+ {
+ cfa_base_preserved_val = v;
+ cfa_base_preserved_regno = regno;
+ }
+}
+
+/* Clean all non-constant expressions in the hash table, but retain
+ their values. */
+
+void
+cselib_preserve_only_values (void)
+{
+ int i;
+
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ cselib_invalidate_regno (i, reg_raw_mode[i]);
+
+ cselib_invalidate_mem (callmem);
+
+ remove_useless_values ();
+
+ gcc_assert (first_containing_mem == &dummy_val);
+}
+
+/* Return the mode in which a register was last set. If X is not a
+ register, return its mode. If the mode in which the register was
+ set is not known, or the value was already clobbered, return
+ VOIDmode. */
+
+enum machine_mode
+cselib_reg_set_mode (const_rtx x)
+{
+ if (!REG_P (x))
+ return GET_MODE (x);
+
+ if (REG_VALUES (REGNO (x)) == NULL
+ || REG_VALUES (REGNO (x))->elt == NULL)
+ return VOIDmode;
+
+ return GET_MODE (REG_VALUES (REGNO (x))->elt->val_rtx);
}
/* Return nonzero if we can prove that X and Y contain the same value, taking
our gathered information into account. */
int
-rtx_equal_for_cselib_p (x, y)
- rtx x, y;
+rtx_equal_for_cselib_p (rtx x, rtx y)
{
enum rtx_code code;
const char *fmt;
int i;
-
- if (GET_CODE (x) == REG || GET_CODE (x) == MEM)
+
+ if (REG_P (x) || MEM_P (x))
{
cselib_val *e = cselib_lookup (x, GET_MODE (x), 0);
if (e)
- x = e->u.val_rtx;
+ x = e->val_rtx;
}
- if (GET_CODE (y) == REG || GET_CODE (y) == MEM)
+ if (REG_P (y) || MEM_P (y))
{
cselib_val *e = cselib_lookup (y, GET_MODE (y), 0);
if (e)
- y = e->u.val_rtx;
+ y = e->val_rtx;
}
if (x == y)
rtx t = l->loc;
/* Avoid infinite recursion. */
- if (GET_CODE (t) == REG || GET_CODE (t) == MEM)
+ if (REG_P (t) || MEM_P (t))
continue;
else if (rtx_equal_for_cselib_p (t, y))
return 1;
}
-
+
return 0;
}
{
rtx t = l->loc;
- if (GET_CODE (t) == REG || GET_CODE (t) == MEM)
+ if (REG_P (t) || MEM_P (t))
continue;
else if (rtx_equal_for_cselib_p (x, t))
return 1;
}
-
+
return 0;
}
if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y))
return 0;
- /* This won't be handled correctly by the code below. */
- if (GET_CODE (x) == LABEL_REF)
- return XEXP (x, 0) == XEXP (y, 0);
-
+ /* These won't be handled correctly by the code below. */
+ switch (GET_CODE (x))
+ {
+ case CONST_DOUBLE:
+ case CONST_FIXED:
+ case DEBUG_EXPR:
+ return 0;
+
+ case DEBUG_IMPLICIT_PTR:
+ return DEBUG_IMPLICIT_PTR_DECL (x)
+ == DEBUG_IMPLICIT_PTR_DECL (y);
+
+ case LABEL_REF:
+ return XEXP (x, 0) == XEXP (y, 0);
+
+ default:
+ break;
+ }
+
code = GET_CODE (x);
fmt = GET_RTX_FORMAT (code);
break;
case 'e':
+ if (i == 1
+ && targetm.commutative_p (x, UNKNOWN)
+ && rtx_equal_for_cselib_p (XEXP (x, 1), XEXP (y, 0))
+ && rtx_equal_for_cselib_p (XEXP (x, 0), XEXP (y, 1)))
+ return 1;
if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i)))
return 0;
break;
contain anything but integers and other rtx's,
except for within LABEL_REFs and SYMBOL_REFs. */
default:
- abort ();
+ gcc_unreachable ();
}
}
return 1;
functions. For that purpose, wrap them in a CONST of the appropriate
mode. */
static rtx
-wrap_constant (mode, x)
- enum machine_mode mode;
- rtx x;
+wrap_constant (enum machine_mode mode, rtx x)
{
- if (GET_CODE (x) != CONST_INT
+ if (!CONST_INT_P (x) && GET_CODE (x) != CONST_FIXED
&& (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode))
return x;
- if (mode == VOIDmode)
- abort ();
+ gcc_assert (mode != VOIDmode);
return gen_rtx_CONST (mode, x);
}
Possible reasons for return 0 are: the object is volatile, or we couldn't
find a register or memory location in the table and CREATE is zero. If
CREATE is nonzero, table elts are created for regs and mem.
- MODE is used in hashing for CONST_INTs only;
- otherwise the mode of X is used. */
+ N.B. this hash function returns the same hash value for RTXes that
+ differ only in the order of operands, thus it is suitable for comparisons
+ that take commutativity into account.
+ If we wanted to also support associative rules, we'd have to use a different
+ strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
+ We used to have a MODE argument for hashing for CONST_INTs, but that
+ didn't make sense, since it caused spurious hash differences between
+ (set (reg:SI 1) (const_int))
+ (plus:SI (reg:SI 2) (reg:SI 1))
+ and
+ (plus:SI (reg:SI 2) (const_int))
+ If the mode is important in any context, it must be checked specifically
+ in a comparison anyway, since relying on hash differences is unsafe. */
static unsigned int
-hash_rtx (x, mode, create)
- rtx x;
- enum machine_mode mode;
- int create;
+cselib_hash_rtx (rtx x, int create)
{
cselib_val *e;
int i, j;
if (! e)
return 0;
- return e->value;
+ return e->hash;
+
+ case DEBUG_EXPR:
+ hash += ((unsigned) DEBUG_EXPR << 7)
+ + DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (x));
+ return hash ? hash : (unsigned int) DEBUG_EXPR;
+
+ case DEBUG_IMPLICIT_PTR:
+ hash += ((unsigned) DEBUG_IMPLICIT_PTR << 7)
+ + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x));
+ return hash ? hash : (unsigned int) DEBUG_IMPLICIT_PTR;
case CONST_INT:
- hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + INTVAL (x);
+ hash += ((unsigned) CONST_INT << 7) + INTVAL (x);
return hash ? hash : (unsigned int) CONST_INT;
case CONST_DOUBLE:
the integers representing the constant. */
hash += (unsigned) code + (unsigned) GET_MODE (x);
if (GET_MODE (x) != VOIDmode)
- for (i = 2; i < GET_RTX_LENGTH (CONST_DOUBLE); i++)
- hash += XWINT (x, i);
+ hash += real_hash (CONST_DOUBLE_REAL_VALUE (x));
else
hash += ((unsigned) CONST_DOUBLE_LOW (x)
+ (unsigned) CONST_DOUBLE_HIGH (x));
return hash ? hash : (unsigned int) CONST_DOUBLE;
+ case CONST_FIXED:
+ hash += (unsigned int) code + (unsigned int) GET_MODE (x);
+ hash += fixed_hash (CONST_FIXED_VALUE (x));
+ return hash ? hash : (unsigned int) CONST_FIXED;
+
+ case CONST_VECTOR:
+ {
+ int units;
+ rtx elt;
+
+ units = CONST_VECTOR_NUNITS (x);
+
+ for (i = 0; i < units; ++i)
+ {
+ elt = CONST_VECTOR_ELT (x, i);
+ hash += cselib_hash_rtx (elt, 0);
+ }
+
+ return hash;
+ }
+
/* Assume there is only one rtx object for any given label. */
case LABEL_REF:
- hash
- += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0);
+ /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
+ differences and differences between each stage's debugging dumps. */
+ hash += (((unsigned int) LABEL_REF << 7)
+ + CODE_LABEL_NUMBER (XEXP (x, 0)));
return hash ? hash : (unsigned int) LABEL_REF;
case SYMBOL_REF:
- hash
- += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0);
- return hash ? hash : (unsigned int) SYMBOL_REF;
+ {
+ /* Don't hash on the symbol's address to avoid bootstrap differences.
+ Different hash values may cause expressions to be recorded in
+ different orders and thus different registers to be used in the
+ final assembler. This also avoids differences in the dump files
+ between various stages. */
+ unsigned int h = 0;
+ const unsigned char *p = (const unsigned char *) XSTR (x, 0);
+
+ while (*p)
+ h += (h << 7) + *p++; /* ??? revisit */
+
+ hash += ((unsigned int) SYMBOL_REF << 7) + h;
+ return hash ? hash : (unsigned int) SYMBOL_REF;
+ }
case PRE_DEC:
case PRE_INC:
return 0;
break;
-
+
default:
break;
}
fmt = GET_RTX_FORMAT (code);
for (; i >= 0; i--)
{
- if (fmt[i] == 'e')
+ switch (fmt[i])
{
- rtx tem = XEXP (x, i);
- unsigned int tem_hash = hash_rtx (tem, 0, create);
-
- if (tem_hash == 0)
- return 0;
-
- hash += tem_hash;
- }
- else if (fmt[i] == 'E')
- for (j = 0; j < XVECLEN (x, i); j++)
+ case 'e':
{
- unsigned int tem_hash = hash_rtx (XVECEXP (x, i, j), 0, create);
+ rtx tem = XEXP (x, i);
+ unsigned int tem_hash = cselib_hash_rtx (tem, create);
if (tem_hash == 0)
return 0;
hash += tem_hash;
}
- else if (fmt[i] == 's')
- {
- const unsigned char *p = (const unsigned char *) XSTR (x, i);
+ break;
+ case 'E':
+ for (j = 0; j < XVECLEN (x, i); j++)
+ {
+ unsigned int tem_hash
+ = cselib_hash_rtx (XVECEXP (x, i, j), create);
+
+ if (tem_hash == 0)
+ return 0;
+
+ hash += tem_hash;
+ }
+ break;
+
+ case 's':
+ {
+ const unsigned char *p = (const unsigned char *) XSTR (x, i);
+
+ if (p)
+ while (*p)
+ hash += *p++;
+ break;
+ }
+
+ case 'i':
+ hash += XINT (x, i);
+ break;
+
+ case '0':
+ case 't':
+ /* unused */
+ break;
- if (p)
- while (*p)
- hash += *p++;
+ default:
+ gcc_unreachable ();
}
- else if (fmt[i] == 'i')
- hash += XINT (x, i);
- else if (fmt[i] == '0' || fmt[i] == 't')
- /* unused */;
- else
- abort ();
}
return hash ? hash : 1 + (unsigned int) GET_CODE (x);
/* Create a new value structure for VALUE and initialize it. The mode of the
value is MODE. */
-static cselib_val *
-new_cselib_val (value, mode)
- unsigned int value;
- enum machine_mode mode;
+static inline cselib_val *
+new_cselib_val (unsigned int hash, enum machine_mode mode, rtx x)
{
- cselib_val *e = empty_vals;
-
- if (e)
- empty_vals = e->u.next_free;
- else
- e = (cselib_val *) obstack_alloc (&cselib_obstack, sizeof (cselib_val));
-
- if (value == 0)
- abort ();
-
- e->value = value;
- e->u.val_rtx = gen_rtx_VALUE (mode);
- CSELIB_VAL_PTR (e->u.val_rtx) = e;
+ cselib_val *e = (cselib_val *) pool_alloc (cselib_val_pool);
+
+ gcc_assert (hash);
+ gcc_assert (next_uid);
+
+ e->hash = hash;
+ e->uid = next_uid++;
+ /* We use an alloc pool to allocate this RTL construct because it
+ accounts for about 8% of the overall memory usage. We know
+ precisely when we can have VALUE RTXen (when cselib is active)
+ so we don't need to put them in garbage collected memory.
+ ??? Why should a VALUE be an RTX in the first place? */
+ e->val_rtx = (rtx) pool_alloc (value_pool);
+ memset (e->val_rtx, 0, RTX_HDR_SIZE);
+ PUT_CODE (e->val_rtx, VALUE);
+ PUT_MODE (e->val_rtx, mode);
+ CSELIB_VAL_PTR (e->val_rtx) = e;
e->addr_list = 0;
e->locs = 0;
+ e->next_containing_mem = 0;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "cselib value %u:%u ", e->uid, hash);
+ if (flag_dump_noaddr || flag_dump_unnumbered)
+ fputs ("# ", dump_file);
+ else
+ fprintf (dump_file, "%p ", (void*)e);
+ print_rtl_single (dump_file, x);
+ fputc ('\n', dump_file);
+ }
+
return e;
}
value. Update the two value structures to represent this situation. */
static void
-add_mem_for_addr (addr_elt, mem_elt, x)
- cselib_val *addr_elt, *mem_elt;
- rtx x;
+add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x)
{
struct elt_loc_list *l;
/* Avoid duplicates. */
for (l = mem_elt->locs; l; l = l->next)
- if (GET_CODE (l->loc) == MEM
+ if (MEM_P (l->loc)
&& CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt)
- return;
+ {
+ promote_debug_loc (l);
+ return;
+ }
addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt);
mem_elt->locs
= new_elt_loc_list (mem_elt->locs,
- replace_equiv_address_nv (x, addr_elt->u.val_rtx));
+ replace_equiv_address_nv (x, addr_elt->val_rtx));
+ if (mem_elt->next_containing_mem == NULL)
+ {
+ mem_elt->next_containing_mem = first_containing_mem;
+ first_containing_mem = mem_elt;
+ }
}
/* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx.
If CREATE, make a new one if we haven't seen it before. */
static cselib_val *
-cselib_lookup_mem (x, create)
- rtx x;
- int create;
+cselib_lookup_mem (rtx x, int create)
{
enum machine_mode mode = GET_MODE (x);
void **slot;
struct elt_list *l;
if (MEM_VOLATILE_P (x) || mode == BLKmode
+ || !cselib_record_memory
|| (FLOAT_MODE_P (mode) && flag_float_store))
return 0;
/* Find a value that describes a value of our mode at that address. */
for (l = addr->addr_list; l; l = l->next)
- if (GET_MODE (l->elt->u.val_rtx) == mode)
- return l->elt;
+ if (GET_MODE (l->elt->val_rtx) == mode)
+ {
+ promote_debug_loc (l->elt->locs);
+ return l->elt;
+ }
if (! create)
return 0;
- mem_elt = new_cselib_val (++next_unknown_value, mode);
+ mem_elt = new_cselib_val (next_uid, mode, x);
add_mem_for_addr (addr, mem_elt, x);
- slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x),
- mem_elt->value, INSERT);
+ slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
+ mem_elt->hash, INSERT);
*slot = mem_elt;
return mem_elt;
}
+/* Search thru the possible substitutions in P. We prefer a non reg
+ substitution because this allows us to expand the tree further. If
+ we find, just a reg, take the lowest regno. There may be several
+ non-reg results, we just take the first one because they will all
+ expand to the same place. */
+
+static rtx
+expand_loc (struct elt_loc_list *p, struct expand_value_data *evd,
+ int max_depth)
+{
+ rtx reg_result = NULL;
+ unsigned int regno = UINT_MAX;
+ struct elt_loc_list *p_in = p;
+
+ for (; p; p = p -> next)
+ {
+ /* Avoid infinite recursion trying to expand a reg into a
+ the same reg. */
+ if ((REG_P (p->loc))
+ && (REGNO (p->loc) < regno)
+ && !bitmap_bit_p (evd->regs_active, REGNO (p->loc)))
+ {
+ reg_result = p->loc;
+ regno = REGNO (p->loc);
+ }
+ /* Avoid infinite recursion and do not try to expand the
+ value. */
+ else if (GET_CODE (p->loc) == VALUE
+ && CSELIB_VAL_PTR (p->loc)->locs == p_in)
+ continue;
+ else if (!REG_P (p->loc))
+ {
+ rtx result, note;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ print_inline_rtx (dump_file, p->loc, 0);
+ fprintf (dump_file, "\n");
+ }
+ if (GET_CODE (p->loc) == LO_SUM
+ && GET_CODE (XEXP (p->loc, 1)) == SYMBOL_REF
+ && p->setting_insn
+ && (note = find_reg_note (p->setting_insn, REG_EQUAL, NULL_RTX))
+ && XEXP (note, 0) == XEXP (p->loc, 1))
+ return XEXP (p->loc, 1);
+ result = cselib_expand_value_rtx_1 (p->loc, evd, max_depth - 1);
+ if (result)
+ return result;
+ }
+
+ }
+
+ if (regno != UINT_MAX)
+ {
+ rtx result;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "r%d\n", regno);
+
+ result = cselib_expand_value_rtx_1 (reg_result, evd, max_depth - 1);
+ if (result)
+ return result;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ if (reg_result)
+ {
+ print_inline_rtx (dump_file, reg_result, 0);
+ fprintf (dump_file, "\n");
+ }
+ else
+ fprintf (dump_file, "NULL\n");
+ }
+ return reg_result;
+}
+
+
+/* Forward substitute and expand an expression out to its roots.
+ This is the opposite of common subexpression. Because local value
+ numbering is such a weak optimization, the expanded expression is
+ pretty much unique (not from a pointer equals point of view but
+ from a tree shape point of view.
+
+ This function returns NULL if the expansion fails. The expansion
+ will fail if there is no value number for one of the operands or if
+ one of the operands has been overwritten between the current insn
+ and the beginning of the basic block. For instance x has no
+ expansion in:
+
+ r1 <- r1 + 3
+ x <- r1 + 8
+
+ REGS_ACTIVE is a scratch bitmap that should be clear when passing in.
+ It is clear on return. */
+
+rtx
+cselib_expand_value_rtx (rtx orig, bitmap regs_active, int max_depth)
+{
+ struct expand_value_data evd;
+
+ evd.regs_active = regs_active;
+ evd.callback = NULL;
+ evd.callback_arg = NULL;
+ evd.dummy = false;
+
+ return cselib_expand_value_rtx_1 (orig, &evd, max_depth);
+}
+
+/* Same as cselib_expand_value_rtx, but using a callback to try to
+ resolve some expressions. The CB function should return ORIG if it
+ can't or does not want to deal with a certain RTX. Any other
+ return value, including NULL, will be used as the expansion for
+ VALUE, without any further changes. */
+
+rtx
+cselib_expand_value_rtx_cb (rtx orig, bitmap regs_active, int max_depth,
+ cselib_expand_callback cb, void *data)
+{
+ struct expand_value_data evd;
+
+ evd.regs_active = regs_active;
+ evd.callback = cb;
+ evd.callback_arg = data;
+ evd.dummy = false;
+
+ return cselib_expand_value_rtx_1 (orig, &evd, max_depth);
+}
+
+/* Similar to cselib_expand_value_rtx_cb, but no rtxs are actually copied
+ or simplified. Useful to find out whether cselib_expand_value_rtx_cb
+ would return NULL or non-NULL, without allocating new rtx. */
+
+bool
+cselib_dummy_expand_value_rtx_cb (rtx orig, bitmap regs_active, int max_depth,
+ cselib_expand_callback cb, void *data)
+{
+ struct expand_value_data evd;
+
+ evd.regs_active = regs_active;
+ evd.callback = cb;
+ evd.callback_arg = data;
+ evd.dummy = true;
+
+ return cselib_expand_value_rtx_1 (orig, &evd, max_depth) != NULL;
+}
+
+/* Internal implementation of cselib_expand_value_rtx and
+ cselib_expand_value_rtx_cb. */
+
+static rtx
+cselib_expand_value_rtx_1 (rtx orig, struct expand_value_data *evd,
+ int max_depth)
+{
+ rtx copy, scopy;
+ int i, j;
+ RTX_CODE code;
+ const char *format_ptr;
+ enum machine_mode mode;
+
+ code = GET_CODE (orig);
+
+ /* For the context of dse, if we end up expand into a huge tree, we
+ will not have a useful address, so we might as well just give up
+ quickly. */
+ if (max_depth <= 0)
+ return NULL;
+
+ switch (code)
+ {
+ case REG:
+ {
+ struct elt_list *l = REG_VALUES (REGNO (orig));
+
+ if (l && l->elt == NULL)
+ l = l->next;
+ for (; l; l = l->next)
+ if (GET_MODE (l->elt->val_rtx) == GET_MODE (orig))
+ {
+ rtx result;
+ int regno = REGNO (orig);
+
+ /* The only thing that we are not willing to do (this
+ is requirement of dse and if others potential uses
+ need this function we should add a parm to control
+ it) is that we will not substitute the
+ STACK_POINTER_REGNUM, FRAME_POINTER or the
+ HARD_FRAME_POINTER.
+
+ These expansions confuses the code that notices that
+ stores into the frame go dead at the end of the
+ function and that the frame is not effected by calls
+ to subroutines. If you allow the
+ STACK_POINTER_REGNUM substitution, then dse will
+ think that parameter pushing also goes dead which is
+ wrong. If you allow the FRAME_POINTER or the
+ HARD_FRAME_POINTER then you lose the opportunity to
+ make the frame assumptions. */
+ if (regno == STACK_POINTER_REGNUM
+ || regno == FRAME_POINTER_REGNUM
+ || regno == HARD_FRAME_POINTER_REGNUM)
+ return orig;
+
+ bitmap_set_bit (evd->regs_active, regno);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "expanding: r%d into: ", regno);
+
+ result = expand_loc (l->elt->locs, evd, max_depth);
+ bitmap_clear_bit (evd->regs_active, regno);
+
+ if (result)
+ return result;
+ else
+ return orig;
+ }
+ }
+
+ case CONST_INT:
+ case CONST_DOUBLE:
+ case CONST_VECTOR:
+ case SYMBOL_REF:
+ case CODE_LABEL:
+ case PC:
+ case CC0:
+ case SCRATCH:
+ /* SCRATCH must be shared because they represent distinct values. */
+ return orig;
+ case CLOBBER:
+ if (REG_P (XEXP (orig, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig, 0))))
+ return orig;
+ break;
+
+ case CONST:
+ if (shared_const_p (orig))
+ return orig;
+ break;
+
+ case SUBREG:
+ {
+ rtx subreg;
+
+ if (evd->callback)
+ {
+ subreg = evd->callback (orig, evd->regs_active, max_depth,
+ evd->callback_arg);
+ if (subreg != orig)
+ return subreg;
+ }
+
+ subreg = cselib_expand_value_rtx_1 (SUBREG_REG (orig), evd,
+ max_depth - 1);
+ if (!subreg)
+ return NULL;
+ scopy = simplify_gen_subreg (GET_MODE (orig), subreg,
+ GET_MODE (SUBREG_REG (orig)),
+ SUBREG_BYTE (orig));
+ if (scopy == NULL
+ || (GET_CODE (scopy) == SUBREG
+ && !REG_P (SUBREG_REG (scopy))
+ && !MEM_P (SUBREG_REG (scopy))))
+ return NULL;
+
+ return scopy;
+ }
+
+ case VALUE:
+ {
+ rtx result;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fputs ("\nexpanding ", dump_file);
+ print_rtl_single (dump_file, orig);
+ fputs (" into...", dump_file);
+ }
+
+ if (evd->callback)
+ {
+ result = evd->callback (orig, evd->regs_active, max_depth,
+ evd->callback_arg);
+
+ if (result != orig)
+ return result;
+ }
+
+ result = expand_loc (CSELIB_VAL_PTR (orig)->locs, evd, max_depth);
+ return result;
+ }
+
+ case DEBUG_EXPR:
+ if (evd->callback)
+ return evd->callback (orig, evd->regs_active, max_depth,
+ evd->callback_arg);
+ return orig;
+
+ default:
+ break;
+ }
+
+ /* Copy the various flags, fields, and other information. We assume
+ that all fields need copying, and then clear the fields that should
+ not be copied. That is the sensible default behavior, and forces
+ us to explicitly document why we are *not* copying a flag. */
+ if (evd->dummy)
+ copy = NULL;
+ else
+ copy = shallow_copy_rtx (orig);
+
+ format_ptr = GET_RTX_FORMAT (code);
+
+ for (i = 0; i < GET_RTX_LENGTH (code); i++)
+ switch (*format_ptr++)
+ {
+ case 'e':
+ if (XEXP (orig, i) != NULL)
+ {
+ rtx result = cselib_expand_value_rtx_1 (XEXP (orig, i), evd,
+ max_depth - 1);
+ if (!result)
+ return NULL;
+ if (copy)
+ XEXP (copy, i) = result;
+ }
+ break;
+
+ case 'E':
+ case 'V':
+ if (XVEC (orig, i) != NULL)
+ {
+ if (copy)
+ XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
+ for (j = 0; j < XVECLEN (orig, i); j++)
+ {
+ rtx result = cselib_expand_value_rtx_1 (XVECEXP (orig, i, j),
+ evd, max_depth - 1);
+ if (!result)
+ return NULL;
+ if (copy)
+ XVECEXP (copy, i, j) = result;
+ }
+ }
+ break;
+
+ case 't':
+ case 'w':
+ case 'i':
+ case 's':
+ case 'S':
+ case 'T':
+ case 'u':
+ case 'B':
+ case '0':
+ /* These are left unchanged. */
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
+ if (evd->dummy)
+ return orig;
+
+ mode = GET_MODE (copy);
+ /* If an operand has been simplified into CONST_INT, which doesn't
+ have a mode and the mode isn't derivable from whole rtx's mode,
+ try simplify_*_operation first with mode from original's operand
+ and as a fallback wrap CONST_INT into gen_rtx_CONST. */
+ scopy = copy;
+ switch (GET_RTX_CLASS (code))
+ {
+ case RTX_UNARY:
+ if (CONST_INT_P (XEXP (copy, 0))
+ && GET_MODE (XEXP (orig, 0)) != VOIDmode)
+ {
+ scopy = simplify_unary_operation (code, mode, XEXP (copy, 0),
+ GET_MODE (XEXP (orig, 0)));
+ if (scopy)
+ return scopy;
+ }
+ break;
+ case RTX_COMM_ARITH:
+ case RTX_BIN_ARITH:
+ /* These expressions can derive operand modes from the whole rtx's mode. */
+ break;
+ case RTX_TERNARY:
+ case RTX_BITFIELD_OPS:
+ if (CONST_INT_P (XEXP (copy, 0))
+ && GET_MODE (XEXP (orig, 0)) != VOIDmode)
+ {
+ scopy = simplify_ternary_operation (code, mode,
+ GET_MODE (XEXP (orig, 0)),
+ XEXP (copy, 0), XEXP (copy, 1),
+ XEXP (copy, 2));
+ if (scopy)
+ return scopy;
+ }
+ break;
+ case RTX_COMPARE:
+ case RTX_COMM_COMPARE:
+ if (CONST_INT_P (XEXP (copy, 0))
+ && GET_MODE (XEXP (copy, 1)) == VOIDmode
+ && (GET_MODE (XEXP (orig, 0)) != VOIDmode
+ || GET_MODE (XEXP (orig, 1)) != VOIDmode))
+ {
+ scopy = simplify_relational_operation (code, mode,
+ (GET_MODE (XEXP (orig, 0))
+ != VOIDmode)
+ ? GET_MODE (XEXP (orig, 0))
+ : GET_MODE (XEXP (orig, 1)),
+ XEXP (copy, 0),
+ XEXP (copy, 1));
+ if (scopy)
+ return scopy;
+ }
+ break;
+ default:
+ break;
+ }
+ scopy = simplify_rtx (copy);
+ if (scopy)
+ return scopy;
+ return copy;
+}
+
/* Walk rtx X and replace all occurrences of REG and MEM subexpressions
with VALUE expressions. This way, it becomes independent of changes
to registers and memory.
X isn't actually modified; if modifications are needed, new rtl is
allocated. However, the return value can share rtl with X. */
-static rtx
-cselib_subst_to_values (x)
- rtx x;
+rtx
+cselib_subst_to_values (rtx x)
{
enum rtx_code code = GET_CODE (x);
const char *fmt = GET_RTX_FORMAT (code);
switch (code)
{
case REG:
- for (l = REG_VALUES (REGNO (x)); l; l = l->next)
- if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x))
- return l->elt->u.val_rtx;
+ l = REG_VALUES (REGNO (x));
+ if (l && l->elt == NULL)
+ l = l->next;
+ for (; l; l = l->next)
+ if (GET_MODE (l->elt->val_rtx) == GET_MODE (x))
+ return l->elt->val_rtx;
- abort ();
+ gcc_unreachable ();
case MEM:
e = cselib_lookup_mem (x, 0);
if (! e)
- abort ();
- return e->u.val_rtx;
+ {
+ /* This happens for autoincrements. Assign a value that doesn't
+ match any other. */
+ e = new_cselib_val (next_uid, GET_MODE (x), x);
+ }
+ return e->val_rtx;
- /* CONST_DOUBLEs must be special-cased here so that we won't try to
- look up the CONST_DOUBLE_MEM inside. */
case CONST_DOUBLE:
+ case CONST_VECTOR:
case CONST_INT:
+ case CONST_FIXED:
return x;
+ case POST_INC:
+ case PRE_INC:
+ case POST_DEC:
+ case PRE_DEC:
+ case POST_MODIFY:
+ case PRE_MODIFY:
+ e = new_cselib_val (next_uid, GET_MODE (x), x);
+ return e->val_rtx;
+
default:
break;
}
{
rtx t = cselib_subst_to_values (XEXP (x, i));
- if (t != XEXP (x, i) && x == copy)
- copy = shallow_copy_rtx (x);
-
- XEXP (copy, i) = t;
+ if (t != XEXP (x, i))
+ {
+ if (x == copy)
+ copy = shallow_copy_rtx (x);
+ XEXP (copy, i) = t;
+ }
}
else if (fmt[i] == 'E')
{
- int j, k;
+ int j;
for (j = 0; j < XVECLEN (x, i); j++)
{
rtx t = cselib_subst_to_values (XVECEXP (x, i, j));
- if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i))
+ if (t != XVECEXP (x, i, j))
{
- if (x == copy)
- copy = shallow_copy_rtx (x);
-
- XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i));
- for (k = 0; k < j; k++)
- XVECEXP (copy, i, k) = XVECEXP (x, i, k);
+ if (XVEC (x, i) == XVEC (copy, i))
+ {
+ if (x == copy)
+ copy = shallow_copy_rtx (x);
+ XVEC (copy, i) = shallow_copy_rtvec (XVEC (x, i));
+ }
+ XVECEXP (copy, i, j) = t;
}
-
- XVECEXP (copy, i, j) = t;
}
}
}
we create a new one if possible, using mode MODE if X doesn't have a mode
(i.e. because it's a constant). */
-cselib_val *
-cselib_lookup (x, mode, create)
- rtx x;
- enum machine_mode mode;
- int create;
+static cselib_val *
+cselib_lookup_1 (rtx x, enum machine_mode mode, int create)
{
void **slot;
cselib_val *e;
if (GET_CODE (x) == VALUE)
return CSELIB_VAL_PTR (x);
- if (GET_CODE (x) == REG)
+ if (REG_P (x))
{
struct elt_list *l;
unsigned int i = REGNO (x);
- for (l = REG_VALUES (i); l; l = l->next)
- if (mode == GET_MODE (l->elt->u.val_rtx))
- return l->elt;
+ l = REG_VALUES (i);
+ if (l && l->elt == NULL)
+ l = l->next;
+ for (; l; l = l->next)
+ if (mode == GET_MODE (l->elt->val_rtx))
+ {
+ promote_debug_loc (l->elt->locs);
+ return l->elt;
+ }
if (! create)
return 0;
- e = new_cselib_val (++next_unknown_value, GET_MODE (x));
+ if (i < FIRST_PSEUDO_REGISTER)
+ {
+ unsigned int n = hard_regno_nregs[i][mode];
+
+ if (n > max_value_regs)
+ max_value_regs = n;
+ }
+
+ e = new_cselib_val (next_uid, GET_MODE (x), x);
e->locs = new_elt_loc_list (e->locs, x);
if (REG_VALUES (i) == 0)
- VARRAY_PUSH_UINT (used_regs, i);
- REG_VALUES (i) = new_elt_list (REG_VALUES (i), e);
- slot = htab_find_slot_with_hash (hash_table, x, e->value, INSERT);
+ {
+ /* Maintain the invariant that the first entry of
+ REG_VALUES, if present, must be the value used to set the
+ register, or NULL. */
+ used_regs[n_used_regs++] = i;
+ REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL);
+ }
+ REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e);
+ slot = htab_find_slot_with_hash (cselib_hash_table, x, e->hash, INSERT);
*slot = e;
return e;
}
- if (GET_CODE (x) == MEM)
+ if (MEM_P (x))
return cselib_lookup_mem (x, create);
- hashval = hash_rtx (x, mode, create);
+ hashval = cselib_hash_rtx (x, create);
/* Can't even create if hashing is not possible. */
if (! hashval)
return 0;
- slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x),
+ slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
hashval, create ? INSERT : NO_INSERT);
if (slot == 0)
return 0;
if (e)
return e;
- e = new_cselib_val (hashval, mode);
+ e = new_cselib_val (hashval, mode, x);
/* We have to fill the slot before calling cselib_subst_to_values:
the hash table is inconsistent until we do so, and
return e;
}
+/* Wrapper for cselib_lookup, that indicates X is in INSN. */
+
+cselib_val *
+cselib_lookup_from_insn (rtx x, enum machine_mode mode,
+ int create, rtx insn)
+{
+ cselib_val *ret;
+
+ gcc_assert (!cselib_current_insn);
+ cselib_current_insn = insn;
+
+ ret = cselib_lookup (x, mode, create);
+
+ cselib_current_insn = NULL;
+
+ return ret;
+}
+
+/* Wrapper for cselib_lookup_1, that logs the lookup result and
+ maintains invariants related with debug insns. */
+
+cselib_val *
+cselib_lookup (rtx x, enum machine_mode mode, int create)
+{
+ cselib_val *ret = cselib_lookup_1 (x, mode, create);
+
+ /* ??? Should we return NULL if we're not to create an entry, the
+ found loc is a debug loc and cselib_current_insn is not DEBUG?
+ If so, we should also avoid converting val to non-DEBUG; probably
+ easiest setting cselib_current_insn to NULL before the call
+ above. */
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fputs ("cselib lookup ", dump_file);
+ print_inline_rtx (dump_file, x, 2);
+ fprintf (dump_file, " => %u:%u\n",
+ ret ? ret->uid : 0,
+ ret ? ret->hash : 0);
+ }
+
+ return ret;
+}
+
/* Invalidate any entries in reg_values that overlap REGNO. This is called
if REGNO is changing. MODE is the mode of the assignment to REGNO, which
is used to determine how many hard registers are being changed. If MODE
invalidating call clobbered registers across a call. */
static void
-cselib_invalidate_regno (regno, mode)
- unsigned int regno;
- enum machine_mode mode;
+cselib_invalidate_regno (unsigned int regno, enum machine_mode mode)
{
unsigned int endregno;
unsigned int i;
/* If we see pseudos after reload, something is _wrong_. */
- if (reload_completed && regno >= FIRST_PSEUDO_REGISTER
- && reg_renumber[regno] >= 0)
- abort ();
+ gcc_assert (!reload_completed || regno < FIRST_PSEUDO_REGISTER
+ || reg_renumber[regno] < 0);
/* Determine the range of registers that must be invalidated. For
pseudos, only REGNO is affected. For hard regs, we must take MODE
into account, and we must also invalidate lower register numbers
if they contain values that overlap REGNO. */
- endregno = regno + 1;
- if (regno < FIRST_PSEUDO_REGISTER && mode != VOIDmode)
- endregno = regno + HARD_REGNO_NREGS (regno, mode);
+ if (regno < FIRST_PSEUDO_REGISTER)
+ {
+ gcc_assert (mode != VOIDmode);
+
+ if (regno < max_value_regs)
+ i = 0;
+ else
+ i = regno - max_value_regs;
- for (i = 0; i < endregno; i++)
+ endregno = end_hard_regno (mode, regno);
+ }
+ else
+ {
+ i = regno;
+ endregno = regno + 1;
+ }
+
+ for (; i < endregno; i++)
{
struct elt_list **l = ®_VALUES (i);
while (*l)
{
cselib_val *v = (*l)->elt;
+ bool had_locs;
+ rtx setting_insn;
struct elt_loc_list **p;
unsigned int this_last = i;
- if (i < FIRST_PSEUDO_REGISTER)
- this_last += HARD_REGNO_NREGS (i, GET_MODE (v->u.val_rtx)) - 1;
+ if (i < FIRST_PSEUDO_REGISTER && v != NULL)
+ this_last = end_hard_regno (GET_MODE (v->val_rtx), i) - 1;
- if (this_last < regno)
+ if (this_last < regno || v == NULL
+ || (v == cfa_base_preserved_val
+ && i == cfa_base_preserved_regno))
{
l = &(*l)->next;
continue;
}
/* We have an overlap. */
- unchain_one_elt_list (l);
+ if (*l == REG_VALUES (i))
+ {
+ /* Maintain the invariant that the first entry of
+ REG_VALUES, if present, must be the value used to set
+ the register, or NULL. This is also nice because
+ then we won't push the same regno onto user_regs
+ multiple times. */
+ (*l)->elt = NULL;
+ l = &(*l)->next;
+ }
+ else
+ unchain_one_elt_list (l);
+
+ had_locs = v->locs != NULL;
+ setting_insn = v->locs ? v->locs->setting_insn : NULL;
/* Now, we clear the mapping from value to reg. It must exist, so
this code will crash intentionally if it doesn't. */
{
rtx x = (*p)->loc;
- if (GET_CODE (x) == REG && REGNO (x) == i)
+ if (REG_P (x) && REGNO (x) == i)
{
unchain_one_elt_loc_list (p);
break;
}
}
- if (v->locs == 0)
- n_useless_values++;
+
+ if (had_locs && v->locs == 0 && !PRESERVED_VALUE_P (v->val_rtx))
+ {
+ if (setting_insn && DEBUG_INSN_P (setting_insn))
+ n_useless_debug_values++;
+ else
+ n_useless_values++;
+ }
}
}
}
+\f
+/* Return 1 if X has a value that can vary even between two
+ executions of the program. 0 means X can be compared reliably
+ against certain constants or near-constants. */
-/* The memory at address MEM_BASE is being changed.
- Return whether this change will invalidate VAL. */
-
-static int
-cselib_mem_conflict_p (mem_base, val)
- rtx mem_base;
- rtx val;
+static bool
+cselib_rtx_varies_p (const_rtx x ATTRIBUTE_UNUSED, bool from_alias ATTRIBUTE_UNUSED)
{
- enum rtx_code code;
- const char *fmt;
- int i, j;
-
- code = GET_CODE (val);
- switch (code)
- {
- /* Get rid of a few simple cases quickly. */
- case REG:
- case PC:
- case CC0:
- case SCRATCH:
- case CONST:
- case CONST_INT:
- case CONST_DOUBLE:
- case SYMBOL_REF:
- case LABEL_REF:
- return 0;
-
- case MEM:
- if (GET_MODE (mem_base) == BLKmode
- || GET_MODE (val) == BLKmode
- || anti_dependence (val, mem_base))
- return 1;
-
- /* The address may contain nested MEMs. */
- break;
-
- default:
- break;
- }
-
- fmt = GET_RTX_FORMAT (code);
- for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- {
- if (fmt[i] == 'e')
- {
- if (cselib_mem_conflict_p (mem_base, XEXP (val, i)))
- return 1;
- }
- else if (fmt[i] == 'E')
- for (j = 0; j < XVECLEN (val, i); j++)
- if (cselib_mem_conflict_p (mem_base, XVECEXP (val, i, j)))
- return 1;
- }
-
+ /* We actually don't need to verify very hard. This is because
+ if X has actually changed, we invalidate the memory anyway,
+ so assume that all common memory addresses are
+ invariant. */
return 0;
}
-/* For the value found in SLOT, walk its locations to determine if any overlap
- INFO (which is a MEM rtx). */
+/* Invalidate any locations in the table which are changed because of a
+ store to MEM_RTX. If this is called because of a non-const call
+ instruction, MEM_RTX is (mem:BLK const0_rtx). */
-static int
-cselib_invalidate_mem_1 (slot, info)
- void **slot;
- void *info;
+static void
+cselib_invalidate_mem (rtx mem_rtx)
{
- cselib_val *v = (cselib_val *) *slot;
- rtx mem_rtx = (rtx) info;
- struct elt_loc_list **p = &v->locs;
- int had_locs = v->locs != 0;
+ cselib_val **vp, *v, *next;
+ int num_mems = 0;
+ rtx mem_addr;
- while (*p)
+ mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0)));
+ mem_rtx = canon_rtx (mem_rtx);
+
+ vp = &first_containing_mem;
+ for (v = *vp; v != &dummy_val; v = next)
{
- rtx x = (*p)->loc;
- cselib_val *addr;
- struct elt_list **mem_chain;
-
- /* MEMs may occur in locations only at the top level; below
- that every MEM or REG is substituted by its VALUE. */
- if (GET_CODE (x) != MEM
- || ! cselib_mem_conflict_p (mem_rtx, x))
- {
- p = &(*p)->next;
- continue;
- }
+ bool has_mem = false;
+ struct elt_loc_list **p = &v->locs;
+ bool had_locs = v->locs != NULL;
+ rtx setting_insn = v->locs ? v->locs->setting_insn : NULL;
- /* This one overlaps. */
- /* We must have a mapping from this MEM's address to the
- value (E). Remove that, too. */
- addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0);
- mem_chain = &addr->addr_list;
- for (;;)
+ while (*p)
{
- if ((*mem_chain)->elt == v)
+ rtx x = (*p)->loc;
+ cselib_val *addr;
+ struct elt_list **mem_chain;
+
+ /* MEMs may occur in locations only at the top level; below
+ that every MEM or REG is substituted by its VALUE. */
+ if (!MEM_P (x))
{
- unchain_one_elt_list (mem_chain);
- break;
+ p = &(*p)->next;
+ continue;
+ }
+ if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS)
+ && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr,
+ x, NULL_RTX, cselib_rtx_varies_p))
+ {
+ has_mem = true;
+ num_mems++;
+ p = &(*p)->next;
+ continue;
}
- mem_chain = &(*mem_chain)->next;
- }
-
- unchain_one_elt_loc_list (p);
- }
+ /* This one overlaps. */
+ /* We must have a mapping from this MEM's address to the
+ value (E). Remove that, too. */
+ addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0);
+ mem_chain = &addr->addr_list;
+ for (;;)
+ {
+ if ((*mem_chain)->elt == v)
+ {
+ unchain_one_elt_list (mem_chain);
+ break;
+ }
- if (had_locs && v->locs == 0)
- n_useless_values++;
+ mem_chain = &(*mem_chain)->next;
+ }
- return 1;
-}
+ unchain_one_elt_loc_list (p);
+ }
-/* Invalidate any locations in the table which are changed because of a
- store to MEM_RTX. If this is called because of a non-const call
- instruction, MEM_RTX is (mem:BLK const0_rtx). */
+ if (had_locs && v->locs == 0 && !PRESERVED_VALUE_P (v->val_rtx))
+ {
+ if (setting_insn && DEBUG_INSN_P (setting_insn))
+ n_useless_debug_values++;
+ else
+ n_useless_values++;
+ }
-static void
-cselib_invalidate_mem (mem_rtx)
- rtx mem_rtx;
-{
- htab_traverse (hash_table, cselib_invalidate_mem_1, mem_rtx);
+ next = v->next_containing_mem;
+ if (has_mem)
+ {
+ *vp = v;
+ vp = &(*vp)->next_containing_mem;
+ }
+ else
+ v->next_containing_mem = NULL;
+ }
+ *vp = &dummy_val;
}
-/* Invalidate DEST, which is being assigned to or clobbered. The second and
- the third parameter exist so that this function can be passed to
- note_stores; they are ignored. */
+/* Invalidate DEST, which is being assigned to or clobbered. */
-static void
-cselib_invalidate_rtx (dest, ignore, data)
- rtx dest;
- rtx ignore ATTRIBUTE_UNUSED;
- void *data ATTRIBUTE_UNUSED;
+void
+cselib_invalidate_rtx (rtx dest)
{
- while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SIGN_EXTRACT
- || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG)
+ while (GET_CODE (dest) == SUBREG
+ || GET_CODE (dest) == ZERO_EXTRACT
+ || GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
- if (GET_CODE (dest) == REG)
+ if (REG_P (dest))
cselib_invalidate_regno (REGNO (dest), GET_MODE (dest));
- else if (GET_CODE (dest) == MEM)
+ else if (MEM_P (dest))
cselib_invalidate_mem (dest);
/* Some machines don't define AUTO_INC_DEC, but they still use push
invalidate the stack pointer correctly. Note that invalidating
the stack pointer is different from invalidating DEST. */
if (push_operand (dest, GET_MODE (dest)))
- cselib_invalidate_rtx (stack_pointer_rtx, NULL_RTX, NULL);
+ cselib_invalidate_rtx (stack_pointer_rtx);
+}
+
+/* A wrapper for cselib_invalidate_rtx to be called via note_stores. */
+
+static void
+cselib_invalidate_rtx_note_stores (rtx dest, const_rtx ignore ATTRIBUTE_UNUSED,
+ void *data ATTRIBUTE_UNUSED)
+{
+ cselib_invalidate_rtx (dest);
}
/* Record the result of a SET instruction. DEST is being set; the source
describes its address. */
static void
-cselib_record_set (dest, src_elt, dest_addr_elt)
- rtx dest;
- cselib_val *src_elt, *dest_addr_elt;
+cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt)
{
- int dreg = GET_CODE (dest) == REG ? (int) REGNO (dest) : -1;
+ int dreg = REG_P (dest) ? (int) REGNO (dest) : -1;
if (src_elt == 0 || side_effects_p (dest))
return;
if (dreg >= 0)
{
+ if (dreg < FIRST_PSEUDO_REGISTER)
+ {
+ unsigned int n = hard_regno_nregs[dreg][GET_MODE (dest)];
+
+ if (n > max_value_regs)
+ max_value_regs = n;
+ }
+
if (REG_VALUES (dreg) == 0)
- VARRAY_PUSH_UINT (used_regs, dreg);
+ {
+ used_regs[n_used_regs++] = dreg;
+ REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt);
+ }
+ else
+ {
+ /* The register should have been invalidated. */
+ gcc_assert (REG_VALUES (dreg)->elt == 0);
+ REG_VALUES (dreg)->elt = src_elt;
+ }
- REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt);
- if (src_elt->locs == 0)
+ if (src_elt->locs == 0 && !PRESERVED_VALUE_P (src_elt->val_rtx))
n_useless_values--;
src_elt->locs = new_elt_loc_list (src_elt->locs, dest);
}
- else if (GET_CODE (dest) == MEM && dest_addr_elt != 0)
+ else if (MEM_P (dest) && dest_addr_elt != 0
+ && cselib_record_memory)
{
- if (src_elt->locs == 0)
+ if (src_elt->locs == 0 && !PRESERVED_VALUE_P (src_elt->val_rtx))
n_useless_values--;
add_mem_for_addr (dest_addr_elt, src_elt, dest);
}
}
-/* Describe a single set that is part of an insn. */
-struct set
-{
- rtx src;
- rtx dest;
- cselib_val *src_elt;
- cselib_val *dest_addr_elt;
-};
-
/* There is no good way to determine how many elements there can be
in a PARALLEL. Since it's fairly cheap, use a really large number. */
#define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
/* Record the effects of any sets in INSN. */
static void
-cselib_record_sets (insn)
- rtx insn;
+cselib_record_sets (rtx insn)
{
int n_sets = 0;
int i;
- struct set sets[MAX_SETS];
+ struct cselib_set sets[MAX_SETS];
rtx body = PATTERN (insn);
rtx cond = 0;
}
}
+ if (n_sets == 1
+ && MEM_P (sets[0].src)
+ && !cselib_record_memory
+ && MEM_READONLY_P (sets[0].src))
+ {
+ rtx note = find_reg_equal_equiv_note (insn);
+
+ if (note && CONSTANT_P (XEXP (note, 0)))
+ sets[0].src = XEXP (note, 0);
+ }
+
/* Look up the values that are read. Do this before invalidating the
locations that are written. */
for (i = 0; i < n_sets; i++)
sets[i].dest = dest = XEXP (dest, 0);
/* We don't know how to record anything but REG or MEM. */
- if (GET_CODE (dest) == REG || GET_CODE (dest) == MEM)
+ if (REG_P (dest)
+ || (MEM_P (dest) && cselib_record_memory))
{
rtx src = sets[i].src;
if (cond)
- src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest);
- sets[i].src_elt = cselib_lookup (sets[i].src, GET_MODE (dest), 1);
- if (GET_CODE (dest) == MEM)
- sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1);
+ src = gen_rtx_IF_THEN_ELSE (GET_MODE (dest), cond, src, dest);
+ sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1);
+ if (MEM_P (dest))
+ {
+ enum machine_mode address_mode
+ = targetm.addr_space.address_mode (MEM_ADDR_SPACE (dest));
+
+ sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0),
+ address_mode, 1);
+ }
else
sets[i].dest_addr_elt = 0;
}
}
+ if (cselib_record_sets_hook)
+ cselib_record_sets_hook (insn, sets, n_sets);
+
/* Invalidate all locations written by this insn. Note that the elts we
looked up in the previous loop aren't affected, just some of their
locations may go away. */
- note_stores (body, cselib_invalidate_rtx, NULL);
+ note_stores (body, cselib_invalidate_rtx_note_stores, NULL);
+
+ /* If this is an asm, look for duplicate sets. This can happen when the
+ user uses the same value as an output multiple times. This is valid
+ if the outputs are not actually used thereafter. Treat this case as
+ if the value isn't actually set. We do this by smashing the destination
+ to pc_rtx, so that we won't record the value later. */
+ if (n_sets >= 2 && asm_noperands (body) >= 0)
+ {
+ for (i = 0; i < n_sets; i++)
+ {
+ rtx dest = sets[i].dest;
+ if (REG_P (dest) || MEM_P (dest))
+ {
+ int j;
+ for (j = i + 1; j < n_sets; j++)
+ if (rtx_equal_p (dest, sets[j].dest))
+ {
+ sets[i].dest = pc_rtx;
+ sets[j].dest = pc_rtx;
+ }
+ }
+ }
+ }
/* Now enter the equivalences in our tables. */
for (i = 0; i < n_sets; i++)
{
rtx dest = sets[i].dest;
- if (GET_CODE (dest) == REG || GET_CODE (dest) == MEM)
+ if (REG_P (dest)
+ || (MEM_P (dest) && cselib_record_memory))
cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt);
}
}
/* Record the effects of INSN. */
void
-cselib_process_insn (insn)
- rtx insn;
+cselib_process_insn (rtx insn)
{
int i;
rtx x;
cselib_current_insn = insn;
/* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */
- if (GET_CODE (insn) == CODE_LABEL
- || (GET_CODE (insn) == CALL
+ if (LABEL_P (insn)
+ || (CALL_P (insn)
&& find_reg_note (insn, REG_SETJMP, NULL))
- || (GET_CODE (insn) == INSN
+ || (NONJUMP_INSN_P (insn)
&& GET_CODE (PATTERN (insn)) == ASM_OPERANDS
&& MEM_VOLATILE_P (PATTERN (insn))))
{
- clear_table (0);
+ cselib_reset_table (next_uid);
+ cselib_current_insn = NULL_RTX;
return;
}
if (! INSN_P (insn))
{
- cselib_current_insn = 0;
+ cselib_current_insn = NULL_RTX;
return;
}
/* If this is a call instruction, forget anything stored in a
call clobbered register, or, if this is not a const call, in
memory. */
- if (GET_CODE (insn) == CALL_INSN)
+ if (CALL_P (insn))
{
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (call_used_regs[i])
- cselib_invalidate_regno (i, VOIDmode);
-
- if (! CONST_OR_PURE_CALL_P (insn))
+ if (call_used_regs[i]
+ || (REG_VALUES (i) && REG_VALUES (i)->elt
+ && HARD_REGNO_CALL_PART_CLOBBERED (i,
+ GET_MODE (REG_VALUES (i)->elt->val_rtx))))
+ cselib_invalidate_regno (i, reg_raw_mode[i]);
+
+ /* Since it is not clear how cselib is going to be used, be
+ conservative here and treat looping pure or const functions
+ as if they were regular functions. */
+ if (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn)
+ || !(RTL_CONST_OR_PURE_CALL_P (insn)))
cselib_invalidate_mem (callmem);
}
unlikely to help. */
for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
if (REG_NOTE_KIND (x) == REG_INC)
- cselib_invalidate_rtx (XEXP (x, 0), NULL_RTX, NULL);
+ cselib_invalidate_rtx (XEXP (x, 0));
#endif
/* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
after we have processed the insn. */
- if (GET_CODE (insn) == CALL_INSN)
+ if (CALL_P (insn))
for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1))
if (GET_CODE (XEXP (x, 0)) == CLOBBER)
- cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0), NULL_RTX, NULL);
-
- cselib_current_insn = 0;
-
- if (n_useless_values > MAX_USELESS_VALUES)
+ cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
+
+ cselib_current_insn = NULL_RTX;
+
+ if (n_useless_values > MAX_USELESS_VALUES
+ /* remove_useless_values is linear in the hash table size. Avoid
+ quadratic behavior for very large hashtables with very few
+ useless elements. */
+ && ((unsigned int)n_useless_values
+ > (cselib_hash_table->n_elements
+ - cselib_hash_table->n_deleted
+ - n_debug_values) / 4))
remove_useless_values ();
}
-/* Make sure our varrays are big enough. Not called from any cselib routines;
- it must be called by the user if it allocated new registers. */
+/* Initialize cselib for one pass. The caller must also call
+ init_alias_analysis. */
void
-cselib_update_varray_sizes ()
+cselib_init (int record_what)
{
- unsigned int nregs = max_reg_num ();
+ elt_list_pool = create_alloc_pool ("elt_list",
+ sizeof (struct elt_list), 10);
+ elt_loc_list_pool = create_alloc_pool ("elt_loc_list",
+ sizeof (struct elt_loc_list), 10);
+ cselib_val_pool = create_alloc_pool ("cselib_val_list",
+ sizeof (cselib_val), 10);
+ value_pool = create_alloc_pool ("value", RTX_CODE_SIZE (VALUE), 100);
+ cselib_record_memory = record_what & CSELIB_RECORD_MEMORY;
+ cselib_preserve_constants = record_what & CSELIB_PRESERVE_CONSTANTS;
+
+ /* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
+ see canon_true_dependence. This is only created once. */
+ if (! callmem)
+ callmem = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode));
- if (nregs == cselib_nregs)
- return;
+ cselib_nregs = max_reg_num ();
- cselib_nregs = nregs;
- VARRAY_GROW (reg_values, nregs);
- VARRAY_GROW (used_regs, nregs);
+ /* We preserve reg_values to allow expensive clearing of the whole thing.
+ Reallocate it however if it happens to be too large. */
+ if (!reg_values || reg_values_size < cselib_nregs
+ || (reg_values_size > 10 && reg_values_size > cselib_nregs * 4))
+ {
+ if (reg_values)
+ free (reg_values);
+ /* Some space for newly emit instructions so we don't end up
+ reallocating in between passes. */
+ reg_values_size = cselib_nregs + (63 + cselib_nregs) / 16;
+ reg_values = XCNEWVEC (struct elt_list *, reg_values_size);
+ }
+ used_regs = XNEWVEC (unsigned int, cselib_nregs);
+ n_used_regs = 0;
+ cselib_hash_table = htab_create (31, get_value_hash,
+ entry_and_rtx_equal_p, NULL);
+ next_uid = 1;
}
-/* Initialize cselib for one pass. The caller must also call
- init_alias_analysis. */
+/* Called when the current user is done with cselib. */
void
-cselib_init ()
+cselib_finish (void)
{
- /* These are only created once. */
- if (! callmem)
+ cselib_discard_hook = NULL;
+ cselib_preserve_constants = false;
+ cfa_base_preserved_val = NULL;
+ cfa_base_preserved_regno = INVALID_REGNUM;
+ free_alloc_pool (elt_list_pool);
+ free_alloc_pool (elt_loc_list_pool);
+ free_alloc_pool (cselib_val_pool);
+ free_alloc_pool (value_pool);
+ cselib_clear_table ();
+ htab_delete (cselib_hash_table);
+ free (used_regs);
+ used_regs = 0;
+ cselib_hash_table = 0;
+ n_useless_values = 0;
+ n_useless_debug_values = 0;
+ n_debug_values = 0;
+ next_uid = 0;
+}
+
+/* Dump the cselib_val *X to FILE *info. */
+
+static int
+dump_cselib_val (void **x, void *info)
+{
+ cselib_val *v = (cselib_val *)*x;
+ FILE *out = (FILE *)info;
+ bool need_lf = true;
+
+ print_inline_rtx (out, v->val_rtx, 0);
+
+ if (v->locs)
+ {
+ struct elt_loc_list *l = v->locs;
+ if (need_lf)
+ {
+ fputc ('\n', out);
+ need_lf = false;
+ }
+ fputs (" locs:", out);
+ do
+ {
+ fprintf (out, "\n from insn %i ",
+ INSN_UID (l->setting_insn));
+ print_inline_rtx (out, l->loc, 4);
+ }
+ while ((l = l->next));
+ fputc ('\n', out);
+ }
+ else
{
- gcc_obstack_init (&cselib_obstack);
- cselib_startobj = obstack_alloc (&cselib_obstack, 0);
+ fputs (" no locs", out);
+ need_lf = true;
+ }
- callmem = gen_rtx_MEM (BLKmode, const0_rtx);
- ggc_add_rtx_root (&callmem, 1);
+ if (v->addr_list)
+ {
+ struct elt_list *e = v->addr_list;
+ if (need_lf)
+ {
+ fputc ('\n', out);
+ need_lf = false;
+ }
+ fputs (" addr list:", out);
+ do
+ {
+ fputs ("\n ", out);
+ print_inline_rtx (out, e->elt->val_rtx, 2);
+ }
+ while ((e = e->next));
+ fputc ('\n', out);
+ }
+ else
+ {
+ fputs (" no addrs", out);
+ need_lf = true;
}
- cselib_nregs = max_reg_num ();
- VARRAY_ELT_LIST_INIT (reg_values, cselib_nregs, "reg_values");
- VARRAY_UINT_INIT (used_regs, cselib_nregs, "used_regs");
- hash_table = htab_create (31, get_value_hash, entry_and_rtx_equal_p, NULL);
- clear_table (1);
+ if (v->next_containing_mem == &dummy_val)
+ fputs (" last mem\n", out);
+ else if (v->next_containing_mem)
+ {
+ fputs (" next mem ", out);
+ print_inline_rtx (out, v->next_containing_mem->val_rtx, 2);
+ fputc ('\n', out);
+ }
+ else if (need_lf)
+ fputc ('\n', out);
+
+ return 1;
}
-/* Called when the current user is done with cselib. */
+/* Dump to OUT everything in the CSELIB table. */
void
-cselib_finish ()
+dump_cselib_table (FILE *out)
{
- clear_table (0);
- VARRAY_FREE (reg_values);
- VARRAY_FREE (used_regs);
- htab_delete (hash_table);
+ fprintf (out, "cselib hash table:\n");
+ htab_traverse (cselib_hash_table, dump_cselib_val, out);
+ if (first_containing_mem != &dummy_val)
+ {
+ fputs ("first mem ", out);
+ print_inline_rtx (out, first_containing_mem->val_rtx, 2);
+ fputc ('\n', out);
+ }
+ fprintf (out, "next uid %i\n", next_uid);
}
+
+#include "gt-cselib.h"
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