Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 1303 insertions, 0 deletions

diff --git a/gcc-4.9/gcc/reginfo.c b/gcc-4.9/gcc/reginfo.c
new file mode 100644
index 000000000..bdb980da3
--- /dev/null
+++ b/gcc-4.9/gcc/reginfo.c
@@ -0,0 +1,1303 @@
+/* Compute different info about registers.
+   Copyright (C) 1987-2014 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/>.  */
+
+
+/* This file contains regscan pass of the compiler and passes for
+   dealing with info about modes of pseudo-registers inside
+   subregisters.  It also defines some tables of information about the
+   hardware registers, function init_reg_sets to initialize the
+   tables, and other auxiliary functions to deal with info about
+   registers and their classes.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "hard-reg-set.h"
+#include "tree.h"
+#include "rtl.h"
+#include "expr.h"
+#include "tm_p.h"
+#include "flags.h"
+#include "basic-block.h"
+#include "regs.h"
+#include "addresses.h"
+#include "function.h"
+#include "insn-config.h"
+#include "recog.h"
+#include "reload.h"
+#include "diagnostic-core.h"
+#include "output.h"
+#include "hashtab.h"
+#include "target.h"
+#include "tree-pass.h"
+#include "df.h"
+#include "ira.h"
+
+/* Maximum register number used in this function, plus one.  */
+
+int max_regno;
+
+
+struct target_hard_regs default_target_hard_regs;
+struct target_regs default_target_regs;
+#if SWITCHABLE_TARGET
+struct target_hard_regs *this_target_hard_regs = &default_target_hard_regs;
+struct target_regs *this_target_regs = &default_target_regs;
+#endif
+
+/* Data for initializing fixed_regs.  */
+static const char initial_fixed_regs[] = FIXED_REGISTERS;
+
+/* Data for initializing call_used_regs.  */
+static const char initial_call_used_regs[] = CALL_USED_REGISTERS;
+
+#ifdef CALL_REALLY_USED_REGISTERS
+/* Data for initializing call_really_used_regs.  */
+static const char initial_call_really_used_regs[] = CALL_REALLY_USED_REGISTERS;
+#endif
+
+#ifdef CALL_REALLY_USED_REGISTERS
+#define CALL_REALLY_USED_REGNO_P(X)  call_really_used_regs[X]
+#else
+#define CALL_REALLY_USED_REGNO_P(X)  call_used_regs[X]
+#endif
+
+/* Indexed by hard register number, contains 1 for registers
+   that are being used for global register decls.
+   These must be exempt from ordinary flow analysis
+   and are also considered fixed.  */
+char global_regs[FIRST_PSEUDO_REGISTER];
+
+/* Declaration for the global register. */
+tree global_regs_decl[FIRST_PSEUDO_REGISTER];
+
+/* Same information as REGS_INVALIDATED_BY_CALL but in regset form to be used
+   in dataflow more conveniently.  */
+regset regs_invalidated_by_call_regset;
+
+/* Same information as FIXED_REG_SET but in regset form.  */
+regset fixed_reg_set_regset;
+
+/* The bitmap_obstack is used to hold some static variables that
+   should not be reset after each function is compiled.  */
+static bitmap_obstack persistent_obstack;
+
+/* Used to initialize reg_alloc_order.  */
+#ifdef REG_ALLOC_ORDER
+static int initial_reg_alloc_order[FIRST_PSEUDO_REGISTER] = REG_ALLOC_ORDER;
+#endif
+
+/* The same information, but as an array of unsigned ints.  We copy from
+   these unsigned ints to the table above.  We do this so the tm.h files
+   do not have to be aware of the wordsize for machines with <= 64 regs.
+   Note that we hard-code 32 here, not HOST_BITS_PER_INT.  */
+#define N_REG_INTS  \
+  ((FIRST_PSEUDO_REGISTER + (32 - 1)) / 32)
+
+static const unsigned int_reg_class_contents[N_REG_CLASSES][N_REG_INTS]
+  = REG_CLASS_CONTENTS;
+
+/* Array containing all of the register names.  */
+static const char *const initial_reg_names[] = REGISTER_NAMES;
+
+/* Array containing all of the register class names.  */
+const char * reg_class_names[] = REG_CLASS_NAMES;
+
+/* No more global register variables may be declared; true once
+   reginfo has been initialized.  */
+static int no_global_reg_vars = 0;
+
+/* Given a register bitmap, turn on the bits in a HARD_REG_SET that
+   correspond to the hard registers, if any, set in that map.  This
+   could be done far more efficiently by having all sorts of special-cases
+   with moving single words, but probably isn't worth the trouble.  */
+void
+reg_set_to_hard_reg_set (HARD_REG_SET *to, const_bitmap from)
+{
+  unsigned i;
+  bitmap_iterator bi;
+
+  EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
+    {
+      if (i >= FIRST_PSEUDO_REGISTER)
+	return;
+      SET_HARD_REG_BIT (*to, i);
+    }
+}
+
+/* Function called only once per target_globals to initialize the
+   target_hard_regs structure.  Once this is done, various switches
+   may override.  */
+void
+init_reg_sets (void)
+{
+  int i, j;
+
+  /* First copy the register information from the initial int form into
+     the regsets.  */
+
+  for (i = 0; i < N_REG_CLASSES; i++)
+    {
+      CLEAR_HARD_REG_SET (reg_class_contents[i]);
+
+      /* Note that we hard-code 32 here, not HOST_BITS_PER_INT.  */
+      for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
+	if (int_reg_class_contents[i][j / 32]
+	    & ((unsigned) 1 << (j % 32)))
+	  SET_HARD_REG_BIT (reg_class_contents[i], j);
+    }
+
+  /* Sanity check: make sure the target macros FIXED_REGISTERS and
+     CALL_USED_REGISTERS had the right number of initializers.  */
+  gcc_assert (sizeof fixed_regs == sizeof initial_fixed_regs);
+  gcc_assert (sizeof call_used_regs == sizeof initial_call_used_regs);
+#ifdef CALL_REALLY_USED_REGISTERS
+  gcc_assert (sizeof call_really_used_regs
+	      == sizeof initial_call_really_used_regs);
+#endif
+#ifdef REG_ALLOC_ORDER
+  gcc_assert (sizeof reg_alloc_order == sizeof initial_reg_alloc_order);
+#endif
+  gcc_assert (sizeof reg_names == sizeof initial_reg_names);
+
+  memcpy (fixed_regs, initial_fixed_regs, sizeof fixed_regs);
+  memcpy (call_used_regs, initial_call_used_regs, sizeof call_used_regs);
+#ifdef CALL_REALLY_USED_REGISTERS
+  memcpy (call_really_used_regs, initial_call_really_used_regs,
+	  sizeof call_really_used_regs);
+#endif
+#ifdef REG_ALLOC_ORDER
+  memcpy (reg_alloc_order, initial_reg_alloc_order, sizeof reg_alloc_order);
+#endif
+  memcpy (reg_names, initial_reg_names, sizeof reg_names);
+
+  SET_HARD_REG_SET (accessible_reg_set);
+  SET_HARD_REG_SET (operand_reg_set);
+}
+
+/* We need to save copies of some of the register information which
+   can be munged by command-line switches so we can restore it during
+   subsequent back-end reinitialization.  */
+static char saved_fixed_regs[FIRST_PSEUDO_REGISTER];
+static char saved_call_used_regs[FIRST_PSEUDO_REGISTER];
+#ifdef CALL_REALLY_USED_REGISTERS
+static char saved_call_really_used_regs[FIRST_PSEUDO_REGISTER];
+#endif
+static const char *saved_reg_names[FIRST_PSEUDO_REGISTER];
+static HARD_REG_SET saved_accessible_reg_set;
+static HARD_REG_SET saved_operand_reg_set;
+
+/* Save the register information.  */
+void
+save_register_info (void)
+{
+  /* Sanity check:  make sure the target macros FIXED_REGISTERS and
+     CALL_USED_REGISTERS had the right number of initializers.  */
+  gcc_assert (sizeof fixed_regs == sizeof saved_fixed_regs);
+  gcc_assert (sizeof call_used_regs == sizeof saved_call_used_regs);
+  memcpy (saved_fixed_regs, fixed_regs, sizeof fixed_regs);
+  memcpy (saved_call_used_regs, call_used_regs, sizeof call_used_regs);
+
+  /* Likewise for call_really_used_regs.  */
+#ifdef CALL_REALLY_USED_REGISTERS
+  gcc_assert (sizeof call_really_used_regs
+	      == sizeof saved_call_really_used_regs);
+  memcpy (saved_call_really_used_regs, call_really_used_regs,
+	  sizeof call_really_used_regs);
+#endif
+
+  /* And similarly for reg_names.  */
+  gcc_assert (sizeof reg_names == sizeof saved_reg_names);
+  memcpy (saved_reg_names, reg_names, sizeof reg_names);
+  COPY_HARD_REG_SET (saved_accessible_reg_set, accessible_reg_set);
+  COPY_HARD_REG_SET (saved_operand_reg_set, operand_reg_set);
+}
+
+/* Restore the register information.  */
+static void
+restore_register_info (void)
+{
+  memcpy (fixed_regs, saved_fixed_regs, sizeof fixed_regs);
+  memcpy (call_used_regs, saved_call_used_regs, sizeof call_used_regs);
+
+#ifdef CALL_REALLY_USED_REGISTERS
+  memcpy (call_really_used_regs, saved_call_really_used_regs,
+	  sizeof call_really_used_regs);
+#endif
+
+  memcpy (reg_names, saved_reg_names, sizeof reg_names);
+  COPY_HARD_REG_SET (accessible_reg_set, saved_accessible_reg_set);
+  COPY_HARD_REG_SET (operand_reg_set, saved_operand_reg_set);
+}
+
+/* After switches have been processed, which perhaps alter
+   `fixed_regs' and `call_used_regs', convert them to HARD_REG_SETs.  */
+static void
+init_reg_sets_1 (void)
+{
+  unsigned int i, j;
+  unsigned int /* enum machine_mode */ m;
+
+  restore_register_info ();
+
+#ifdef REG_ALLOC_ORDER
+  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+    inv_reg_alloc_order[reg_alloc_order[i]] = i;
+#endif
+
+  /* Let the target tweak things if necessary.  */
+
+  targetm.conditional_register_usage ();
+
+  /* Compute number of hard regs in each class.  */
+
+  memset (reg_class_size, 0, sizeof reg_class_size);
+  for (i = 0; i < N_REG_CLASSES; i++)
+    {
+      bool any_nonfixed = false;
+      for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)	
+	if (TEST_HARD_REG_BIT (reg_class_contents[i], j))
+	  {
+	    reg_class_size[i]++;
+	    if (!fixed_regs[j])
+	      any_nonfixed = true;
+	  }
+      class_only_fixed_regs[i] = !any_nonfixed;
+    }
+
+  /* Initialize the table of subunions.
+     reg_class_subunion[I][J] gets the largest-numbered reg-class
+     that is contained in the union of classes I and J.  */
+
+  memset (reg_class_subunion, 0, sizeof reg_class_subunion);
+  for (i = 0; i < N_REG_CLASSES; i++)
+    {
+      for (j = 0; j < N_REG_CLASSES; j++)
+	{
+	  HARD_REG_SET c;
+	  int k;
+
+	  COPY_HARD_REG_SET (c, reg_class_contents[i]);
+	  IOR_HARD_REG_SET (c, reg_class_contents[j]);
+	  for (k = 0; k < N_REG_CLASSES; k++)
+	    if (hard_reg_set_subset_p (reg_class_contents[k], c)
+		&& !hard_reg_set_subset_p (reg_class_contents[k],
+					  reg_class_contents
+					  [(int) reg_class_subunion[i][j]]))
+	      reg_class_subunion[i][j] = (enum reg_class) k;
+	}
+    }
+
+  /* Initialize the table of superunions.
+     reg_class_superunion[I][J] gets the smallest-numbered reg-class
+     containing the union of classes I and J.  */
+
+  memset (reg_class_superunion, 0, sizeof reg_class_superunion);
+  for (i = 0; i < N_REG_CLASSES; i++)
+    {
+      for (j = 0; j < N_REG_CLASSES; j++)
+	{
+	  HARD_REG_SET c;
+	  int k;
+
+	  COPY_HARD_REG_SET (c, reg_class_contents[i]);
+	  IOR_HARD_REG_SET (c, reg_class_contents[j]);
+	  for (k = 0; k < N_REG_CLASSES; k++)
+	    if (hard_reg_set_subset_p (c, reg_class_contents[k]))
+	      break;
+
+	  reg_class_superunion[i][j] = (enum reg_class) k;
+	}
+    }
+
+  /* Initialize the tables of subclasses and superclasses of each reg class.
+     First clear the whole table, then add the elements as they are found.  */
+
+  for (i = 0; i < N_REG_CLASSES; i++)
+    {
+      for (j = 0; j < N_REG_CLASSES; j++)
+	reg_class_subclasses[i][j] = LIM_REG_CLASSES;
+    }
+
+  for (i = 0; i < N_REG_CLASSES; i++)
+    {
+      if (i == (int) NO_REGS)
+	continue;
+
+      for (j = i + 1; j < N_REG_CLASSES; j++)
+	if (hard_reg_set_subset_p (reg_class_contents[i],
+				  reg_class_contents[j]))
+	  {
+	    /* Reg class I is a subclass of J.
+	       Add J to the table of superclasses of I.  */
+	    enum reg_class *p;
+
+	    /* Add I to the table of superclasses of J.  */
+	    p = &reg_class_subclasses[j][0];
+	    while (*p != LIM_REG_CLASSES) p++;
+	    *p = (enum reg_class) i;
+	  }
+    }
+
+  /* Initialize "constant" tables.  */
+
+  CLEAR_HARD_REG_SET (fixed_reg_set);
+  CLEAR_HARD_REG_SET (call_used_reg_set);
+  CLEAR_HARD_REG_SET (call_fixed_reg_set);
+  CLEAR_HARD_REG_SET (regs_invalidated_by_call);
+  if (!regs_invalidated_by_call_regset)
+    {
+      bitmap_obstack_initialize (&persistent_obstack);
+      regs_invalidated_by_call_regset = ALLOC_REG_SET (&persistent_obstack);
+    }
+  else
+    CLEAR_REG_SET (regs_invalidated_by_call_regset);
+  if (!fixed_reg_set_regset)
+    fixed_reg_set_regset = ALLOC_REG_SET (&persistent_obstack);
+  else
+    CLEAR_REG_SET (fixed_reg_set_regset);
+
+  AND_HARD_REG_SET (operand_reg_set, accessible_reg_set);
+  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+    {
+      /* As a special exception, registers whose class is NO_REGS are
+	 not accepted by `register_operand'.  The reason for this change
+	 is to allow the representation of special architecture artifacts
+	 (such as a condition code register) without extending the rtl
+	 definitions.  Since registers of class NO_REGS cannot be used
+	 as registers in any case where register classes are examined,
+	 it is better to apply this exception in a target-independent way.  */
+      if (REGNO_REG_CLASS (i) == NO_REGS)
+	CLEAR_HARD_REG_BIT (operand_reg_set, i);
+
+      /* If a register is too limited to be treated as a register operand,
+	 then it should never be allocated to a pseudo.  */
+      if (!TEST_HARD_REG_BIT (operand_reg_set, i))
+	{
+	  fixed_regs[i] = 1;
+	  call_used_regs[i] = 1;
+	}
+
+      /* call_used_regs must include fixed_regs.  */
+      gcc_assert (!fixed_regs[i] || call_used_regs[i]);
+#ifdef CALL_REALLY_USED_REGISTERS
+      /* call_used_regs must include call_really_used_regs.  */
+      gcc_assert (!call_really_used_regs[i] || call_used_regs[i]);
+#endif
+
+      if (fixed_regs[i])
+	{
+	  SET_HARD_REG_BIT (fixed_reg_set, i);
+	  SET_REGNO_REG_SET (fixed_reg_set_regset, i);
+	}
+
+      if (call_used_regs[i])
+	SET_HARD_REG_BIT (call_used_reg_set, i);
+
+      /* There are a couple of fixed registers that we know are safe to
+	 exclude from being clobbered by calls:
+
+	 The frame pointer is always preserved across calls.  The arg
+	 pointer is if it is fixed.  The stack pointer usually is,
+	 unless TARGET_RETURN_POPS_ARGS, in which case an explicit
+	 CLOBBER will be present.  If we are generating PIC code, the
+	 PIC offset table register is preserved across calls, though the
+	 target can override that.  */
+
+      if (i == STACK_POINTER_REGNUM)
+	;
+      else if (global_regs[i])
+        {
+	  SET_HARD_REG_BIT (regs_invalidated_by_call, i);
+	  SET_REGNO_REG_SET (regs_invalidated_by_call_regset, i);
+	}
+      else if (i == FRAME_POINTER_REGNUM)
+	;
+#if !HARD_FRAME_POINTER_IS_FRAME_POINTER
+      else if (i == HARD_FRAME_POINTER_REGNUM)
+	;
+#endif
+#if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
+      else if (i == ARG_POINTER_REGNUM && fixed_regs[i])
+	;
+#endif
+      else if (!PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
+	       && i == (unsigned) PIC_OFFSET_TABLE_REGNUM && fixed_regs[i])
+	;
+      else if (CALL_REALLY_USED_REGNO_P (i))
+        {
+	  SET_HARD_REG_BIT (regs_invalidated_by_call, i);
+	  SET_REGNO_REG_SET (regs_invalidated_by_call_regset, i);
+        }
+    }
+
+  COPY_HARD_REG_SET (call_fixed_reg_set, fixed_reg_set);
+
+  /* Preserve global registers if called more than once.  */
+  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+    {
+      if (global_regs[i])
+	{
+	  fixed_regs[i] = call_used_regs[i] = 1;
+	  SET_HARD_REG_BIT (fixed_reg_set, i);
+	  SET_HARD_REG_BIT (call_used_reg_set, i);
+	  SET_HARD_REG_BIT (call_fixed_reg_set, i);
+	}
+    }
+
+  memset (have_regs_of_mode, 0, sizeof (have_regs_of_mode));
+  memset (contains_reg_of_mode, 0, sizeof (contains_reg_of_mode));
+  for (m = 0; m < (unsigned int) MAX_MACHINE_MODE; m++)
+    {
+      HARD_REG_SET ok_regs;
+      CLEAR_HARD_REG_SET (ok_regs);
+      for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
+	if (!fixed_regs [j] && HARD_REGNO_MODE_OK (j, (enum machine_mode) m))
+	  SET_HARD_REG_BIT (ok_regs, j);
+
+      for (i = 0; i < N_REG_CLASSES; i++)
+	if ((targetm.class_max_nregs ((reg_class_t) i, (enum machine_mode) m)
+	     <= reg_class_size[i])
+	    && hard_reg_set_intersect_p (ok_regs, reg_class_contents[i]))
+	  {
+	     contains_reg_of_mode [i][m] = 1;
+	     have_regs_of_mode [m] = 1;
+	  }
+     }
+}
+
+/* Compute the table of register modes.
+   These values are used to record death information for individual registers
+   (as opposed to a multi-register mode).
+   This function might be invoked more than once, if the target has support
+   for changing register usage conventions on a per-function basis.
+*/
+void
+init_reg_modes_target (void)
+{
+  int i, j;
+
+  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+    for (j = 0; j < MAX_MACHINE_MODE; j++)
+      hard_regno_nregs[i][j] = HARD_REGNO_NREGS (i, (enum machine_mode)j);
+
+  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+    {
+      reg_raw_mode[i] = choose_hard_reg_mode (i, 1, false);
+
+      /* If we couldn't find a valid mode, just use the previous mode
+	 if it is suitable, otherwise fall back on word_mode.  */
+      if (reg_raw_mode[i] == VOIDmode)
+    	{
+	  if (i > 0 && hard_regno_nregs[i][reg_raw_mode[i - 1]] == 1)
+	    reg_raw_mode[i] = reg_raw_mode[i - 1];
+	  else
+	    reg_raw_mode[i] = word_mode;
+	}
+    }
+}
+
+/* Finish initializing the register sets and initialize the register modes.
+   This function might be invoked more than once, if the target has support
+   for changing register usage conventions on a per-function basis.
+*/
+void
+init_regs (void)
+{
+  /* This finishes what was started by init_reg_sets, but couldn't be done
+     until after register usage was specified.  */
+  init_reg_sets_1 ();
+}
+
+/* The same as previous function plus initializing IRA.  */
+void
+reinit_regs (void)
+{
+  init_regs ();
+  /* caller_save needs to be re-initialized.  */
+  caller_save_initialized_p = false;
+  ira_init ();
+}
+
+/* Initialize some fake stack-frame MEM references for use in
+   memory_move_secondary_cost.  */
+void
+init_fake_stack_mems (void)
+{
+  int i;
+
+  for (i = 0; i < MAX_MACHINE_MODE; i++)
+    top_of_stack[i] = gen_rtx_MEM ((enum machine_mode) i, stack_pointer_rtx);
+}
+
+
+/* Compute cost of moving data from a register of class FROM to one of
+   TO, using MODE.  */
+
+int
+register_move_cost (enum machine_mode mode, reg_class_t from, reg_class_t to)
+{
+  return targetm.register_move_cost (mode, from, to);
+}
+
+/* Compute cost of moving registers to/from memory.  */
+
+int
+memory_move_cost (enum machine_mode mode, reg_class_t rclass, bool in)
+{
+  return targetm.memory_move_cost (mode, rclass, in);
+}
+
+/* Compute extra cost of moving registers to/from memory due to reloads.
+   Only needed if secondary reloads are required for memory moves.  */
+int
+memory_move_secondary_cost (enum machine_mode mode, reg_class_t rclass,
+			    bool in)
+{
+  reg_class_t altclass;
+  int partial_cost = 0;
+  /* We need a memory reference to feed to SECONDARY... macros.  */
+  /* mem may be unused even if the SECONDARY_ macros are defined.  */
+  rtx mem ATTRIBUTE_UNUSED = top_of_stack[(int) mode];
+
+  altclass = secondary_reload_class (in ? 1 : 0, rclass, mode, mem);
+
+  if (altclass == NO_REGS)
+    return 0;
+
+  if (in)
+    partial_cost = register_move_cost (mode, altclass, rclass);
+  else
+    partial_cost = register_move_cost (mode, rclass, altclass);
+
+  if (rclass == altclass)
+    /* This isn't simply a copy-to-temporary situation.  Can't guess
+       what it is, so TARGET_MEMORY_MOVE_COST really ought not to be
+       calling here in that case.
+
+       I'm tempted to put in an assert here, but returning this will
+       probably only give poor estimates, which is what we would've
+       had before this code anyways.  */
+    return partial_cost;
+
+  /* Check if the secondary reload register will also need a
+     secondary reload.  */
+  return memory_move_secondary_cost (mode, altclass, in) + partial_cost;
+}
+
+/* Return a machine mode that is legitimate for hard reg REGNO and large
+   enough to save nregs.  If we can't find one, return VOIDmode.
+   If CALL_SAVED is true, only consider modes that are call saved.  */
+enum machine_mode
+choose_hard_reg_mode (unsigned int regno ATTRIBUTE_UNUSED,
+		      unsigned int nregs, bool call_saved)
+{
+  unsigned int /* enum machine_mode */ m;
+  enum machine_mode found_mode = VOIDmode, mode;
+
+  /* We first look for the largest integer mode that can be validly
+     held in REGNO.  If none, we look for the largest floating-point mode.
+     If we still didn't find a valid mode, try CCmode.  */
+
+  for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
+       mode != VOIDmode;
+       mode = GET_MODE_WIDER_MODE (mode))
+    if ((unsigned) hard_regno_nregs[regno][mode] == nregs
+	&& HARD_REGNO_MODE_OK (regno, mode)
+	&& (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode))
+	&& GET_MODE_SIZE (mode) > GET_MODE_SIZE (found_mode))
+      found_mode = mode;
+
+  for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
+       mode != VOIDmode;
+       mode = GET_MODE_WIDER_MODE (mode))
+    if ((unsigned) hard_regno_nregs[regno][mode] == nregs
+	&& HARD_REGNO_MODE_OK (regno, mode)
+	&& (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode))
+	&& GET_MODE_SIZE (mode) > GET_MODE_SIZE (found_mode))
+      found_mode = mode;
+
+  for (mode = GET_CLASS_NARROWEST_MODE (MODE_VECTOR_FLOAT);
+       mode != VOIDmode;
+       mode = GET_MODE_WIDER_MODE (mode))
+    if ((unsigned) hard_regno_nregs[regno][mode] == nregs
+	&& HARD_REGNO_MODE_OK (regno, mode)
+	&& (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode))
+	&& GET_MODE_SIZE (mode) > GET_MODE_SIZE (found_mode))
+      found_mode = mode;
+
+  for (mode = GET_CLASS_NARROWEST_MODE (MODE_VECTOR_INT);
+       mode != VOIDmode;
+       mode = GET_MODE_WIDER_MODE (mode))
+    if ((unsigned) hard_regno_nregs[regno][mode] == nregs
+	&& HARD_REGNO_MODE_OK (regno, mode)
+	&& (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode))
+	&& GET_MODE_SIZE (mode) > GET_MODE_SIZE (found_mode))
+      found_mode = mode;
+
+  if (found_mode != VOIDmode)
+    return found_mode;
+
+  /* Iterate over all of the CCmodes.  */
+  for (m = (unsigned int) CCmode; m < (unsigned int) NUM_MACHINE_MODES; ++m)
+    {
+      mode = (enum machine_mode) m;
+      if ((unsigned) hard_regno_nregs[regno][mode] == nregs
+	  && HARD_REGNO_MODE_OK (regno, mode)
+	  && (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode)))
+	return mode;
+    }
+
+  /* We can't find a mode valid for this register.  */
+  return VOIDmode;
+}
+
+/* Specify the usage characteristics of the register named NAME.
+   It should be a fixed register if FIXED and a
+   call-used register if CALL_USED.  */
+void
+fix_register (const char *name, int fixed, int call_used)
+{
+  int i;
+  int reg, nregs;
+
+  /* Decode the name and update the primary form of
+     the register info.  */
+
+  if ((reg = decode_reg_name_and_count (name, &nregs)) >= 0)
+    {
+      gcc_assert (nregs >= 1);
+      for (i = reg; i < reg + nregs; i++)
+	{
+	  if ((i == STACK_POINTER_REGNUM
+#ifdef HARD_FRAME_POINTER_REGNUM
+	       || i == HARD_FRAME_POINTER_REGNUM
+#else
+	       || i == FRAME_POINTER_REGNUM
+#endif
+	       )
+	      && (fixed == 0 || call_used == 0))
+	    {
+	      switch (fixed)
+		{
+		case 0:
+		  switch (call_used)
+		    {
+		    case 0:
+		      error ("can%'t use %qs as a call-saved register", name);
+		      break;
+
+		    case 1:
+		      error ("can%'t use %qs as a call-used register", name);
+		      break;
+
+		    default:
+		      gcc_unreachable ();
+		    }
+		  break;
+
+		case 1:
+		  switch (call_used)
+		    {
+		    case 1:
+		      error ("can%'t use %qs as a fixed register", name);
+		      break;
+
+		    case 0:
+		    default:
+		      gcc_unreachable ();
+		    }
+		  break;
+
+		default:
+		  gcc_unreachable ();
+		}
+	    }
+	  else
+	    {
+	      fixed_regs[i] = fixed;
+	      call_used_regs[i] = call_used;
+#ifdef CALL_REALLY_USED_REGISTERS
+	      if (fixed == 0)
+		call_really_used_regs[i] = call_used;
+#endif
+	    }
+	}
+    }
+  else
+    {
+      warning (0, "unknown register name: %s", name);
+    }
+}
+
+/* Mark register number I as global.  */
+void
+globalize_reg (tree decl, int i)
+{
+  location_t loc = DECL_SOURCE_LOCATION (decl);
+
+#ifdef STACK_REGS
+  if (IN_RANGE (i, FIRST_STACK_REG, LAST_STACK_REG))
+    {
+      error ("stack register used for global register variable");
+      return;
+    }
+#endif
+
+  if (fixed_regs[i] == 0 && no_global_reg_vars)
+    error_at (loc, "global register variable follows a function definition");
+
+  if (global_regs[i])
+    {
+      warning_at (loc, 0, 
+		  "register of %qD used for multiple global register variables",
+		  decl);
+      inform (DECL_SOURCE_LOCATION (global_regs_decl[i]),
+	      "conflicts with %qD", global_regs_decl[i]); 
+      return;
+    }
+
+  if (call_used_regs[i] && ! fixed_regs[i])
+    warning_at (loc, 0, "call-clobbered register used for global register variable");
+
+  global_regs[i] = 1;
+  global_regs_decl[i] = decl;
+
+  /* If we're globalizing the frame pointer, we need to set the
+     appropriate regs_invalidated_by_call bit, even if it's already
+     set in fixed_regs.  */
+  if (i != STACK_POINTER_REGNUM)
+    {
+      SET_HARD_REG_BIT (regs_invalidated_by_call, i);
+      SET_REGNO_REG_SET (regs_invalidated_by_call_regset, i);
+    }
+
+  /* If already fixed, nothing else to do.  */
+  if (fixed_regs[i])
+    return;
+
+  fixed_regs[i] = call_used_regs[i] = 1;
+#ifdef CALL_REALLY_USED_REGISTERS
+  call_really_used_regs[i] = 1;
+#endif
+
+  SET_HARD_REG_BIT (fixed_reg_set, i);
+  SET_HARD_REG_BIT (call_used_reg_set, i);
+  SET_HARD_REG_BIT (call_fixed_reg_set, i);
+
+  reinit_regs ();
+}
+
+
+/* Structure used to record preferences of given pseudo.  */
+struct reg_pref
+{
+  /* (enum reg_class) prefclass is the preferred class.  May be
+     NO_REGS if no class is better than memory.  */
+  char prefclass;
+
+  /* altclass is a register class that we should use for allocating
+     pseudo if no register in the preferred class is available.
+     If no register in this class is available, memory is preferred.
+
+     It might appear to be more general to have a bitmask of classes here,
+     but since it is recommended that there be a class corresponding to the
+     union of most major pair of classes, that generality is not required.  */
+  char altclass;
+
+  /* allocnoclass is a register class that IRA uses for allocating
+     the pseudo.  */
+  char allocnoclass;
+};
+
+/* Record preferences of each pseudo.  This is available after RA is
+   run.  */
+static struct reg_pref *reg_pref;
+
+/* Current size of reg_info.  */
+static int reg_info_size;
+/* Max_reg_num still last resize_reg_info call.  */
+static int max_regno_since_last_resize;
+
+/* Return the reg_class in which pseudo reg number REGNO is best allocated.
+   This function is sometimes called before the info has been computed.
+   When that happens, just return GENERAL_REGS, which is innocuous.  */
+enum reg_class
+reg_preferred_class (int regno)
+{
+  if (reg_pref == 0)
+    return GENERAL_REGS;
+
+  gcc_assert (regno < reg_info_size);
+  return (enum reg_class) reg_pref[regno].prefclass;
+}
+
+enum reg_class
+reg_alternate_class (int regno)
+{
+  if (reg_pref == 0)
+    return ALL_REGS;
+
+  gcc_assert (regno < reg_info_size);
+  return (enum reg_class) reg_pref[regno].altclass;
+}
+
+/* Return the reg_class which is used by IRA for its allocation.  */
+enum reg_class
+reg_allocno_class (int regno)
+{
+  if (reg_pref == 0)
+    return NO_REGS;
+
+  gcc_assert (regno < reg_info_size);
+  return (enum reg_class) reg_pref[regno].allocnoclass;
+}
+
+
+
+/* Allocate space for reg info and initilize it.  */
+static void
+allocate_reg_info (void)
+{
+  int i;
+
+  max_regno_since_last_resize = max_reg_num ();
+  reg_info_size = max_regno_since_last_resize * 3 / 2 + 1;
+  gcc_assert (! reg_pref && ! reg_renumber);
+  reg_renumber = XNEWVEC (short, reg_info_size);
+  reg_pref = XCNEWVEC (struct reg_pref, reg_info_size);
+  memset (reg_renumber, -1, reg_info_size * sizeof (short));
+  for (i = 0; i < reg_info_size; i++)
+    {
+      reg_pref[i].prefclass = GENERAL_REGS;
+      reg_pref[i].altclass = ALL_REGS;
+      reg_pref[i].allocnoclass = GENERAL_REGS;
+    }
+}
+
+
+/* Resize reg info. The new elements will be initialized.  Return TRUE
+   if new pseudos were added since the last call.  */
+bool
+resize_reg_info (void)
+{
+  int old, i;
+  bool change_p;
+
+  if (reg_pref == NULL)
+    {
+      allocate_reg_info ();
+      return true;
+    }
+  change_p = max_regno_since_last_resize != max_reg_num ();
+  max_regno_since_last_resize = max_reg_num ();
+  if (reg_info_size >= max_reg_num ())
+    return change_p;
+  old = reg_info_size;
+  reg_info_size = max_reg_num () * 3 / 2 + 1;
+  gcc_assert (reg_pref && reg_renumber);
+  reg_renumber = XRESIZEVEC (short, reg_renumber, reg_info_size);
+  reg_pref = XRESIZEVEC (struct reg_pref, reg_pref, reg_info_size);
+  memset (reg_pref + old, -1,
+	  (reg_info_size - old) * sizeof (struct reg_pref));
+  memset (reg_renumber + old, -1, (reg_info_size - old) * sizeof (short));
+  for (i = old; i < reg_info_size; i++)
+    {
+      reg_pref[i].prefclass = GENERAL_REGS;
+      reg_pref[i].altclass = ALL_REGS;
+      reg_pref[i].allocnoclass = GENERAL_REGS;
+    }
+  return true;
+}
+
+
+/* Free up the space allocated by allocate_reg_info.  */
+void
+free_reg_info (void)
+{
+  if (reg_pref)
+    {
+      free (reg_pref);
+      reg_pref = NULL;
+    }
+
+  if (reg_renumber)
+    {
+      free (reg_renumber);
+      reg_renumber = NULL;
+    }
+}
+
+/* Initialize some global data for this pass.  */
+static unsigned int
+reginfo_init (void)
+{
+  if (df)
+    df_compute_regs_ever_live (true);
+
+  /* This prevents dump_reg_info from losing if called
+     before reginfo is run.  */
+  reg_pref = NULL;
+  reg_info_size = max_regno_since_last_resize = 0;
+  /* No more global register variables may be declared.  */
+  no_global_reg_vars = 1;
+  return 1;
+}
+
+namespace {
+
+const pass_data pass_data_reginfo_init =
+{
+  RTL_PASS, /* type */
+  "reginfo", /* name */
+  OPTGROUP_NONE, /* optinfo_flags */
+  false, /* has_gate */
+  true, /* has_execute */
+  TV_NONE, /* tv_id */
+  0, /* properties_required */
+  0, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  0, /* todo_flags_finish */
+};
+
+class pass_reginfo_init : public rtl_opt_pass
+{
+public:
+  pass_reginfo_init (gcc::context *ctxt)
+    : rtl_opt_pass (pass_data_reginfo_init, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  unsigned int execute () { return reginfo_init (); }
+
+}; // class pass_reginfo_init
+
+} // anon namespace
+
+rtl_opt_pass *
+make_pass_reginfo_init (gcc::context *ctxt)
+{
+  return new pass_reginfo_init (ctxt);
+}
+
+
+
+/* Set up preferred, alternate, and allocno classes for REGNO as
+   PREFCLASS, ALTCLASS, and ALLOCNOCLASS.  */
+void
+setup_reg_classes (int regno,
+		   enum reg_class prefclass, enum reg_class altclass,
+		   enum reg_class allocnoclass)
+{
+  if (reg_pref == NULL)
+    return;
+  gcc_assert (reg_info_size >= max_reg_num ());
+  reg_pref[regno].prefclass = prefclass;
+  reg_pref[regno].altclass = altclass;
+  reg_pref[regno].allocnoclass = allocnoclass;
+}
+
+
+/* This is the `regscan' pass of the compiler, run just before cse and
+   again just before loop.  It finds the first and last use of each
+   pseudo-register.  */
+
+static void reg_scan_mark_refs (rtx, rtx);
+
+void
+reg_scan (rtx f, unsigned int nregs ATTRIBUTE_UNUSED)
+{
+  rtx insn;
+
+  timevar_push (TV_REG_SCAN);
+
+  for (insn = f; insn; insn = NEXT_INSN (insn))
+    if (INSN_P (insn))
+      {
+	reg_scan_mark_refs (PATTERN (insn), insn);
+	if (REG_NOTES (insn))
+	  reg_scan_mark_refs (REG_NOTES (insn), insn);
+      }
+
+  timevar_pop (TV_REG_SCAN);
+}
+
+
+/* X is the expression to scan.  INSN is the insn it appears in.
+   NOTE_FLAG is nonzero if X is from INSN's notes rather than its body.
+   We should only record information for REGs with numbers
+   greater than or equal to MIN_REGNO.  */
+static void
+reg_scan_mark_refs (rtx x, rtx insn)
+{
+  enum rtx_code code;
+  rtx dest;
+  rtx note;
+
+  if (!x)
+    return;
+  code = GET_CODE (x);
+  switch (code)
+    {
+    case CONST:
+    CASE_CONST_ANY:
+    case CC0:
+    case PC:
+    case SYMBOL_REF:
+    case LABEL_REF:
+    case ADDR_VEC:
+    case ADDR_DIFF_VEC:
+    case REG:
+      return;
+
+    case EXPR_LIST:
+      if (XEXP (x, 0))
+	reg_scan_mark_refs (XEXP (x, 0), insn);
+      if (XEXP (x, 1))
+	reg_scan_mark_refs (XEXP (x, 1), insn);
+      break;
+
+    case INSN_LIST:
+    case INT_LIST:
+      if (XEXP (x, 1))
+	reg_scan_mark_refs (XEXP (x, 1), insn);
+      break;
+
+    case CLOBBER:
+      if (MEM_P (XEXP (x, 0)))
+	reg_scan_mark_refs (XEXP (XEXP (x, 0), 0), insn);
+      break;
+
+    case SET:
+      /* Count a set of the destination if it is a register.  */
+      for (dest = SET_DEST (x);
+	   GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
+	   || GET_CODE (dest) == ZERO_EXTEND;
+	   dest = XEXP (dest, 0))
+	;
+
+      /* If this is setting a pseudo from another pseudo or the sum of a
+	 pseudo and a constant integer and the other pseudo is known to be
+	 a pointer, set the destination to be a pointer as well.
+
+	 Likewise if it is setting the destination from an address or from a
+	 value equivalent to an address or to the sum of an address and
+	 something else.
+
+	 But don't do any of this if the pseudo corresponds to a user
+	 variable since it should have already been set as a pointer based
+	 on the type.  */
+
+      if (REG_P (SET_DEST (x))
+	  && REGNO (SET_DEST (x)) >= FIRST_PSEUDO_REGISTER
+	  /* If the destination pseudo is set more than once, then other
+	     sets might not be to a pointer value (consider access to a
+	     union in two threads of control in the presence of global
+	     optimizations).  So only set REG_POINTER on the destination
+	     pseudo if this is the only set of that pseudo.  */
+	  && DF_REG_DEF_COUNT (REGNO (SET_DEST (x))) == 1
+	  && ! REG_USERVAR_P (SET_DEST (x))
+	  && ! REG_POINTER (SET_DEST (x))
+	  && ((REG_P (SET_SRC (x))
+	       && REG_POINTER (SET_SRC (x)))
+	      || ((GET_CODE (SET_SRC (x)) == PLUS
+		   || GET_CODE (SET_SRC (x)) == LO_SUM)
+		  && CONST_INT_P (XEXP (SET_SRC (x), 1))
+		  && REG_P (XEXP (SET_SRC (x), 0))
+		  && REG_POINTER (XEXP (SET_SRC (x), 0)))
+	      || GET_CODE (SET_SRC (x)) == CONST
+	      || GET_CODE (SET_SRC (x)) == SYMBOL_REF
+	      || GET_CODE (SET_SRC (x)) == LABEL_REF
+	      || (GET_CODE (SET_SRC (x)) == HIGH
+		  && (GET_CODE (XEXP (SET_SRC (x), 0)) == CONST
+		      || GET_CODE (XEXP (SET_SRC (x), 0)) == SYMBOL_REF
+		      || GET_CODE (XEXP (SET_SRC (x), 0)) == LABEL_REF))
+	      || ((GET_CODE (SET_SRC (x)) == PLUS
+		   || GET_CODE (SET_SRC (x)) == LO_SUM)
+		  && (GET_CODE (XEXP (SET_SRC (x), 1)) == CONST
+		      || GET_CODE (XEXP (SET_SRC (x), 1)) == SYMBOL_REF
+		      || GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF))
+	      || ((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
+		  && (GET_CODE (XEXP (note, 0)) == CONST
+		      || GET_CODE (XEXP (note, 0)) == SYMBOL_REF
+		      || GET_CODE (XEXP (note, 0)) == LABEL_REF))))
+	REG_POINTER (SET_DEST (x)) = 1;
+
+      /* If this is setting a register from a register or from a simple
+	 conversion of a register, propagate REG_EXPR.  */
+      if (REG_P (dest) && !REG_ATTRS (dest))
+	set_reg_attrs_from_value (dest, SET_SRC (x));
+
+      /* ... fall through ...  */
+
+    default:
+      {
+	const char *fmt = GET_RTX_FORMAT (code);
+	int i;
+	for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+	  {
+	    if (fmt[i] == 'e')
+	      reg_scan_mark_refs (XEXP (x, i), insn);
+	    else if (fmt[i] == 'E' && XVEC (x, i) != 0)
+	      {
+		int j;
+		for (j = XVECLEN (x, i) - 1; j >= 0; j--)
+		  reg_scan_mark_refs (XVECEXP (x, i, j), insn);
+	      }
+	  }
+      }
+    }
+}
+
+
+/* Return nonzero if C1 is a subset of C2, i.e., if every register in C1
+   is also in C2.  */
+int
+reg_class_subset_p (reg_class_t c1, reg_class_t c2)
+{
+  return (c1 == c2
+	  || c2 == ALL_REGS
+	  || hard_reg_set_subset_p (reg_class_contents[(int) c1],
+				   reg_class_contents[(int) c2]));
+}
+
+/* Return nonzero if there is a register that is in both C1 and C2.  */
+int
+reg_classes_intersect_p (reg_class_t c1, reg_class_t c2)
+{
+  return (c1 == c2
+	  || c1 == ALL_REGS
+	  || c2 == ALL_REGS
+	  || hard_reg_set_intersect_p (reg_class_contents[(int) c1],
+				      reg_class_contents[(int) c2]));
+}
+
+
+
+/* Passes for keeping and updating info about modes of registers
+   inside subregisters.  */
+
+#ifdef CANNOT_CHANGE_MODE_CLASS
+
+static bitmap invalid_mode_changes;
+
+static void
+record_subregs_of_mode (rtx subreg, bitmap subregs_of_mode)
+{
+  enum machine_mode mode;
+  unsigned int regno;
+
+  if (!REG_P (SUBREG_REG (subreg)))
+    return;
+
+  regno = REGNO (SUBREG_REG (subreg));
+  mode = GET_MODE (subreg);
+
+  if (regno < FIRST_PSEUDO_REGISTER)
+    return;
+
+  if (bitmap_set_bit (subregs_of_mode,
+		      regno * NUM_MACHINE_MODES + (unsigned int) mode))
+    {
+      unsigned int rclass;
+      for (rclass = 0; rclass < N_REG_CLASSES; rclass++)
+	if (!bitmap_bit_p (invalid_mode_changes,
+			   regno * N_REG_CLASSES + rclass)
+	    && CANNOT_CHANGE_MODE_CLASS (PSEUDO_REGNO_MODE (regno),
+					 mode, (enum reg_class) rclass))
+	  bitmap_set_bit (invalid_mode_changes,
+			  regno * N_REG_CLASSES + rclass);
+    }
+}
+
+/* Call record_subregs_of_mode for all the subregs in X.  */
+static void
+find_subregs_of_mode (rtx x, bitmap subregs_of_mode)
+{
+  enum rtx_code code = GET_CODE (x);
+  const char * const fmt = GET_RTX_FORMAT (code);
+  int i;
+
+  if (code == SUBREG)
+    record_subregs_of_mode (x, subregs_of_mode);
+
+  /* Time for some deep diving.  */
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    {
+      if (fmt[i] == 'e')
+	find_subregs_of_mode (XEXP (x, i), subregs_of_mode);
+      else if (fmt[i] == 'E')
+	{
+	  int j;
+	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
+	    find_subregs_of_mode (XVECEXP (x, i, j), subregs_of_mode);
+	}
+    }
+}
+
+void
+init_subregs_of_mode (void)
+{
+  basic_block bb;
+  rtx insn;
+  bitmap_obstack srom_obstack;
+  bitmap subregs_of_mode;
+
+  gcc_assert (invalid_mode_changes == NULL);
+  invalid_mode_changes = BITMAP_ALLOC (NULL);
+  bitmap_obstack_initialize (&srom_obstack);
+  subregs_of_mode = BITMAP_ALLOC (&srom_obstack);
+
+  FOR_EACH_BB_FN (bb, cfun)
+    FOR_BB_INSNS (bb, insn)
+      if (NONDEBUG_INSN_P (insn))
+        find_subregs_of_mode (PATTERN (insn), subregs_of_mode);
+
+  BITMAP_FREE (subregs_of_mode);
+  bitmap_obstack_release (&srom_obstack);
+}
+
+/* Return 1 if REGNO has had an invalid mode change in CLASS from FROM
+   mode.  */
+bool
+invalid_mode_change_p (unsigned int regno,
+		       enum reg_class rclass)
+{
+  return bitmap_bit_p (invalid_mode_changes,
+		       regno * N_REG_CLASSES + (unsigned) rclass);
+}
+
+void
+finish_subregs_of_mode (void)
+{
+  BITMAP_FREE (invalid_mode_changes);
+}
+#else
+void
+init_subregs_of_mode (void)
+{
+}
+void
+finish_subregs_of_mode (void)
+{
+}
+
+#endif /* CANNOT_CHANGE_MODE_CLASS */