/* Common subexpression elimination library for GNU compiler.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009
- Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
+ 2012 Free Software Foundation, Inc.
This file is part of GCC.
#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 "emit-rtl.h"
-#include "toplev.h"
+#include "diagnostic-core.h"
#include "output.h"
#include "ggc.h"
#include "hashtab.h"
#include "params.h"
#include "alloc-pool.h"
#include "target.h"
+#include "bitmap.h"
+
+/* A list of cselib_val structures. */
+struct elt_list {
+ struct elt_list *next;
+ cselib_val *elt;
+};
static bool cselib_record_memory;
+static bool cselib_preserve_constants;
+static bool cselib_any_perm_equivs;
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 new_elt_loc_list (cselib_val *, 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 int rtx_equal_for_cselib_1 (rtx, rtx, enum machine_mode);
+static unsigned int cselib_hash_rtx (rtx, int, enum machine_mode);
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);
bitmap regs_active;
cselib_expand_callback callback;
void *callback_arg;
+ bool dummy;
};
static rtx cselib_expand_value_rtx_1 (rtx, struct expand_value_data *, int);
/* 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
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 = INVALID_REGNUM;
+
/* 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. */
#define PRESERVED_VALUE_P(RTX) \
(RTL_FLAG_CHECK1("PRESERVED_VALUE_P", (RTX), VALUE)->unchanging)
-#define LONG_TERM_PRESERVED_VALUE_P(RTX) \
- (RTL_FLAG_CHECK1("LONG_TERM_PRESERVED_VALUE_P", (RTX), VALUE)->in_struct)
\f
return el;
}
-/* Allocate a struct elt_loc_list and fill in its two elements with the
- arguments. */
+/* Allocate a struct elt_loc_list with LOC and prepend it to VAL's loc
+ list. */
-static inline struct elt_loc_list *
-new_elt_loc_list (struct elt_loc_list *next, rtx loc)
+static inline void
+new_elt_loc_list (cselib_val *val, rtx loc)
{
- struct elt_loc_list *el;
+ struct elt_loc_list *el, *next = val->locs;
+
+ gcc_checking_assert (!next || !next->setting_insn
+ || !DEBUG_INSN_P (next->setting_insn)
+ || cselib_current_insn == 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++;
+
+ val = canonical_cselib_val (val);
+ next = val->locs;
+
+ if (GET_CODE (loc) == VALUE)
+ {
+ loc = canonical_cselib_val (CSELIB_VAL_PTR (loc))->val_rtx;
+
+ gcc_checking_assert (PRESERVED_VALUE_P (loc)
+ == PRESERVED_VALUE_P (val->val_rtx));
+
+ if (val->val_rtx == loc)
+ return;
+ else if (val->uid > CSELIB_VAL_PTR (loc)->uid)
+ {
+ /* Reverse the insertion. */
+ new_elt_loc_list (CSELIB_VAL_PTR (loc), val->val_rtx);
+ return;
+ }
+
+ gcc_checking_assert (val->uid < CSELIB_VAL_PTR (loc)->uid);
+
+ if (CSELIB_VAL_PTR (loc)->locs)
+ {
+ /* Bring all locs from LOC to VAL. */
+ for (el = CSELIB_VAL_PTR (loc)->locs; el->next; el = el->next)
+ {
+ /* Adjust values that have LOC as canonical so that VAL
+ becomes their canonical. */
+ if (el->loc && GET_CODE (el->loc) == VALUE)
+ {
+ gcc_checking_assert (CSELIB_VAL_PTR (el->loc)->locs->loc
+ == loc);
+ CSELIB_VAL_PTR (el->loc)->locs->loc = val->val_rtx;
+ }
+ }
+ el->next = val->locs;
+ next = val->locs = CSELIB_VAL_PTR (loc)->locs;
+ }
+
+ if (CSELIB_VAL_PTR (loc)->addr_list)
+ {
+ /* Bring in addr_list into canonical node. */
+ struct elt_list *last = CSELIB_VAL_PTR (loc)->addr_list;
+ while (last->next)
+ last = last->next;
+ last->next = val->addr_list;
+ val->addr_list = CSELIB_VAL_PTR (loc)->addr_list;
+ CSELIB_VAL_PTR (loc)->addr_list = NULL;
+ }
+
+ if (CSELIB_VAL_PTR (loc)->next_containing_mem != NULL
+ && val->next_containing_mem == NULL)
+ {
+ /* Add VAL to the containing_mem list after LOC. LOC will
+ be removed when we notice it doesn't contain any
+ MEMs. */
+ val->next_containing_mem = CSELIB_VAL_PTR (loc)->next_containing_mem;
+ CSELIB_VAL_PTR (loc)->next_containing_mem = val;
+ }
+
+ /* Chain LOC back to VAL. */
+ el = (struct elt_loc_list *) pool_alloc (elt_loc_list_pool);
+ el->loc = val->val_rtx;
+ el->setting_insn = cselib_current_insn;
+ el->next = NULL;
+ CSELIB_VAL_PTR (loc)->locs = el;
+ }
+
el = (struct elt_loc_list *) pool_alloc (elt_loc_list_pool);
- el->next = next;
el->loc = loc;
el->setting_insn = cselib_current_insn;
- return el;
+ el->next = next;
+ val->locs = 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 && 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;
+ if (cselib_preserve_constants && l->next)
+ {
+ gcc_assert (l->next->setting_insn
+ && DEBUG_INSN_P (l->next->setting_insn)
+ && !l->next->next);
+ l->next->setting_insn = cselib_current_insn;
+ }
+ else
+ gcc_assert (!l->next);
+ }
}
/* The elt_list at *PL is no longer needed. Unchain it and free its
cselib_reset_table (1);
}
+/* Return TRUE if V is a constant, a function invariant or a VALUE
+ equivalence; FALSE otherwise. */
+
+static bool
+invariant_or_equiv_p (cselib_val *v)
+{
+ struct elt_loc_list *l;
+
+ if (v == cfa_base_preserved_val)
+ return true;
+
+ /* Keep VALUE equivalences around. */
+ for (l = v->locs; l; l = l->next)
+ if (GET_CODE (l->loc) == VALUE)
+ return true;
+
+ 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 true;
+ /* Although a debug expr may be bound to different expressions,
+ we can preserve it as if it was constant, to get unification
+ and proper merging within var-tracking. */
+ if (GET_CODE (v->locs->loc) == DEBUG_EXPR
+ || GET_CODE (v->locs->loc) == DEBUG_IMPLICIT_PTR
+ || GET_CODE (v->locs->loc) == ENTRY_VALUE
+ || GET_CODE (v->locs->loc) == DEBUG_PARAMETER_REF)
+ return true;
+
+ /* (plus (value V) (const_int C)) is invariant iff V is invariant. */
+ if (GET_CODE (v->locs->loc) == PLUS
+ && CONST_INT_P (XEXP (v->locs->loc, 1))
+ && GET_CODE (XEXP (v->locs->loc, 0)) == VALUE
+ && invariant_or_equiv_p (CSELIB_VAL_PTR (XEXP (v->locs->loc, 0))))
+ return true;
+ }
+
+ return false;
+}
+
+/* Remove from hash table all VALUEs except constants, function
+ invariants and VALUE equivalences. */
+
+static int
+preserve_constants_and_equivs (void **x, void *info ATTRIBUTE_UNUSED)
+{
+ cselib_val *v = (cselib_val *)*x;
+
+ if (!invariant_or_equiv_p (v))
+ 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. */
{
unsigned int i;
- for (i = 0; i < n_used_regs; i++)
- REG_VALUES (used_regs[i]) = 0;
-
max_value_regs = 0;
- n_used_regs = 0;
+ 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;
+ }
- /* ??? Preserve constants? */
- htab_empty (cselib_hash_table);
+ if (cselib_preserve_constants)
+ htab_traverse (cselib_hash_table, preserve_constants_and_equivs, NULL);
+ else
+ {
+ htab_empty (cselib_hash_table);
+ gcc_checking_assert (!cselib_any_perm_equivs);
+ }
n_useless_values = 0;
+ n_useless_debug_values = 0;
+ n_debug_values = 0;
next_uid = num;
return next_uid;
}
+/* See the documentation of cselib_find_slot below. */
+static enum machine_mode find_slot_memmode;
+
+/* Search for X, whose hashcode is HASH, in CSELIB_HASH_TABLE,
+ INSERTing if requested. When X is part of the address of a MEM,
+ MEMMODE should specify the mode of the MEM. While searching the
+ table, MEMMODE is held in FIND_SLOT_MEMMODE, so that autoinc RTXs
+ in X can be resolved. */
+
+static void **
+cselib_find_slot (rtx x, hashval_t hash, enum insert_option insert,
+ enum machine_mode memmode)
+{
+ void **slot;
+ find_slot_memmode = memmode;
+ slot = htab_find_slot_with_hash (cselib_hash_table, x, hash, insert);
+ find_slot_memmode = VOIDmode;
+ return slot;
+}
+
/* The equality test for our hash table. The first argument ENTRY is a table
element (i.e. a cselib_val), while the second arg X is an rtx. We know
that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
/* 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;
+ if (rtx_equal_for_cselib_1 (l->loc, x, find_slot_memmode))
+ {
+ promote_debug_loc (l);
+ return 1;
+ }
return 0;
}
int i, j;
if (GET_CODE (x) == VALUE
- && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0))
+ && (! only_useless ||
+ (CSELIB_VAL_PTR (x)->locs == 0 && !PRESERVED_VALUE_P (x))))
return 1;
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
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)
{
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;
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
p = &first_containing_mem;
for (v = *p; v != &dummy_val; v = v->next_containing_mem)
- if (v->locs)
+ if (v->locs && v == canonical_cselib_val (v))
{
*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);
return PRESERVED_VALUE_P (v->val_rtx);
}
-/* Mark preserved values as preserved for the long term. */
+/* Arrange for a REG value to be assumed constant through the whole function,
+ never invalidated and preserved across cselib_reset_table calls. */
-static int
-cselib_preserve_definitely (void **slot, void *info ATTRIBUTE_UNUSED)
-{
- cselib_val *v = (cselib_val *)*slot;
-
- if (PRESERVED_VALUE_P (v->val_rtx)
- && !LONG_TERM_PRESERVED_VALUE_P (v->val_rtx))
- LONG_TERM_PRESERVED_VALUE_P (v->val_rtx) = true;
-
- return 1;
-}
-
-/* Clear the preserve marks for values not preserved for the long
- term. */
-
-static int
-cselib_clear_preserve (void **slot, void *info ATTRIBUTE_UNUSED)
+void
+cselib_preserve_cfa_base_value (cselib_val *v, unsigned int regno)
{
- cselib_val *v = (cselib_val *)*slot;
-
- if (PRESERVED_VALUE_P (v->val_rtx)
- && !LONG_TERM_PRESERVED_VALUE_P (v->val_rtx))
+ if (cselib_preserve_constants
+ && v->locs
+ && REG_P (v->locs->loc))
{
- PRESERVED_VALUE_P (v->val_rtx) = false;
- if (!v->locs)
- n_useless_values++;
+ cfa_base_preserved_val = v;
+ cfa_base_preserved_regno = regno;
}
-
- return 1;
}
/* Clean all non-constant expressions in the hash table, but retain
their values. */
void
-cselib_preserve_only_values (bool retain)
+cselib_preserve_only_values (void)
{
int i;
- htab_traverse (cselib_hash_table,
- retain ? cselib_preserve_definitely : cselib_clear_preserve,
- NULL);
-
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
cselib_invalidate_regno (i, reg_raw_mode[i]);
int
rtx_equal_for_cselib_p (rtx x, rtx y)
{
+ return rtx_equal_for_cselib_1 (x, y, VOIDmode);
+}
+
+/* If x is a PLUS or an autoinc operation, expand the operation,
+ storing the offset, if any, in *OFF. */
+
+static rtx
+autoinc_split (rtx x, rtx *off, enum machine_mode memmode)
+{
+ switch (GET_CODE (x))
+ {
+ case PLUS:
+ *off = XEXP (x, 1);
+ return XEXP (x, 0);
+
+ case PRE_DEC:
+ if (memmode == VOIDmode)
+ return x;
+
+ *off = GEN_INT (-GET_MODE_SIZE (memmode));
+ return XEXP (x, 0);
+ break;
+
+ case PRE_INC:
+ if (memmode == VOIDmode)
+ return x;
+
+ *off = GEN_INT (GET_MODE_SIZE (memmode));
+ return XEXP (x, 0);
+
+ case PRE_MODIFY:
+ return XEXP (x, 1);
+
+ case POST_DEC:
+ case POST_INC:
+ case POST_MODIFY:
+ return XEXP (x, 0);
+
+ default:
+ return x;
+ }
+}
+
+/* Return nonzero if we can prove that X and Y contain the same value,
+ taking our gathered information into account. MEMMODE holds the
+ mode of the enclosing MEM, if any, as required to deal with autoinc
+ addressing modes. If X and Y are not (known to be) part of
+ addresses, MEMMODE should be VOIDmode. */
+
+static int
+rtx_equal_for_cselib_1 (rtx x, rtx y, enum machine_mode memmode)
+{
enum rtx_code code;
const char *fmt;
int i;
if (REG_P (x) || MEM_P (x))
{
- cselib_val *e = cselib_lookup (x, GET_MODE (x), 0);
+ cselib_val *e = cselib_lookup (x, GET_MODE (x), 0, memmode);
if (e)
x = e->val_rtx;
if (REG_P (y) || MEM_P (y))
{
- cselib_val *e = cselib_lookup (y, GET_MODE (y), 0);
+ cselib_val *e = cselib_lookup (y, GET_MODE (y), 0, memmode);
if (e)
y = e->val_rtx;
if (x == y)
return 1;
- if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE)
- return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y);
-
if (GET_CODE (x) == VALUE)
{
- cselib_val *e = CSELIB_VAL_PTR (x);
+ cselib_val *e = canonical_cselib_val (CSELIB_VAL_PTR (x));
struct elt_loc_list *l;
+ if (GET_CODE (y) == VALUE)
+ return e == canonical_cselib_val (CSELIB_VAL_PTR (y));
+
for (l = e->locs; l; l = l->next)
{
rtx t = l->loc;
- /* Avoid infinite recursion. */
- if (REG_P (t) || MEM_P (t))
+ /* Avoid infinite recursion. We know we have the canonical
+ value, so we can just skip any values in the equivalence
+ list. */
+ if (REG_P (t) || MEM_P (t) || GET_CODE (t) == VALUE)
continue;
- else if (rtx_equal_for_cselib_p (t, y))
+ else if (rtx_equal_for_cselib_1 (t, y, memmode))
return 1;
}
return 0;
}
-
- if (GET_CODE (y) == VALUE)
+ else if (GET_CODE (y) == VALUE)
{
- cselib_val *e = CSELIB_VAL_PTR (y);
+ cselib_val *e = canonical_cselib_val (CSELIB_VAL_PTR (y));
struct elt_loc_list *l;
for (l = e->locs; l; l = l->next)
{
rtx t = l->loc;
- if (REG_P (t) || MEM_P (t))
+ if (REG_P (t) || MEM_P (t) || GET_CODE (t) == VALUE)
continue;
- else if (rtx_equal_for_cselib_p (x, t))
+ else if (rtx_equal_for_cselib_1 (x, t, memmode))
return 1;
}
return 0;
}
- if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y))
+ if (GET_MODE (x) != GET_MODE (y))
return 0;
+ if (GET_CODE (x) != GET_CODE (y))
+ {
+ rtx xorig = x, yorig = y;
+ rtx xoff = NULL, yoff = NULL;
+
+ x = autoinc_split (x, &xoff, memmode);
+ y = autoinc_split (y, &yoff, memmode);
+
+ if (!xoff != !yoff)
+ return 0;
+
+ if (xoff && !rtx_equal_for_cselib_1 (xoff, yoff, memmode))
+ return 0;
+
+ /* Don't recurse if nothing changed. */
+ if (x != xorig || y != yorig)
+ return rtx_equal_for_cselib_1 (x, y, memmode);
+
+ return 0;
+ }
+
/* These won't be handled correctly by the code below. */
switch (GET_CODE (x))
{
case DEBUG_EXPR:
return 0;
+ case DEBUG_IMPLICIT_PTR:
+ return DEBUG_IMPLICIT_PTR_DECL (x)
+ == DEBUG_IMPLICIT_PTR_DECL (y);
+
+ case DEBUG_PARAMETER_REF:
+ return DEBUG_PARAMETER_REF_DECL (x)
+ == DEBUG_PARAMETER_REF_DECL (y);
+
+ case ENTRY_VALUE:
+ /* ENTRY_VALUEs are function invariant, it is thus undesirable to
+ use rtx_equal_for_cselib_1 to compare the operands. */
+ return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y));
+
case LABEL_REF:
return XEXP (x, 0) == XEXP (y, 0);
+ case MEM:
+ /* We have to compare any autoinc operations in the addresses
+ using this MEM's mode. */
+ return rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 0), GET_MODE (x));
+
default:
break;
}
/* And the corresponding elements must match. */
for (j = 0; j < XVECLEN (x, i); j++)
- if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j),
- XVECEXP (y, i, j)))
+ if (! rtx_equal_for_cselib_1 (XVECEXP (x, i, j),
+ XVECEXP (y, i, j), memmode))
return 0;
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)))
+ && rtx_equal_for_cselib_1 (XEXP (x, 1), XEXP (y, 0), memmode)
+ && rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 1), memmode))
return 1;
- if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i)))
+ if (! rtx_equal_for_cselib_1 (XEXP (x, i), XEXP (y, i), memmode))
return 0;
break;
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) .
+ MEMMODE indicates the mode of an enclosing MEM, and it's only
+ used to compute autoinc values.
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))
in a comparison anyway, since relying on hash differences is unsafe. */
static unsigned int
-cselib_hash_rtx (rtx x, int create)
+cselib_hash_rtx (rtx x, int create, enum machine_mode memmode)
{
cselib_val *e;
int i, j;
switch (code)
{
+ case VALUE:
+ e = CSELIB_VAL_PTR (x);
+ return e->hash;
+
case MEM:
case REG:
- e = cselib_lookup (x, GET_MODE (x), create);
+ e = cselib_lookup (x, GET_MODE (x), create, memmode);
if (! e)
return 0;
+ 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 DEBUG_PARAMETER_REF:
+ hash += ((unsigned) DEBUG_PARAMETER_REF << 7)
+ + DECL_UID (DEBUG_PARAMETER_REF_DECL (x));
+ return hash ? hash : (unsigned int) DEBUG_PARAMETER_REF;
+
+ case ENTRY_VALUE:
+ /* ENTRY_VALUEs are function invariant, thus try to avoid
+ recursing on argument if ENTRY_VALUE is one of the
+ forms emitted by expand_debug_expr, otherwise
+ ENTRY_VALUE hash would depend on the current value
+ in some register or memory. */
+ if (REG_P (ENTRY_VALUE_EXP (x)))
+ hash += (unsigned int) REG
+ + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x))
+ + (unsigned int) REGNO (ENTRY_VALUE_EXP (x));
+ else if (MEM_P (ENTRY_VALUE_EXP (x))
+ && REG_P (XEXP (ENTRY_VALUE_EXP (x), 0)))
+ hash += (unsigned int) MEM
+ + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x), 0))
+ + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x), 0));
+ else
+ hash += cselib_hash_rtx (ENTRY_VALUE_EXP (x), create, memmode);
+ return hash ? hash : (unsigned int) ENTRY_VALUE;
+
case CONST_INT:
hash += ((unsigned) CONST_INT << 7) + INTVAL (x);
return hash ? hash : (unsigned int) CONST_INT;
for (i = 0; i < units; ++i)
{
elt = CONST_VECTOR_ELT (x, i);
- hash += cselib_hash_rtx (elt, 0);
+ hash += cselib_hash_rtx (elt, 0, memmode);
}
return hash;
case PRE_DEC:
case PRE_INC:
+ /* We can't compute these without knowing the MEM mode. */
+ gcc_assert (memmode != VOIDmode);
+ i = GET_MODE_SIZE (memmode);
+ if (code == PRE_DEC)
+ i = -i;
+ /* Adjust the hash so that (mem:MEMMODE (pre_* (reg))) hashes
+ like (mem:MEMMODE (plus (reg) (const_int I))). */
+ hash += (unsigned) PLUS - (unsigned)code
+ + cselib_hash_rtx (XEXP (x, 0), create, memmode)
+ + cselib_hash_rtx (GEN_INT (i), create, memmode);
+ return hash ? hash : 1 + (unsigned) PLUS;
+
+ case PRE_MODIFY:
+ gcc_assert (memmode != VOIDmode);
+ return cselib_hash_rtx (XEXP (x, 1), create, memmode);
+
case POST_DEC:
case POST_INC:
case POST_MODIFY:
- case PRE_MODIFY:
+ gcc_assert (memmode != VOIDmode);
+ return cselib_hash_rtx (XEXP (x, 0), create, memmode);
+
case PC:
case CC0:
case CALL:
case 'e':
{
rtx tem = XEXP (x, i);
- unsigned int tem_hash = cselib_hash_rtx (tem, create);
+ unsigned int tem_hash = cselib_hash_rtx (tem, create, memmode);
if (tem_hash == 0)
return 0;
for (j = 0; j < XVECLEN (x, i); j++)
{
unsigned int tem_hash
- = cselib_hash_rtx (XVECEXP (x, i, j), create);
+ = cselib_hash_rtx (XVECEXP (x, i, j), create, memmode);
if (tem_hash == 0)
return 0;
e->locs = 0;
e->next_containing_mem = 0;
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (dump_file && (dump_flags & TDF_CSELIB))
{
fprintf (dump_file, "cselib value %u:%u ", e->uid, hash);
if (flag_dump_noaddr || flag_dump_unnumbered)
{
struct elt_loc_list *l;
+ addr_elt = canonical_cselib_val (addr_elt);
+ mem_elt = canonical_cselib_val (mem_elt);
+
/* Avoid duplicates. */
for (l = mem_elt->locs; l; l = l->next)
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->val_rtx));
+ new_elt_loc_list (mem_elt,
+ replace_equiv_address_nv (x, addr_elt->val_rtx));
if (mem_elt->next_containing_mem == NULL)
{
mem_elt->next_containing_mem = first_containing_mem;
cselib_lookup_mem (rtx x, int create)
{
enum machine_mode mode = GET_MODE (x);
+ enum machine_mode addr_mode;
void **slot;
cselib_val *addr;
cselib_val *mem_elt;
|| (FLOAT_MODE_P (mode) && flag_float_store))
return 0;
+ addr_mode = GET_MODE (XEXP (x, 0));
+ if (addr_mode == VOIDmode)
+ addr_mode = Pmode;
+
/* Look up the value for the address. */
- addr = cselib_lookup (XEXP (x, 0), mode, create);
+ addr = cselib_lookup (XEXP (x, 0), addr_mode, create, mode);
if (! addr)
return 0;
+ addr = canonical_cselib_val (addr);
/* 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->val_rtx) == mode)
- return l->elt;
+ {
+ promote_debug_loc (l->elt->locs);
+ return l->elt;
+ }
if (! create)
return 0;
mem_elt = new_cselib_val (next_uid, mode, x);
add_mem_for_addr (addr, mem_elt, x);
- slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
- mem_elt->hash, INSERT);
+ slot = cselib_find_slot (wrap_constant (mode, x), mem_elt->hash,
+ INSERT, mode);
*slot = mem_elt;
return mem_elt;
}
unsigned int regno = UINT_MAX;
struct elt_loc_list *p_in = p;
- for (; p; p = p -> next)
+ for (; p; p = p->next)
{
+ /* Return these right away to avoid returning stack pointer based
+ expressions for frame pointer and vice versa, which is something
+ that would confuse DSE. See the comment in cselib_expand_value_rtx_1
+ for more details. */
+ if (REG_P (p->loc)
+ && (REGNO (p->loc) == STACK_POINTER_REGNUM
+ || REGNO (p->loc) == FRAME_POINTER_REGNUM
+ || REGNO (p->loc) == HARD_FRAME_POINTER_REGNUM
+ || REGNO (p->loc) == cfa_base_preserved_regno))
+ return p->loc;
/* Avoid infinite recursion trying to expand a reg into a
the same reg. */
if ((REG_P (p->loc))
else if (!REG_P (p->loc))
{
rtx result, note;
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (dump_file && (dump_flags & TDF_CSELIB))
{
print_inline_rtx (dump_file, p->loc, 0);
fprintf (dump_file, "\n");
if (regno != UINT_MAX)
{
rtx result;
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (dump_file && (dump_flags & TDF_CSELIB))
fprintf (dump_file, "r%d\n", regno);
result = cselib_expand_value_rtx_1 (reg_result, evd, max_depth - 1);
return result;
}
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (dump_file && (dump_flags & TDF_CSELIB))
{
if (reg_result)
{
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);
}
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. */
if (GET_MODE (l->elt->val_rtx) == GET_MODE (orig))
{
rtx result;
- int regno = REGNO (orig);
+ unsigned regno = REGNO (orig);
/* The only thing that we are not willing to do (this
is requirement of dse and if others potential uses
make the frame assumptions. */
if (regno == STACK_POINTER_REGNUM
|| regno == FRAME_POINTER_REGNUM
- || regno == HARD_FRAME_POINTER_REGNUM)
+ || regno == HARD_FRAME_POINTER_REGNUM
+ || regno == cfa_base_preserved_regno)
return orig;
bitmap_set_bit (evd->regs_active, regno);
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (dump_file && (dump_flags & TDF_CSELIB))
fprintf (dump_file, "expanding: r%d into: ", regno);
result = expand_loc (l->elt->locs, evd, max_depth);
{
rtx result;
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (dump_file && (dump_flags & TDF_CSELIB))
{
fputs ("\nexpanding ", dump_file);
print_rtl_single (dump_file, orig);
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. */
- copy = shallow_copy_rtx (orig);
+ if (evd->dummy)
+ copy = NULL;
+ else
+ copy = shallow_copy_rtx (orig);
format_ptr = GET_RTX_FORMAT (code);
max_depth - 1);
if (!result)
return NULL;
- XEXP (copy, i) = result;
+ if (copy)
+ XEXP (copy, i) = result;
}
break;
case 'V':
if (XVEC (orig, i) != NULL)
{
- XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
- for (j = 0; j < XVECLEN (copy, i); j++)
+ 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;
- XVECEXP (copy, i, j) = result;
+ if (copy)
+ XVECEXP (copy, i, j) = result;
}
}
break;
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,
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. */
+ allocated. However, the return value can share rtl with X.
+ If X is within a MEM, MEMMODE must be the mode of the MEM. */
rtx
-cselib_subst_to_values (rtx x)
+cselib_subst_to_values (rtx x, enum machine_mode memmode)
{
enum rtx_code code = GET_CODE (x);
const char *fmt = GET_RTX_FORMAT (code);
case MEM:
e = cselib_lookup_mem (x, 0);
+ /* This used to happen for autoincrements, but we deal with them
+ properly now. Remove the if stmt for the next release. */
if (! e)
{
- /* This happens for autoincrements. Assign a value that doesn't
- match any other. */
+ /* Assign a value that doesn't match any other. */
e = new_cselib_val (next_uid, GET_MODE (x), x);
}
return e->val_rtx;
+ case ENTRY_VALUE:
+ e = cselib_lookup (x, GET_MODE (x), 0, memmode);
+ if (! e)
+ break;
+ return e->val_rtx;
+
case CONST_DOUBLE:
case CONST_VECTOR:
case CONST_INT:
case CONST_FIXED:
return x;
- case POST_INC:
+ case PRE_DEC:
case PRE_INC:
+ gcc_assert (memmode != VOIDmode);
+ i = GET_MODE_SIZE (memmode);
+ if (code == PRE_DEC)
+ i = -i;
+ return cselib_subst_to_values (plus_constant (XEXP (x, 0), i),
+ memmode);
+
+ case PRE_MODIFY:
+ gcc_assert (memmode != VOIDmode);
+ return cselib_subst_to_values (XEXP (x, 1), memmode);
+
case POST_DEC:
- case PRE_DEC:
+ case POST_INC:
case POST_MODIFY:
- case PRE_MODIFY:
- e = new_cselib_val (next_uid, GET_MODE (x), x);
- return e->val_rtx;
+ gcc_assert (memmode != VOIDmode);
+ return cselib_subst_to_values (XEXP (x, 0), memmode);
default:
break;
{
if (fmt[i] == 'e')
{
- rtx t = cselib_subst_to_values (XEXP (x, i));
+ rtx t = cselib_subst_to_values (XEXP (x, i), memmode);
if (t != XEXP (x, i))
{
for (j = 0; j < XVECLEN (x, i); j++)
{
- rtx t = cselib_subst_to_values (XVECEXP (x, i, j));
+ rtx t = cselib_subst_to_values (XVECEXP (x, i, j), memmode);
if (t != XVECEXP (x, i, j))
{
return copy;
}
-/* Log a lookup of X to the cselib table along with the result RET. */
+/* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */
-static cselib_val *
-cselib_log_lookup (rtx x, cselib_val *ret)
+rtx
+cselib_subst_to_values_from_insn (rtx x, enum machine_mode memmode, rtx insn)
{
- 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);
- }
-
+ rtx ret;
+ gcc_assert (!cselib_current_insn);
+ cselib_current_insn = insn;
+ ret = cselib_subst_to_values (x, memmode);
+ cselib_current_insn = NULL;
return ret;
}
-/* Look up the rtl expression X in our tables and return the value it has.
- If CREATE is zero, we return NULL if we don't know the value. Otherwise,
- we create a new one if possible, using mode MODE if X doesn't have a mode
- (i.e. because it's a constant). */
+/* Look up the rtl expression X in our tables and return the value it
+ has. If CREATE is zero, we return NULL if we don't know the value.
+ Otherwise, we create a new one if possible, using mode MODE if X
+ doesn't have a mode (i.e. because it's a constant). When X is part
+ of an address, MEMMODE should be the mode of the enclosing MEM if
+ we're tracking autoinc expressions. */
-cselib_val *
-cselib_lookup (rtx x, enum machine_mode mode, int create)
+static cselib_val *
+cselib_lookup_1 (rtx x, enum machine_mode mode,
+ int create, enum machine_mode memmode)
{
void **slot;
cselib_val *e;
l = l->next;
for (; l; l = l->next)
if (mode == GET_MODE (l->elt->val_rtx))
- return cselib_log_lookup (x, l->elt);
+ {
+ promote_debug_loc (l->elt->locs);
+ return l->elt;
+ }
if (! create)
- return cselib_log_lookup (x, 0);
+ return 0;
if (i < FIRST_PSEUDO_REGISTER)
{
}
e = new_cselib_val (next_uid, GET_MODE (x), x);
- e->locs = new_elt_loc_list (e->locs, x);
+ new_elt_loc_list (e, x);
if (REG_VALUES (i) == 0)
{
/* Maintain the invariant that the first entry of
used_regs[n_used_regs++] = i;
REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL);
}
+ else if (cselib_preserve_constants
+ && GET_MODE_CLASS (mode) == MODE_INT)
+ {
+ /* During var-tracking, try harder to find equivalences
+ for SUBREGs. If a setter sets say a DImode register
+ and user uses that register only in SImode, add a lowpart
+ subreg location. */
+ struct elt_list *lwider = NULL;
+ l = REG_VALUES (i);
+ if (l && l->elt == NULL)
+ l = l->next;
+ for (; l; l = l->next)
+ if (GET_MODE_CLASS (GET_MODE (l->elt->val_rtx)) == MODE_INT
+ && GET_MODE_SIZE (GET_MODE (l->elt->val_rtx))
+ > GET_MODE_SIZE (mode)
+ && (lwider == NULL
+ || GET_MODE_SIZE (GET_MODE (l->elt->val_rtx))
+ < GET_MODE_SIZE (GET_MODE (lwider->elt->val_rtx))))
+ {
+ struct elt_loc_list *el;
+ if (i < FIRST_PSEUDO_REGISTER
+ && hard_regno_nregs[i][GET_MODE (l->elt->val_rtx)] != 1)
+ continue;
+ for (el = l->elt->locs; el; el = el->next)
+ if (!REG_P (el->loc))
+ break;
+ if (el)
+ lwider = l;
+ }
+ if (lwider)
+ {
+ rtx sub = lowpart_subreg (mode, lwider->elt->val_rtx,
+ GET_MODE (lwider->elt->val_rtx));
+ if (sub)
+ new_elt_loc_list (e, sub);
+ }
+ }
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 = cselib_find_slot (x, e->hash, INSERT, memmode);
*slot = e;
- return cselib_log_lookup (x, e);
+ return e;
}
if (MEM_P (x))
- return cselib_log_lookup (x, cselib_lookup_mem (x, create));
+ return cselib_lookup_mem (x, create);
- hashval = cselib_hash_rtx (x, create);
+ hashval = cselib_hash_rtx (x, create, memmode);
/* Can't even create if hashing is not possible. */
if (! hashval)
- return cselib_log_lookup (x, 0);
+ return 0;
- slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
- hashval, create ? INSERT : NO_INSERT);
+ slot = cselib_find_slot (wrap_constant (mode, x), hashval,
+ create ? INSERT : NO_INSERT, memmode);
if (slot == 0)
- return cselib_log_lookup (x, 0);
+ return 0;
e = (cselib_val *) *slot;
if (e)
- return cselib_log_lookup (x, e);
+ return e;
e = new_cselib_val (hashval, mode, x);
the hash table is inconsistent until we do so, and
cselib_subst_to_values will need to do lookups. */
*slot = (void *) e;
- e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x));
- return cselib_log_lookup (x, e);
+ new_elt_loc_list (e, cselib_subst_to_values (x, memmode));
+ 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, enum machine_mode memmode, rtx insn)
+{
+ cselib_val *ret;
+
+ gcc_assert (!cselib_current_insn);
+ cselib_current_insn = insn;
+
+ ret = cselib_lookup (x, mode, create, memmode);
+
+ 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, enum machine_mode memmode)
+{
+ cselib_val *ret = cselib_lookup_1 (x, mode, create, memmode);
+
+ /* ??? 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_CSELIB))
+ {
+ 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
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 && v != NULL)
this_last = end_hard_regno (GET_MODE (v->val_rtx), i) - 1;
- if (this_last < regno || v == NULL)
+ if (this_last < regno || v == NULL
+ || (v == cfa_base_preserved_val
+ && i == cfa_base_preserved_regno))
{
l = &(*l)->next;
continue;
else
unchain_one_elt_list (l);
+ v = canonical_cselib_val (v);
+
+ 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. */
for (p = &v->locs; ; p = &(*p)->next)
break;
}
}
- if (v->locs == 0 && !PRESERVED_VALUE_P (v->val_rtx))
- 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. */
-
-static bool
-cselib_rtx_varies_p (const_rtx x ATTRIBUTE_UNUSED, bool from_alias ATTRIBUTE_UNUSED)
-{
- /* 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;
-}
-
/* 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). */
{
bool has_mem = false;
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)
{
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))
+ && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx),
+ mem_addr, x, NULL_RTX))
{
has_mem = true;
num_mems++;
/* 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);
+ addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0, GET_MODE (x));
+ addr = canonical_cselib_val (addr);
+ gcc_checking_assert (v == canonical_cselib_val (v));
mem_chain = &addr->addr_list;
for (;;)
{
- if ((*mem_chain)->elt == v)
+ cselib_val *canon = canonical_cselib_val ((*mem_chain)->elt);
+
+ if (canon == v)
{
unchain_one_elt_list (mem_chain);
break;
}
+ /* Record canonicalized elt. */
+ (*mem_chain)->elt = canon;
+
mem_chain = &(*mem_chain)->next;
}
}
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++;
+ }
next = v->next_containing_mem;
if (has_mem)
cselib_invalidate_regno (REGNO (dest), GET_MODE (dest));
else if (MEM_P (dest))
cselib_invalidate_mem (dest);
-
- /* Some machines don't define AUTO_INC_DEC, but they still use push
- instructions. We need to catch that case here in order to
- 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);
}
/* A wrapper for cselib_invalidate_rtx to be called via note_stores. */
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);
+ new_elt_loc_list (src_elt, dest);
}
else if (MEM_P (dest) && dest_addr_elt != 0
&& cselib_record_memory)
}
}
+/* Make ELT and X's VALUE equivalent to each other at INSN. */
+
+void
+cselib_add_permanent_equiv (cselib_val *elt, rtx x, rtx insn)
+{
+ cselib_val *nelt;
+ rtx save_cselib_current_insn = cselib_current_insn;
+
+ gcc_checking_assert (elt);
+ gcc_checking_assert (PRESERVED_VALUE_P (elt->val_rtx));
+ gcc_checking_assert (!side_effects_p (x));
+
+ cselib_current_insn = insn;
+
+ nelt = cselib_lookup (x, GET_MODE (elt->val_rtx), 1, VOIDmode);
+
+ if (nelt != elt)
+ {
+ cselib_any_perm_equivs = true;
+
+ if (!PRESERVED_VALUE_P (nelt->val_rtx))
+ cselib_preserve_value (nelt);
+
+ new_elt_loc_list (nelt, elt->val_rtx);
+ }
+
+ cselib_current_insn = save_cselib_current_insn;
+}
+
+/* Return TRUE if any permanent equivalences have been recorded since
+ the table was last initialized. */
+bool
+cselib_have_permanent_equivalences (void)
+{
+ return cselib_any_perm_equivs;
+}
+
/* 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. */
+struct cselib_record_autoinc_data
+{
+ struct cselib_set *sets;
+ int n_sets;
+};
+
+/* Callback for for_each_inc_dec. Records in ARG the SETs implied by
+ autoinc RTXs: SRC plus SRCOFF if non-NULL is stored in DEST. */
+
+static int
+cselib_record_autoinc_cb (rtx mem ATTRIBUTE_UNUSED, rtx op ATTRIBUTE_UNUSED,
+ rtx dest, rtx src, rtx srcoff, void *arg)
+{
+ struct cselib_record_autoinc_data *data;
+ data = (struct cselib_record_autoinc_data *)arg;
+
+ data->sets[data->n_sets].dest = dest;
+
+ if (srcoff)
+ data->sets[data->n_sets].src = gen_rtx_PLUS (GET_MODE (src), src, srcoff);
+ else
+ data->sets[data->n_sets].src = src;
+
+ data->n_sets++;
+
+ return -1;
+}
+
+/* Record the effects of any sets and autoincs in INSN. */
static void
cselib_record_sets (rtx insn)
{
struct cselib_set sets[MAX_SETS];
rtx body = PATTERN (insn);
rtx cond = 0;
+ int n_sets_before_autoinc;
+ struct cselib_record_autoinc_data data;
body = PATTERN (insn);
if (GET_CODE (body) == COND_EXEC)
sets[0].src = XEXP (note, 0);
}
+ data.sets = sets;
+ data.n_sets = n_sets_before_autoinc = n_sets;
+ for_each_inc_dec (&insn, cselib_record_autoinc_cb, &data);
+ n_sets = data.n_sets;
+
/* Look up the values that are read. Do this before invalidating the
locations that are written. */
for (i = 0; i < n_sets; i++)
rtx src = sets[i].src;
if (cond)
src = gen_rtx_IF_THEN_ELSE (GET_MODE (dest), cond, src, dest);
- sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1);
+ sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1, VOIDmode);
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);
+ address_mode, 1,
+ GET_MODE (dest));
}
else
sets[i].dest_addr_elt = 0;
locations may go away. */
note_stores (body, cselib_invalidate_rtx_note_stores, NULL);
+ for (i = n_sets_before_autoinc; i < n_sets; i++)
+ cselib_invalidate_rtx (sets[i].dest);
+
/* 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
&& MEM_VOLATILE_P (PATTERN (insn))))
{
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;
}
cselib_record_sets (insn);
-#ifdef AUTO_INC_DEC
- /* Clobber any registers which appear in REG_INC notes. We
- could keep track of the changes to their values, but it is
- 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));
-#endif
-
/* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
after we have processed the insn. */
if (CALL_P (insn))
if (GET_CODE (XEXP (x, 0)) == CLOBBER)
cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
- cselib_current_insn = 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 / 4)
+ && ((unsigned int)n_useless_values
+ > (cselib_hash_table->n_elements
+ - cselib_hash_table->n_deleted
+ - n_debug_values) / 4))
remove_useless_values ();
}
init_alias_analysis. */
void
-cselib_init (bool record_memory)
+cselib_init (int record_what)
{
elt_list_pool = create_alloc_pool ("elt_list",
sizeof (struct elt_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_memory;
+ cselib_record_memory = record_what & CSELIB_RECORD_MEMORY;
+ cselib_preserve_constants = record_what & CSELIB_PRESERVE_CONSTANTS;
+ cselib_any_perm_equivs = false;
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
see canon_true_dependence. This is only created once. */
if (!reg_values || reg_values_size < cselib_nregs
|| (reg_values_size > 10 && reg_values_size > cselib_nregs * 4))
{
- if (reg_values)
- free (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;
cselib_finish (void)
{
cselib_discard_hook = NULL;
+ cselib_preserve_constants = false;
+ cselib_any_perm_equivs = 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);
used_regs = 0;
cselib_hash_table = 0;
n_useless_values = 0;
+ n_useless_debug_values = 0;
+ n_debug_values = 0;
next_uid = 0;
}
fputs (" locs:", out);
do
{
- fprintf (out, "\n from insn %i ",
- INSN_UID (l->setting_insn));
+ if (l->setting_insn)
+ fprintf (out, "\n from insn %i ",
+ INSN_UID (l->setting_insn));
+ else
+ fprintf (out, "\n ");
print_inline_rtx (out, l->loc, 4);
}
while ((l = l->next));
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