/* Web construction code for GNU compiler.
Contributed by Jan Hubicka.
- Copyright (C) 2001, 2002, 2004, 2006, 2007
+ Copyright (C) 2001, 2002, 2004, 2006, 2007, 2008, 2010
Free Software Foundation, Inc.
This file is part of GCC.
is almost unusable.
TODO
- - Add code to keep debugging up-to-date after splitting user variable
- pseudos. This can be done by keeping track of all the pseudos used
- for the variable and using life analysis information before reload
- to determine which one is live and, in case more than one are live,
- choose the one with the latest definition.
-
- Other optimization passes can benefit from the infrastructure too.
-
- We may use profile information and ignore infrequent use for the
purpose of web unifying, inserting the compensation code later to
implement full induction variable expansion for loops (currently
#include "output.h"
#include "df.h"
#include "function.h"
+#include "insn-config.h"
+#include "recog.h"
#include "timevar.h"
#include "tree-pass.h"
-static rtx entry_register (struct web_entry *, df_ref, char *);
-static void replace_ref (df_ref, rtx);
-
/* Find the root of unionfind tree (the representative of set). */
struct web_entry *
return element;
}
-/* Union sets.
+/* Union sets.
Return true if FIRST and SECOND points to the same web entry structure and
nothing is done. Otherwise, return false. */
return false;
}
+/* For INSN, union all defs and uses that are linked by match_dup.
+ FUN is the function that does the union. */
+
+static void
+union_match_dups (rtx insn, struct web_entry *def_entry,
+ struct web_entry *use_entry,
+ bool (*fun) (struct web_entry *, struct web_entry *))
+{
+ struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
+ df_ref *use_link = DF_INSN_INFO_USES (insn_info);
+ df_ref *def_link = DF_INSN_INFO_DEFS (insn_info);
+ int i;
+
+ extract_insn (insn);
+
+ for (i = 0; i < recog_data.n_dups; i++)
+ {
+ int op = recog_data.dup_num[i];
+ enum op_type type = recog_data.operand_type[op];
+ df_ref *ref, *dupref;
+ struct web_entry *entry;
+
+ for (dupref = use_link; *dupref; dupref++)
+ if (DF_REF_LOC (*dupref) == recog_data.dup_loc[i])
+ break;
+
+ if (*dupref == NULL
+ || DF_REF_REGNO (*dupref) < FIRST_PSEUDO_REGISTER)
+ continue;
+
+ ref = type == OP_IN ? use_link : def_link;
+ entry = type == OP_IN ? use_entry : def_entry;
+ for (; *ref; ref++)
+ if (DF_REF_LOC (*ref) == recog_data.operand_loc[op])
+ break;
+
+ (*fun) (use_entry + DF_REF_ID (*dupref), entry + DF_REF_ID (*ref));
+ }
+}
+
/* For each use, all possible defs reaching it must come in the same
register, union them.
- FUN is the function that does the union. */
+ FUN is the function that does the union.
+
+ In USED, we keep the DF_REF_ID of the first uninitialized uses of a
+ register, so that all uninitialized uses of the register can be
+ combined into a single web. We actually offset it by 2, because
+ the values 0 and 1 are reserved for use by entry_register. */
void
union_defs (df_ref use, struct web_entry *def_entry,
- struct web_entry *use_entry,
+ unsigned int *used, struct web_entry *use_entry,
bool (*fun) (struct web_entry *, struct web_entry *))
{
struct df_insn_info *insn_info = DF_REF_INSN_INFO (use);
struct df_link *link = DF_REF_CHAIN (use);
- df_ref *use_link;
df_ref *eq_use_link;
df_ref *def_link;
rtx set;
if (insn_info)
{
rtx insn = insn_info->insn;
- use_link = DF_INSN_INFO_USES (insn_info);
eq_use_link = DF_INSN_INFO_EQ_USES (insn_info);
def_link = DF_INSN_INFO_DEFS (insn_info);
set = single_set (insn);
else
{
/* An artificial use. It links up with nothing. */
- use_link = NULL;
eq_use_link = NULL;
def_link = NULL;
set = NULL;
}
- /* Some instructions may use match_dup for their operands. In case the
- operands are dead, we will assign them different pseudos, creating
- invalid instructions, so union all uses of the same operand for each
- insn. */
-
- if (use_link)
- while (*use_link)
- {
- if (use != *use_link
- && DF_REF_REAL_REG (use) == DF_REF_REAL_REG (*use_link))
- (*fun) (use_entry + DF_REF_ID (use),
- use_entry + DF_REF_ID (*use_link));
- use_link++;
- }
+ /* Union all occurrences of the same register in reg notes. */
if (eq_use_link)
while (*eq_use_link)
def_link++;
}
}
+
+ /* UD chains of uninitialized REGs are empty. Keeping all uses of
+ the same uninitialized REG in a single web is not necessary for
+ correctness, since the uses are undefined, but it's wasteful to
+ allocate one register or slot for each reference. Furthermore,
+ creating new pseudos for uninitialized references in debug insns
+ (see PR 42631) causes -fcompare-debug failures. We record the
+ number of the first uninitialized reference we found, and merge
+ with it any other uninitialized references to the same
+ register. */
+ if (!link)
+ {
+ int regno = REGNO (DF_REF_REAL_REG (use));
+ if (used[regno])
+ (*fun) (use_entry + DF_REF_ID (use), use_entry + used[regno] - 2);
+ else
+ used[regno] = DF_REF_ID (use) + 2;
+ }
+
while (link)
{
(*fun) (use_entry + DF_REF_ID (use),
/* Find the corresponding register for the given entry. */
static rtx
-entry_register (struct web_entry *entry, df_ref ref, char *used)
+entry_register (struct web_entry *entry, df_ref ref, unsigned int *used)
{
struct web_entry *root;
rtx reg, newreg;
/* We are seeing this web for the first time, do the assignment. */
reg = DF_REF_REAL_REG (ref);
- /* In case the original register is already assigned, generate new one. */
- if (!used[REGNO (reg)])
+ /* In case the original register is already assigned, generate new
+ one. Since we use USED to merge uninitialized refs into a single
+ web, we might found an element to be nonzero without our having
+ used it. Test for 1, because union_defs saves it for our use,
+ and there won't be any use for the other values when we get to
+ this point. */
+ if (used[REGNO (reg)] != 1)
newreg = reg, used[REGNO (reg)] = 1;
- else if (REG_USERVAR_P (reg) && 0/*&& !flag_messy_debugging*/)
- {
- newreg = reg;
- if (dump_file)
- fprintf (dump_file,
- "New web forced to keep reg=%i (user variable)\n",
- REGNO (reg));
- }
else
{
newreg = gen_reg_rtx (GET_MODE (reg));
return;
if (dump_file)
fprintf (dump_file, "Updating insn %i (%i->%i)\n",
- uid, REGNO (oldreg), REGNO (reg));
+ uid, REGNO (oldreg), REGNO (reg));
*loc = reg;
df_insn_rescan (DF_REF_INSN (ref));
}
struct web_entry *def_entry;
struct web_entry *use_entry;
unsigned int max = max_reg_num ();
- char *used;
+ unsigned int *used;
basic_block bb;
unsigned int uses_num = 0;
rtx insn;
FOR_BB_INSNS (bb, insn)
{
unsigned int uid = INSN_UID (insn);
- if (INSN_P (insn))
+ if (NONDEBUG_INSN_P (insn))
{
df_ref *use_rec;
for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
/* Record the number of uses and defs at the beginning of the optimization. */
def_entry = XCNEWVEC (struct web_entry, DF_DEFS_TABLE_SIZE());
- used = XCNEWVEC (char, max);
+ used = XCNEWVEC (unsigned, max);
use_entry = XCNEWVEC (struct web_entry, uses_num);
/* Produce the web. */
FOR_BB_INSNS (bb, insn)
{
unsigned int uid = INSN_UID (insn);
- if (INSN_P (insn))
+ if (NONDEBUG_INSN_P (insn))
{
df_ref *use_rec;
+ union_match_dups (insn, def_entry, use_entry, unionfind_union);
for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
{
df_ref use = *use_rec;
if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER)
- union_defs (use, def_entry, use_entry, unionfind_union);
+ union_defs (use, def_entry, used, use_entry, unionfind_union);
}
for (use_rec = DF_INSN_UID_EQ_USES (uid); *use_rec; use_rec++)
{
df_ref use = *use_rec;
if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER)
- union_defs (use, def_entry, use_entry, unionfind_union);
+ union_defs (use, def_entry, used, use_entry, unionfind_union);
}
}
}
FOR_BB_INSNS (bb, insn)
{
unsigned int uid = INSN_UID (insn);
- if (INSN_P (insn))
+ if (NONDEBUG_INSN_P (insn))
{
df_ref *use_rec;
df_ref *def_rec;
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_df_finish | TODO_verify_rtl_sharing |
+ TODO_df_finish | TODO_verify_rtl_sharing |
TODO_dump_func /* todo_flags_finish */
}
};
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