/* Web construction code for GNU compiler.
Contributed by Jan Hubicka.
- Copyright (C) 2001, 2002 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2004 Free Software Foundation, Inc.
This file is part of GCC.
02111-1307, USA. */
/* Simple optimization pass that splits independent uses of each pseudo,
- increasing effectivity of other optimizations. The optimization can
+ increasing effectiveness of other optimizations. The optimization can
serve as an example of use for the dataflow module.
We don't split registers with REG_USERVAR set unless -fmessy-debugging
#include "rtl.h"
#include "hard-reg-set.h"
#include "flags.h"
+#include "obstack.h"
#include "basic-block.h"
#include "output.h"
#include "df.h"
rtx reg;
};
-static struct web_entry *unionfind_root PARAMS ((struct web_entry *));
-static void unionfind_union PARAMS ((struct web_entry *,
- struct web_entry *));
-static void union_defs PARAMS ((struct df *, struct ref *,
- struct web_entry *,
- struct web_entry *));
-static rtx entry_register PARAMS ((struct web_entry *,
- struct ref *, char *, char *));
-static void replace_ref PARAMS ((struct ref *, rtx));
-static int mark_addressof PARAMS ((rtx *, void *));
+static struct web_entry *unionfind_root (struct web_entry *);
+static void unionfind_union (struct web_entry *, struct web_entry *);
+static void union_defs (struct df *, struct ref *, struct web_entry *,
+ struct web_entry *);
+static rtx entry_register (struct web_entry *, struct ref *, char *);
+static void replace_ref (struct ref *, rtx);
/* Find the root of unionfind tree (the representative of set). */
static struct web_entry *
-unionfind_root (element)
- struct web_entry *element;
+unionfind_root (struct web_entry *element)
{
struct web_entry *element1 = element, *element2;
/* Union sets. */
static void
-unionfind_union (first, second)
- struct web_entry *first, *second;
+unionfind_union (struct web_entry *first, struct web_entry *second)
{
first = unionfind_root (first);
second = unionfind_root (second);
register, union them. */
static void
-union_defs (df, use, def_entry, use_entry)
- struct df *df;
- struct ref *use;
- struct web_entry *def_entry;
- struct web_entry *use_entry;
+union_defs (struct df *df, struct ref *use, struct web_entry *def_entry,
+ struct web_entry *use_entry)
{
rtx insn = DF_REF_INSN (use);
struct df_link *link = DF_REF_CHAIN (use);
{
struct df_link *link = DF_INSN_DEFS (df, DF_REF_INSN (use));
- while (DF_REF_REAL_REG (link->ref) != DF_REF_REAL_REG (use))
- link = link->next;
-
- unionfind_union (use_entry + DF_REF_ID (use),
- def_entry + DF_REF_ID (link->ref));
+ while (link)
+ {
+ if (DF_REF_REAL_REG (link->ref) == DF_REF_REAL_REG (use))
+ unionfind_union (use_entry + DF_REF_ID (use),
+ def_entry + DF_REF_ID (link->ref));
+ link = link->next;
+ }
}
}
/* Find the corresponding register for the given entry. */
static rtx
-entry_register (entry, ref, used, use_addressof)
- struct web_entry *entry;
- struct ref *ref;
- char *used;
- char *use_addressof;
+entry_register (struct web_entry *entry, struct ref *ref, char *used)
{
struct web_entry *root;
rtx reg, newreg;
else if (REG_USERVAR_P (reg) && 0/*&& !flag_messy_debugging*/)
{
newreg = reg;
- if (rtl_dump_file)
- fprintf (rtl_dump_file,
+ if (dump_file)
+ fprintf (dump_file,
"New web forced to keep reg=%i (user variable)\n",
REGNO (reg));
}
- else if (use_addressof [REGNO (reg)])
- {
- newreg = reg;
- if (rtl_dump_file)
- fprintf (rtl_dump_file,
- "New web forced to keep reg=%i (address taken)\n",
- REGNO (reg));
- }
else
{
newreg = gen_reg_rtx (GET_MODE (reg));
REG_USERVAR_P (newreg) = REG_USERVAR_P (reg);
REG_POINTER (newreg) = REG_POINTER (reg);
- REG_LOOP_TEST_P (newreg) = REG_LOOP_TEST_P (reg);
- RTX_UNCHANGING_P (newreg) = RTX_UNCHANGING_P (reg);
REG_ATTRS (newreg) = REG_ATTRS (reg);
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Web oldreg=%i newreg=%i\n", REGNO (reg),
+ if (dump_file)
+ fprintf (dump_file, "Web oldreg=%i newreg=%i\n", REGNO (reg),
REGNO (newreg));
}
/* Replace the reference by REG. */
static void
-replace_ref (ref, reg)
- struct ref *ref;
- rtx reg;
+replace_ref (struct ref *ref, rtx reg)
{
rtx oldreg = DF_REF_REAL_REG (ref);
rtx *loc = DF_REF_REAL_LOC (ref);
if (oldreg == reg)
return;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Updating insn %i (%i->%i)\n",
+ if (dump_file)
+ fprintf (dump_file, "Updating insn %i (%i->%i)\n",
INSN_UID (DF_REF_INSN (ref)), REGNO (oldreg), REGNO (reg));
*loc = reg;
}
-/* Mark each pseudo whose address is taken. */
-
-static int
-mark_addressof (rtl, data)
- rtx *rtl;
- void *data;
-{
- if (!*rtl)
- return 0;
- if (GET_CODE (*rtl) == ADDRESSOF
- && REG_P (XEXP (*rtl, 0)))
- ((char *)data)[REGNO (XEXP (*rtl, 0))] = 1;
- return 0;
-}
-
/* Main entry point. */
void
-web_main ()
+web_main (void)
{
struct df *df;
struct web_entry *def_entry;
unsigned int i;
int max = max_reg_num ();
char *used;
- char *use_addressof;
- rtx insn;
df = df_init ();
- df_analyse (df, 0, DF_UD_CHAIN | DF_EQUIV_NOTES);
+ df_analyze (df, 0, DF_UD_CHAIN | DF_EQUIV_NOTES);
- def_entry =
- (struct web_entry *) xcalloc (df->n_defs, sizeof (struct web_entry));
- use_entry =
- (struct web_entry *) xcalloc (df->n_uses, sizeof (struct web_entry));
- used = (char *) xcalloc (max, sizeof (char));
- use_addressof = (char *) xcalloc (max, sizeof (char));
+ def_entry = xcalloc (df->n_defs, sizeof (struct web_entry));
+ use_entry = xcalloc (df->n_uses, sizeof (struct web_entry));
+ used = xcalloc (max, sizeof (char));
- if (rtl_dump_file)
- df_dump (df, DF_UD_CHAIN | DF_DU_CHAIN, rtl_dump_file);
+ if (dump_file)
+ df_dump (df, DF_UD_CHAIN | DF_DU_CHAIN, dump_file);
/* Produce the web. */
for (i = 0; i < df->n_uses; i++)
union_defs (df, df->uses[i], def_entry, use_entry);
- /* We can not safely rename registers whose address is taken. */
- for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
- if (INSN_P (insn))
- for_each_rtx (&PATTERN (insn), mark_addressof, use_addressof);
-
/* Update the instruction stream, allocating new registers for split pseudos
in progress. */
for (i = 0; i < df->n_uses; i++)
replace_ref (df->uses[i], entry_register (use_entry + i, df->uses[i],
- used, use_addressof));
+ used));
for (i = 0; i < df->n_defs; i++)
replace_ref (df->defs[i], entry_register (def_entry + i, df->defs[i],
- used, use_addressof));
+ used));
/* Dataflow information is corrupt here, but it can be easily updated
by creating new entries for new registers and updates or calling
free (def_entry);
free (use_entry);
free (used);
- free (use_addressof);
df_finish (df);
}
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