diff gcc/gensupport.c @ 0:a06113de4d67

first commit
author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
parents
children 77e2b8dfacca
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/gensupport.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,1455 @@
+/* Support routines for the various generation passes.
+   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+   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 "gensupport.h"
+
+
+/* In case some macros used by files we include need it, define this here.  */
+int target_flags;
+
+int insn_elision = 1;
+
+const char *in_fname;
+
+/* This callback will be invoked whenever an rtl include directive is
+   processed.  To be used for creation of the dependency file.  */
+void (*include_callback) (const char *);
+
+static struct obstack obstack;
+struct obstack *rtl_obstack = &obstack;
+
+static int sequence_num;
+static int errors;
+
+static int predicable_default;
+static const char *predicable_true;
+static const char *predicable_false;
+
+static htab_t condition_table;
+
+static char *base_dir = NULL;
+
+/* We initially queue all patterns, process the define_insn and
+   define_cond_exec 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;
+};
+
+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 *other_queue;
+static struct queue_elem **other_tail = &other_queue;
+
+static struct queue_elem *queue_pattern (rtx, struct queue_elem ***,
+					 const char *, int);
+
+/* Current maximum length of directory names in the search path
+   for include files.  (Altered as we get more of them.)  */
+
+size_t max_include_len;
+
+struct file_name_list
+  {
+    struct file_name_list *next;
+    const char *fname;
+  };
+
+struct file_name_list *first_dir_md_include = 0;  /* First dir to search */
+        /* First dir to search for <file> */
+struct file_name_list *first_bracket_include = 0;
+struct file_name_list *last_dir_md_include = 0;        /* Last in chain */
+
+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 process_include (rtx, int);
+static char *save_string (const char *, int);
+static void init_predicate_table (void);
+static void record_insn_name (int, const char *);
+
+void
+message_with_line (int lineno, const char *msg, ...)
+{
+  va_list ap;
+
+  va_start (ap, msg);
+
+  fprintf (stderr, "%s:%d: ", read_rtx_filename, lineno);
+  vfprintf (stderr, msg, ap);
+  fputc ('\n', stderr);
+
+  va_end (ap);
+}
+
+/* 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;
+}
+
+/* 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;
+}
+
+/* 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 an include file assuming that it lives in gcc/config/{target}/
+   if the include looks like (include "file").  */
+
+static void
+process_include (rtx desc, int lineno)
+{
+  const char *filename = XSTR (desc, 0);
+  const char *old_filename;
+  int old_lineno;
+  char *pathname;
+  FILE *input_file;
+
+  /* If specified file name is absolute, skip the include stack.  */
+  if (! IS_ABSOLUTE_PATH (filename))
+    {
+      struct file_name_list *stackp;
+
+      /* Search directory path, trying to open the file.  */
+      for (stackp = first_dir_md_include; stackp; stackp = stackp->next)
+	{
+	  static const char sep[2] = { DIR_SEPARATOR, '\0' };
+
+	  pathname = concat (stackp->fname, sep, filename, NULL);
+	  input_file = fopen (pathname, "r");
+	  if (input_file != NULL)
+	    goto success;
+	  free (pathname);
+	}
+    }
+
+  if (base_dir)
+    pathname = concat (base_dir, filename, NULL);
+  else
+    pathname = xstrdup (filename);
+  input_file = fopen (pathname, "r");
+  if (input_file == NULL)
+    {
+      free (pathname);
+      message_with_line (lineno, "include file `%s' not found", filename);
+      errors = 1;
+      return;
+    }
+ success:
+
+  /* Save old cursor; setup new for the new file.  Note that "lineno" the
+     argument to this function is the beginning of the include statement,
+     while read_rtx_lineno has already been advanced.  */
+  old_filename = read_rtx_filename;
+  old_lineno = read_rtx_lineno;
+  read_rtx_filename = pathname;
+  read_rtx_lineno = 1;
+
+  if (include_callback)
+    include_callback (pathname);
+
+  /* Read the entire file.  */
+  while (read_rtx (input_file, &desc, &lineno))
+    process_rtx (desc, lineno);
+
+  /* Do not free pathname.  It is attached to the various rtx queue
+     elements.  */
+
+  read_rtx_filename = old_filename;
+  read_rtx_lineno = old_lineno;
+
+  fclose (input_file);
+}
+
+/* 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_rtx_filename, lineno);
+      break;
+
+    case DEFINE_COND_EXEC:
+      queue_pattern (desc, &define_cond_exec_tail, read_rtx_filename, lineno);
+      break;
+
+    case DEFINE_ATTR:
+      queue_pattern (desc, &define_attr_tail, read_rtx_filename, lineno);
+      break;
+
+    case DEFINE_PREDICATE:
+    case DEFINE_SPECIAL_PREDICATE:
+    case DEFINE_CONSTRAINT:
+    case DEFINE_REGISTER_CONSTRAINT:
+    case DEFINE_MEMORY_CONSTRAINT:
+    case DEFINE_ADDRESS_CONSTRAINT:
+      queue_pattern (desc, &define_pred_tail, read_rtx_filename, lineno);
+      break;
+
+    case INCLUDE:
+      process_include (desc, 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_rtx_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_rtx_filename, 
+			   lineno);
+	split_elem
+	  = queue_pattern (split, &other_tail, read_rtx_filename, lineno);
+	insn_elem->split = split_elem;
+	break;
+      }
+
+    default:
+      queue_pattern (desc, &other_tail, read_rtx_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)
+	    {
+	      message_with_line (elem->lineno,
+				 "multiple alternatives for `predicable'");
+	      errors = 1;
+	      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.  */
+	  message_with_line (elem->lineno,
+			     "non-constant value for `predicable'");
+	  errors = 1;
+	  return 0;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  return predicable_default;
+
+ found:
+  /* Verify that predicability does not vary on the alternative.  */
+  /* ??? It should be possible to handle this by simply eliminating
+     the non-predicable alternatives from the insn.  FRV would like
+     to do this.  Delay this until we've got the basics solid.  */
+  if (strchr (value, ',') != NULL)
+    {
+      message_with_line (elem->lineno,
+			 "multiple alternatives for `predicable'");
+      errors = 1;
+      return 0;
+    }
+
+  /* Find out which value we're looking at.  */
+  if (strcmp (value, predicable_true) == 0)
+    return 1;
+  if (strcmp (value, predicable_false) == 0)
+    return 0;
+
+  message_with_line (elem->lineno,
+		     "unknown value `%s' for `predicable' attribute",
+		     value);
+  errors = 1;
+  return 0;
+}
+
+/* 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;
+
+  message_with_line (define_cond_exec_queue->lineno,
+		     "attribute `predicable' not defined");
+  errors = 1;
+  return;
+
+ found:
+  value = XSTR (elem->data, 1);
+  p_false = xstrdup (value);
+  p_true = strchr (p_false, ',');
+  if (p_true == NULL || strchr (++p_true, ',') != NULL)
+    {
+      message_with_line (elem->lineno,
+			 "attribute `predicable' is not a boolean");
+      errors = 1;
+      if (p_false)
+        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:
+      message_with_line (elem->lineno,
+			 "attribute `predicable' cannot be const");
+      errors = 1;
+      if (p_false)
+	free (p_false);
+      return;
+
+    default:
+      message_with_line (elem->lineno,
+			 "attribute `predicable' must have a constant default");
+      errors = 1;
+      if (p_false)
+	free (p_false);
+      return;
+    }
+
+  if (strcmp (value, p_true) == 0)
+    predicable_default = 1;
+  else if (strcmp (value, p_false) == 0)
+    predicable_default = 0;
+  else
+    {
+      message_with_line (elem->lineno,
+			 "unknown value `%s' for `predicable' attribute",
+			 value);
+      errors = 1;
+      if (p_false)
+	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;
+}
+
+/* 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)
+	  {
+	    message_with_line (lineno,
+			       "too many alternatives for operand %d",
+			       XINT (pattern, 0));
+	    errors = 1;
+	    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;
+}
+
+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));
+}
+
+/* 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;
+}
+
+/* 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;
+      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)
+	{
+	  message_with_line (ce_elem->lineno,
+			     "too many patterns in predicate");
+	  errors = 1;
+	  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);
+      XSTR (insn, 0) = "";
+      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;
+	}
+
+      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);
+
+      /* ??? Set `predicable' to false.  Not crucial since it's really
+         only used here, and we won't reprocess this new pattern.  */
+
+      /* 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_rtx_filename, 
+		     insn_elem->split->lineno);
+    }
+}
+
+/* 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 (errors)
+    return;
+
+  for (elem = define_cond_exec_queue; elem ; elem = elem->next)
+    process_one_cond_exec (elem);
+}
+
+static char *
+save_string (const char *s, int len)
+{
+  char *result = XNEWVEC (char, len + 1);
+
+  memcpy (result, s, len);
+  result[len] = 0;
+  return result;
+}
+
+
+/* The entry point for initializing the reader.  */
+
+int
+init_md_reader_args_cb (int argc, char **argv, bool (*parse_opt)(const char *))
+{
+  FILE *input_file;
+  int c, i, lineno;
+  char *lastsl;
+  rtx desc;
+  bool no_more_options;
+  bool already_read_stdin;
+
+  /* Unlock the stdio streams.  */
+  unlock_std_streams ();
+
+  /* First we loop over all the options.  */
+  for (i = 1; i < argc; i++)
+    {
+      if (argv[i][0] != '-')
+	continue;
+      
+      c = argv[i][1];
+      switch (c)
+	{
+	case 'I':		/* Add directory to path for includes.  */
+	  {
+	    struct file_name_list *dirtmp;
+
+	    dirtmp = XNEW (struct file_name_list);
+	    dirtmp->next = 0;	/* New one goes on the end */
+	    if (first_dir_md_include == 0)
+	      first_dir_md_include = dirtmp;
+	    else
+	      last_dir_md_include->next = dirtmp;
+	    last_dir_md_include = dirtmp;	/* Tail follows the last one */
+	    if (argv[i][1] == 'I' && argv[i][2] != 0)
+	      dirtmp->fname = argv[i] + 2;
+	    else if (i + 1 == argc)
+	      fatal ("directory name missing after -I option");
+	    else
+	      dirtmp->fname = argv[++i];
+	    if (strlen (dirtmp->fname) > max_include_len)
+	      max_include_len = strlen (dirtmp->fname);
+	  }
+	  break;
+
+	case '\0':
+	  /* An argument consisting of exactly one dash is a request to
+	     read stdin.  This will be handled in the second loop.  */
+	  continue;
+
+	case '-':
+	  /* An argument consisting of just two dashes causes option
+	     parsing to cease.  */
+	  if (argv[i][2] == '\0')
+	    goto stop_parsing_options;
+
+	default:
+	  /* The program may have provided a callback so it can
+	     accept its own options.  */
+	  if (parse_opt && parse_opt (argv[i]))
+	    break;
+
+	  fatal ("invalid option `%s'", argv[i]);
+	}
+    }
+
+ stop_parsing_options:
+
+  /* Prepare to read input.  */
+  condition_table = htab_create (500, hash_c_test, cmp_c_test, NULL);
+  init_predicate_table ();
+  obstack_init (rtl_obstack);
+  errors = 0;
+  sequence_num = 0;
+  no_more_options = false;
+  already_read_stdin = false;
+
+
+  /* Now loop over all input files.  */
+  for (i = 1; i < argc; i++)
+    {
+      if (argv[i][0] == '-')
+	{
+	  if (argv[i][1] == '\0')
+	    {
+	      /* Read stdin.  */
+	      if (already_read_stdin)
+		fatal ("cannot read standard input twice");
+	      
+	      base_dir = NULL;
+	      read_rtx_filename = in_fname = "<stdin>";
+	      read_rtx_lineno = 1;
+	      input_file = stdin;
+	      already_read_stdin = true;
+
+	      while (read_rtx (input_file, &desc, &lineno))
+		process_rtx (desc, lineno);
+	      fclose (input_file);
+	      continue;
+	    }
+	  else if (argv[i][1] == '-' && argv[i][2] == '\0')
+	    {
+	      /* No further arguments are to be treated as options.  */
+	      no_more_options = true;
+	      continue;
+	    }
+	  else if (!no_more_options)
+	    continue;
+	}
+
+      /* If we get here we are looking at a non-option argument, i.e.
+	 a file to be processed.  */
+
+      in_fname = argv[i];
+      lastsl = strrchr (in_fname, '/');
+      if (lastsl != NULL)
+	base_dir = save_string (in_fname, lastsl - in_fname + 1 );
+      else
+	base_dir = NULL;
+
+      read_rtx_filename = in_fname;
+      read_rtx_lineno = 1;
+      input_file = fopen (in_fname, "r");
+      if (input_file == 0)
+	{
+	  perror (in_fname);
+	  return FATAL_EXIT_CODE;
+	}
+
+      while (read_rtx (input_file, &desc, &lineno))
+	process_rtx (desc, lineno);
+      fclose (input_file);
+    }
+
+  /* If we get to this point without having seen any files to process,
+     read standard input now.  */
+  if (!in_fname)
+    {
+      base_dir = NULL;
+      read_rtx_filename = in_fname = "<stdin>";
+      read_rtx_lineno = 1;
+      input_file = stdin;
+
+      while (read_rtx (input_file, &desc, &lineno))
+	process_rtx (desc, lineno);
+      fclose (input_file);
+    }
+
+  /* Process define_cond_exec patterns.  */
+  if (define_cond_exec_queue != NULL)
+    process_define_cond_exec ();
+
+  return errors ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE;
+}
+
+/* Programs that don't have their own options can use this entry point
+   instead.  */
+int
+init_md_reader_args (int argc, char **argv)
+{
+  return init_md_reader_args_cb (argc, argv, 0);
+}
+
+/* The entry point for reading a single rtx from an md file.  */
+
+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_rtx_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
+     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:
+      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);
+}
+
+
+/* Given a string, return the number of comma-separated elements in it.
+   Return 0 for the null string.  */
+int
+n_comma_elts (const char *s)
+{
+  int n;
+
+  if (*s == '\0')
+    return 0;
+
+  for (n = 1; *s; s++)
+    if (*s == ',')
+      n++;
+
+  return n;
+}
+
+/* Given a pointer to a (char *), return a pointer to the beginning of the
+   next comma-separated element in the string.  Advance the pointer given
+   to the end of that element.  Return NULL if at end of string.  Caller
+   is responsible for copying the string if necessary.  White space between
+   a comma and an element is ignored.  */
+
+const char *
+scan_comma_elt (const char **pstr)
+{
+  const char *start;
+  const char *p = *pstr;
+
+  if (*p == ',')
+    p++;
+  while (ISSPACE(*p))
+    p++;
+
+  if (*p == '\0')
+    return NULL;
+
+  start = p;
+
+  while (*p != ',' && *p != '\0')
+    p++;
+
+  *pstr = p;
+  return start;
+}
+
+/* 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)
+	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, {0}},
+  {"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}},
+  {"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, 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;
+}