Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 2981 insertions, 0 deletions

diff --git a/gcc-4.9/gcc/gensupport.c b/gcc-4.9/gcc/gensupport.c
new file mode 100644
index 000000000..33ea81363
--- /dev/null
+++ b/gcc-4.9/gcc/gensupport.c
@@ -0,0 +1,2981 @@
+/* Support routines for the various generation passes.
+   Copyright (C) 2000-2014 Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   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.
+
+   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 GCC; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "bconfig.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "rtl.h"
+#include "obstack.h"
+#include "errors.h"
+#include "hashtab.h"
+#include "read-md.h"
+#include "gensupport.h"
+
+#define MAX_OPERANDS 40
+
+static rtx operand_data[MAX_OPERANDS];
+static rtx match_operand_entries_in_pattern[MAX_OPERANDS];
+static char used_operands_numbers[MAX_OPERANDS];
+
+
+/* In case some macros used by files we include need it, define this here.  */
+int target_flags;
+
+int insn_elision = 1;
+
+static struct obstack obstack;
+struct obstack *rtl_obstack = &obstack;
+
+/* Counter for patterns that generate code: define_insn, define_expand,
+   define_split, define_peephole, and define_peephole2.  See read_md_rtx().
+   Any define_insn_and_splits are already in separate queues so that the
+   insn and the splitter get a unique number also.  */
+static int sequence_num;
+
+static int predicable_default;
+static const char *predicable_true;
+static const char *predicable_false;
+
+static const char *subst_true = "yes";
+static const char *subst_false = "no";
+
+static htab_t condition_table;
+
+/* We initially queue all patterns, process the define_insn,
+   define_cond_exec and define_subst patterns, then return
+   them one at a time.  */
+
+struct queue_elem
+{
+  rtx data;
+  const char *filename;
+  int lineno;
+  struct queue_elem *next;
+  /* In a DEFINE_INSN that came from a DEFINE_INSN_AND_SPLIT, SPLIT
+     points to the generated DEFINE_SPLIT.  */
+  struct queue_elem *split;
+};
+
+#define MNEMONIC_ATTR_NAME "mnemonic"
+#define MNEMONIC_HTAB_SIZE 1024
+
+static struct queue_elem *define_attr_queue;
+static struct queue_elem **define_attr_tail = &define_attr_queue;
+static struct queue_elem *define_pred_queue;
+static struct queue_elem **define_pred_tail = &define_pred_queue;
+static struct queue_elem *define_insn_queue;
+static struct queue_elem **define_insn_tail = &define_insn_queue;
+static struct queue_elem *define_cond_exec_queue;
+static struct queue_elem **define_cond_exec_tail = &define_cond_exec_queue;
+static struct queue_elem *define_subst_queue;
+static struct queue_elem **define_subst_tail = &define_subst_queue;
+static struct queue_elem *other_queue;
+static struct queue_elem **other_tail = &other_queue;
+static struct queue_elem *define_subst_attr_queue;
+static struct queue_elem **define_subst_attr_tail = &define_subst_attr_queue;
+
+static struct queue_elem *queue_pattern (rtx, struct queue_elem ***,
+					 const char *, int);
+
+static void remove_constraints (rtx);
+static void process_rtx (rtx, int);
+
+static int is_predicable (struct queue_elem *);
+static void identify_predicable_attribute (void);
+static int n_alternatives (const char *);
+static void collect_insn_data (rtx, int *, int *);
+static rtx alter_predicate_for_insn (rtx, int, int, int);
+static const char *alter_test_for_insn (struct queue_elem *,
+					struct queue_elem *);
+static char *shift_output_template (char *, const char *, int);
+static const char *alter_output_for_insn (struct queue_elem *,
+					  struct queue_elem *,
+					  int, int);
+static void process_one_cond_exec (struct queue_elem *);
+static void process_define_cond_exec (void);
+static void init_predicate_table (void);
+static void record_insn_name (int, const char *);
+
+static bool has_subst_attribute (struct queue_elem *, struct queue_elem *);
+static bool subst_pattern_match (rtx, rtx, int);
+static int get_alternatives_number (rtx, int *, int);
+static const char * alter_output_for_subst_insn (rtx, int);
+static void alter_attrs_for_subst_insn (struct queue_elem *, int);
+static void process_substs_on_one_elem (struct queue_elem *,
+					struct queue_elem *);
+static rtx subst_dup (rtx, int, int);
+static void process_define_subst (void);
+
+static const char * duplicate_alternatives (const char *, int);
+static const char * duplicate_each_alternative (const char * str, int n_dup);
+
+typedef const char * (*constraints_handler_t) (const char *, int);
+static rtx alter_constraints (rtx, int, constraints_handler_t);
+static rtx adjust_operands_numbers (rtx);
+static rtx replace_duplicating_operands_in_pattern (rtx);
+
+/* Make a version of gen_rtx_CONST_INT so that GEN_INT can be used in
+   the gensupport programs.  */
+
+rtx
+gen_rtx_CONST_INT (enum machine_mode ARG_UNUSED (mode),
+		   HOST_WIDE_INT arg)
+{
+  rtx rt = rtx_alloc (CONST_INT);
+
+  XWINT (rt, 0) = arg;
+  return rt;
+}
+
+/* Predicate handling.
+
+   We construct from the machine description a table mapping each
+   predicate to a list of the rtl codes it can possibly match.  The
+   function 'maybe_both_true' uses it to deduce that there are no
+   expressions that can be matches by certain pairs of tree nodes.
+   Also, if a predicate can match only one code, we can hardwire that
+   code into the node testing the predicate.
+
+   Some predicates are flagged as special.  validate_pattern will not
+   warn about modeless match_operand expressions if they have a
+   special predicate.  Predicates that allow only constants are also
+   treated as special, for this purpose.
+
+   validate_pattern will warn about predicates that allow non-lvalues
+   when they appear in destination operands.
+
+   Calculating the set of rtx codes that can possibly be accepted by a
+   predicate expression EXP requires a three-state logic: any given
+   subexpression may definitively accept a code C (Y), definitively
+   reject a code C (N), or may have an indeterminate effect (I).  N
+   and I is N; Y or I is Y; Y and I, N or I are both I.  Here are full
+   truth tables.
+
+     a b  a&b  a|b
+     Y Y   Y    Y
+     N Y   N    Y
+     N N   N    N
+     I Y   I    Y
+     I N   N    I
+     I I   I    I
+
+   We represent Y with 1, N with 0, I with 2.  If any code is left in
+   an I state by the complete expression, we must assume that that
+   code can be accepted.  */
+
+#define N 0
+#define Y 1
+#define I 2
+
+#define TRISTATE_AND(a,b)			\
+  ((a) == I ? ((b) == N ? N : I) :		\
+   (b) == I ? ((a) == N ? N : I) :		\
+   (a) && (b))
+
+#define TRISTATE_OR(a,b)			\
+  ((a) == I ? ((b) == Y ? Y : I) :		\
+   (b) == I ? ((a) == Y ? Y : I) :		\
+   (a) || (b))
+
+#define TRISTATE_NOT(a)				\
+  ((a) == I ? I : !(a))
+
+/* 0 means no warning about that code yet, 1 means warned.  */
+static char did_you_mean_codes[NUM_RTX_CODE];
+
+/* Recursively calculate the set of rtx codes accepted by the
+   predicate expression EXP, writing the result to CODES.  LINENO is
+   the line number on which the directive containing EXP appeared.  */
+
+static void
+compute_predicate_codes (rtx exp, int lineno, char codes[NUM_RTX_CODE])
+{
+  char op0_codes[NUM_RTX_CODE];
+  char op1_codes[NUM_RTX_CODE];
+  char op2_codes[NUM_RTX_CODE];
+  int i;
+
+  switch (GET_CODE (exp))
+    {
+    case AND:
+      compute_predicate_codes (XEXP (exp, 0), lineno, op0_codes);
+      compute_predicate_codes (XEXP (exp, 1), lineno, op1_codes);
+      for (i = 0; i < NUM_RTX_CODE; i++)
+	codes[i] = TRISTATE_AND (op0_codes[i], op1_codes[i]);
+      break;
+
+    case IOR:
+      compute_predicate_codes (XEXP (exp, 0), lineno, op0_codes);
+      compute_predicate_codes (XEXP (exp, 1), lineno, op1_codes);
+      for (i = 0; i < NUM_RTX_CODE; i++)
+	codes[i] = TRISTATE_OR (op0_codes[i], op1_codes[i]);
+      break;
+    case NOT:
+      compute_predicate_codes (XEXP (exp, 0), lineno, op0_codes);
+      for (i = 0; i < NUM_RTX_CODE; i++)
+	codes[i] = TRISTATE_NOT (op0_codes[i]);
+      break;
+
+    case IF_THEN_ELSE:
+      /* a ? b : c  accepts the same codes as (a & b) | (!a & c).  */
+      compute_predicate_codes (XEXP (exp, 0), lineno, op0_codes);
+      compute_predicate_codes (XEXP (exp, 1), lineno, op1_codes);
+      compute_predicate_codes (XEXP (exp, 2), lineno, op2_codes);
+      for (i = 0; i < NUM_RTX_CODE; i++)
+	codes[i] = TRISTATE_OR (TRISTATE_AND (op0_codes[i], op1_codes[i]),
+				TRISTATE_AND (TRISTATE_NOT (op0_codes[i]),
+					      op2_codes[i]));
+      break;
+
+    case MATCH_CODE:
+      /* MATCH_CODE allows a specified list of codes.  However, if it
+	 does not apply to the top level of the expression, it does not
+	 constrain the set of codes for the top level.  */
+      if (XSTR (exp, 1)[0] != '\0')
+	{
+	  memset (codes, Y, NUM_RTX_CODE);
+	  break;
+	}
+
+      memset (codes, N, NUM_RTX_CODE);
+      {
+	const char *next_code = XSTR (exp, 0);
+	const char *code;
+
+	if (*next_code == '\0')
+	  {
+	    error_with_line (lineno, "empty match_code expression");
+	    break;
+	  }
+
+	while ((code = scan_comma_elt (&next_code)) != 0)
+	  {
+	    size_t n = next_code - code;
+	    int found_it = 0;
+
+	    for (i = 0; i < NUM_RTX_CODE; i++)
+	      if (!strncmp (code, GET_RTX_NAME (i), n)
+		  && GET_RTX_NAME (i)[n] == '\0')
+		{
+		  codes[i] = Y;
+		  found_it = 1;
+		  break;
+		}
+	    if (!found_it)
+	      {
+		error_with_line (lineno,
+				 "match_code \"%.*s\" matches nothing",
+				 (int) n, code);
+		for (i = 0; i < NUM_RTX_CODE; i++)
+		  if (!strncasecmp (code, GET_RTX_NAME (i), n)
+		      && GET_RTX_NAME (i)[n] == '\0'
+		      && !did_you_mean_codes[i])
+		    {
+		      did_you_mean_codes[i] = 1;
+		      message_with_line (lineno, "(did you mean \"%s\"?)",
+					 GET_RTX_NAME (i));
+		    }
+	      }
+	  }
+      }
+      break;
+
+    case MATCH_OPERAND:
+      /* MATCH_OPERAND disallows the set of codes that the named predicate
+	 disallows, and is indeterminate for the codes that it does allow.  */
+      {
+	struct pred_data *p = lookup_predicate (XSTR (exp, 1));
+	if (!p)
+	  {
+	    error_with_line (lineno, "reference to unknown predicate '%s'",
+			     XSTR (exp, 1));
+	    break;
+	  }
+	for (i = 0; i < NUM_RTX_CODE; i++)
+	  codes[i] = p->codes[i] ? I : N;
+      }
+      break;
+
+
+    case MATCH_TEST:
+      /* (match_test WHATEVER) is completely indeterminate.  */
+      memset (codes, I, NUM_RTX_CODE);
+      break;
+
+    default:
+      error_with_line (lineno,
+		       "'%s' cannot be used in a define_predicate expression",
+		       GET_RTX_NAME (GET_CODE (exp)));
+      memset (codes, I, NUM_RTX_CODE);
+      break;
+    }
+}
+
+#undef TRISTATE_OR
+#undef TRISTATE_AND
+#undef TRISTATE_NOT
+
+/* Return true if NAME is a valid predicate name.  */
+
+static bool
+valid_predicate_name_p (const char *name)
+{
+  const char *p;
+
+  if (!ISALPHA (name[0]) && name[0] != '_')
+    return false;
+  for (p = name + 1; *p; p++)
+    if (!ISALNUM (*p) && *p != '_')
+      return false;
+  return true;
+}
+
+/* Process define_predicate directive DESC, which appears on line number
+   LINENO.  Compute the set of codes that can be matched, and record this
+   as a known predicate.  */
+
+static void
+process_define_predicate (rtx desc, int lineno)
+{
+  struct pred_data *pred;
+  char codes[NUM_RTX_CODE];
+  int i;
+
+  if (!valid_predicate_name_p (XSTR (desc, 0)))
+    {
+      error_with_line (lineno,
+		       "%s: predicate name must be a valid C function name",
+		       XSTR (desc, 0));
+      return;
+    }
+
+  pred = XCNEW (struct pred_data);
+  pred->name = XSTR (desc, 0);
+  pred->exp = XEXP (desc, 1);
+  pred->c_block = XSTR (desc, 2);
+  if (GET_CODE (desc) == DEFINE_SPECIAL_PREDICATE)
+    pred->special = true;
+
+  compute_predicate_codes (XEXP (desc, 1), lineno, codes);
+
+  for (i = 0; i < NUM_RTX_CODE; i++)
+    if (codes[i] != N)
+      add_predicate_code (pred, (enum rtx_code) i);
+
+  add_predicate (pred);
+}
+#undef I
+#undef N
+#undef Y
+
+/* Queue PATTERN on LIST_TAIL.  Return the address of the new queue
+   element.  */
+
+static struct queue_elem *
+queue_pattern (rtx pattern, struct queue_elem ***list_tail,
+	       const char *filename, int lineno)
+{
+  struct queue_elem *e = XNEW (struct queue_elem);
+  e->data = pattern;
+  e->filename = filename;
+  e->lineno = lineno;
+  e->next = NULL;
+  e->split = NULL;
+  **list_tail = e;
+  *list_tail = &e->next;
+  return e;
+}
+
+/* Remove element ELEM from QUEUE.  */
+static void
+remove_from_queue (struct queue_elem *elem, struct queue_elem **queue)
+{
+  struct queue_elem *prev, *e;
+  prev = NULL;
+  for (e = *queue; e ; e = e->next)
+    {
+      if (e == elem)
+	break;
+      prev = e;
+    }
+  if (e == NULL)
+    return;
+
+  if (prev)
+    prev->next = elem->next;
+  else
+    *queue = elem->next;
+}
+
+/* Build a define_attr for an binary attribute with name NAME and
+   possible values "yes" and "no", and queue it.  */
+static void
+add_define_attr (const char *name)
+{
+  struct queue_elem *e = XNEW (struct queue_elem);
+  rtx t1 = rtx_alloc (DEFINE_ATTR);
+  XSTR (t1, 0) = name;
+  XSTR (t1, 1) = "no,yes";
+  XEXP (t1, 2) = rtx_alloc (CONST_STRING);
+  XSTR (XEXP (t1, 2), 0) = "yes";
+  e->data = t1;
+  e->filename = "built-in";
+  e->lineno = -1;
+  e->next = define_attr_queue;
+  define_attr_queue = e;
+
+}
+
+/* Recursively remove constraints from an rtx.  */
+
+static void
+remove_constraints (rtx part)
+{
+  int i, j;
+  const char *format_ptr;
+
+  if (part == 0)
+    return;
+
+  if (GET_CODE (part) == MATCH_OPERAND)
+    XSTR (part, 2) = "";
+  else if (GET_CODE (part) == MATCH_SCRATCH)
+    XSTR (part, 1) = "";
+
+  format_ptr = GET_RTX_FORMAT (GET_CODE (part));
+
+  for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
+    switch (*format_ptr++)
+      {
+      case 'e':
+      case 'u':
+	remove_constraints (XEXP (part, i));
+	break;
+      case 'E':
+	if (XVEC (part, i) != NULL)
+	  for (j = 0; j < XVECLEN (part, i); j++)
+	    remove_constraints (XVECEXP (part, i, j));
+	break;
+      }
+}
+
+/* Process a top level rtx in some way, queuing as appropriate.  */
+
+static void
+process_rtx (rtx desc, int lineno)
+{
+  switch (GET_CODE (desc))
+    {
+    case DEFINE_INSN:
+      queue_pattern (desc, &define_insn_tail, read_md_filename, lineno);
+      break;
+
+    case DEFINE_COND_EXEC:
+      queue_pattern (desc, &define_cond_exec_tail, read_md_filename, lineno);
+      break;
+
+    case DEFINE_SUBST:
+      queue_pattern (desc, &define_subst_tail, read_md_filename, lineno);
+      break;
+
+    case DEFINE_SUBST_ATTR:
+      queue_pattern (desc, &define_subst_attr_tail, read_md_filename, lineno);
+      break;
+
+    case DEFINE_ATTR:
+    case DEFINE_ENUM_ATTR:
+      queue_pattern (desc, &define_attr_tail, read_md_filename, lineno);
+      break;
+
+    case DEFINE_PREDICATE:
+    case DEFINE_SPECIAL_PREDICATE:
+      process_define_predicate (desc, lineno);
+      /* Fall through.  */
+
+    case DEFINE_CONSTRAINT:
+    case DEFINE_REGISTER_CONSTRAINT:
+    case DEFINE_MEMORY_CONSTRAINT:
+    case DEFINE_ADDRESS_CONSTRAINT:
+      queue_pattern (desc, &define_pred_tail, read_md_filename, lineno);
+      break;
+
+    case DEFINE_INSN_AND_SPLIT:
+      {
+	const char *split_cond;
+	rtx split;
+	rtvec attr;
+	int i;
+	struct queue_elem *insn_elem;
+	struct queue_elem *split_elem;
+
+	/* Create a split with values from the insn_and_split.  */
+	split = rtx_alloc (DEFINE_SPLIT);
+
+	i = XVECLEN (desc, 1);
+	XVEC (split, 0) = rtvec_alloc (i);
+	while (--i >= 0)
+	  {
+	    XVECEXP (split, 0, i) = copy_rtx (XVECEXP (desc, 1, i));
+	    remove_constraints (XVECEXP (split, 0, i));
+	  }
+
+	/* If the split condition starts with "&&", append it to the
+	   insn condition to create the new split condition.  */
+	split_cond = XSTR (desc, 4);
+	if (split_cond[0] == '&' && split_cond[1] == '&')
+	  {
+	    copy_md_ptr_loc (split_cond + 2, split_cond);
+	    split_cond = join_c_conditions (XSTR (desc, 2), split_cond + 2);
+	  }
+	XSTR (split, 1) = split_cond;
+	XVEC (split, 2) = XVEC (desc, 5);
+	XSTR (split, 3) = XSTR (desc, 6);
+
+	/* Fix up the DEFINE_INSN.  */
+	attr = XVEC (desc, 7);
+	PUT_CODE (desc, DEFINE_INSN);
+	XVEC (desc, 4) = attr;
+
+	/* Queue them.  */
+	insn_elem
+	  = queue_pattern (desc, &define_insn_tail, read_md_filename,
+			   lineno);
+	split_elem
+	  = queue_pattern (split, &other_tail, read_md_filename, lineno);
+	insn_elem->split = split_elem;
+	break;
+      }
+
+    default:
+      queue_pattern (desc, &other_tail, read_md_filename, lineno);
+      break;
+    }
+}
+
+/* Return true if attribute PREDICABLE is true for ELEM, which holds
+   a DEFINE_INSN.  */
+
+static int
+is_predicable (struct queue_elem *elem)
+{
+  rtvec vec = XVEC (elem->data, 4);
+  const char *value;
+  int i;
+
+  if (! vec)
+    return predicable_default;
+
+  for (i = GET_NUM_ELEM (vec) - 1; i >= 0; --i)
+    {
+      rtx sub = RTVEC_ELT (vec, i);
+      switch (GET_CODE (sub))
+	{
+	case SET_ATTR:
+	  if (strcmp (XSTR (sub, 0), "predicable") == 0)
+	    {
+	      value = XSTR (sub, 1);
+	      goto found;
+	    }
+	  break;
+
+	case SET_ATTR_ALTERNATIVE:
+	  if (strcmp (XSTR (sub, 0), "predicable") == 0)
+	    {
+	      error_with_line (elem->lineno,
+			       "multiple alternatives for `predicable'");
+	      return 0;
+	    }
+	  break;
+
+	case SET:
+	  if (GET_CODE (SET_DEST (sub)) != ATTR
+	      || strcmp (XSTR (SET_DEST (sub), 0), "predicable") != 0)
+	    break;
+	  sub = SET_SRC (sub);
+	  if (GET_CODE (sub) == CONST_STRING)
+	    {
+	      value = XSTR (sub, 0);
+	      goto found;
+	    }
+
+	  /* ??? It would be possible to handle this if we really tried.
+	     It's not easy though, and I'm not going to bother until it
+	     really proves necessary.  */
+	  error_with_line (elem->lineno,
+			   "non-constant value for `predicable'");
+	  return 0;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  return predicable_default;
+
+ found:
+  /* Find out which value we're looking at.  Multiple alternatives means at
+     least one is predicable.  */
+  if (strchr (value, ',') != NULL)
+    return 1;
+  if (strcmp (value, predicable_true) == 0)
+    return 1;
+  if (strcmp (value, predicable_false) == 0)
+    return 0;
+
+  error_with_line (elem->lineno,
+		   "unknown value `%s' for `predicable' attribute", value);
+  return 0;
+}
+
+/* Find attribute SUBST in ELEM and assign NEW_VALUE to it.  */
+static void
+change_subst_attribute (struct queue_elem *elem,
+			struct queue_elem *subst_elem,
+			const char *new_value)
+{
+  rtvec attrs_vec = XVEC (elem->data, 4);
+  const char *subst_name = XSTR (subst_elem->data, 0);
+  int i;
+
+  if (! attrs_vec)
+    return;
+
+  for (i = GET_NUM_ELEM (attrs_vec) - 1; i >= 0; --i)
+    {
+      rtx cur_attr = RTVEC_ELT (attrs_vec, i);
+      if (GET_CODE (cur_attr) != SET_ATTR)
+	continue;
+      if (strcmp (XSTR (cur_attr, 0), subst_name) == 0)
+	{
+	  XSTR (cur_attr, 1) = new_value;
+	  return;
+	}
+    }
+}
+
+/* Return true if ELEM has the attribute with the name of DEFINE_SUBST
+   represented by SUBST_ELEM and this attribute has value SUBST_TRUE.
+   DEFINE_SUBST isn't applied to patterns without such attribute.  In other
+   words, we suppose the default value of the attribute to be 'no' since it is
+   always generated automaticaly in read-rtl.c.  */
+static bool
+has_subst_attribute (struct queue_elem *elem, struct queue_elem *subst_elem)
+{
+  rtvec attrs_vec = XVEC (elem->data, 4);
+  const char *value, *subst_name = XSTR (subst_elem->data, 0);
+  int i;
+
+  if (! attrs_vec)
+    return false;
+
+  for (i = GET_NUM_ELEM (attrs_vec) - 1; i >= 0; --i)
+    {
+      rtx cur_attr = RTVEC_ELT (attrs_vec, i);
+      switch (GET_CODE (cur_attr))
+	{
+	case SET_ATTR:
+	  if (strcmp (XSTR (cur_attr, 0), subst_name) == 0)
+	    {
+	      value = XSTR (cur_attr, 1);
+	      goto found;
+	    }
+	  break;
+
+	case SET:
+	  if (GET_CODE (SET_DEST (cur_attr)) != ATTR
+	      || strcmp (XSTR (SET_DEST (cur_attr), 0), subst_name) != 0)
+	    break;
+	  cur_attr = SET_SRC (cur_attr);
+	  if (GET_CODE (cur_attr) == CONST_STRING)
+	    {
+	      value = XSTR (cur_attr, 0);
+	      goto found;
+	    }
+
+	  /* Only (set_attr "subst" "yes/no") and
+		  (set (attr "subst" (const_string "yes/no")))
+	     are currently allowed.  */
+	  error_with_line (elem->lineno,
+			   "unsupported value for `%s'", subst_name);
+	  return false;
+
+	case SET_ATTR_ALTERNATIVE:
+	  error_with_line (elem->lineno,
+			   "%s: `set_attr_alternative' is unsupported by "
+			   "`define_subst'",
+			   XSTR (elem->data, 0));
+	  return false;
+
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  return false;
+
+ found:
+  if (strcmp (value, subst_true) == 0)
+    return true;
+  if (strcmp (value, subst_false) == 0)
+    return false;
+
+  error_with_line (elem->lineno,
+		   "unknown value `%s' for `%s' attribute", value, subst_name);
+  return false;
+}
+
+/* Compare RTL-template of original define_insn X to input RTL-template of
+   define_subst PT.  Return 1 if the templates match, 0 otherwise.
+   During the comparison, the routine also fills global_array OPERAND_DATA.  */
+static bool
+subst_pattern_match (rtx x, rtx pt, int lineno)
+{
+  RTX_CODE code, code_pt;
+  int i, j, len;
+  const char *fmt, *pred_name;
+
+  code = GET_CODE (x);
+  code_pt = GET_CODE (pt);
+
+  if (code_pt == MATCH_OPERAND)
+    {
+      /* MATCH_DUP, and MATCH_OP_DUP don't have a specified mode, so we
+	 always accept them.  */
+      if (GET_MODE (pt) != VOIDmode && GET_MODE (x) != GET_MODE (pt)
+	  && (code != MATCH_DUP && code != MATCH_OP_DUP))
+	return false; /* Modes don't match.  */
+
+      if (code == MATCH_OPERAND)
+	{
+	  pred_name = XSTR (pt, 1);
+	  if (pred_name[0] != 0)
+	    {
+	      const struct pred_data *pred_pt = lookup_predicate (pred_name);
+	      if (!pred_pt || pred_pt != lookup_predicate (XSTR (x, 1)))
+		return false; /* Predicates don't match.  */
+	    }
+	}
+
+      gcc_assert (XINT (pt, 0) >= 0 && XINT (pt, 0) < MAX_OPERANDS);
+      operand_data[XINT (pt, 0)] = x;
+      return true;
+    }
+
+  if (code_pt == MATCH_OPERATOR)
+    {
+      int x_vecexp_pos = -1;
+
+      /* Compare modes.  */
+      if (GET_MODE (pt) != VOIDmode && GET_MODE (x) != GET_MODE (pt))
+	return false;
+
+      /* In case X is also match_operator, compare predicates.  */
+      if (code == MATCH_OPERATOR)
+	{
+	  pred_name = XSTR (pt, 1);
+	  if (pred_name[0] != 0)
+	    {
+	      const struct pred_data *pred_pt = lookup_predicate (pred_name);
+	      if (!pred_pt || pred_pt != lookup_predicate (XSTR (x, 1)))
+		return false;
+	    }
+	}
+
+      /* Compare operands.
+	 MATCH_OPERATOR in input template could match in original template
+	 either 1) MATCH_OPERAND, 2) UNSPEC, 3) ordinary operation (like PLUS).
+	 In the first case operands are at (XVECEXP (x, 2, j)), in the second
+	 - at (XVECEXP (x, 0, j)), in the last one - (XEXP (x, j)).
+	 X_VECEXP_POS variable shows, where to look for these operands.  */
+      if (code == UNSPEC
+	  || code == UNSPEC_VOLATILE)
+	x_vecexp_pos = 0;
+      else if (code == MATCH_OPERATOR)
+	x_vecexp_pos = 2;
+      else
+	x_vecexp_pos = -1;
+
+      /* MATCH_OPERATOR or UNSPEC case.  */
+      if (x_vecexp_pos >= 0)
+	{
+	  /* Compare operands number in X and PT.  */
+	  if (XVECLEN (x, x_vecexp_pos) != XVECLEN (pt, 2))
+	    return false;
+	  for (j = 0; j < XVECLEN (pt, 2); j++)
+	    if (!subst_pattern_match (XVECEXP (x, x_vecexp_pos, j),
+				      XVECEXP (pt, 2, j), lineno))
+	      return false;
+	}
+
+      /* Ordinary operator.  */
+      else
+	{
+	  /* Compare operands number in X and PT.
+	     We count operands differently for X and PT since we compare
+	     an operator (with operands directly in RTX) and MATCH_OPERATOR
+	     (that has a vector with operands).  */
+	  if (GET_RTX_LENGTH (code) != XVECLEN (pt, 2))
+	    return false;
+	  for (j = 0; j < XVECLEN (pt, 2); j++)
+	    if (!subst_pattern_match (XEXP (x, j), XVECEXP (pt, 2, j), lineno))
+	      return false;
+	}
+
+      /* Store the operand to OPERAND_DATA array.  */
+      gcc_assert (XINT (pt, 0) >= 0 && XINT (pt, 0) < MAX_OPERANDS);
+      operand_data[XINT (pt, 0)] = x;
+      return true;
+    }
+
+  if (code_pt == MATCH_PAR_DUP
+      || code_pt == MATCH_DUP
+      || code_pt == MATCH_OP_DUP
+      || code_pt == MATCH_SCRATCH
+      || code_pt == MATCH_PARALLEL)
+    {
+      /* Currently interface for these constructions isn't defined -
+	 probably they aren't needed in input template of define_subst at all.
+	 So, for now their usage in define_subst is forbidden.  */
+      error_with_line (lineno, "%s cannot be used in define_subst",
+		       GET_RTX_NAME (code_pt));
+    }
+
+  gcc_assert (code != MATCH_PAR_DUP
+      && code_pt != MATCH_DUP
+      && code_pt != MATCH_OP_DUP
+      && code_pt != MATCH_SCRATCH
+      && code_pt != MATCH_PARALLEL
+      && code_pt != MATCH_OPERAND
+      && code_pt != MATCH_OPERATOR);
+  /* If PT is none of the handled above, then we match only expressions with
+     the same code in X.  */
+  if (code != code_pt)
+    return false;
+
+  fmt = GET_RTX_FORMAT (code_pt);
+  len = GET_RTX_LENGTH (code_pt);
+
+  for (i = 0; i < len; i++)
+    {
+      if (fmt[i] == '0')
+	break;
+
+      switch (fmt[i])
+	{
+	case 'i': case 'w': case 's':
+	  continue;
+
+	case 'e': case 'u':
+	  if (!subst_pattern_match (XEXP (x, i), XEXP (pt, i), lineno))
+	    return false;
+	  break;
+	case 'E':
+	  {
+	    if (XVECLEN (x, i) != XVECLEN (pt, i))
+	      return false;
+	    for (j = 0; j < XVECLEN (pt, i); j++)
+	      if (!subst_pattern_match (XVECEXP (x, i, j), XVECEXP (pt, i, j),
+					lineno))
+		return false;
+	    break;
+	  }
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  return true;
+}
+
+/* Examine the attribute "predicable"; discover its boolean values
+   and its default.  */
+
+static void
+identify_predicable_attribute (void)
+{
+  struct queue_elem *elem;
+  char *p_true, *p_false;
+  const char *value;
+
+  /* Look for the DEFINE_ATTR for `predicable', which must exist.  */
+  for (elem = define_attr_queue; elem ; elem = elem->next)
+    if (strcmp (XSTR (elem->data, 0), "predicable") == 0)
+      goto found;
+
+  error_with_line (define_cond_exec_queue->lineno,
+		   "attribute `predicable' not defined");
+  return;
+
+ found:
+  value = XSTR (elem->data, 1);
+  p_false = xstrdup (value);
+  p_true = strchr (p_false, ',');
+  if (p_true == NULL || strchr (++p_true, ',') != NULL)
+    {
+      error_with_line (elem->lineno, "attribute `predicable' is not a boolean");
+      free (p_false);
+      return;
+    }
+  p_true[-1] = '\0';
+
+  predicable_true = p_true;
+  predicable_false = p_false;
+
+  switch (GET_CODE (XEXP (elem->data, 2)))
+    {
+    case CONST_STRING:
+      value = XSTR (XEXP (elem->data, 2), 0);
+      break;
+
+    case CONST:
+      error_with_line (elem->lineno, "attribute `predicable' cannot be const");
+      free (p_false);
+      return;
+
+    default:
+      error_with_line (elem->lineno,
+		       "attribute `predicable' must have a constant default");
+      free (p_false);
+      return;
+    }
+
+  if (strcmp (value, p_true) == 0)
+    predicable_default = 1;
+  else if (strcmp (value, p_false) == 0)
+    predicable_default = 0;
+  else
+    {
+      error_with_line (elem->lineno,
+		       "unknown value `%s' for `predicable' attribute", value);
+      free (p_false);
+    }
+}
+
+/* Return the number of alternatives in constraint S.  */
+
+static int
+n_alternatives (const char *s)
+{
+  int n = 1;
+
+  if (s)
+    while (*s)
+      n += (*s++ == ',');
+
+  return n;
+}
+
+/* The routine scans rtl PATTERN, find match_operand in it and counts
+   number of alternatives.  If PATTERN contains several match_operands
+   with different number of alternatives, error is emitted, and the
+   routine returns 0.  If all match_operands in PATTERN have the same
+   number of alternatives, it's stored in N_ALT, and the routine returns 1.
+   Argument LINENO is used in when the error is emitted.  */
+static int
+get_alternatives_number (rtx pattern, int *n_alt, int lineno)
+{
+  const char *fmt;
+  enum rtx_code code;
+  int i, j, len;
+
+  if (!n_alt)
+    return 0;
+
+  code = GET_CODE (pattern);
+  switch (code)
+    {
+    case MATCH_OPERAND:
+      i = n_alternatives (XSTR (pattern, 2));
+      /* n_alternatives returns 1 if constraint string is empty -
+	 here we fix it up.  */
+      if (!*(XSTR (pattern, 2)))
+	i = 0;
+      if (*n_alt <= 0)
+	*n_alt = i;
+
+      else if (i && i != *n_alt)
+	{
+	  error_with_line (lineno,
+			   "wrong number of alternatives in operand %d",
+			   XINT (pattern, 0));
+	  return 0;
+	}
+
+    default:
+      break;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  len = GET_RTX_LENGTH (code);
+  for (i = 0; i < len; i++)
+    {
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  if (!get_alternatives_number (XEXP (pattern, i), n_alt, lineno))
+		return 0;
+	  break;
+
+	case 'V':
+	  if (XVEC (pattern, i) == NULL)
+	    break;
+
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    if (!get_alternatives_number (XVECEXP (pattern, i, j),
+					  n_alt, lineno))
+		return 0;
+	  break;
+
+	case 'i': case 'w': case '0': case 's': case 'S': case 'T':
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+    return 1;
+}
+
+/* Determine how many alternatives there are in INSN, and how many
+   operands.  */
+
+static void
+collect_insn_data (rtx pattern, int *palt, int *pmax)
+{
+  const char *fmt;
+  enum rtx_code code;
+  int i, j, len;
+
+  code = GET_CODE (pattern);
+  switch (code)
+    {
+    case MATCH_OPERAND:
+      i = n_alternatives (XSTR (pattern, 2));
+      *palt = (i > *palt ? i : *palt);
+      /* Fall through.  */
+
+    case MATCH_OPERATOR:
+    case MATCH_SCRATCH:
+    case MATCH_PARALLEL:
+      i = XINT (pattern, 0);
+      if (i > *pmax)
+	*pmax = i;
+      break;
+
+    default:
+      break;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  len = GET_RTX_LENGTH (code);
+  for (i = 0; i < len; i++)
+    {
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  collect_insn_data (XEXP (pattern, i), palt, pmax);
+	  break;
+
+	case 'V':
+	  if (XVEC (pattern, i) == NULL)
+	    break;
+	  /* Fall through.  */
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    collect_insn_data (XVECEXP (pattern, i, j), palt, pmax);
+	  break;
+
+	case 'i': case 'w': case '0': case 's': case 'S': case 'T':
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+}
+
+static rtx
+alter_predicate_for_insn (rtx pattern, int alt, int max_op, int lineno)
+{
+  const char *fmt;
+  enum rtx_code code;
+  int i, j, len;
+
+  code = GET_CODE (pattern);
+  switch (code)
+    {
+    case MATCH_OPERAND:
+      {
+	const char *c = XSTR (pattern, 2);
+
+	if (n_alternatives (c) != 1)
+	  {
+	    error_with_line (lineno, "too many alternatives for operand %d",
+			     XINT (pattern, 0));
+	    return NULL;
+	  }
+
+	/* Replicate C as needed to fill out ALT alternatives.  */
+	if (c && *c && alt > 1)
+	  {
+	    size_t c_len = strlen (c);
+	    size_t len = alt * (c_len + 1);
+	    char *new_c = XNEWVEC (char, len);
+
+	    memcpy (new_c, c, c_len);
+	    for (i = 1; i < alt; ++i)
+	      {
+		new_c[i * (c_len + 1) - 1] = ',';
+		memcpy (&new_c[i * (c_len + 1)], c, c_len);
+	      }
+	    new_c[len - 1] = '\0';
+	    XSTR (pattern, 2) = new_c;
+	  }
+      }
+      /* Fall through.  */
+
+    case MATCH_OPERATOR:
+    case MATCH_SCRATCH:
+    case MATCH_PARALLEL:
+      XINT (pattern, 0) += max_op;
+      break;
+
+    default:
+      break;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  len = GET_RTX_LENGTH (code);
+  for (i = 0; i < len; i++)
+    {
+      rtx r;
+
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  r = alter_predicate_for_insn (XEXP (pattern, i), alt,
+					max_op, lineno);
+	  if (r == NULL)
+	    return r;
+	  break;
+
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    {
+	      r = alter_predicate_for_insn (XVECEXP (pattern, i, j),
+					    alt, max_op, lineno);
+	      if (r == NULL)
+		return r;
+	    }
+	  break;
+
+	case 'i': case 'w': case '0': case 's':
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  return pattern;
+}
+
+/* Duplicate constraints in PATTERN.  If pattern is from original
+   rtl-template, we need to duplicate each alternative - for that we
+   need to use duplicate_each_alternative () as a functor ALTER.
+   If pattern is from output-pattern of define_subst, we need to
+   duplicate constraints in another way - with duplicate_alternatives ().
+   N_DUP is multiplication factor.  */
+static rtx
+alter_constraints (rtx pattern, int n_dup, constraints_handler_t alter)
+{
+  const char *fmt;
+  enum rtx_code code;
+  int i, j, len;
+
+  code = GET_CODE (pattern);
+  switch (code)
+    {
+    case MATCH_OPERAND:
+      XSTR (pattern, 2) = alter (XSTR (pattern, 2), n_dup);
+      break;
+
+    default:
+      break;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  len = GET_RTX_LENGTH (code);
+  for (i = 0; i < len; i++)
+    {
+      rtx r;
+
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  r = alter_constraints (XEXP (pattern, i), n_dup, alter);
+	  if (r == NULL)
+	    return r;
+	  break;
+
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    {
+	      r = alter_constraints (XVECEXP (pattern, i, j), n_dup, alter);
+	      if (r == NULL)
+		return r;
+	    }
+	  break;
+
+	case 'i': case 'w': case '0': case 's':
+	  break;
+
+	default:
+	  break;
+	}
+    }
+
+  return pattern;
+}
+
+static const char *
+alter_test_for_insn (struct queue_elem *ce_elem,
+		     struct queue_elem *insn_elem)
+{
+  return join_c_conditions (XSTR (ce_elem->data, 1),
+			    XSTR (insn_elem->data, 2));
+}
+
+/* Modify VAL, which is an attribute expression for the "enabled" attribute,
+   to take "ce_enabled" into account.  Return the new expression.  */
+static rtx
+modify_attr_enabled_ce (rtx val)
+{
+  rtx eq_attr, str;
+  rtx ite;
+  eq_attr = rtx_alloc (EQ_ATTR);
+  ite = rtx_alloc (IF_THEN_ELSE);
+  str = rtx_alloc (CONST_STRING);
+
+  XSTR (eq_attr, 0) = "ce_enabled";
+  XSTR (eq_attr, 1) = "yes";
+  XSTR (str, 0) = "no";
+  XEXP (ite, 0) = eq_attr;
+  XEXP (ite, 1) = val;
+  XEXP (ite, 2) = str;
+
+  return ite;
+}
+
+/* Alter the attribute vector of INSN, which is a COND_EXEC variant created
+   from a define_insn pattern.  We must modify the "predicable" attribute
+   to be named "ce_enabled", and also change any "enabled" attribute that's
+   present so that it takes ce_enabled into account.
+   We rely on the fact that INSN was created with copy_rtx, and modify data
+   in-place.  */
+
+static void
+alter_attrs_for_insn (rtx insn)
+{
+  static bool global_changes_made = false;
+  rtvec vec = XVEC (insn, 4);
+  rtvec new_vec;
+  rtx val, set;
+  int num_elem;
+  int predicable_idx = -1;
+  int enabled_idx = -1;
+  int i;
+
+  if (! vec)
+    return;
+
+  num_elem = GET_NUM_ELEM (vec);
+  for (i = num_elem - 1; i >= 0; --i)
+    {
+      rtx sub = RTVEC_ELT (vec, i);
+      switch (GET_CODE (sub))
+	{
+	case SET_ATTR:
+	  if (strcmp (XSTR (sub, 0), "predicable") == 0)
+	    {
+	      predicable_idx = i;
+	      XSTR (sub, 0) = "ce_enabled";
+	    }
+	  else if (strcmp (XSTR (sub, 0), "enabled") == 0)
+	    {
+	      enabled_idx = i;
+	      XSTR (sub, 0) = "nonce_enabled";
+	    }
+	  break;
+
+	case SET_ATTR_ALTERNATIVE:
+	  if (strcmp (XSTR (sub, 0), "predicable") == 0)
+	    /* We already give an error elsewhere.  */
+	    return;
+	  else if (strcmp (XSTR (sub, 0), "enabled") == 0)
+	    {
+	      enabled_idx = i;
+	      XSTR (sub, 0) = "nonce_enabled";
+	    }
+	  break;
+
+	case SET:
+	  if (GET_CODE (SET_DEST (sub)) != ATTR)
+	    break;
+	  if (strcmp (XSTR (SET_DEST (sub), 0), "predicable") == 0)
+	    {
+	      sub = SET_SRC (sub);
+	      if (GET_CODE (sub) == CONST_STRING)
+		{
+		  predicable_idx = i;
+		  XSTR (sub, 0) = "ce_enabled";
+		}
+	      else
+		/* We already give an error elsewhere.  */
+		return;
+	      break;
+	    }
+	  if (strcmp (XSTR (SET_DEST (sub), 0), "enabled") == 0)
+	    {
+	      enabled_idx = i;
+	      XSTR (SET_DEST (sub), 0) = "nonce_enabled";
+	    }
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+  if (predicable_idx == -1)
+    return;
+
+  if (!global_changes_made)
+    {
+      struct queue_elem *elem;
+
+      global_changes_made = true;
+      add_define_attr ("ce_enabled");
+      add_define_attr ("nonce_enabled");
+
+      for (elem = define_attr_queue; elem ; elem = elem->next)
+	if (strcmp (XSTR (elem->data, 0), "enabled") == 0)
+	  {
+	    XEXP (elem->data, 2)
+	      = modify_attr_enabled_ce (XEXP (elem->data, 2));
+	  }
+    }
+  if (enabled_idx == -1)
+    return;
+
+  new_vec = rtvec_alloc (num_elem + 1);
+  for (i = 0; i < num_elem; i++)
+    RTVEC_ELT (new_vec, i) = RTVEC_ELT (vec, i);
+  val = rtx_alloc (IF_THEN_ELSE);
+  XEXP (val, 0) = rtx_alloc (EQ_ATTR);
+  XEXP (val, 1) = rtx_alloc (CONST_STRING);
+  XEXP (val, 2) = rtx_alloc (CONST_STRING);
+  XSTR (XEXP (val, 0), 0) = "nonce_enabled";
+  XSTR (XEXP (val, 0), 1) = "yes";
+  XSTR (XEXP (val, 1), 0) = "yes";
+  XSTR (XEXP (val, 2), 0) = "no";
+  set = rtx_alloc (SET);
+  SET_DEST (set) = rtx_alloc (ATTR);
+  XSTR (SET_DEST (set), 0) = "enabled";
+  SET_SRC (set) = modify_attr_enabled_ce (val);
+  RTVEC_ELT (new_vec, i) = set;
+  XVEC (insn, 4) = new_vec;
+}
+
+/* As number of constraints is changed after define_subst, we need to
+   process attributes as well - we need to duplicate them the same way
+   that we duplicated constraints in original pattern
+   ELEM is a queue element, containing our rtl-template,
+   N_DUP - multiplication factor.  */
+static void
+alter_attrs_for_subst_insn (struct queue_elem * elem, int n_dup)
+{
+  rtvec vec = XVEC (elem->data, 4);
+  int num_elem;
+  int i;
+
+  if (n_dup < 2 || ! vec)
+    return;
+
+  num_elem = GET_NUM_ELEM (vec);
+  for (i = num_elem - 1; i >= 0; --i)
+    {
+      rtx sub = RTVEC_ELT (vec, i);
+      switch (GET_CODE (sub))
+	{
+	case SET_ATTR:
+	  if (strchr (XSTR (sub, 1), ',') != NULL)
+	    XSTR (sub, 1) = duplicate_alternatives (XSTR (sub, 1), n_dup);
+	    break;
+
+	case SET_ATTR_ALTERNATIVE:
+	case SET:
+	  error_with_line (elem->lineno,
+			   "%s: `define_subst' does not support attributes "
+			   "assigned by `set' and `set_attr_alternative'",
+			   XSTR (elem->data, 0));
+	  return;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+}
+
+/* Adjust all of the operand numbers in SRC to match the shift they'll
+   get from an operand displacement of DISP.  Return a pointer after the
+   adjusted string.  */
+
+static char *
+shift_output_template (char *dest, const char *src, int disp)
+{
+  while (*src)
+    {
+      char c = *src++;
+      *dest++ = c;
+      if (c == '%')
+	{
+	  c = *src++;
+	  if (ISDIGIT ((unsigned char) c))
+	    c += disp;
+	  else if (ISALPHA (c))
+	    {
+	      *dest++ = c;
+	      c = *src++ + disp;
+	    }
+	  *dest++ = c;
+	}
+    }
+
+  return dest;
+}
+
+static const char *
+alter_output_for_insn (struct queue_elem *ce_elem,
+		       struct queue_elem *insn_elem,
+		       int alt, int max_op)
+{
+  const char *ce_out, *insn_out;
+  char *result, *p;
+  size_t len, ce_len, insn_len;
+
+  /* ??? Could coordinate with genoutput to not duplicate code here.  */
+
+  ce_out = XSTR (ce_elem->data, 2);
+  insn_out = XTMPL (insn_elem->data, 3);
+  if (!ce_out || *ce_out == '\0')
+    return insn_out;
+
+  ce_len = strlen (ce_out);
+  insn_len = strlen (insn_out);
+
+  if (*insn_out == '*')
+    /* You must take care of the predicate yourself.  */
+    return insn_out;
+
+  if (*insn_out == '@')
+    {
+      len = (ce_len + 1) * alt + insn_len + 1;
+      p = result = XNEWVEC (char, len);
+
+      do
+	{
+	  do
+	    *p++ = *insn_out++;
+	  while (ISSPACE ((unsigned char) *insn_out));
+
+	  if (*insn_out != '#')
+	    {
+	      p = shift_output_template (p, ce_out, max_op);
+	      *p++ = ' ';
+	    }
+
+	  do
+	    *p++ = *insn_out++;
+	  while (*insn_out && *insn_out != '\n');
+	}
+      while (*insn_out);
+      *p = '\0';
+    }
+  else
+    {
+      len = ce_len + 1 + insn_len + 1;
+      result = XNEWVEC (char, len);
+
+      p = shift_output_template (result, ce_out, max_op);
+      *p++ = ' ';
+      memcpy (p, insn_out, insn_len + 1);
+    }
+
+  return result;
+}
+
+/* From string STR "a,b,c" produce "a,b,c,a,b,c,a,b,c", i.e. original
+   string, duplicated N_DUP times.  */
+
+static const char *
+duplicate_alternatives (const char * str, int n_dup)
+{
+  int i, len, new_len;
+  char *result, *sp;
+  const char *cp;
+
+  if (n_dup < 2)
+    return str;
+
+  while (ISSPACE (*str))
+    str++;
+
+  if (*str == '\0')
+    return str;
+
+  cp = str;
+  len = strlen (str);
+  new_len = (len + 1) * n_dup;
+
+  sp = result = XNEWVEC (char, new_len);
+
+  /* Global modifier characters mustn't be duplicated: skip if found.  */
+  if (*cp == '=' || *cp == '+' || *cp == '%')
+    {
+      *sp++ = *cp++;
+      len--;
+    }
+
+  /* Copy original constraints N_DUP times.  */
+  for (i = 0; i < n_dup; i++, sp += len+1)
+    {
+      memcpy (sp, cp, len);
+      *(sp+len) = (i == n_dup - 1) ? '\0' : ',';
+    }
+
+  return result;
+}
+
+/* From string STR "a,b,c" produce "a,a,a,b,b,b,c,c,c", i.e. string where
+   each alternative from the original string is duplicated N_DUP times.  */
+static const char *
+duplicate_each_alternative (const char * str, int n_dup)
+{
+  int i, len, new_len;
+  char *result, *sp, *ep, *cp;
+
+  if (n_dup < 2)
+    return str;
+
+  while (ISSPACE (*str))
+    str++;
+
+  if (*str == '\0')
+    return str;
+
+  cp = xstrdup (str);
+
+  new_len = (strlen (cp) + 1) * n_dup;
+
+  sp = result = XNEWVEC (char, new_len);
+
+  /* Global modifier characters mustn't be duplicated: skip if found.  */
+  if (*cp == '=' || *cp == '+' || *cp == '%')
+      *sp++ = *cp++;
+
+  do
+    {
+      if ((ep = strchr (cp, ',')) != NULL)
+	*ep++ = '\0';
+      len = strlen (cp);
+
+      /* Copy a constraint N_DUP times.  */
+      for (i = 0; i < n_dup; i++, sp += len + 1)
+	{
+	  memcpy (sp, cp, len);
+	  *(sp+len) = (ep == NULL && i == n_dup - 1) ? '\0' : ',';
+	}
+
+      cp = ep;
+    }
+  while (cp != NULL);
+
+  return result;
+}
+
+/* Alter the output of INSN whose pattern was modified by
+   DEFINE_SUBST.  We must replicate output strings according
+   to the new number of alternatives ALT in substituted pattern.
+   If ALT equals 1, output has one alternative or defined by C
+   code, then output is returned without any changes.  */
+
+static const char *
+alter_output_for_subst_insn (rtx insn, int alt)
+{
+  const char *insn_out, *sp ;
+  char *old_out, *new_out, *cp;
+  int i, j, new_len;
+
+  insn_out = XTMPL (insn, 3);
+
+  if (alt < 2 || *insn_out == '*' || *insn_out != '@')
+    return insn_out;
+
+  old_out = XNEWVEC (char, strlen (insn_out)),
+  sp = insn_out;
+
+  while (ISSPACE (*sp) || *sp == '@')
+    sp++;
+
+  for (i = 0; *sp;)
+    old_out[i++] = *sp++;
+
+  new_len = alt * (i + 1) + 1;
+
+  new_out = XNEWVEC (char, new_len);
+  new_out[0] = '@';
+
+  for (j = 0, cp = new_out + 1; j < alt; j++, cp += i + 1)
+    {
+      memcpy (cp, old_out, i);
+      *(cp+i) = (j == alt - 1) ? '\0' : '\n';
+    }
+
+  return new_out;
+}
+
+/* Replicate insns as appropriate for the given DEFINE_COND_EXEC.  */
+
+static void
+process_one_cond_exec (struct queue_elem *ce_elem)
+{
+  struct queue_elem *insn_elem;
+  for (insn_elem = define_insn_queue; insn_elem ; insn_elem = insn_elem->next)
+    {
+      int alternatives, max_operand;
+      rtx pred, insn, pattern, split;
+      char *new_name;
+      int i;
+
+      if (! is_predicable (insn_elem))
+	continue;
+
+      alternatives = 1;
+      max_operand = -1;
+      collect_insn_data (insn_elem->data, &alternatives, &max_operand);
+      max_operand += 1;
+
+      if (XVECLEN (ce_elem->data, 0) != 1)
+	{
+	  error_with_line (ce_elem->lineno, "too many patterns in predicate");
+	  return;
+	}
+
+      pred = copy_rtx (XVECEXP (ce_elem->data, 0, 0));
+      pred = alter_predicate_for_insn (pred, alternatives, max_operand,
+				       ce_elem->lineno);
+      if (pred == NULL)
+	return;
+
+      /* Construct a new pattern for the new insn.  */
+      insn = copy_rtx (insn_elem->data);
+      new_name = XNEWVAR (char, strlen XSTR (insn_elem->data, 0) + 4);
+      sprintf (new_name, "*p %s", XSTR (insn_elem->data, 0));
+      XSTR (insn, 0) = new_name;
+      pattern = rtx_alloc (COND_EXEC);
+      XEXP (pattern, 0) = pred;
+      if (XVECLEN (insn, 1) == 1)
+	{
+	  XEXP (pattern, 1) = XVECEXP (insn, 1, 0);
+	  XVECEXP (insn, 1, 0) = pattern;
+	  PUT_NUM_ELEM (XVEC (insn, 1), 1);
+	}
+      else
+	{
+	  XEXP (pattern, 1) = rtx_alloc (PARALLEL);
+	  XVEC (XEXP (pattern, 1), 0) = XVEC (insn, 1);
+	  XVEC (insn, 1) = rtvec_alloc (1);
+	  XVECEXP (insn, 1, 0) = pattern;
+	}
+
+       if (XVEC (ce_elem->data, 3) != NULL)
+	{
+	  rtvec attributes = rtvec_alloc (XVECLEN (insn, 4)
+	                                  + XVECLEN (ce_elem->data, 3));
+	  int i = 0;
+	  int j = 0;
+	  for (i = 0; i < XVECLEN (insn, 4); i++)
+	    RTVEC_ELT (attributes, i) = XVECEXP (insn, 4, i);
+
+	  for (j = 0; j < XVECLEN (ce_elem->data, 3); j++, i++)
+	    RTVEC_ELT (attributes, i) = XVECEXP (ce_elem->data, 3, j);
+
+	  XVEC (insn, 4) = attributes;
+	}
+
+      XSTR (insn, 2) = alter_test_for_insn (ce_elem, insn_elem);
+      XTMPL (insn, 3) = alter_output_for_insn (ce_elem, insn_elem,
+					      alternatives, max_operand);
+      alter_attrs_for_insn (insn);
+
+      /* Put the new pattern on the `other' list so that it
+	 (a) is not reprocessed by other define_cond_exec patterns
+	 (b) appears after all normal define_insn patterns.
+
+	 ??? B is debatable.  If one has normal insns that match
+	 cond_exec patterns, they will be preferred over these
+	 generated patterns.  Whether this matters in practice, or if
+	 it's a good thing, or whether we should thread these new
+	 patterns into the define_insn chain just after their generator
+	 is something we'll have to experiment with.  */
+
+      queue_pattern (insn, &other_tail, insn_elem->filename,
+		     insn_elem->lineno);
+
+      if (!insn_elem->split)
+	continue;
+
+      /* If the original insn came from a define_insn_and_split,
+	 generate a new split to handle the predicated insn.  */
+      split = copy_rtx (insn_elem->split->data);
+      /* Predicate the pattern matched by the split.  */
+      pattern = rtx_alloc (COND_EXEC);
+      XEXP (pattern, 0) = pred;
+      if (XVECLEN (split, 0) == 1)
+	{
+	  XEXP (pattern, 1) = XVECEXP (split, 0, 0);
+	  XVECEXP (split, 0, 0) = pattern;
+	  PUT_NUM_ELEM (XVEC (split, 0), 1);
+	}
+      else
+	{
+	  XEXP (pattern, 1) = rtx_alloc (PARALLEL);
+	  XVEC (XEXP (pattern, 1), 0) = XVEC (split, 0);
+	  XVEC (split, 0) = rtvec_alloc (1);
+	  XVECEXP (split, 0, 0) = pattern;
+	}
+      /* Predicate all of the insns generated by the split.  */
+      for (i = 0; i < XVECLEN (split, 2); i++)
+	{
+	  pattern = rtx_alloc (COND_EXEC);
+	  XEXP (pattern, 0) = pred;
+	  XEXP (pattern, 1) = XVECEXP (split, 2, i);
+	  XVECEXP (split, 2, i) = pattern;
+	}
+      /* Add the new split to the queue.  */
+      queue_pattern (split, &other_tail, read_md_filename,
+		     insn_elem->split->lineno);
+    }
+}
+
+/* Try to apply define_substs to the given ELEM.
+   Only define_substs, specified via attributes would be applied.
+   If attribute, requiring define_subst, is set, but no define_subst
+   was applied, ELEM would be deleted.  */
+
+static void
+process_substs_on_one_elem (struct queue_elem *elem,
+			    struct queue_elem *queue)
+{
+  struct queue_elem *subst_elem;
+  int i, j, patterns_match;
+
+  for (subst_elem = define_subst_queue;
+       subst_elem; subst_elem = subst_elem->next)
+    {
+      int alternatives, alternatives_subst;
+      rtx subst_pattern;
+      rtvec subst_pattern_vec;
+
+      if (!has_subst_attribute (elem, subst_elem))
+	continue;
+
+      /* Compare original rtl-pattern from define_insn with input
+	 pattern from define_subst.
+	 Also, check if numbers of alternatives are the same in all
+	 match_operands.  */
+      if (XVECLEN (elem->data, 1) != XVECLEN (subst_elem->data, 1))
+	continue;
+      patterns_match = 1;
+      alternatives = -1;
+      alternatives_subst = -1;
+      for (j = 0; j < XVECLEN (elem->data, 1); j++)
+	{
+	  if (!subst_pattern_match (XVECEXP (elem->data, 1, j),
+				    XVECEXP (subst_elem->data, 1, j),
+				    subst_elem->lineno))
+	    {
+	      patterns_match = 0;
+	      break;
+	    }
+
+	  if (!get_alternatives_number (XVECEXP (elem->data, 1, j),
+					&alternatives, subst_elem->lineno))
+	    {
+	      patterns_match = 0;
+	      break;
+	    }
+	}
+
+      /* Check if numbers of alternatives are the same in all
+	 match_operands in output template of define_subst.  */
+      for (j = 0; j < XVECLEN (subst_elem->data, 3); j++)
+	{
+	  if (!get_alternatives_number (XVECEXP (subst_elem->data, 3, j),
+					&alternatives_subst,
+					subst_elem->lineno))
+	    {
+	      patterns_match = 0;
+	      break;
+	    }
+	}
+
+      if (!patterns_match)
+	continue;
+
+      /* Clear array in which we save occupied indexes of operands.  */
+      memset (used_operands_numbers, 0, sizeof (used_operands_numbers));
+
+      /* Create a pattern, based on the output one from define_subst.  */
+      subst_pattern_vec = rtvec_alloc (XVECLEN (subst_elem->data, 3));
+      for (j = 0; j < XVECLEN (subst_elem->data, 3); j++)
+	{
+	  subst_pattern = copy_rtx (XVECEXP (subst_elem->data, 3, j));
+
+	  /* Duplicate constraints in substitute-pattern.  */
+	  subst_pattern = alter_constraints (subst_pattern, alternatives,
+					     duplicate_each_alternative);
+
+	  subst_pattern = adjust_operands_numbers (subst_pattern);
+
+	  /* Substitute match_dup and match_op_dup in the new pattern and
+	     duplicate constraints.  */
+	  subst_pattern = subst_dup (subst_pattern, alternatives,
+				     alternatives_subst);
+
+	  replace_duplicating_operands_in_pattern (subst_pattern);
+
+	  /* We don't need any constraints in DEFINE_EXPAND.  */
+	  if (GET_CODE (elem->data) == DEFINE_EXPAND)
+	    remove_constraints (subst_pattern);
+
+	  RTVEC_ELT (subst_pattern_vec, j) = subst_pattern;
+	}
+      XVEC (elem->data, 1) = subst_pattern_vec;
+
+      for (i = 0; i < MAX_OPERANDS; i++)
+	  match_operand_entries_in_pattern[i] = NULL;
+
+      if (GET_CODE (elem->data) == DEFINE_INSN)
+	{
+	  XTMPL (elem->data, 3) =
+	    alter_output_for_subst_insn (elem->data, alternatives_subst);
+	  alter_attrs_for_subst_insn (elem, alternatives_subst);
+	}
+
+      /* Recalculate condition, joining conditions from original and
+	 DEFINE_SUBST input patterns.  */
+      XSTR (elem->data, 2) = join_c_conditions (XSTR (subst_elem->data, 2),
+						XSTR (elem->data, 2));
+      /* Mark that subst was applied by changing attribute from "yes"
+	 to "no".  */
+      change_subst_attribute (elem, subst_elem, subst_false);
+    }
+
+  /* If ELEM contains a subst attribute with value "yes", then we
+     expected that a subst would be applied, but it wasn't - so,
+     we need to remove that elementto avoid duplicating.  */
+  for (subst_elem = define_subst_queue;
+       subst_elem; subst_elem = subst_elem->next)
+    {
+      if (has_subst_attribute (elem, subst_elem))
+	{
+	  remove_from_queue (elem, &queue);
+	  return;
+	}
+    }
+}
+
+/* This is a subroutine of mark_operands_used_in_match_dup.
+   This routine is marks all MATCH_OPERANDs inside PATTERN as occupied.  */
+static void
+mark_operands_from_match_dup (rtx pattern)
+{
+  const char *fmt;
+  int i, j, len, opno;
+
+  if (GET_CODE (pattern) == MATCH_OPERAND
+      || GET_CODE (pattern) == MATCH_OPERATOR
+      || GET_CODE (pattern) == MATCH_PARALLEL)
+    {
+      opno = XINT (pattern, 0);
+      gcc_assert (opno >= 0 && opno < MAX_OPERANDS);
+      used_operands_numbers [opno] = 1;
+    }
+  fmt = GET_RTX_FORMAT (GET_CODE (pattern));
+  len = GET_RTX_LENGTH (GET_CODE (pattern));
+  for (i = 0; i < len; i++)
+    {
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  mark_operands_from_match_dup (XEXP (pattern, i));
+	  break;
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    mark_operands_from_match_dup (XVECEXP (pattern, i, j));
+	  break;
+	}
+    }
+}
+
+/* This is a subroutine of adjust_operands_numbers.
+   It goes through all expressions in PATTERN and when MATCH_DUP is
+   met, all MATCH_OPERANDs inside it is marked as occupied.  The
+   process of marking is done by routin mark_operands_from_match_dup.  */
+static void
+mark_operands_used_in_match_dup (rtx pattern)
+{
+  const char *fmt;
+  int i, j, len, opno;
+
+  if (GET_CODE (pattern) == MATCH_DUP)
+    {
+      opno = XINT (pattern, 0);
+      gcc_assert (opno >= 0 && opno < MAX_OPERANDS);
+      mark_operands_from_match_dup (operand_data[opno]);
+      return;
+    }
+  fmt = GET_RTX_FORMAT (GET_CODE (pattern));
+  len = GET_RTX_LENGTH (GET_CODE (pattern));
+  for (i = 0; i < len; i++)
+    {
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  mark_operands_used_in_match_dup (XEXP (pattern, i));
+	  break;
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    mark_operands_used_in_match_dup (XVECEXP (pattern, i, j));
+	  break;
+	}
+    }
+}
+
+/* This is subroutine of renumerate_operands_in_pattern.
+   It finds first not-occupied operand-index.  */
+static int
+find_first_unused_number_of_operand ()
+{
+  int i;
+  for (i = 0; i < MAX_OPERANDS; i++)
+    if (!used_operands_numbers[i])
+      return i;
+  return MAX_OPERANDS;
+}
+
+/* This is subroutine of adjust_operands_numbers.
+   It visits all expressions in PATTERN and assigns not-occupied
+   operand indexes to MATCH_OPERANDs and MATCH_OPERATORs of this
+   PATTERN.  */
+static void
+renumerate_operands_in_pattern (rtx pattern)
+{
+  const char *fmt;
+  enum rtx_code code;
+  int i, j, len, new_opno;
+  code = GET_CODE (pattern);
+
+  if (code == MATCH_OPERAND
+      || code == MATCH_OPERATOR)
+    {
+      new_opno = find_first_unused_number_of_operand ();
+      gcc_assert (new_opno >= 0 && new_opno < MAX_OPERANDS);
+      XINT (pattern, 0) = new_opno;
+      used_operands_numbers [new_opno] = 1;
+    }
+
+  fmt = GET_RTX_FORMAT (GET_CODE (pattern));
+  len = GET_RTX_LENGTH (GET_CODE (pattern));
+  for (i = 0; i < len; i++)
+    {
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  renumerate_operands_in_pattern (XEXP (pattern, i));
+	  break;
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    renumerate_operands_in_pattern (XVECEXP (pattern, i, j));
+	  break;
+	}
+    }
+}
+
+/* If output pattern of define_subst contains MATCH_DUP, then this
+   expression would be replaced with the pattern, matched with
+   MATCH_OPERAND from input pattern.  This pattern could contain any
+   number of MATCH_OPERANDs, MATCH_OPERATORs etc., so it's possible
+   that a MATCH_OPERAND from output_pattern (if any) would have the
+   same number, as MATCH_OPERAND from copied pattern.  To avoid such
+   indexes overlapping, we assign new indexes to MATCH_OPERANDs,
+   laying in the output pattern outside of MATCH_DUPs.  */
+static rtx
+adjust_operands_numbers (rtx pattern)
+{
+  mark_operands_used_in_match_dup (pattern);
+
+  renumerate_operands_in_pattern (pattern);
+
+  return pattern;
+}
+
+/* Generate RTL expression
+   (match_dup OPNO)
+   */
+static rtx
+generate_match_dup (int opno)
+{
+  rtx return_rtx = rtx_alloc (MATCH_DUP);
+  PUT_CODE (return_rtx, MATCH_DUP);
+  XINT (return_rtx, 0) = opno;
+  return return_rtx;
+}
+
+/* This routine checks all match_operands in PATTERN and if some of
+   have the same index, it replaces all of them except the first one  to
+   match_dup.
+   Usually, match_operands with the same indexes are forbidden, but
+   after define_subst copy an RTL-expression from original template,
+   indexes of existed and just-copied match_operands could coincide.
+   To fix it, we replace one of them with match_dup.  */
+static rtx
+replace_duplicating_operands_in_pattern (rtx pattern)
+{
+  const char *fmt;
+  int i, j, len, opno;
+  rtx mdup;
+
+  if (GET_CODE (pattern) == MATCH_OPERAND)
+    {
+      opno = XINT (pattern, 0);
+      gcc_assert (opno >= 0 && opno < MAX_OPERANDS);
+      if (match_operand_entries_in_pattern[opno] == NULL)
+	{
+	  match_operand_entries_in_pattern[opno] = pattern;
+	  return NULL;
+	}
+      else
+	{
+	  /* Compare predicates before replacing with match_dup.  */
+	  if (strcmp (XSTR (pattern, 1),
+		      XSTR (match_operand_entries_in_pattern[opno], 1)))
+	    {
+	      error ("duplicated match_operands with different predicates were"
+		     " found.");
+	      return NULL;
+	    }
+	  return generate_match_dup (opno);
+	}
+    }
+  fmt = GET_RTX_FORMAT (GET_CODE (pattern));
+  len = GET_RTX_LENGTH (GET_CODE (pattern));
+  for (i = 0; i < len; i++)
+    {
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  mdup = replace_duplicating_operands_in_pattern (XEXP (pattern, i));
+	  if (mdup)
+	    XEXP (pattern, i) = mdup;
+	  break;
+	case 'E':
+	  for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	    {
+	      mdup =
+		replace_duplicating_operands_in_pattern (XVECEXP
+							 (pattern, i, j));
+	      if (mdup)
+		XVECEXP (pattern, i, j) = mdup;
+	    }
+	  break;
+	}
+    }
+  return NULL;
+}
+
+/* The routine modifies given input PATTERN of define_subst, replacing
+   MATCH_DUP and MATCH_OP_DUP with operands from define_insn original
+   pattern, whose operands are stored in OPERAND_DATA array.
+   It also duplicates constraints in operands - constraints from
+   define_insn operands are duplicated N_SUBST_ALT times, constraints
+   from define_subst operands are duplicated N_ALT times.
+   After the duplication, returned output rtl-pattern contains every
+   combination of input constraints Vs constraints from define_subst
+   output.  */
+static rtx
+subst_dup (rtx pattern, int n_alt, int n_subst_alt)
+{
+  const char *fmt;
+  enum rtx_code code;
+  int i, j, len, opno;
+
+  code = GET_CODE (pattern);
+  switch (code)
+    {
+    case MATCH_DUP:
+    case MATCH_OP_DUP:
+      opno = XINT (pattern, 0);
+
+      gcc_assert (opno >= 0 && opno < MAX_OPERANDS);
+
+      if (operand_data[opno])
+	{
+	  pattern = copy_rtx (operand_data[opno]);
+
+	  /* Duplicate constraints.  */
+	  pattern = alter_constraints (pattern, n_subst_alt,
+				       duplicate_alternatives);
+	}
+      break;
+
+    default:
+      break;
+    }
+
+  fmt = GET_RTX_FORMAT (GET_CODE (pattern));
+  len = GET_RTX_LENGTH (GET_CODE (pattern));
+  for (i = 0; i < len; i++)
+    {
+      switch (fmt[i])
+	{
+	case 'e': case 'u':
+	  if (code != MATCH_DUP && code != MATCH_OP_DUP)
+	    XEXP (pattern, i) = subst_dup (XEXP (pattern, i),
+					   n_alt, n_subst_alt);
+	  break;
+	case 'V':
+	  if (XVEC (pattern, i) == NULL)
+	    break;
+	case 'E':
+	  if (code != MATCH_DUP && code != MATCH_OP_DUP)
+	    for (j = XVECLEN (pattern, i) - 1; j >= 0; --j)
+	      XVECEXP (pattern, i, j) = subst_dup (XVECEXP (pattern, i, j),
+						   n_alt, n_subst_alt);
+	  break;
+
+	case 'i': case 'w': case '0': case 's': case 'S': case 'T':
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+  return pattern;
+}
+
+/* If we have any DEFINE_COND_EXEC patterns, expand the DEFINE_INSN
+   patterns appropriately.  */
+
+static void
+process_define_cond_exec (void)
+{
+  struct queue_elem *elem;
+
+  identify_predicable_attribute ();
+  if (have_error)
+    return;
+
+  for (elem = define_cond_exec_queue; elem ; elem = elem->next)
+    process_one_cond_exec (elem);
+}
+
+/* If we have any DEFINE_SUBST patterns, expand DEFINE_INSN and
+   DEFINE_EXPAND patterns appropriately.  */
+
+static void
+process_define_subst (void)
+{
+  struct queue_elem *elem, *elem_attr;
+
+  /* Check if each define_subst has corresponding define_subst_attr.  */
+  for (elem = define_subst_queue; elem ; elem = elem->next)
+    {
+      for (elem_attr = define_subst_attr_queue;
+	   elem_attr;
+	   elem_attr = elem_attr->next)
+	if (strcmp (XSTR (elem->data, 0), XSTR (elem_attr->data, 1)) == 0)
+	    goto found;
+
+	error_with_line (elem->lineno,
+			 "%s: `define_subst' must have at least one "
+			 "corresponding `define_subst_attr'",
+			 XSTR (elem->data, 0));
+	return;
+      found:
+	continue;
+    }
+
+  for (elem = define_insn_queue; elem ; elem = elem->next)
+    process_substs_on_one_elem (elem, define_insn_queue);
+  for (elem = other_queue; elem ; elem = elem->next)
+    {
+      if (GET_CODE (elem->data) != DEFINE_EXPAND)
+	continue;
+      process_substs_on_one_elem (elem, other_queue);
+    }
+}
+
+/* A read_md_files callback for reading an rtx.  */
+
+static void
+rtx_handle_directive (int lineno, const char *rtx_name)
+{
+  rtx queue, x;
+
+  if (read_rtx (rtx_name, &queue))
+    for (x = queue; x; x = XEXP (x, 1))
+      process_rtx (XEXP (x, 0), lineno);
+}
+
+/* Comparison function for the mnemonic hash table.  */
+
+static int
+htab_eq_string (const void *s1, const void *s2)
+{
+  return strcmp ((const char*)s1, (const char*)s2) == 0;
+}
+
+/* Add mnemonic STR with length LEN to the mnemonic hash table
+   MNEMONIC_HTAB.  A trailing zero end character is appendend to STR
+   and a permanent heap copy of STR is created.  */
+
+static void
+add_mnemonic_string (htab_t mnemonic_htab, const char *str, int len)
+{
+  char *new_str;
+  void **slot;
+  char *str_zero = (char*)alloca (len + 1);
+
+  memcpy (str_zero, str, len);
+  str_zero[len] = '\0';
+
+  slot = htab_find_slot (mnemonic_htab, str_zero, INSERT);
+
+  if (*slot)
+    return;
+
+  /* Not found; create a permanent copy and add it to the hash table.  */
+  new_str = XNEWVAR (char, len + 1);
+  memcpy (new_str, str_zero, len + 1);
+  *slot = new_str;
+}
+
+/* Scan INSN for mnemonic strings and add them to the mnemonic hash
+   table in MNEMONIC_HTAB.
+
+   The mnemonics cannot be found if they are emitted using C code.
+
+   If a mnemonic string contains ';' or a newline the string assumed
+   to consist of more than a single instruction.  The attribute value
+   will then be set to the user defined default value.  */
+
+static void
+gen_mnemonic_setattr (htab_t mnemonic_htab, rtx insn)
+{
+  const char *template_code, *cp;
+  int i;
+  int vec_len;
+  rtx set_attr;
+  char *attr_name;
+  rtvec new_vec;
+
+  template_code = XTMPL (insn, 3);
+
+  /* Skip patterns which use C code to emit the template.  */
+  if (template_code[0] == '*')
+    return;
+
+  if (template_code[0] == '@')
+    cp = &template_code[1];
+  else
+    cp = &template_code[0];
+
+  for (i = 0; *cp; )
+    {
+      const char *ep, *sp;
+      int size = 0;
+
+      while (ISSPACE (*cp))
+	cp++;
+
+      for (ep = sp = cp; !IS_VSPACE (*ep) && *ep != '\0'; ++ep)
+	if (!ISSPACE (*ep))
+	  sp = ep + 1;
+
+      if (i > 0)
+	obstack_1grow (&string_obstack, ',');
+
+      while (cp < sp && ((*cp >= '0' && *cp <= '9')
+			 || (*cp >= 'a' && *cp <= 'z')))
+
+	{
+	  obstack_1grow (&string_obstack, *cp);
+	  cp++;
+	  size++;
+	}
+
+      while (cp < sp)
+	{
+	  if (*cp == ';' || (*cp == '\\' && cp[1] == 'n'))
+	    {
+	      /* Don't set a value if there are more than one
+		 instruction in the string.  */
+	      obstack_next_free (&string_obstack) =
+		obstack_next_free (&string_obstack) - size;
+	      size = 0;
+
+	      cp = sp;
+	      break;
+	    }
+	  cp++;
+	}
+      if (size == 0)
+	obstack_1grow (&string_obstack, '*');
+      else
+	add_mnemonic_string (mnemonic_htab,
+			     obstack_next_free (&string_obstack) - size,
+			     size);
+      i++;
+    }
+
+  /* An insn definition might emit an empty string.  */
+  if (obstack_object_size (&string_obstack) == 0)
+    return;
+
+  obstack_1grow (&string_obstack, '\0');
+
+  set_attr = rtx_alloc (SET_ATTR);
+  XSTR (set_attr, 1) = XOBFINISH (&string_obstack, char *);
+  attr_name = XNEWVAR (char, strlen (MNEMONIC_ATTR_NAME) + 1);
+  strcpy (attr_name, MNEMONIC_ATTR_NAME);
+  XSTR (set_attr, 0) = attr_name;
+
+  if (!XVEC (insn, 4))
+    vec_len = 0;
+  else
+    vec_len = XVECLEN (insn, 4);
+
+  new_vec = rtvec_alloc (vec_len + 1);
+  for (i = 0; i < vec_len; i++)
+    RTVEC_ELT (new_vec, i) = XVECEXP (insn, 4, i);
+  RTVEC_ELT (new_vec, vec_len) = set_attr;
+  XVEC (insn, 4) = new_vec;
+}
+
+/* This function is called for the elements in the mnemonic hashtable
+   and generates a comma separated list of the mnemonics.  */
+
+static int
+mnemonic_htab_callback (void **slot, void *info ATTRIBUTE_UNUSED)
+{
+  obstack_grow (&string_obstack, (char*)*slot, strlen ((char*)*slot));
+  obstack_1grow (&string_obstack, ',');
+  return 1;
+}
+
+/* Generate (set_attr "mnemonic" "..") RTXs and append them to every
+   insn definition in case the back end requests it by defining the
+   mnemonic attribute.  The values for the attribute will be extracted
+   from the output patterns of the insn definitions as far as
+   possible.  */
+
+static void
+gen_mnemonic_attr (void)
+{
+  struct queue_elem *elem;
+  rtx mnemonic_attr = NULL;
+  htab_t mnemonic_htab;
+  const char *str, *p;
+  int i;
+
+  if (have_error)
+    return;
+
+  /* Look for the DEFINE_ATTR for `mnemonic'.  */
+  for (elem = define_attr_queue; elem != *define_attr_tail; elem = elem->next)
+    if (GET_CODE (elem->data) == DEFINE_ATTR
+	&& strcmp (XSTR (elem->data, 0), MNEMONIC_ATTR_NAME) == 0)
+      {
+	mnemonic_attr = elem->data;
+	break;
+      }
+
+  /* A (define_attr "mnemonic" "...") indicates that the back-end
+     wants a mnemonic attribute to be generated.  */
+  if (!mnemonic_attr)
+    return;
+
+  mnemonic_htab = htab_create_alloc (MNEMONIC_HTAB_SIZE, htab_hash_string,
+				     htab_eq_string, 0, xcalloc, free);
+
+  for (elem = define_insn_queue; elem; elem = elem->next)
+    {
+      rtx insn = elem->data;
+      bool found = false;
+
+      /* Check if the insn definition already has
+	 (set_attr "mnemonic" ...) or (set (attr "mnemonic") ...).  */
+      if (XVEC (insn, 4))
+ 	for (i = 0; i < XVECLEN (insn, 4); i++)
+	  {
+	    rtx set_attr = XVECEXP (insn, 4, i);
+
+	    switch (GET_CODE (set_attr))
+	      {
+	      case SET_ATTR:
+	      case SET_ATTR_ALTERNATIVE:
+		if (strcmp (XSTR (set_attr, 0), MNEMONIC_ATTR_NAME) == 0)
+		  found = true;
+		break;
+	      case SET:
+		if (GET_CODE (SET_DEST (set_attr)) == ATTR
+		    && strcmp (XSTR (SET_DEST (set_attr), 0),
+			       MNEMONIC_ATTR_NAME) == 0)
+		  found = true;
+		break;
+	      default:
+		break;
+	      }
+	  }
+
+      if (!found)
+	gen_mnemonic_setattr (mnemonic_htab, insn);
+    }
+
+  /* Add the user defined values to the hash table.  */
+  str = XSTR (mnemonic_attr, 1);
+  while ((p = scan_comma_elt (&str)) != NULL)
+    add_mnemonic_string (mnemonic_htab, p, str - p);
+
+  htab_traverse (mnemonic_htab, mnemonic_htab_callback, NULL);
+
+  /* Replace the last ',' with the zero end character.  */
+  *((char *)obstack_next_free (&string_obstack) - 1) = '\0';
+  XSTR (mnemonic_attr, 1) = XOBFINISH (&string_obstack, char *);
+}
+
+/* Check if there are DEFINE_ATTRs with the same name.  */
+static void
+check_define_attr_duplicates ()
+{
+  struct queue_elem *elem;
+  htab_t attr_htab;
+  char * attr_name;
+  void **slot;
+
+  attr_htab = htab_create (500, htab_hash_string, htab_eq_string, NULL);
+
+  for (elem = define_attr_queue; elem; elem = elem->next)
+    {
+      attr_name = xstrdup (XSTR (elem->data, 0));
+
+      slot = htab_find_slot (attr_htab, attr_name, INSERT);
+
+      /* Duplicate.  */
+      if (*slot)
+	{
+	  error_with_line (elem->lineno, "redefinition of attribute '%s'",
+			   attr_name);
+	  htab_delete (attr_htab);
+	  return;
+	}
+
+      *slot = attr_name;
+    }
+
+  htab_delete (attr_htab);
+}
+
+/* The entry point for initializing the reader.  */
+
+bool
+init_rtx_reader_args_cb (int argc, char **argv,
+			 bool (*parse_opt) (const char *))
+{
+  /* Prepare to read input.  */
+  condition_table = htab_create (500, hash_c_test, cmp_c_test, NULL);
+  init_predicate_table ();
+  obstack_init (rtl_obstack);
+
+  /* Start at 1, to make 0 available for CODE_FOR_nothing.  */
+  sequence_num = 1;
+
+  read_md_files (argc, argv, parse_opt, rtx_handle_directive);
+
+  if (define_attr_queue != NULL)
+    check_define_attr_duplicates ();
+
+  /* Process define_cond_exec patterns.  */
+  if (define_cond_exec_queue != NULL)
+    process_define_cond_exec ();
+
+  /* Process define_subst patterns.  */
+  if (define_subst_queue != NULL)
+    process_define_subst ();
+
+  if (define_attr_queue != NULL)
+    gen_mnemonic_attr ();
+
+  return !have_error;
+}
+
+/* Programs that don't have their own options can use this entry point
+   instead.  */
+bool
+init_rtx_reader_args (int argc, char **argv)
+{
+  return init_rtx_reader_args_cb (argc, argv, 0);
+}
+
+/* The entry point for reading a single rtx from an md file.  Return
+   the rtx, or NULL if the md file has been fully processed.
+   Return the line where the rtx was found in LINENO.
+   Return the number of code generating rtx'en read since the start
+   of the md file in SEQNR.  */
+
+rtx
+read_md_rtx (int *lineno, int *seqnr)
+{
+  struct queue_elem **queue, *elem;
+  rtx desc;
+
+ discard:
+
+  /* Read all patterns from a given queue before moving on to the next.  */
+  if (define_attr_queue != NULL)
+    queue = &define_attr_queue;
+  else if (define_pred_queue != NULL)
+    queue = &define_pred_queue;
+  else if (define_insn_queue != NULL)
+    queue = &define_insn_queue;
+  else if (other_queue != NULL)
+    queue = &other_queue;
+  else
+    return NULL_RTX;
+
+  elem = *queue;
+  *queue = elem->next;
+  desc = elem->data;
+  read_md_filename = elem->filename;
+  *lineno = elem->lineno;
+  *seqnr = sequence_num;
+
+  free (elem);
+
+  /* Discard insn patterns which we know can never match (because
+     their C test is provably always false).  If insn_elision is
+     false, our caller needs to see all the patterns.  Note that the
+     elided patterns are never counted by the sequence numbering; it
+     is the caller's responsibility, when insn_elision is false, not
+     to use elided pattern numbers for anything.  */
+  switch (GET_CODE (desc))
+    {
+    case DEFINE_INSN:
+    case DEFINE_EXPAND:
+    case DEFINE_SUBST:
+      if (maybe_eval_c_test (XSTR (desc, 2)) != 0)
+	sequence_num++;
+      else if (insn_elision)
+	goto discard;
+
+      /* *seqnr is used here so the name table will match caller's
+	 idea of insn numbering, whether or not elision is active.  */
+      record_insn_name (*seqnr, XSTR (desc, 0));
+      break;
+
+    case DEFINE_SPLIT:
+    case DEFINE_PEEPHOLE:
+    case DEFINE_PEEPHOLE2:
+      if (maybe_eval_c_test (XSTR (desc, 1)) != 0)
+	sequence_num++;
+      else if (insn_elision)
+	    goto discard;
+      break;
+
+    default:
+      break;
+    }
+
+  return desc;
+}
+
+/* Helper functions for insn elision.  */
+
+/* Compute a hash function of a c_test structure, which is keyed
+   by its ->expr field.  */
+hashval_t
+hash_c_test (const void *x)
+{
+  const struct c_test *a = (const struct c_test *) x;
+  const unsigned char *base, *s = (const unsigned char *) a->expr;
+  hashval_t hash;
+  unsigned char c;
+  unsigned int len;
+
+  base = s;
+  hash = 0;
+
+  while ((c = *s++) != '\0')
+    {
+      hash += c + (c << 17);
+      hash ^= hash >> 2;
+    }
+
+  len = s - base;
+  hash += len + (len << 17);
+  hash ^= hash >> 2;
+
+  return hash;
+}
+
+/* Compare two c_test expression structures.  */
+int
+cmp_c_test (const void *x, const void *y)
+{
+  const struct c_test *a = (const struct c_test *) x;
+  const struct c_test *b = (const struct c_test *) y;
+
+  return !strcmp (a->expr, b->expr);
+}
+
+/* Given a string representing a C test expression, look it up in the
+   condition_table and report whether or not its value is known
+   at compile time.  Returns a tristate: 1 for known true, 0 for
+   known false, -1 for unknown.  */
+int
+maybe_eval_c_test (const char *expr)
+{
+  const struct c_test *test;
+  struct c_test dummy;
+
+  if (expr[0] == 0)
+    return 1;
+
+  dummy.expr = expr;
+  test = (const struct c_test *)htab_find (condition_table, &dummy);
+  if (!test)
+    return -1;
+  return test->value;
+}
+
+/* Record the C test expression EXPR in the condition_table, with
+   value VAL.  Duplicates clobber previous entries.  */
+
+void
+add_c_test (const char *expr, int value)
+{
+  struct c_test *test;
+
+  if (expr[0] == 0)
+    return;
+
+  test = XNEW (struct c_test);
+  test->expr = expr;
+  test->value = value;
+
+  *(htab_find_slot (condition_table, test, INSERT)) = test;
+}
+
+/* For every C test, call CALLBACK with two arguments: a pointer to
+   the condition structure and INFO.  Stops when CALLBACK returns zero.  */
+void
+traverse_c_tests (htab_trav callback, void *info)
+{
+  if (condition_table)
+    htab_traverse (condition_table, callback, info);
+}
+
+/* Helper functions for define_predicate and define_special_predicate
+   processing.  Shared between genrecog.c and genpreds.c.  */
+
+static htab_t predicate_table;
+struct pred_data *first_predicate;
+static struct pred_data **last_predicate = &first_predicate;
+
+static hashval_t
+hash_struct_pred_data (const void *ptr)
+{
+  return htab_hash_string (((const struct pred_data *)ptr)->name);
+}
+
+static int
+eq_struct_pred_data (const void *a, const void *b)
+{
+  return !strcmp (((const struct pred_data *)a)->name,
+		  ((const struct pred_data *)b)->name);
+}
+
+struct pred_data *
+lookup_predicate (const char *name)
+{
+  struct pred_data key;
+  key.name = name;
+  return (struct pred_data *) htab_find (predicate_table, &key);
+}
+
+/* Record that predicate PRED can accept CODE.  */
+
+void
+add_predicate_code (struct pred_data *pred, enum rtx_code code)
+{
+  if (!pred->codes[code])
+    {
+      pred->num_codes++;
+      pred->codes[code] = true;
+
+      if (GET_RTX_CLASS (code) != RTX_CONST_OBJ)
+	pred->allows_non_const = true;
+
+      if (code != REG
+	  && code != SUBREG
+	  && code != MEM
+	  && code != CONCAT
+	  && code != PARALLEL
+	  && code != STRICT_LOW_PART
+	  && code != SCRATCH)
+	pred->allows_non_lvalue = true;
+
+      if (pred->num_codes == 1)
+	pred->singleton = code;
+      else if (pred->num_codes == 2)
+	pred->singleton = UNKNOWN;
+    }
+}
+
+void
+add_predicate (struct pred_data *pred)
+{
+  void **slot = htab_find_slot (predicate_table, pred, INSERT);
+  if (*slot)
+    {
+      error ("duplicate predicate definition for '%s'", pred->name);
+      return;
+    }
+  *slot = pred;
+  *last_predicate = pred;
+  last_predicate = &pred->next;
+}
+
+/* This array gives the initial content of the predicate table.  It
+   has entries for all predicates defined in recog.c.  */
+
+struct std_pred_table
+{
+  const char *name;
+  bool special;
+  bool allows_const_p;
+  RTX_CODE codes[NUM_RTX_CODE];
+};
+
+static const struct std_pred_table std_preds[] = {
+  {"general_operand", false, true, {SUBREG, REG, MEM}},
+  {"address_operand", true, true, {SUBREG, REG, MEM, PLUS, MINUS, MULT}},
+  {"register_operand", false, false, {SUBREG, REG}},
+  {"pmode_register_operand", true, false, {SUBREG, REG}},
+  {"scratch_operand", false, false, {SCRATCH, REG}},
+  {"immediate_operand", false, true, {UNKNOWN}},
+  {"const_int_operand", false, false, {CONST_INT}},
+  {"const_double_operand", false, false, {CONST_INT, CONST_DOUBLE}},
+  {"nonimmediate_operand", false, false, {SUBREG, REG, MEM}},
+  {"nonmemory_operand", false, true, {SUBREG, REG}},
+  {"push_operand", false, false, {MEM}},
+  {"pop_operand", false, false, {MEM}},
+  {"memory_operand", false, false, {SUBREG, MEM}},
+  {"indirect_operand", false, false, {SUBREG, MEM}},
+  {"ordered_comparison_operator", false, false, {EQ, NE,
+						 LE, LT, GE, GT,
+						 LEU, LTU, GEU, GTU}},
+  {"comparison_operator", false, false, {EQ, NE,
+					 LE, LT, GE, GT,
+					 LEU, LTU, GEU, GTU,
+					 UNORDERED, ORDERED,
+					 UNEQ, UNGE, UNGT,
+					 UNLE, UNLT, LTGT}}
+};
+#define NUM_KNOWN_STD_PREDS ARRAY_SIZE (std_preds)
+
+/* Initialize the table of predicate definitions, starting with
+   the information we have on generic predicates.  */
+
+static void
+init_predicate_table (void)
+{
+  size_t i, j;
+  struct pred_data *pred;
+
+  predicate_table = htab_create_alloc (37, hash_struct_pred_data,
+				       eq_struct_pred_data, 0,
+				       xcalloc, free);
+
+  for (i = 0; i < NUM_KNOWN_STD_PREDS; i++)
+    {
+      pred = XCNEW (struct pred_data);
+      pred->name = std_preds[i].name;
+      pred->special = std_preds[i].special;
+
+      for (j = 0; std_preds[i].codes[j] != 0; j++)
+	add_predicate_code (pred, std_preds[i].codes[j]);
+
+      if (std_preds[i].allows_const_p)
+	for (j = 0; j < NUM_RTX_CODE; j++)
+	  if (GET_RTX_CLASS (j) == RTX_CONST_OBJ)
+	    add_predicate_code (pred, (enum rtx_code) j);
+
+      add_predicate (pred);
+    }
+}
+
+/* These functions allow linkage with print-rtl.c.  Also, some generators
+   like to annotate their output with insn names.  */
+
+/* Holds an array of names indexed by insn_code_number.  */
+static char **insn_name_ptr = 0;
+static int insn_name_ptr_size = 0;
+
+const char *
+get_insn_name (int code)
+{
+  if (code < insn_name_ptr_size)
+    return insn_name_ptr[code];
+  else
+    return NULL;
+}
+
+static void
+record_insn_name (int code, const char *name)
+{
+  static const char *last_real_name = "insn";
+  static int last_real_code = 0;
+  char *new_name;
+
+  if (insn_name_ptr_size <= code)
+    {
+      int new_size;
+      new_size = (insn_name_ptr_size ? insn_name_ptr_size * 2 : 512);
+      insn_name_ptr = XRESIZEVEC (char *, insn_name_ptr, new_size);
+      memset (insn_name_ptr + insn_name_ptr_size, 0,
+	      sizeof (char *) * (new_size - insn_name_ptr_size));
+      insn_name_ptr_size = new_size;
+    }
+
+  if (!name || name[0] == '\0')
+    {
+      new_name = XNEWVAR (char, strlen (last_real_name) + 10);
+      sprintf (new_name, "%s+%d", last_real_name, code - last_real_code);
+    }
+  else
+    {
+      last_real_name = new_name = xstrdup (name);
+      last_real_code = code;
+    }
+
+  insn_name_ptr[code] = new_name;
+}
+
+/* Make STATS describe the operands that appear in rtx X.  */
+
+static void
+get_pattern_stats_1 (struct pattern_stats *stats, rtx x)
+{
+  RTX_CODE code;
+  int i;
+  int len;
+  const char *fmt;
+
+  if (x == NULL_RTX)
+    return;
+
+  code = GET_CODE (x);
+  switch (code)
+    {
+    case MATCH_OPERAND:
+    case MATCH_OPERATOR:
+    case MATCH_PARALLEL:
+      stats->max_opno = MAX (stats->max_opno, XINT (x, 0));
+      break;
+
+    case MATCH_DUP:
+    case MATCH_OP_DUP:
+    case MATCH_PAR_DUP:
+      stats->num_dups++;
+      stats->max_dup_opno = MAX (stats->max_dup_opno, XINT (x, 0));
+      break;
+
+    case MATCH_SCRATCH:
+      stats->max_scratch_opno = MAX (stats->max_scratch_opno, XINT (x, 0));
+      break;
+
+    default:
+      break;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  len = GET_RTX_LENGTH (code);
+  for (i = 0; i < len; i++)
+    {
+      if (fmt[i] == 'e' || fmt[i] == 'u')
+	get_pattern_stats_1 (stats, XEXP (x, i));
+      else if (fmt[i] == 'E')
+	{
+	  int j;
+	  for (j = 0; j < XVECLEN (x, i); j++)
+	    get_pattern_stats_1 (stats, XVECEXP (x, i, j));
+	}
+    }
+}
+
+/* Make STATS describe the operands that appear in instruction pattern
+   PATTERN.  */
+
+void
+get_pattern_stats (struct pattern_stats *stats, rtvec pattern)
+{
+  int i, len;
+
+  stats->max_opno = -1;
+  stats->max_dup_opno = -1;
+  stats->max_scratch_opno = -1;
+  stats->num_dups = 0;
+
+  len = GET_NUM_ELEM (pattern);
+  for (i = 0; i < len; i++)
+    get_pattern_stats_1 (stats, RTVEC_ELT (pattern, i));
+
+  stats->num_generator_args = stats->max_opno + 1;
+  stats->num_insn_operands = MAX (stats->max_opno,
+				  stats->max_scratch_opno) + 1;
+  stats->num_operand_vars = MAX (stats->max_opno,
+				  MAX (stats->max_dup_opno,
+				       stats->max_scratch_opno)) + 1;
+}