gcc/gimple-lower-bitint.cc

/* Lower _BitInt(N) operations to scalar operations.
   Copyright (C) 2023 Free Software Foundation, Inc.
   Contributed by Jakub Jelinek <jakub@redhat.com>.

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 "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "rtl.h"
#include "tree.h"
#include "gimple.h"
#include "cfghooks.h"
#include "tree-pass.h"
#include "ssa.h"
#include "fold-const.h"
#include "gimplify.h"
#include "gimple-iterator.h"
#include "tree-cfg.h"
#include "tree-dfa.h"
#include "cfgloop.h"
#include "cfganal.h"
#include "target.h"
#include "tree-ssa-live.h"
#include "tree-ssa-coalesce.h"
#include "domwalk.h"
#include "memmodel.h"
#include "optabs.h"
#include "varasm.h"
#include "gimple-range.h"
#include "value-range.h"
#include "langhooks.h"
#include "gimplify-me.h"
#include "diagnostic-core.h"
#include "tree-eh.h"
#include "tree-pretty-print.h"
#include "alloc-pool.h"
#include "tree-into-ssa.h"
#include "tree-cfgcleanup.h"
#include "tree-switch-conversion.h"
#include "ubsan.h"
#include "gimple-lower-bitint.h"

/* Split BITINT_TYPE precisions in 4 categories.  Small _BitInt, where
   target hook says it is a single limb, middle _BitInt which per ABI
   does not, but there is some INTEGER_TYPE in which arithmetics can be
   performed (operations on such _BitInt are lowered to casts to that
   arithmetic type and cast back; e.g. on x86_64 limb is DImode, but
   target supports TImode, so _BitInt(65) to _BitInt(128) are middle
   ones), large _BitInt which should by straight line code and
   finally huge _BitInt which should be handled by loops over the limbs.  */

enum bitint_prec_kind {
  bitint_prec_small,
  bitint_prec_middle,
  bitint_prec_large,
  bitint_prec_huge
};

/* Caches to speed up bitint_precision_kind.  */

static int small_max_prec, mid_min_prec, large_min_prec, huge_min_prec;
static int limb_prec;

/* Categorize _BitInt(PREC) as small, middle, large or huge.  */

static bitint_prec_kind
bitint_precision_kind (int prec)
{
  if (prec <= small_max_prec)
    return bitint_prec_small;
  if (huge_min_prec && prec >= huge_min_prec)
    return bitint_prec_huge;
  if (large_min_prec && prec >= large_min_prec)
    return bitint_prec_large;
  if (mid_min_prec && prec >= mid_min_prec)
    return bitint_prec_middle;

  struct bitint_info info;
  bool ok = targetm.c.bitint_type_info (prec, &info);
  gcc_assert (ok);
  scalar_int_mode limb_mode = as_a <scalar_int_mode> (info.limb_mode);
  if (prec <= GET_MODE_PRECISION (limb_mode))
    {
      small_max_prec = prec;
      return bitint_prec_small;
    }
  if (!large_min_prec
      && GET_MODE_PRECISION (limb_mode) < MAX_FIXED_MODE_SIZE)
    large_min_prec = MAX_FIXED_MODE_SIZE + 1;
  if (!limb_prec)
    limb_prec = GET_MODE_PRECISION (limb_mode);
  if (!huge_min_prec)
    {
      if (4 * limb_prec >= MAX_FIXED_MODE_SIZE)
	huge_min_prec = 4 * limb_prec;
      else
	huge_min_prec = MAX_FIXED_MODE_SIZE + 1;
    }
  if (prec <= MAX_FIXED_MODE_SIZE)
    {
      if (!mid_min_prec || prec < mid_min_prec)
	mid_min_prec = prec;
      return bitint_prec_middle;
    }
  if (large_min_prec && prec <= large_min_prec)
    return bitint_prec_large;
  return bitint_prec_huge;
}

/* Same for a TYPE.  */

static bitint_prec_kind
bitint_precision_kind (tree type)
{
  return bitint_precision_kind (TYPE_PRECISION (type));
}

/* Return minimum precision needed to describe INTEGER_CST
   CST.  All bits above that precision up to precision of
   TREE_TYPE (CST) are cleared if EXT is set to 0, or set
   if EXT is set to -1.  */

static unsigned
bitint_min_cst_precision (tree cst, int &ext)
{
  ext = tree_int_cst_sgn (cst) < 0 ? -1 : 0;
  wide_int w = wi::to_wide (cst);
  unsigned min_prec = wi::min_precision (w, TYPE_SIGN (TREE_TYPE (cst)));
  /* For signed values, we don't need to count the sign bit,
     we'll use constant 0 or -1 for the upper bits.  */
  if (!TYPE_UNSIGNED (TREE_TYPE (cst)))
    --min_prec;
  else
    {
      /* For unsigned values, also try signed min_precision
	 in case the constant has lots of most significant bits set.  */
      unsigned min_prec2 = wi::min_precision (w, SIGNED) - 1;
      if (min_prec2 < min_prec)
	{
	  ext = -1;
	  return min_prec2;
	}
    }
  return min_prec;
}

namespace {

/* If OP is middle _BitInt, cast it to corresponding INTEGER_TYPE
   cached in TYPE and return it.  */

tree
maybe_cast_middle_bitint (gimple_stmt_iterator *gsi, tree op, tree &type)
{
  if (op == NULL_TREE
      || TREE_CODE (TREE_TYPE (op)) != BITINT_TYPE
      || bitint_precision_kind (TREE_TYPE (op)) != bitint_prec_middle)
    return op;

  int prec = TYPE_PRECISION (TREE_TYPE (op));
  int uns = TYPE_UNSIGNED (TREE_TYPE (op));
  if (type == NULL_TREE
      || TYPE_PRECISION (type) != prec
      || TYPE_UNSIGNED (type) != uns)
    type = build_nonstandard_integer_type (prec, uns);

  if (TREE_CODE (op) != SSA_NAME)
    {
      tree nop = fold_convert (type, op);
      if (is_gimple_val (nop))
	return nop;
    }

  tree nop = make_ssa_name (type);
  gimple *g = gimple_build_assign (nop, NOP_EXPR, op);
  gsi_insert_before (gsi, g, GSI_SAME_STMT);
  return nop;
}

/* Return true if STMT can be handled in a loop from least to most
   significant limb together with its dependencies.  */

bool
mergeable_op (gimple *stmt)
{
  if (!is_gimple_assign (stmt))
    return false;
  switch (gimple_assign_rhs_code (stmt))
    {
    case PLUS_EXPR:
    case MINUS_EXPR:
    case NEGATE_EXPR:
    case BIT_AND_EXPR:
    case BIT_IOR_EXPR:
    case BIT_XOR_EXPR:
    case BIT_NOT_EXPR:
    case SSA_NAME:
    case INTEGER_CST:
      return true;
    case LSHIFT_EXPR:
      {
	tree cnt = gimple_assign_rhs2 (stmt);
	if (tree_fits_uhwi_p (cnt)
	    && tree_to_uhwi (cnt) < (unsigned HOST_WIDE_INT) limb_prec)
	  return true;
      }
      break;
    CASE_CONVERT:
    case VIEW_CONVERT_EXPR:
      {
	tree lhs_type = TREE_TYPE (gimple_assign_lhs (stmt));
	tree rhs_type = TREE_TYPE (gimple_assign_rhs1 (stmt));
	if (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
	    && TREE_CODE (lhs_type) == BITINT_TYPE
	    && TREE_CODE (rhs_type) == BITINT_TYPE
	    && bitint_precision_kind (lhs_type) >= bitint_prec_large
	    && bitint_precision_kind (rhs_type) >= bitint_prec_large
	    && tree_int_cst_equal (TYPE_SIZE (lhs_type), TYPE_SIZE (rhs_type)))
	  {
	    if (TYPE_PRECISION (rhs_type) >= TYPE_PRECISION (lhs_type))
	      return true;
	    if ((unsigned) TYPE_PRECISION (lhs_type) % (2 * limb_prec) != 0)
	      return true;
	    if (bitint_precision_kind (lhs_type) == bitint_prec_large)
	      return true;
	  }
	break;
      }
    default:
      break;
    }
  return false;
}

/* Return non-zero if stmt is .{ADD,SUB,MUL}_OVERFLOW call with
   _Complex large/huge _BitInt lhs which has at most two immediate uses,
   at most one use in REALPART_EXPR stmt in the same bb and exactly one
   IMAGPART_EXPR use in the same bb with a single use which casts it to
   non-BITINT_TYPE integral type.  If there is a REALPART_EXPR use,
   return 2.  Such cases (most common uses of those builtins) can be
   optimized by marking their lhs and lhs of IMAGPART_EXPR and maybe lhs
   of REALPART_EXPR as not needed to be backed up by a stack variable.
   For .UBSAN_CHECK_{ADD,SUB,MUL} return 3.  */

int
optimizable_arith_overflow (gimple *stmt)
{
  bool is_ubsan = false;
  if (!is_gimple_call (stmt) || !gimple_call_internal_p (stmt))
    return false;
  switch (gimple_call_internal_fn (stmt))
    {
    case IFN_ADD_OVERFLOW:
    case IFN_SUB_OVERFLOW:
    case IFN_MUL_OVERFLOW:
      break;
    case IFN_UBSAN_CHECK_ADD:
    case IFN_UBSAN_CHECK_SUB:
    case IFN_UBSAN_CHECK_MUL:
      is_ubsan = true;
      break;
    default:
      return 0;
    }
  tree lhs = gimple_call_lhs (stmt);
  if (!lhs)
    return 0;
  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
    return 0;
  tree type = is_ubsan ? TREE_TYPE (lhs) : TREE_TYPE (TREE_TYPE (lhs));
  if (TREE_CODE (type) != BITINT_TYPE
      || bitint_precision_kind (type) < bitint_prec_large)
    return 0;

  if (is_ubsan)
    {
      use_operand_p use_p;
      gimple *use_stmt;
      if (!single_imm_use (lhs, &use_p, &use_stmt)
	  || gimple_bb (use_stmt) != gimple_bb (stmt)
	  || !gimple_store_p (use_stmt)
	  || !is_gimple_assign (use_stmt)
	  || gimple_has_volatile_ops (use_stmt)
	  || stmt_ends_bb_p (use_stmt))
	return 0;
      return 3;
    }

  imm_use_iterator ui;
  use_operand_p use_p;
  int seen = 0;
  FOR_EACH_IMM_USE_FAST (use_p, ui, lhs)
    {
      gimple *g = USE_STMT (use_p);
      if (is_gimple_debug (g))
	continue;
      if (!is_gimple_assign (g) || gimple_bb (g) != gimple_bb (stmt))
	return 0;
      if (gimple_assign_rhs_code (g) == REALPART_EXPR)
	{
	  if ((seen & 1) != 0)
	    return 0;
	  seen |= 1;
	}
      else if (gimple_assign_rhs_code (g) == IMAGPART_EXPR)
	{
	  if ((seen & 2) != 0)
	    return 0;
	  seen |= 2;

	  use_operand_p use2_p;
	  gimple *use_stmt;
	  tree lhs2 = gimple_assign_lhs (g);
	  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs2))
	    return 0;
	  if (!single_imm_use (lhs2, &use2_p, &use_stmt)
	      || gimple_bb (use_stmt) != gimple_bb (stmt)
	      || !gimple_assign_cast_p (use_stmt))
	    return 0;

	  lhs2 = gimple_assign_lhs (use_stmt);
	  if (!INTEGRAL_TYPE_P (TREE_TYPE (lhs2))
	      || TREE_CODE (TREE_TYPE (lhs2)) == BITINT_TYPE)
	    return 0;
	}
      else
	return 0;
    }
  if ((seen & 2) == 0)
    return 0;
  return seen == 3 ? 2 : 1;
}

/* If STMT is some kind of comparison (GIMPLE_COND, comparison assignment)
   comparing large/huge _BitInt types, return the comparison code and if
   non-NULL fill in the comparison operands to *POP1 and *POP2.  */

tree_code
comparison_op (gimple *stmt, tree *pop1, tree *pop2)
{
  tree op1 = NULL_TREE, op2 = NULL_TREE;
  tree_code code = ERROR_MARK;
  if (gimple_code (stmt) == GIMPLE_COND)
    {
      code = gimple_cond_code (stmt);
      op1 = gimple_cond_lhs (stmt);
      op2 = gimple_cond_rhs (stmt);
    }
  else if (is_gimple_assign (stmt))
    {
      code = gimple_assign_rhs_code (stmt);
      op1 = gimple_assign_rhs1 (stmt);
      if (TREE_CODE_CLASS (code) == tcc_comparison
	  || TREE_CODE_CLASS (code) == tcc_binary)
	op2 = gimple_assign_rhs2 (stmt);
    }
  if (TREE_CODE_CLASS (code) != tcc_comparison)
    return ERROR_MARK;
  tree type = TREE_TYPE (op1);
  if (TREE_CODE (type) != BITINT_TYPE
      || bitint_precision_kind (type) < bitint_prec_large)
    return ERROR_MARK;
  if (pop1)
    {
      *pop1 = op1;
      *pop2 = op2;
    }
  return code;
}

/* Class used during large/huge _BitInt lowering containing all the
   state for the methods.  */

struct bitint_large_huge
{
  bitint_large_huge ()
    : m_names (NULL), m_loads (NULL), m_preserved (NULL),
      m_single_use_names (NULL), m_map (NULL), m_vars (NULL),
      m_limb_type (NULL_TREE), m_data (vNULL) {}

  ~bitint_large_huge ();

  void insert_before (gimple *);
  tree limb_access_type (tree, tree);
  tree limb_access (tree, tree, tree, bool);
  void if_then (gimple *, profile_probability, edge &, edge &);
  void if_then_else (gimple *, profile_probability, edge &, edge &);
  void if_then_if_then_else (gimple *g, gimple *,
			     profile_probability, profile_probability,
			     edge &, edge &, edge &);
  tree handle_operand (tree, tree);
  tree prepare_data_in_out (tree, tree, tree *);
  tree add_cast (tree, tree);
  tree handle_plus_minus (tree_code, tree, tree, tree);
  tree handle_lshift (tree, tree, tree);
  tree handle_cast (tree, tree, tree);
  tree handle_load (gimple *, tree);
  tree handle_stmt (gimple *, tree);
  tree handle_operand_addr (tree, gimple *, int *, int *);
  tree create_loop (tree, tree *);
  tree lower_mergeable_stmt (gimple *, tree_code &, tree, tree);
  tree lower_comparison_stmt (gimple *, tree_code &, tree, tree);
  void lower_shift_stmt (tree, gimple *);
  void lower_muldiv_stmt (tree, gimple *);
  void lower_float_conv_stmt (tree, gimple *);
  tree arith_overflow_extract_bits (unsigned int, unsigned int, tree,
				    unsigned int, bool);
  void finish_arith_overflow (tree, tree, tree, tree, tree, tree, gimple *,
			      tree_code);
  void lower_addsub_overflow (tree, gimple *);
  void lower_mul_overflow (tree, gimple *);
  void lower_cplxpart_stmt (tree, gimple *);
  void lower_complexexpr_stmt (gimple *);
  void lower_bit_query (gimple *);
  void lower_call (tree, gimple *);
  void lower_asm (gimple *);
  void lower_stmt (gimple *);

  /* Bitmap of large/huge _BitInt SSA_NAMEs except those can be
     merged with their uses.  */
  bitmap m_names;
  /* Subset of those for lhs of load statements.  These will be
     cleared in m_names if the loads will be mergeable with all
     their uses.  */
  bitmap m_loads;
  /* Bitmap of large/huge _BitInt SSA_NAMEs that should survive
     to later passes (arguments or return values of calls).  */
  bitmap m_preserved;
  /* Subset of m_names which have a single use.  As the lowering
     can replace various original statements with their lowered
     form even before it is done iterating over all basic blocks,
     testing has_single_use for the purpose of emitting clobbers
     doesn't work properly.  */
  bitmap m_single_use_names;
  /* Used for coalescing/partitioning of large/huge _BitInt SSA_NAMEs
     set in m_names.  */
  var_map m_map;
  /* Mapping of the partitions to corresponding decls.  */
  tree *m_vars;
  /* Unsigned integer type with limb precision.  */
  tree m_limb_type;
  /* Its TYPE_SIZE_UNIT.  */
  unsigned HOST_WIDE_INT m_limb_size;
  /* Location of a gimple stmt which is being currently lowered.  */
  location_t m_loc;
  /* Current stmt iterator where code is being lowered currently.  */
  gimple_stmt_iterator m_gsi;
  /* Statement after which any clobbers should be added if non-NULL.  */
  gimple *m_after_stmt;
  /* Set when creating loops to the loop header bb and its preheader.  */
  basic_block m_bb, m_preheader_bb;
  /* Stmt iterator after which initialization statements should be emitted.  */
  gimple_stmt_iterator m_init_gsi;
  /* Decl into which a mergeable statement stores result.  */
  tree m_lhs;
  /* handle_operand/handle_stmt can be invoked in various ways.

     lower_mergeable_stmt for large _BitInt calls those with constant
     idx only, expanding to straight line code, for huge _BitInt
     emits a loop from least significant limb upwards, where each loop
     iteration handles 2 limbs, plus there can be up to one full limb
     and one partial limb processed after the loop, where handle_operand
     and/or handle_stmt are called with constant idx.  m_upwards_2limb
     is set for this case, false otherwise.  m_upwards is true if it
     is either large or huge _BitInt handled by lower_mergeable_stmt,
     i.e. indexes always increase.

     Another way is used by lower_comparison_stmt, which walks limbs
     from most significant to least significant, partial limb if any
     processed first with constant idx and then loop processing a single
     limb per iteration with non-constant idx.

     Another way is used in lower_shift_stmt, where for LSHIFT_EXPR
     destination limbs are processed from most significant to least
     significant or for RSHIFT_EXPR the other way around, in loops or
     straight line code, but idx usually is non-constant (so from
     handle_operand/handle_stmt POV random access).  The LSHIFT_EXPR
     handling there can access even partial limbs using non-constant
     idx (then m_var_msb should be true, for all the other cases
     including lower_mergeable_stmt/lower_comparison_stmt that is
     not the case and so m_var_msb should be false.

     m_first should be set the first time handle_operand/handle_stmt
     is called and clear when it is called for some other limb with
     the same argument.  If the lowering of an operand (e.g. INTEGER_CST)
     or statement (e.g. +/-/<< with < limb_prec constant) needs some
     state between the different calls, when m_first is true it should
     push some trees to m_data vector and also make sure m_data_cnt is
     incremented by how many trees were pushed, and when m_first is
     false, it can use the m_data[m_data_cnt] etc. data or update them,
     just needs to bump m_data_cnt by the same amount as when it was
     called with m_first set.  The toplevel calls to
     handle_operand/handle_stmt should set m_data_cnt to 0 and truncate
     m_data vector when setting m_first to true.

     m_cast_conditional and m_bitfld_load are used when handling a
     bit-field load inside of a widening cast.  handle_cast sometimes
     needs to do runtime comparisons and handle_operand only conditionally
     or even in two separate conditional blocks for one idx (once with
     constant index after comparing the runtime one for equality with the
     constant).  In these cases, m_cast_conditional is set to true and
     the bit-field load then communicates its m_data_cnt to handle_cast
     using m_bitfld_load.  */
  bool m_first;
  bool m_var_msb;
  unsigned m_upwards_2limb;
  bool m_upwards;
  bool m_cast_conditional;
  unsigned m_bitfld_load;
  vec<tree> m_data;
  unsigned int m_data_cnt;
};

bitint_large_huge::~bitint_large_huge ()
{
  BITMAP_FREE (m_names);
  BITMAP_FREE (m_loads);
  BITMAP_FREE (m_preserved);
  BITMAP_FREE (m_single_use_names);
  if (m_map)
    delete_var_map (m_map);
  XDELETEVEC (m_vars);
  m_data.release ();
}

/* Insert gimple statement G before current location
   and set its gimple_location.  */

void
bitint_large_huge::insert_before (gimple *g)
{
  gimple_set_location (g, m_loc);
  gsi_insert_before (&m_gsi, g, GSI_SAME_STMT);
}

/* Return type for accessing limb IDX of BITINT_TYPE TYPE.
   This is normally m_limb_type, except for a partial most
   significant limb if any.  */

tree
bitint_large_huge::limb_access_type (tree type, tree idx)
{
  if (type == NULL_TREE)
    return m_limb_type;
  unsigned HOST_WIDE_INT i = tree_to_uhwi (idx);
  unsigned int prec = TYPE_PRECISION (type);
  gcc_assert (i * limb_prec < prec);
  if ((i + 1) * limb_prec <= prec)
    return m_limb_type;
  else
    return build_nonstandard_integer_type (prec % limb_prec,
					   TYPE_UNSIGNED (type));
}

/* Return a tree how to access limb IDX of VAR corresponding to BITINT_TYPE
   TYPE.  If WRITE_P is true, it will be a store, otherwise a read.  */

tree
bitint_large_huge::limb_access (tree type, tree var, tree idx, bool write_p)
{
  tree atype = (tree_fits_uhwi_p (idx)
		? limb_access_type (type, idx) : m_limb_type);
  tree ret;
  if (DECL_P (var) && tree_fits_uhwi_p (idx))
    {
      tree ptype = build_pointer_type (strip_array_types (TREE_TYPE (var)));
      unsigned HOST_WIDE_INT off = tree_to_uhwi (idx) * m_limb_size;
      ret = build2 (MEM_REF, m_limb_type,
		    build_fold_addr_expr (var),
		    build_int_cst (ptype, off));
      TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (var);
      TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (var);
    }
  else if (TREE_CODE (var) == MEM_REF && tree_fits_uhwi_p (idx))
    {
      ret
	= build2 (MEM_REF, m_limb_type, TREE_OPERAND (var, 0),
		  size_binop (PLUS_EXPR, TREE_OPERAND (var, 1),
			      build_int_cst (TREE_TYPE (TREE_OPERAND (var, 1)),
					     tree_to_uhwi (idx)
					     * m_limb_size)));
      TREE_THIS_VOLATILE (ret) = TREE_THIS_VOLATILE (var);
      TREE_SIDE_EFFECTS (ret) = TREE_SIDE_EFFECTS (var);
      TREE_THIS_NOTRAP (ret) = TREE_THIS_NOTRAP (var);
    }
  else
    {
      var = unshare_expr (var);
      if (TREE_CODE (TREE_TYPE (var)) != ARRAY_TYPE
	  || !useless_type_conversion_p (m_limb_type,
					 TREE_TYPE (TREE_TYPE (var))))
	{
	  unsigned HOST_WIDE_INT nelts
	    = CEIL (tree_to_uhwi (TYPE_SIZE (type)), limb_prec);
	  tree atype = build_array_type_nelts (m_limb_type, nelts);
	  var = build1 (VIEW_CONVERT_EXPR, atype, var);
	}
      ret = build4 (ARRAY_REF, m_limb_type, var, idx, NULL_TREE, NULL_TREE);
    }
  if (!write_p && !useless_type_conversion_p (atype, m_limb_type))
    {
      gimple *g = gimple_build_assign (make_ssa_name (m_limb_type), ret);
      insert_before (g);
      ret = gimple_assign_lhs (g);
      ret = build1 (NOP_EXPR, atype, ret);
    }
  return ret;
}

/* Emit a half diamond,
   if (COND)
     |\
     | \
     |  \
     | new_bb1
     |  /
     | /
     |/
   or if (COND) new_bb1;
   PROB is the probability that the condition is true.
   Updates m_gsi to start of new_bb1.
   Sets EDGE_TRUE to edge from new_bb1 to successor and
   EDGE_FALSE to the EDGE_FALSE_VALUE edge from if (COND) bb.  */

void
bitint_large_huge::if_then (gimple *cond, profile_probability prob,
			    edge &edge_true, edge &edge_false)
{
  insert_before (cond);
  edge e1 = split_block (gsi_bb (m_gsi), cond);
  edge e2 = split_block (e1->dest, (gimple *) NULL);
  edge e3 = make_edge (e1->src, e2->dest, EDGE_FALSE_VALUE);
  e1->flags = EDGE_TRUE_VALUE;
  e1->probability = prob;
  e3->probability = prob.invert ();
  set_immediate_dominator (CDI_DOMINATORS, e2->dest, e1->src);
  edge_true = e2;
  edge_false = e3;
  m_gsi = gsi_after_labels (e1->dest);
}

/* Emit a full diamond,
       if (COND)
	 /\
	/  \
       /    \
   new_bb1 new_bb2
       \    /
	\  /
	 \/
   or if (COND) new_bb2; else new_bb1;
   PROB is the probability that the condition is true.
   Updates m_gsi to start of new_bb2.
   Sets EDGE_TRUE to edge from new_bb1 to successor and
   EDGE_FALSE to the EDGE_FALSE_VALUE edge from if (COND) bb.  */

void
bitint_large_huge::if_then_else (gimple *cond, profile_probability prob,
				 edge &edge_true, edge &edge_false)
{
  insert_before (cond);
  edge e1 = split_block (gsi_bb (m_gsi), cond);
  edge e2 = split_block (e1->dest, (gimple *) NULL);
  basic_block bb = create_empty_bb (e1->dest);
  add_bb_to_loop (bb, e1->dest->loop_father);
  edge e3 = make_edge (e1->src, bb, EDGE_TRUE_VALUE);
  e1->flags = EDGE_FALSE_VALUE;
  e3->probability = prob;
  e1->probability = prob.invert ();
  bb->count = e1->src->count.apply_probability (prob);
  set_immediate_dominator (CDI_DOMINATORS, bb, e1->src);
  set_immediate_dominator (CDI_DOMINATORS, e2->dest, e1->src);
  edge_true = make_single_succ_edge (bb, e2->dest, EDGE_FALLTHRU);
  edge_false = e2;
  m_gsi = gsi_after_labels (bb);
}

/* Emit a half diamond with full diamond in it
   if (COND1)
     |\
     | \
     |  \
     | if (COND2)
     |    /  \
     |   /    \
     |new_bb1 new_bb2
     |   |    /
     \   |   /
      \  |  /
       \ | /
	\|/
   or if (COND1) { if (COND2) new_bb2; else new_bb1; }
   PROB1 is the probability that the condition 1 is true.
   PROB2 is the probability that the condition 2 is true.
   Updates m_gsi to start of new_bb1.
   Sets EDGE_TRUE_TRUE to edge from new_bb2 to successor,
   EDGE_TRUE_FALSE to edge from new_bb1 to successor and
   EDGE_FALSE to the EDGE_FALSE_VALUE edge from if (COND1) bb.
   If COND2 is NULL, this is equivalent to
   if_then (COND1, PROB1, EDGE_TRUE_FALSE, EDGE_FALSE);
   EDGE_TRUE_TRUE = NULL;  */

void
bitint_large_huge::if_then_if_then_else (gimple *cond1, gimple *cond2,
					 profile_probability prob1,
					 profile_probability prob2,
					 edge &edge_true_true,
					 edge &edge_true_false,
					 edge &edge_false)
{
  edge e2, e3, e4 = NULL;
  if_then (cond1, prob1, e2, e3);
  if (cond2 == NULL)
    {
      edge_true_true = NULL;
      edge_true_false = e2;
      edge_false = e3;
      return;
    }
  insert_before (cond2);
  e2 = split_block (gsi_bb (m_gsi), cond2);
  basic_block bb = create_empty_bb (e2->dest);
  add_bb_to_loop (bb, e2->dest->loop_father);
  e4 = make_edge (e2->src, bb, EDGE_TRUE_VALUE);
  set_immediate_dominator (CDI_DOMINATORS, bb, e2->src);
  e4->probability = prob2;
  e2->flags = EDGE_FALSE_VALUE;
  e2->probability = prob2.invert ();
  bb->count = e2->src->count.apply_probability (prob2);
  e4 = make_single_succ_edge (bb, e3->dest, EDGE_FALLTHRU);
  e2 = find_edge (e2->dest, e3->dest);
  edge_true_true = e4;
  edge_true_false = e2;
  edge_false = e3;
  m_gsi = gsi_after_labels (e2->src);
}

/* Emit code to access limb IDX from OP.  */

tree
bitint_large_huge::handle_operand (tree op, tree idx)
{
  switch (TREE_CODE (op))
    {
    case SSA_NAME:
      if (m_names == NULL
	  || !bitmap_bit_p (m_names, SSA_NAME_VERSION (op)))
	{
	  if (SSA_NAME_IS_DEFAULT_DEF (op))
	    {
	      if (m_first)
		{
		  tree v = create_tmp_reg (m_limb_type);
		  if (SSA_NAME_VAR (op) && VAR_P (SSA_NAME_VAR (op)))
		    {
		      DECL_NAME (v) = DECL_NAME (SSA_NAME_VAR (op));
		      DECL_SOURCE_LOCATION (v)
			= DECL_SOURCE_LOCATION (SSA_NAME_VAR (op));
		    }
		  v = get_or_create_ssa_default_def (cfun, v);
		  m_data.safe_push (v);
		}
	      tree ret = m_data[m_data_cnt];
	      m_data_cnt++;
	      if (tree_fits_uhwi_p (idx))
		{
		  tree type = limb_access_type (TREE_TYPE (op), idx);
		  ret = add_cast (type, ret);
		}
	      return ret;
	    }
	  location_t loc_save = m_loc;
	  m_loc = gimple_location (SSA_NAME_DEF_STMT (op));
	  tree ret = handle_stmt (SSA_NAME_DEF_STMT (op), idx);
	  m_loc = loc_save;
	  return ret;
	}
      int p;
      gimple *g;
      tree t;
      p = var_to_partition (m_map, op);
      gcc_assert (m_vars[p] != NULL_TREE);
      t = limb_access (TREE_TYPE (op), m_vars[p], idx, false);
      g = gimple_build_assign (make_ssa_name (TREE_TYPE (t)), t);
      insert_before (g);
      t = gimple_assign_lhs (g);
      if (m_first
	  && m_single_use_names
	  && m_vars[p] != m_lhs
	  && m_after_stmt
	  && bitmap_bit_p (m_single_use_names, SSA_NAME_VERSION (op)))
	{
	  tree clobber = build_clobber (TREE_TYPE (m_vars[p]), CLOBBER_EOL);
	  g = gimple_build_assign (m_vars[p], clobber);
	  gimple_stmt_iterator gsi = gsi_for_stmt (m_after_stmt);
	  gsi_insert_after (&gsi, g, GSI_SAME_STMT);
	}
      return t;
    case INTEGER_CST:
      if (tree_fits_uhwi_p (idx))
	{
	  tree c, type = limb_access_type (TREE_TYPE (op), idx);
	  unsigned HOST_WIDE_INT i = tree_to_uhwi (idx);
	  if (m_first)
	    {
	      m_data.safe_push (NULL_TREE);
	      m_data.safe_push (NULL_TREE);
	    }
	  if (limb_prec != HOST_BITS_PER_WIDE_INT)
	    {
	      wide_int w = wi::rshift (wi::to_wide (op), i * limb_prec,
				       TYPE_SIGN (TREE_TYPE (op)));
	      c = wide_int_to_tree (type,
				    wide_int::from (w, TYPE_PRECISION (type),
						    UNSIGNED));
	    }
	  else if (i >= TREE_INT_CST_EXT_NUNITS (op))
	    c = build_int_cst (type,
			       tree_int_cst_sgn (op) < 0 ? -1 : 0);
	  else
	    c = build_int_cst (type, TREE_INT_CST_ELT (op, i));
	  m_data_cnt += 2;
	  return c;
	}
      if (m_first
	  || (m_data[m_data_cnt] == NULL_TREE
	      && m_data[m_data_cnt + 1] == NULL_TREE))
	{
	  unsigned int prec = TYPE_PRECISION (TREE_TYPE (op));
	  unsigned int rem = prec % (2 * limb_prec);
	  int ext;
	  unsigned min_prec = bitint_min_cst_precision (op, ext);
	  if (m_first)
	    {
	      m_data.safe_push (NULL_TREE);
	      m_data.safe_push (NULL_TREE);
	    }
	  if (integer_zerop (op))
	    {
	      tree c = build_zero_cst (m_limb_type);
	      m_data[m_data_cnt] = c;
	      m_data[m_data_cnt + 1] = c;
	    }
	  else if (integer_all_onesp (op))
	    {
	      tree c = build_all_ones_cst (m_limb_type);
	      m_data[m_data_cnt] = c;
	      m_data[m_data_cnt + 1] = c;
	    }
	  else if (m_upwards_2limb && min_prec <= (unsigned) limb_prec)
	    {
	      /* Single limb constant.  Use a phi with that limb from
		 the preheader edge and 0 or -1 constant from the other edge
		 and for the second limb in the loop.  */
	      tree out;
	      gcc_assert (m_first);
	      m_data.pop ();
	      m_data.pop ();
	      prepare_data_in_out (fold_convert (m_limb_type, op), idx, &out);
	      g = gimple_build_assign (m_data[m_data_cnt + 1],
				       build_int_cst (m_limb_type, ext));
	      insert_before (g);
	      m_data[m_data_cnt + 1] = gimple_assign_rhs1 (g);
	    }
	  else if (min_prec > prec - rem - 2 * limb_prec)
	    {
	      /* Constant which has enough significant bits that it isn't
		 worth trying to save .rodata space by extending from smaller
		 number.  */
	      tree type;
	      if (m_var_msb)
		type = TREE_TYPE (op);
	      else
		/* If we have a guarantee the most significant partial limb
		   (if any) will be only accessed through handle_operand
		   with INTEGER_CST idx, we don't need to include the partial
		   limb in .rodata.  */
		type = build_bitint_type (prec - rem, 1);
	      tree c = tree_output_constant_def (fold_convert (type, op));
	      m_data[m_data_cnt] = c;
	      m_data[m_data_cnt + 1] = NULL_TREE;
	    }
	  else if (m_upwards_2limb)
	    {
	      /* Constant with smaller number of bits.  Trade conditional
		 code for .rodata space by extending from smaller number.  */
	      min_prec = CEIL (min_prec, 2 * limb_prec) * (2 * limb_prec);
	      tree type = build_bitint_type (min_prec, 1);
	      tree c = tree_output_constant_def (fold_convert (type, op));
	      tree idx2 = make_ssa_name (sizetype);
	      g = gimple_build_assign (idx2, PLUS_EXPR, idx, size_one_node);
	      insert_before (g);
	      g = gimple_build_cond (LT_EXPR, idx,
				     size_int (min_prec / limb_prec),
				     NULL_TREE, NULL_TREE);
	      edge edge_true, edge_false;
	      if_then (g, (min_prec >= (prec - rem) / 2
			   ? profile_probability::likely ()
			   : profile_probability::unlikely ()),
		       edge_true, edge_false);
	      tree c1 = limb_access (TREE_TYPE (op), c, idx, false);
	      g = gimple_build_assign (make_ssa_name (TREE_TYPE (c1)), c1);
	      insert_before (g);
	      c1 = gimple_assign_lhs (g);
	      tree c2 = limb_access (TREE_TYPE (op), c, idx2, false);
	      g = gimple_build_assign (make_ssa_name (TREE_TYPE (c2)), c2);
	      insert_before (g);
	      c2 = gimple_assign_lhs (g);
	      tree c3 = build_int_cst (m_limb_type, ext);
	      m_gsi = gsi_after_labels (edge_true->dest);
	      m_data[m_data_cnt] = make_ssa_name (m_limb_type);
	      m_data[m_data_cnt + 1] = make_ssa_name (m_limb_type);
	      gphi *phi = create_phi_node (m_data[m_data_cnt],
					   edge_true->dest);
	      add_phi_arg (phi, c1, edge_true, UNKNOWN_LOCATION);
	      add_phi_arg (phi, c3, edge_false, UNKNOWN_LOCATION);
	      phi = create_phi_node (m_data[m_data_cnt + 1], edge_true->dest);
	      add_phi_arg (phi, c2, edge_true, UNKNOWN_LOCATION);
	      add_phi_arg (phi, c3, edge_false, UNKNOWN_LOCATION);
	    }
	  else
	    {
	      /* Constant with smaller number of bits.  Trade conditional
		 code for .rodata space by extending from smaller number.
		 Version for loops with random access to the limbs or
		 downwards loops.  */
	      min_prec = CEIL (min_prec, limb_prec) * limb_prec;
	      tree c;
	      if (min_prec <= (unsigned) limb_prec)
		c = fold_convert (m_limb_type, op);
	      else
		{
		  tree type = build_bitint_type (min_prec, 1);
		  c = tree_output_constant_def (fold_convert (type, op));
		}
	      m_data[m_data_cnt] = c;
	      m_data[m_data_cnt + 1] = integer_type_node;
	    }
	  t = m_data[m_data_cnt];
	  if (m_data[m_data_cnt + 1] == NULL_TREE)
	    {
	      t = limb_access (TREE_TYPE (op), t, idx, false);
	      g = gimple_build_assign (make_ssa_name (TREE_TYPE (t)), t);
	      insert_before (g);
	      t = gimple_assign_lhs (g);
	    }
	}
      else if (m_data[m_data_cnt + 1] == NULL_TREE)
	{
	  t = limb_access (TREE_TYPE (op), m_data[m_data_cnt], idx, false);
	  g = gimple_build_assign (make_ssa_name (TREE_TYPE (t)), t);
	  insert_before (g);
	  t = gimple_assign_lhs (g);
	}
      else
	t = m_data[m_data_cnt + 1];
      if (m_data[m_data_cnt + 1] == integer_type_node)
	{
	  unsigned int prec = TYPE_PRECISION (TREE_TYPE (op));
	  unsigned rem = prec % (2 * limb_prec);
	  int ext = tree_int_cst_sgn (op) < 0 ? -1 : 0;
	  tree c = m_data[m_data_cnt];
	  unsigned min_prec = TYPE_PRECISION (TREE_TYPE (c));
	  g = gimple_build_cond (LT_EXPR, idx,
				 size_int (min_prec / limb_prec),
				 NULL_TREE, NULL_TREE);
	  edge edge_true, edge_false;
	  if_then (g, (min_prec >= (prec - rem) / 2
		       ? profile_probability::likely ()
		       : profile_probability::unlikely ()),
		   edge_true, edge_false);
	  if (min_prec > (unsigned) limb_prec)
	    {
	      c = limb_access (TREE_TYPE (op), c, idx, false);
	      g = gimple_build_assign (make_ssa_name (TREE_TYPE (c)), c);
	      insert_before (g);
	      c = gimple_assign_lhs (g);
	    }
	  tree c2 = build_int_cst (m_limb_type, ext);
	  m_gsi = gsi_after_labels (edge_true->dest);
	  t = make_ssa_name (m_limb_type);
	  gphi *phi = create_phi_node (t, edge_true->dest);
	  add_phi_arg (phi, c, edge_true, UNKNOWN_LOCATION);
	  add_phi_arg (phi, c2, edge_false, UNKNOWN_LOCATION);
	}
      m_data_cnt += 2;
      return t;
    default:
      gcc_unreachable ();
    }
}

/* Helper method, add a PHI node with VAL from preheader edge if
   inside of a loop and m_first.  Keep state in a pair of m_data
   elements.  */

tree
bitint_large_huge::prepare_data_in_out (tree val, tree idx, tree *data_out)
{
  if (!m_first)
    {
      *data_out = tree_fits_uhwi_p (idx) ? NULL_TREE : m_data[m_data_cnt + 1];
      return m_data[m_data_cnt];
    }

  *data_out = NULL_TREE;
  if (tree_fits_uhwi_p (idx))
    {
      m_data.safe_push (val);
      m_data.safe_push (NULL_TREE);
      return val;
    }

  tree in = make_ssa_name (TREE_TYPE (val));
  gphi *phi = create_phi_node (in, m_bb);
  edge e1 = find_edge (m_preheader_bb, m_bb);
  edge e2 = EDGE_PRED (m_bb, 0);
  if (e1 == e2)
    e2 = EDGE_PRED (m_bb, 1);
  add_phi_arg (phi, val, e1, UNKNOWN_LOCATION);
  tree out = make_ssa_name (TREE_TYPE (val));
  add_phi_arg (phi, out, e2, UNKNOWN_LOCATION);
  m_data.safe_push (in);
  m_data.safe_push (out);
  return in;
}

/* Return VAL cast to TYPE.  If VAL is INTEGER_CST, just
   convert it without emitting any code, otherwise emit
   the conversion statement before the current location.  */

tree
bitint_large_huge::add_cast (tree type, tree val)
{
  if (TREE_CODE (val) == INTEGER_CST)
    return fold_convert (type, val);

  tree lhs = make_ssa_name (type);
  gimple *g = gimple_build_assign (lhs, NOP_EXPR, val);
  insert_before (g);
  return lhs;
}

/* Helper of handle_stmt method, handle PLUS_EXPR or MINUS_EXPR.  */

tree
bitint_large_huge::handle_plus_minus (tree_code code, tree rhs1, tree rhs2,
				      tree idx)
{
  tree lhs, data_out, ctype;
  tree rhs1_type = TREE_TYPE (rhs1);
  gimple *g;
  tree data_in = prepare_data_in_out (build_zero_cst (m_limb_type), idx,
				      &data_out);

  if (optab_handler (code == PLUS_EXPR ? uaddc5_optab : usubc5_optab,
		     TYPE_MODE (m_limb_type)) != CODE_FOR_nothing)
    {
      ctype = build_complex_type (m_limb_type);
      if (!types_compatible_p (rhs1_type, m_limb_type))
	{
	  if (!TYPE_UNSIGNED (rhs1_type))
	    {
	      tree type = unsigned_type_for (rhs1_type);
	      rhs1 = add_cast (type, rhs1);
	      rhs2 = add_cast (type, rhs2);
	    }
	  rhs1 = add_cast (m_limb_type, rhs1);
	  rhs2 = add_cast (m_limb_type, rhs2);
	}
      lhs = make_ssa_name (ctype);
      g = gimple_build_call_internal (code == PLUS_EXPR
				      ? IFN_UADDC : IFN_USUBC,
				      3, rhs1, rhs2, data_in);
      gimple_call_set_lhs (g, lhs);
      insert_before (g);
      if (data_out == NULL_TREE)
	data_out = make_ssa_name (m_limb_type);
      g = gimple_build_assign (data_out, IMAGPART_EXPR,
			       build1 (IMAGPART_EXPR, m_limb_type, lhs));
      insert_before (g);
    }
  else if (types_compatible_p (rhs1_type, m_limb_type))
    {
      ctype = build_complex_type (m_limb_type);
      lhs = make_ssa_name (ctype);
      g = gimple_build_call_internal (code == PLUS_EXPR
				      ? IFN_ADD_OVERFLOW : IFN_SUB_OVERFLOW,
				      2, rhs1, rhs2);
      gimple_call_set_lhs (g, lhs);
      insert_before (g);
      if (data_out == NULL_TREE)
	data_out = make_ssa_name (m_limb_type);
      if (!integer_zerop (data_in))
	{
	  rhs1 = make_ssa_name (m_limb_type);
	  g = gimple_build_assign (rhs1, REALPART_EXPR,
				   build1 (REALPART_EXPR, m_limb_type, lhs));
	  insert_before (g);
	  rhs2 = make_ssa_name (m_limb_type);
	  g = gimple_build_assign (rhs2, IMAGPART_EXPR,
				   build1 (IMAGPART_EXPR, m_limb_type, lhs));
	  insert_before (g);
	  lhs = make_ssa_name (ctype);
	  g = gimple_build_call_internal (code == PLUS_EXPR
					  ? IFN_ADD_OVERFLOW
					  : IFN_SUB_OVERFLOW,
					  2, rhs1, data_in);
	  gimple_call_set_lhs (g, lhs);
	  insert_before (g);
	  data_in = make_ssa_name (m_limb_type);
	  g = gimple_build_assign (data_in, IMAGPART_EXPR,
				   build1 (IMAGPART_EXPR, m_limb_type, lhs));
	  insert_before (g);
	  g = gimple_build_assign (data_out, PLUS_EXPR, rhs2, data_in);
	  insert_before (g);
	}
      else
	{
	  g = gimple_build_assign (data_out, IMAGPART_EXPR,
				   build1 (IMAGPART_EXPR, m_limb_type, lhs));
	  insert_before (g);
	}
    }
  else
    {
      tree in = add_cast (rhs1_type, data_in);
      lhs = make_ssa_name (rhs1_type);
      g = gimple_build_assign (lhs, code, rhs1, rhs2);
      insert_before (g);
      rhs1 = make_ssa_name (rhs1_type);
      g = gimple_build_assign (rhs1, code, lhs, in);
      insert_before (g);
      m_data[m_data_cnt] = NULL_TREE;
      m_data_cnt += 2;
      return rhs1;
    }
  rhs1 = make_ssa_name (m_limb_type);
  g = gimple_build_assign (rhs1, REALPART_EXPR,
			   build1 (REALPART_EXPR, m_limb_type, lhs));
  insert_before (g);
  if (!types_compatible_p (rhs1_type, m_limb_type))
    rhs1 = add_cast (rhs1_type, rhs1);
  m_data[m_data_cnt] = data_out;
  m_data_cnt += 2;
  return rhs1;
}

/* Helper function for handle_stmt method, handle LSHIFT_EXPR by
   count in [0, limb_prec - 1] range.  */

tree
bitint_large_huge::handle_lshift (tree rhs1, tree rhs2, tree idx)
{
  unsigned HOST_WIDE_INT cnt = tree_to_uhwi (rhs2);
  gcc_checking_assert (cnt < (unsigned) limb_prec);
  if (cnt == 0)
    return rhs1;

  tree lhs, data_out, rhs1_type = TREE_TYPE (rhs1);
  gimple *g;
  tree data_in = prepare_data_in_out (build_zero_cst (m_limb_type), idx,
				      &data_out);

  if (!integer_zerop (data_in))
    {
      lhs = make_ssa_name (m_limb_type);
      g = gimple_build_assign (lhs, RSHIFT_EXPR, data_in,
			       build_int_cst (unsigned_type_node,
					      limb_prec - cnt));
      insert_before (g);
      if (!types_compatible_p (rhs1_type, m_limb_type))
	lhs = add_cast (rhs1_type, lhs);
      data_in = lhs;
    }
  if (types_compatible_p (rhs1_type, m_limb_type))
    {
      if (data_out == NULL_TREE)
	data_out = make_ssa_name (m_limb_type);
      g = gimple_build_assign (data_out, rhs1);
      insert_before (g);
    }
  if (cnt < (unsigned) TYPE_PRECISION (rhs1_type))
    {
      lhs = make_ssa_name (rhs1_type);
      g = gimple_build_assign (lhs, LSHIFT_EXPR, rhs1, rhs2);
      insert_before (g);
      if (!integer_zerop (data_in))
	{
	  rhs1 = lhs;
	  lhs = make_ssa_name (rhs1_type);
	  g = gimple_build_assign (lhs, BIT_IOR_EXPR, rhs1, data_in);
	  insert_before (g);
	}
    }
  else
    lhs = data_in;
  m_data[m_data_cnt] = data_out;
  m_data_cnt += 2;
  return lhs;
}

/* Helper function for handle_stmt method, handle an integral
   to integral conversion.  */

tree
bitint_large_huge::handle_cast (tree lhs_type, tree rhs1, tree idx)
{
  tree rhs_type = TREE_TYPE (rhs1);
  gimple *g;
  if (TREE_CODE (rhs1) == SSA_NAME
      && TREE_CODE (lhs_type) == BITINT_TYPE
      && TREE_CODE (rhs_type) == BITINT_TYPE
      && bitint_precision_kind (lhs_type) >= bitint_prec_large
      && bitint_precision_kind (rhs_type) >= bitint_prec_large)
    {
      if (TYPE_PRECISION (rhs_type) >= TYPE_PRECISION (lhs_type)
	  /* If lhs has bigger precision than rhs, we can use
	     the simple case only if there is a guarantee that
	     the most significant limb is handled in straight
	     line code.  If m_var_msb (on left shifts) or
	     if m_upwards_2limb * limb_prec is equal to
	     lhs precision that is not the case.  */
	  || (!m_var_msb
	      && tree_int_cst_equal (TYPE_SIZE (rhs_type),
				     TYPE_SIZE (lhs_type))
	      && (!m_upwards_2limb
		  || (m_upwards_2limb * limb_prec
		      < TYPE_PRECISION (lhs_type)))))
	{
	  rhs1 = handle_operand (rhs1, idx);
	  if (tree_fits_uhwi_p (idx))
	    {
	      tree type = limb_access_type (lhs_type, idx);
	      if (!types_compatible_p (type, TREE_TYPE (rhs1)))
		rhs1 = add_cast (type, rhs1);
	    }
	  return rhs1;
	}
      tree t;
      /* Indexes lower than this don't need any special processing.  */
      unsigned low = ((unsigned) TYPE_PRECISION (rhs_type)
		      - !TYPE_UNSIGNED (rhs_type)) / limb_prec;
      /* Indexes >= than this always contain an extension.  */
      unsigned high = CEIL ((unsigned) TYPE_PRECISION (rhs_type), limb_prec);
      bool save_first = m_first;
      if (m_first)
	{
	  m_data.safe_push (NULL_TREE);
	  m_data.safe_push (NULL_TREE);
	  m_data.safe_push (NULL_TREE);
	  if (TYPE_UNSIGNED (rhs_type))
	    /* No need to keep state between iterations.  */
	    ;
	  else if (m_upwards && !m_upwards_2limb)
	    /* We need to keep state between iterations, but
	       not within any loop, everything is straight line
	       code with only increasing indexes.  */
	    ;
	  else if (!m_upwards_2limb)
	    {
	      unsigned save_data_cnt = m_data_cnt;
	      gimple_stmt_iterator save_gsi = m_gsi;
	      m_gsi = m_init_gsi;
	      if (gsi_end_p (m_gsi))
		m_gsi = gsi_after_labels (gsi_bb (m_gsi));
	      else
		gsi_next (&m_gsi);
	      m_data_cnt = save_data_cnt + 3;
	      t = handle_operand (rhs1, size_int (low));
	      m_first = false;
	      m_data[save_data_cnt + 2]
		= build_int_cst (NULL_TREE, m_data_cnt);
	      m_data_cnt = save_data_cnt;
	      t = add_cast (signed_type_for (m_limb_type), t);
	      tree lpm1 = build_int_cst (unsigned_type_node, limb_prec - 1);
	      tree n = make_ssa_name (TREE_TYPE (t));
	      g = gimple_build_assign (n, RSHIFT_EXPR, t, lpm1);
	      insert_before (g);
	      m_data[save_data_cnt + 1] = add_cast (m_limb_type, n);
	      m_init_gsi = m_gsi;
	      if (gsi_end_p (m_init_gsi))
		m_init_gsi = gsi_last_bb (gsi_bb (m_init_gsi));
	      else
		gsi_prev (&m_init_gsi);
	      m_gsi = save_gsi;
	    }
	  else if (m_upwards_2limb * limb_prec < TYPE_PRECISION (rhs_type))
	    /* We need to keep state between iterations, but
	       fortunately not within the loop, only afterwards.  */
	    ;
	  else
	    {
	      tree out;
	      m_data.truncate (m_data_cnt);
	      prepare_data_in_out (build_zero_cst (m_limb_type), idx, &out);
	      m_data.safe_push (NULL_TREE);
	    }
	}

      unsigned save_data_cnt = m_data_cnt;
      m_data_cnt += 3;
      if (!tree_fits_uhwi_p (idx))
	{
	  if (m_upwards_2limb
	      && (m_upwards_2limb * limb_prec
		  <= ((unsigned) TYPE_PRECISION (rhs_type)
		      - !TYPE_UNSIGNED (rhs_type))))
	    {
	      rhs1 = handle_operand (rhs1, idx);
	      if (m_first)
		m_data[save_data_cnt + 2]
		  = build_int_cst (NULL_TREE, m_data_cnt);
	      m_first = save_first;
	      return rhs1;
	    }
	  bool single_comparison
	    = low == high || (m_upwards_2limb && (low & 1) == m_first);
	  g = gimple_build_cond (single_comparison ? LT_EXPR : LE_EXPR,
				 idx, size_int (low), NULL_TREE, NULL_TREE);
	  edge edge_true_true, edge_true_false, edge_false;
	  if_then_if_then_else (g, (single_comparison ? NULL
				    : gimple_build_cond (EQ_EXPR, idx,
							 size_int (low),
							 NULL_TREE,
							 NULL_TREE)),
				profile_probability::likely (),
				profile_probability::unlikely (),
				edge_true_true, edge_true_false, edge_false);
	  bool save_cast_conditional = m_cast_conditional;
	  m_cast_conditional = true;
	  m_bitfld_load = 0;
	  tree t1 = handle_operand (rhs1, idx), t2 = NULL_TREE;
	  if (m_first)
	    m_data[save_data_cnt + 2]
	      = build_int_cst (NULL_TREE, m_data_cnt);
	  tree ext = NULL_TREE;
	  tree bitfld = NULL_TREE;
	  if (!single_comparison)
	    {
	      m_gsi = gsi_after_labels (edge_true_true->src);
	      m_first = false;
	      m_data_cnt = save_data_cnt + 3;
	      if (m_bitfld_load)
		{
		  bitfld = m_data[m_bitfld_load];
		  m_data[m_bitfld_load] = m_data[m_bitfld_load + 2];
		  m_bitfld_load = 0;
		}
	      t2 = handle_operand (rhs1, size_int (low));
	      if (!useless_type_conversion_p (m_limb_type, TREE_TYPE (t2)))
		t2 = add_cast (m_limb_type, t2);
	      if (!TYPE_UNSIGNED (rhs_type) && m_upwards_2limb)
		{
		  ext = add_cast (signed_type_for (m_limb_type), t2);
		  tree lpm1 = build_int_cst (unsigned_type_node,
					     limb_prec - 1);
		  tree n = make_ssa_name (TREE_TYPE (ext));
		  g = gimple_build_assign (n, RSHIFT_EXPR, ext, lpm1);
		  insert_before (g);
		  ext = add_cast (m_limb_type, n);
		}
	    }
	  tree t3;
	  if (TYPE_UNSIGNED (rhs_type))
	    t3 = build_zero_cst (m_limb_type);
	  else if (m_upwards_2limb && (save_first || ext != NULL_TREE))
	    t3 = m_data[save_data_cnt];
	  else
	    t3 = m_data[save_data_cnt + 1];
	  m_gsi = gsi_after_labels (edge_true_false->dest);
	  t = make_ssa_name (m_limb_type);
	  gphi *phi = create_phi_node (t, edge_true_false->dest);
	  add_phi_arg (phi, t1, edge_true_false, UNKNOWN_LOCATION);
	  add_phi_arg (phi, t3, edge_false, UNKNOWN_LOCATION);
	  if (edge_true_true)
	    add_phi_arg (phi, t2, edge_true_true, UNKNOWN_LOCATION);
	  if (ext)
	    {
	      tree t4 = make_ssa_name (m_limb_type);
	      phi = create_phi_node (t4, edge_true_false->dest);
	      add_phi_arg (phi, build_zero_cst (m_limb_type), edge_true_false,
			   UNKNOWN_LOCATION);
	      add_phi_arg (phi, m_data[save_data_cnt], edge_false,
			   UNKNOWN_LOCATION);
	      add_phi_arg (phi, ext, edge_true_true, UNKNOWN_LOCATION);
	      g = gimple_build_assign (m_data[save_data_cnt + 1], t4);
	      insert_before (g);
	    }
	  if (m_bitfld_load)
	    {
	      tree t4;
	      if (!m_first)
		t4 = m_data[m_bitfld_load + 1];
	      else
		t4 = make_ssa_name (m_limb_type);
	      phi = create_phi_node (t4, edge_true_false->dest);
	      add_phi_arg (phi,
			   edge_true_true ? bitfld : m_data[m_bitfld_load],
			   edge_true_false, UNKNOWN_LOCATION);
	      add_phi_arg (phi, m_data[m_bitfld_load + 2],
			   edge_false, UNKNOWN_LOCATION);
	      if (edge_true_true)
		add_phi_arg (phi, m_data[m_bitfld_load], edge_true_true,
			     UNKNOWN_LOCATION);
	      m_data[m_bitfld_load] = t4;
	      m_data[m_bitfld_load + 2] = t4;
	      m_bitfld_load = 0;
	    }
	  m_cast_conditional = save_cast_conditional;
	  m_first = save_first;
	  return t;
	}
      else
	{
	  if (tree_to_uhwi (idx) < low)
	    {
	      t = handle_operand (rhs1, idx);
	      if (m_first)
		m_data[save_data_cnt + 2]
		  = build_int_cst (NULL_TREE, m_data_cnt);
	    }
	  else if (tree_to_uhwi (idx) < high)
	    {
	      t = handle_operand (rhs1, size_int (low));
	      if (m_first)
		m_data[save_data_cnt + 2]
		  = build_int_cst (NULL_TREE, m_data_cnt);
	      if (!useless_type_conversion_p (m_limb_type, TREE_TYPE (t)))
		t = add_cast (m_limb_type, t);
	      tree ext = NULL_TREE;
	      if (!TYPE_UNSIGNED (rhs_type) && m_upwards)
		{
		  ext = add_cast (signed_type_for (m_limb_type), t);
		  tree lpm1 = build_int_cst (unsigned_type_node,
					     limb_prec - 1);
		  tree n = make_ssa_name (TREE_TYPE (ext));
		  g = gimple_build_assign (n, RSHIFT_EXPR, ext, lpm1);
		  insert_before (g);
		  ext = add_cast (m_limb_type, n);
		  m_data[save_data_cnt + 1] = ext;
		}
	    }
	  else
	    {
	      if (TYPE_UNSIGNED (rhs_type) && m_first)
		{
		  handle_operand (rhs1, size_zero_node);
		  m_data[save_data_cnt + 2]
		    = build_int_cst (NULL_TREE, m_data_cnt);
		}
	      else
		m_data_cnt = tree_to_uhwi (m_data[save_data_cnt + 2]);
	      if (TYPE_UNSIGNED (rhs_type))
		t = build_zero_cst (m_limb_type);
	      else
		t = m_data[save_data_cnt + 1];
	    }
	  tree type = limb_access_type (lhs_type, idx);
	  if (!useless_type_conversion_p (type, m_limb_type))
	    t = add_cast (type, t);
	  m_first = save_first;
	  return t;
	}
    }
  else if (TREE_CODE (lhs_type) == BITINT_TYPE
	   && bitint_precision_kind (lhs_type) >= bitint_prec_large
	   && INTEGRAL_TYPE_P (rhs_type))
    {
      /* Add support for 3 or more limbs filled in from normal integral
	 type if this assert fails.  If no target chooses limb mode smaller
	 than half of largest supported normal integral type, this will not
	 be needed.  */
      gcc_assert (TYPE_PRECISION (rhs_type) <= 2 * limb_prec);
      tree r1 = NULL_TREE, r2 = NULL_TREE, rext = NULL_TREE;
      if (m_first)
	{
	  gimple_stmt_iterator save_gsi = m_gsi;
	  m_gsi = m_init_gsi;
	  if (gsi_end_p (m_gsi))
	    m_gsi = gsi_after_labels (gsi_bb (m_gsi));
	  else
	    gsi_next (&m_gsi);
	  if (TREE_CODE (rhs_type) == BITINT_TYPE
	      && bitint_precision_kind (rhs_type) == bitint_prec_middle)
	    {
	      tree type = NULL_TREE;
	      rhs1 = maybe_cast_middle_bitint (&m_gsi, rhs1, type);
	      rhs_type = TREE_TYPE (rhs1);
	    }
	  r1 = rhs1;
	  if (!useless_type_conversion_p (m_limb_type, TREE_TYPE (rhs1)))
	    r1 = add_cast (m_limb_type, rhs1);
	  if (TYPE_PRECISION (rhs_type) > limb_prec)
	    {
	      g = gimple_build_assign (make_ssa_name (rhs_type),
				       RSHIFT_EXPR, rhs1,
				       build_int_cst (unsigned_type_node,
						      limb_prec));
	      insert_before (g);
	      r2 = add_cast (m_limb_type, gimple_assign_lhs (g));
	    }
	  if (TYPE_UNSIGNED (rhs_type))
	    rext = build_zero_cst (m_limb_type);
	  else
	    {
	      rext = add_cast (signed_type_for (m_limb_type), r2 ? r2 : r1);
	      g = gimple_build_assign (make_ssa_name (TREE_TYPE (rext)),
				       RSHIFT_EXPR, rext,
				       build_int_cst (unsigned_type_node,
						      limb_prec - 1));
	      insert_before (g);
	      rext = add_cast (m_limb_type, gimple_assign_lhs (g));
	    }
	  m_init_gsi = m_gsi;
	  if (gsi_end_p (m_init_gsi))
	    m_init_gsi = gsi_last_bb (gsi_bb (m_init_gsi));
	  else
	    gsi_prev (&m_init_gsi);
	  m_gsi = save_gsi;
	}
      tree t;
      if (m_upwards_2limb)
	{
	  if (m_first)
	    {
	      tree out1, out2;
	      prepare_data_in_out (r1, idx, &out1);
	      g = gimple_build_assign (m_data[m_data_cnt + 1], rext);
	      insert_before (g);
	      if (TYPE_PRECISION (rhs_type) > limb_prec)
		{
		  prepare_data_in_out (r2, idx, &out2);
		  g = gimple_build_assign (m_data[m_data_cnt + 3], rext);
		  insert_before (g);
		  m_data.pop ();
		  t = m_data.pop ();
		  m_data[m_data_cnt + 1] = t;
		}
	      else
		m_data[m_data_cnt + 1] = rext;
	      m_data.safe_push (rext);
	      t = m_data[m_data_cnt];
	    }
	  else if (!tree_fits_uhwi_p (idx))
	    t = m_data[m_data_cnt + 1];
	  else
	    {
	      tree type = limb_access_type (lhs_type, idx);
	      t = m_data[m_data_cnt + 2];
	      if (!useless_type_conversion_p (type, m_limb_type))
		t = add_cast (type, t);
	    }
	  m_data_cnt += 3;
	  return t;
	}
      else if (m_first)
	{
	  m_data.safe_push (r1);
	  m_data.safe_push (r2);
	  m_data.safe_push (rext);
	}
      if (tree_fits_uhwi_p (idx))
	{
	  tree type = limb_access_type (lhs_type, idx);
	  if (integer_zerop (idx))
	    t = m_data[m_data_cnt];
	  else if (TYPE_PRECISION (rhs_type) > limb_prec
		   && integer_onep (idx))
	    t = m_data[m_data_cnt + 1];
	  else
	    t = m_data[m_data_cnt + 2];
	  if (!useless_type_conversion_p (type, m_limb_type))
	    t = add_cast (type, t);
	  m_data_cnt += 3;
	  return t;
	}
      g = gimple_build_cond (NE_EXPR, idx, size_zero_node,
			     NULL_TREE, NULL_TREE);
      edge e2, e3, e4 = NULL;
      if_then (g, profile_probability::likely (), e2, e3);
      if (m_data[m_data_cnt + 1])
	{
	  g = gimple_build_cond (EQ_EXPR, idx, size_one_node,
				 NULL_TREE, NULL_TREE);
	  insert_before (g);
	  edge e5 = split_block (gsi_bb (m_gsi), g);
	  e4 = make_edge (e5->src, e2->dest, EDGE_TRUE_VALUE);
	  e2 = find_edge (e5->dest, e2->dest);
	  e4->probability = profile_probability::unlikely ();
	  e5->flags = EDGE_FALSE_VALUE;
	  e5->probability = e4->probability.invert ();
	}
      m_gsi = gsi_after_labels (e2->dest);
      t = make_ssa_name (m_limb_type);
      gphi *phi = create_phi_node (t, e2->dest);
      add_phi_arg (phi, m_data[m_data_cnt + 2], e2, UNKNOWN_LOCATION);
      add_phi_arg (phi, m_data[m_data_cnt], e3, UNKNOWN_LOCATION);
      if (e4)
	add_phi_arg (phi, m_data[m_data_cnt + 1], e4, UNKNOWN_LOCATION);
      m_data_cnt += 3;
      return t;
    }
  return NULL_TREE;
}

/* Helper function for handle_stmt method, handle a load from memory.  */

tree
bitint_large_huge::handle_load (gimple *stmt, tree idx)
{
  tree rhs1 = gimple_assign_rhs1 (stmt);
  tree rhs_type = TREE_TYPE (rhs1);
  bool eh = stmt_ends_bb_p (stmt);
  edge eh_edge = NULL;
  gimple *g;

  if (eh)
    {
      edge_iterator ei;
      basic_block bb = gimple_bb (stmt);

      FOR_EACH_EDGE (eh_edge, ei, bb->succs)
	if (eh_edge->flags & EDGE_EH)
	    break;
    }

  if (TREE_CODE (rhs1) == COMPONENT_REF
      && DECL_BIT_FIELD_TYPE (TREE_OPERAND (rhs1, 1)))
    {
      tree fld = TREE_OPERAND (rhs1, 1);
      /* For little-endian, we can allow as inputs bit-fields
	 which start at a limb boundary.  */
      gcc_assert (tree_fits_uhwi_p (DECL_FIELD_BIT_OFFSET (fld)));
      if (DECL_OFFSET_ALIGN (fld) >= TYPE_ALIGN (TREE_TYPE (rhs1))
	  && (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (fld)) % limb_prec) == 0)
	goto normal_load;
      /* Even if DECL_FIELD_BIT_OFFSET (fld) is a multiple of UNITS_PER_BIT,
	 handle it normally for now.  */
      if ((tree_to_uhwi (DECL_FIELD_BIT_OFFSET (fld)) % BITS_PER_UNIT) == 0)
	goto normal_load;
      tree repr = DECL_BIT_FIELD_REPRESENTATIVE (fld);
      poly_int64 bitoffset;
      poly_uint64 field_offset, repr_offset;
      bool var_field_off = false;
      if (poly_int_tree_p (DECL_FIELD_OFFSET (fld), &field_offset)
	  && poly_int_tree_p (DECL_FIELD_OFFSET (repr), &repr_offset))
	bitoffset = (field_offset - repr_offset) * BITS_PER_UNIT;
      else
	{
	  bitoffset = 0;
	  var_field_off = true;
	}
      bitoffset += (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (fld))
		    - tree_to_uhwi (DECL_FIELD_BIT_OFFSET (repr)));
      tree nrhs1 = build3 (COMPONENT_REF, TREE_TYPE (repr),
			   TREE_OPERAND (rhs1, 0), repr,
			   var_field_off ? TREE_OPERAND (rhs1, 2) : NULL_TREE);
      HOST_WIDE_INT bo = bitoffset.to_constant ();
      unsigned bo_idx = (unsigned HOST_WIDE_INT) bo / limb_prec;
      unsigned bo_bit = (unsigned HOST_WIDE_INT) bo % limb_prec;
      if (m_first)
	{
	  if (m_upwards)
	    {
	      gimple_stmt_iterator save_gsi = m_gsi;
	      m_gsi = m_init_gsi;
	      if (gsi_end_p (m_gsi))
		m_gsi = gsi_after_labels (gsi_bb (m_gsi));
	      else
		gsi_next (&m_gsi);
	      tree t = limb_access (rhs_type, nrhs1, size_int (bo_idx), true);
	      tree iv = make_ssa_name (m_limb_type);
	      g = gimple_build_assign (iv, t);
	      insert_before (g);
	      if (eh)
		{
		  maybe_duplicate_eh_stmt (g, stmt);
		  if (eh_edge)
		    {
		      edge e = split_block (gsi_bb (m_gsi), g);
		      make_edge (e->src, eh_edge->dest, EDGE_EH)->probability
			= profile_probability::very_unlikely ();
		      m_gsi = gsi_after_labels (e->dest);
		      if (gsi_bb (save_gsi) == e->src)
			{
			  if (gsi_end_p (save_gsi))
			    save_gsi = gsi_end_bb (e->dest);
			  else
			    save_gsi = gsi_for_stmt (gsi_stmt (save_gsi));
			}
		      if (m_preheader_bb == e->src)
			m_preheader_bb = e->dest;
		    }
		}
	      m_init_gsi = m_gsi;
	      if (gsi_end_p (m_init_gsi))
		m_init_gsi = gsi_last_bb (gsi_bb (m_init_gsi));
	      else
		gsi_prev (&m_init_gsi);
	      m_gsi = save_gsi;
	      tree out;
	      prepare_data_in_out (iv, idx, &out);
	      out = m_data[m_data_cnt];
	      m_data.safe_push (out);
	    }
	  else
	    {
	      m_data.safe_push (NULL_TREE);
	      m_data.safe_push (NULL_TREE);
	      m_data.safe_push (NULL_TREE);
	    }
	}

      tree nidx0 = NULL_TREE, nidx1;
      tree iv = m_data[m_data_cnt];
      if (m_cast_conditional && iv)
	{
	  gcc_assert (!m_bitfld_load);
	  m_bitfld_load = m_data_cnt;
	}
      if (tree_fits_uhwi_p (idx))
	{
	  unsigned prec = TYPE_PRECISION (rhs_type);
	  unsigned HOST_WIDE_INT i = tree_to_uhwi (idx);
	  gcc_assert (i * limb_prec < prec);
	  nidx1 = size_int (i + bo_idx + 1);
	  if ((i + 1) * limb_prec > prec)
	    {
	      prec %= limb_prec;
	      if (prec + bo_bit <= (unsigned) limb_prec)
		nidx1 = NULL_TREE;
	    }
	  if (!iv)
	    nidx0 = size_int (i + bo_idx);
	}
      else
	{
	  if (!iv)
	    {
	      if (bo_idx == 0)
		nidx0 = idx;
	      else
		{
		  nidx0 = make_ssa_name (sizetype);
		  g = gimple_build_assign (nidx0, PLUS_EXPR, idx,
					   size_int (bo_idx));
		  insert_before (g);
		}
	    }
	  nidx1 = make_ssa_name (sizetype);
	  g = gimple_build_assign (nidx1, PLUS_EXPR, idx,
				   size_int (bo_idx + 1));
	  insert_before (g);
	}

      tree iv2 = NULL_TREE;
      if (nidx0)
	{
	  tree t = limb_access (rhs_type, nrhs1, nidx0, true);
	  iv = make_ssa_name (m_limb_type);
	  g = gimple_build_assign (iv, t);
	  insert_before (g);
	  gcc_assert (!eh);
	}
      if (nidx1)
	{
	  bool conditional = m_var_msb && !tree_fits_uhwi_p (idx);
	  unsigned prec = TYPE_PRECISION (rhs_type);
	  if (conditional)
	    {
	      if ((prec % limb_prec) == 0
		  || ((prec % limb_prec) + bo_bit > (unsigned) limb_prec))
		conditional = false;
	    }
	  edge edge_true = NULL, edge_false = NULL;
	  if (conditional)
	    {
	      g = gimple_build_cond (NE_EXPR, idx,
				     size_int (prec / limb_prec),
				     NULL_TREE, NULL_TREE);
	      if_then (g, profile_probability::likely (),
		       edge_true, edge_false);
	    }
	  tree t = limb_access (rhs_type, nrhs1, nidx1, true);
	  if (m_upwards_2limb
	      && !m_first
	      && !m_bitfld_load
	      && !tree_fits_uhwi_p (idx))
	    iv2 = m_data[m_data_cnt + 1];
	  else
	    iv2 = make_ssa_name (m_limb_type);
	  g = gimple_build_assign (iv2, t);
	  insert_before (g);
	  if (eh)
	    {
	      maybe_duplicate_eh_stmt (g, stmt);
	      if (eh_edge)
		{
		  edge e = split_block (gsi_bb (m_gsi), g);
		  m_gsi = gsi_after_labels (e->dest);
		  make_edge (e->src, eh_edge->dest, EDGE_EH)->probability
		    = profile_probability::very_unlikely ();
		}
	    }
	  if (conditional)
	    {
	      tree iv3 = make_ssa_name (m_limb_type);
	      if (eh)
		edge_true = find_edge (gsi_bb (m_gsi), edge_false->dest);
	      gphi *phi = create_phi_node (iv3, edge_true->dest);
	      add_phi_arg (phi, iv2, edge_true, UNKNOWN_LOCATION);
	      add_phi_arg (phi, build_zero_cst (m_limb_type),
			   edge_false, UNKNOWN_LOCATION);
	      m_gsi = gsi_after_labels (edge_true->dest);
	    }
	}
      g = gimple_build_assign (make_ssa_name (m_limb_type), RSHIFT_EXPR,
			       iv, build_int_cst (unsigned_type_node, bo_bit));
      insert_before (g);
      iv = gimple_assign_lhs (g);
      if (iv2)
	{
	  g = gimple_build_assign (make_ssa_name (m_limb_type), LSHIFT_EXPR,
				   iv2, build_int_cst (unsigned_type_node,
						       limb_prec - bo_bit));
	  insert_before (g);
	  g = gimple_build_assign (make_ssa_name (m_limb_type), BIT_IOR_EXPR,
				   gimple_assign_lhs (g), iv);
	  insert_before (g);
	  iv = gimple_assign_lhs (g);
	  if (m_data[m_data_cnt])
	    m_data[m_data_cnt] = iv2;
	}
      if (tree_fits_uhwi_p (idx))
	{
	  tree atype = limb_access_type (rhs_type, idx);
	  if (!useless_type_conversion_p (atype, TREE_TYPE (iv)))
	    iv = add_cast (atype, iv);
	}
      m_data_cnt += 3;
      return iv;
    }

normal_load:
  /* Use write_p = true for loads with EH edges to make
     sure limb_access doesn't add a cast as separate
     statement after it.  */
  rhs1 = limb_access (rhs_type, rhs1, idx, eh);
  tree ret = make_ssa_name (TREE_TYPE (rhs1));
  g = gimple_build_assign (ret, rhs1);
  insert_before (g);
  if (eh)
    {
      maybe_duplicate_eh_stmt (g, stmt);
      if (eh_edge)
	{
	  edge e = split_block (gsi_bb (m_gsi), g);
	  m_gsi = gsi_after_labels (e->dest);
	  make_edge (e->src, eh_edge->dest, EDGE_EH)->probability
	    = profile_probability::very_unlikely ();
	}
      if (tree_fits_uhwi_p (idx))
	{
	  tree atype = limb_access_type (rhs_type, idx);
	  if (!useless_type_conversion_p (atype, TREE_TYPE (rhs1)))
	    ret = add_cast (atype, ret);
	}
    }
  return ret;
}

/* Return a limb IDX from a mergeable statement STMT.  */

tree
bitint_large_huge::handle_stmt (gimple *stmt, tree idx)
{
  tree lhs, rhs1, rhs2 = NULL_TREE;
  gimple *g;
  switch (gimple_code (stmt))
    {
    case GIMPLE_ASSIGN:
      if (gimple_assign_load_p (stmt))
	return handle_load (stmt, idx);
      switch (gimple_assign_rhs_code (stmt))
	{
	case BIT_AND_EXPR:
	case BIT_IOR_EXPR:
	case BIT_XOR_EXPR:
	  rhs2 = handle_operand (gimple_assign_rhs2 (stmt), idx);
	  /* FALLTHRU */
	case BIT_NOT_EXPR:
	  rhs1 = handle_operand (gimple_assign_rhs1 (stmt), idx);
	  lhs = make_ssa_name (TREE_TYPE (rhs1));
	  g = gimple_build_assign (lhs, gimple_assign_rhs_code (stmt),
				   rhs1, rhs2);
	  insert_before (g);
	  return lhs;
	case PLUS_EXPR:
	case MINUS_EXPR:
	  rhs1 = handle_operand (gimple_assign_rhs1 (stmt), idx);
	  rhs2 = handle_operand (gimple_assign_rhs2 (stmt), idx);
	  return handle_plus_minus (gimple_assign_rhs_code (stmt),
				    rhs1, rhs2, idx);
	case NEGATE_EXPR:
	  rhs2 = handle_operand (gimple_assign_rhs1 (stmt), idx);
	  rhs1 = build_zero_cst (TREE_TYPE (rhs2));
	  return handle_plus_minus (MINUS_EXPR, rhs1, rhs2, idx);
	case LSHIFT_EXPR:
	  return handle_lshift (handle_operand (gimple_assign_rhs1 (stmt),
						idx),
				gimple_assign_rhs2 (stmt), idx);
	case SSA_NAME:
	case INTEGER_CST:
	  return handle_operand (gimple_assign_rhs1 (stmt), idx);
	CASE_CONVERT:
	case VIEW_CONVERT_EXPR:
	  return handle_cast (TREE_TYPE (gimple_assign_lhs (stmt)),
			      gimple_assign_rhs1 (stmt), idx);
	default:
	  break;
	}
      break;
    default:
      break;
    }
  gcc_unreachable ();
}

/* Return minimum precision of OP at STMT.
   Positive value is minimum precision above which all bits
   are zero, negative means all bits above negation of the
   value are copies of the sign bit.  */

static int
range_to_prec (tree op, gimple *stmt)
{
  int_range_max r;
  wide_int w;
  tree type = TREE_TYPE (op);
  unsigned int prec = TYPE_PRECISION (type);

  if (!optimize
      || !get_range_query (cfun)->range_of_expr (r, op, stmt)
      || r.undefined_p ())
    {
      if (TYPE_UNSIGNED (type))
	return prec;
      else
	return MIN ((int) -prec, -2);
    }

  if (!TYPE_UNSIGNED (TREE_TYPE (op)))
    {
      w = r.lower_bound ();
      if (wi::neg_p (w))
	{
	  int min_prec1 = wi::min_precision (w, SIGNED);
	  w = r.upper_bound ();
	  int min_prec2 = wi::min_precision (w, SIGNED);
	  int min_prec = MAX (min_prec1, min_prec2);
	  return MIN (-min_prec, -2);
	}
    }

  w = r.upper_bound ();
  int min_prec = wi::min_precision (w, UNSIGNED);
  return MAX (min_prec, 1);
}

/* Return address of the first limb of OP and write into *PREC
   its precision.  If positive, the operand is zero extended
   from that precision, if it is negative, the operand is sign-extended
   from -*PREC.  If PREC_STORED is NULL, it is the toplevel call,
   otherwise *PREC_STORED is prec from the innermost call without
   range optimizations.  */

tree
bitint_large_huge::handle_operand_addr (tree op, gimple *stmt,
					int *prec_stored, int *prec)
{
  wide_int w;
  location_t loc_save = m_loc;
  if ((TREE_CODE (TREE_TYPE (op)) != BITINT_TYPE
       || bitint_precision_kind (TREE_TYPE (op)) < bitint_prec_large)
      && TREE_CODE (op) != INTEGER_CST)
    {
    do_int:
      *prec = range_to_prec (op, stmt);
      bitint_prec_kind kind = bitint_prec_small;
      gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (op)));
      if (TREE_CODE (TREE_TYPE (op)) == BITINT_TYPE)
	kind = bitint_precision_kind (TREE_TYPE (op));
      if (kind == bitint_prec_middle)
	{
	  tree type = NULL_TREE;
	  op = maybe_cast_middle_bitint (&m_gsi, op, type);
	}
      tree op_type = TREE_TYPE (op);
      unsigned HOST_WIDE_INT nelts
	= CEIL (TYPE_PRECISION (op_type), limb_prec);
      /* Add support for 3 or more limbs filled in from normal
	 integral type if this assert fails.  If no target chooses
	 limb mode smaller than half of largest supported normal
	 integral type, this will not be needed.  */
      gcc_assert (nelts <= 2);
      if (prec_stored)
	*prec_stored = (TYPE_UNSIGNED (op_type)
			? TYPE_PRECISION (op_type)
			: -TYPE_PRECISION (op_type));
      if (*prec <= limb_prec && *prec >= -limb_prec)
	{
	  nelts = 1;
	  if (prec_stored)
	    {
	      if (TYPE_UNSIGNED (op_type))
		{
		  if (*prec_stored > limb_prec)
		    *prec_stored = limb_prec;
		}
	      else if (*prec_stored < -limb_prec)
		*prec_stored = -limb_prec;
	    }
	}
      tree atype = build_array_type_nelts (m_limb_type, nelts);
      tree var = create_tmp_var (atype);
      tree t1 = op;
      if (!useless_type_conversion_p (m_limb_type, op_type))
	t1 = add_cast (m_limb_type, t1);
      tree v = build4 (ARRAY_REF, m_limb_type, var, size_zero_node,
		       NULL_TREE, NULL_TREE);
      gimple *g = gimple_build_assign (v, t1);
      insert_before (g);
      if (nelts > 1)
	{
	  tree lp = build_int_cst (unsigned_type_node, limb_prec);
	  g = gimple_build_assign (make_ssa_name (op_type),
				   RSHIFT_EXPR, op, lp);
	  insert_before (g);
	  tree t2 = gimple_assign_lhs (g);
	  t2 = add_cast (m_limb_type, t2);
	  v = build4 (ARRAY_REF, m_limb_type, var, size_one_node,
		      NULL_TREE, NULL_TREE);
	  g = gimple_build_assign (v, t2);
	  insert_before (g);
	}
      tree ret = build_fold_addr_expr (var);
      if (!stmt_ends_bb_p (gsi_stmt (m_gsi)))
	{
	  tree clobber = build_clobber (atype, CLOBBER_EOL);
	  g = gimple_build_assign (var, clobber);
	  gsi_insert_after (&m_gsi, g, GSI_SAME_STMT);
	}
      m_loc = loc_save;
      return ret;
    }
  switch (TREE_CODE (op))
    {
    case SSA_NAME:
      if (m_names == NULL
	  || !bitmap_bit_p (m_names, SSA_NAME_VERSION (op)))
	{
	  gimple *g = SSA_NAME_DEF_STMT (op);
	  tree ret;
	  m_loc = gimple_location (g);
	  if (gimple_assign_load_p (g))
	    {
	      *prec = range_to_prec (op, NULL);
	      if (prec_stored)
		*prec_stored = (TYPE_UNSIGNED (TREE_TYPE (op))
				? TYPE_PRECISION (TREE_TYPE (op))
				: -TYPE_PRECISION (TREE_TYPE (op)));
	      ret = build_fold_addr_expr (gimple_assign_rhs1 (g));
	      ret = force_gimple_operand_gsi (&m_gsi, ret, true,
					      NULL_TREE, true, GSI_SAME_STMT);
	    }
	  else if (gimple_code (g) == GIMPLE_NOP)
	    {
	      *prec = TYPE_UNSIGNED (TREE_TYPE (op)) ? limb_prec : -limb_prec;
	      if (prec_stored)
		*prec_stored = *prec;
	      tree var = create_tmp_var (m_limb_type);
	      TREE_ADDRESSABLE (var) = 1;
	      ret = build_fold_addr_expr (var);
	      if (!stmt_ends_bb_p (gsi_stmt (m_gsi)))
		{
		  tree clobber = build_clobber (m_limb_type, CLOBBER_EOL);
		  g = gimple_build_assign (var, clobber);
		  gsi_insert_after (&m_gsi, g, GSI_SAME_STMT);
		}
	    }
	  else
	    {
	      gcc_assert (gimple_assign_cast_p (g));
	      tree rhs1 = gimple_assign_rhs1 (g);
	      bitint_prec_kind kind = bitint_prec_small;
	      gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)));
	      if (TREE_CODE (TREE_TYPE (rhs1)) == BITINT_TYPE)
		kind = bitint_precision_kind (TREE_TYPE (rhs1));
	      if (kind >= bitint_prec_large)
		{
		  tree lhs_type = TREE_TYPE (op);
		  tree rhs_type = TREE_TYPE (rhs1);
		  int prec_stored_val = 0;
		  ret = handle_operand_addr (rhs1, g, &prec_stored_val, prec);
		  if (TYPE_PRECISION (lhs_type) > TYPE_PRECISION (rhs_type))
		    {
		      if (TYPE_UNSIGNED (lhs_type)
			  && !TYPE_UNSIGNED (rhs_type))
			gcc_assert (*prec >= 0 || prec_stored == NULL);
		    }
		  else
		    {
		      if (*prec > 0 && *prec < TYPE_PRECISION (lhs_type))
			;
		      else if (TYPE_UNSIGNED (lhs_type))
			{
			  gcc_assert (*prec > 0
				      || prec_stored_val > 0
				      || (-prec_stored_val
					  >= TYPE_PRECISION (lhs_type)));
			  *prec = TYPE_PRECISION (lhs_type);
			}
		      else if (*prec < 0 && -*prec < TYPE_PRECISION (lhs_type))
			;
		      else
			*prec = -TYPE_PRECISION (lhs_type);
		    }
		}
	      else
		{
		  op = rhs1;
		  stmt = g;
		  goto do_int;
		}
	    }
	  m_loc = loc_save;
	  return ret;
	}
      else
	{
	  int p = var_to_partition (m_map, op);
	  gcc_assert (m_vars[p] != NULL_TREE);
	  *prec = range_to_prec (op, stmt);
	  if (prec_stored)
	    *prec_stored = (TYPE_UNSIGNED (TREE_TYPE (op))
			    ? TYPE_PRECISION (TREE_TYPE (op))
			    : -TYPE_PRECISION (TREE_TYPE (op)));
	  return build_fold_addr_expr (m_vars[p]);
	}
    case INTEGER_CST:
      unsigned int min_prec, mp;
      tree type;
      w = wi::to_wide (op);
      if (tree_int_cst_sgn (op) >= 0)
	{
	  min_prec = wi::min_precision (w, UNSIGNED);
	  *prec = MAX (min_prec, 1);
	}
      else
	{
	  min_prec = wi::min_precision (w, SIGNED);
	  *prec = MIN ((int) -min_prec, -2);
	}
      mp = CEIL (min_prec, limb_prec) * limb_prec;
      if (mp == 0)
	mp = 1;
      if (mp >= (unsigned) TYPE_PRECISION (TREE_TYPE (op)))
	type = TREE_TYPE (op);
      else
	type = build_bitint_type (mp, 1);
      if (TREE_CODE (type) != BITINT_TYPE
	  || bitint_precision_kind (type) == bitint_prec_small)
	{
	  if (TYPE_PRECISION (type) <= limb_prec)
	    type = m_limb_type;
	  else
	    /* This case is for targets which e.g. have 64-bit
	       limb but categorize up to 128-bits _BitInts as
	       small.  We could use type of m_limb_type[2] and
	       similar instead to save space.  */
	    type = build_bitint_type (mid_min_prec, 1);
	}
      if (prec_stored)
	{
	  if (tree_int_cst_sgn (op) >= 0)
	    *prec_stored = MAX (TYPE_PRECISION (type), 1);
	  else
	    *prec_stored = MIN ((int) -TYPE_PRECISION (type), -2);
	}
      op = tree_output_constant_def (fold_convert (type, op));
      return build_fold_addr_expr (op);
    default:
      gcc_unreachable ();
    }
}

/* Helper function, create a loop before the current location,
   start with sizetype INIT value from the preheader edge.  Return
   a PHI result and set *IDX_NEXT to SSA_NAME it creates and uses
   from the latch edge.  */

tree
bitint_large_huge::create_loop (tree init, tree *idx_next)
{
  if (!gsi_end_p (m_gsi))
    gsi_prev (&m_gsi);
  else
    m_gsi = gsi_last_bb (gsi_bb (m_gsi));
  edge e1 = split_block (gsi_bb (m_gsi), gsi_stmt (m_gsi));
  edge e2 = split_block (e1->dest, (gimple *) NULL);
  edge e3 = make_edge (e1->dest, e1->dest, EDGE_TRUE_VALUE);
  e3->probability = profile_probability::very_unlikely ();
  e2->flags = EDGE_FALSE_VALUE;
  e2->probability = e3->probability.invert ();
  tree idx = make_ssa_name (sizetype);
  gphi *phi = create_phi_node (idx, e1->dest);
  add_phi_arg (phi, init, e1, UNKNOWN_LOCATION);
  *idx_next = make_ssa_name (sizetype);
  add_phi_arg (phi, *idx_next, e3, UNKNOWN_LOCATION);
  m_gsi = gsi_after_labels (e1->dest);
  m_bb = e1->dest;
  m_preheader_bb = e1->src;
  class loop *loop = alloc_loop ();
  loop->header = e1->dest;
  add_loop (loop, e1->src->loop_father);
  return idx;
}

/* Lower large/huge _BitInt statement mergeable or similar STMT which can be
   lowered using iteration from the least significant limb up to the most
   significant limb.  For large _BitInt it is emitted as straight line code
   before current location, for huge _BitInt as a loop handling two limbs
   at once, followed by handling up to limbs in straight line code (at most
   one full and one partial limb).  It can also handle EQ_EXPR/NE_EXPR
   comparisons, in that case CMP_CODE should be the comparison code and
   CMP_OP1/CMP_OP2 the comparison operands.  */

tree
bitint_large_huge::lower_mergeable_stmt (gimple *stmt, tree_code &cmp_code,
					 tree cmp_op1, tree cmp_op2)
{
  bool eq_p = cmp_code != ERROR_MARK;
  tree type;
  if (eq_p)
    type = TREE_TYPE (cmp_op1);
  else
    type = TREE_TYPE (gimple_assign_lhs (stmt));
  gcc_assert (TREE_CODE (type) == BITINT_TYPE);
  bitint_prec_kind kind = bitint_precision_kind (type);
  gcc_assert (kind >= bitint_prec_large);
  gimple *g;
  tree lhs = gimple_get_lhs (stmt);
  tree rhs1, lhs_type = lhs ? TREE_TYPE (lhs) : NULL_TREE;
  if (lhs
      && TREE_CODE (lhs) == SSA_NAME
      && TREE_CODE (TREE_TYPE (lhs)) == BITINT_TYPE
      && bitint_precision_kind (TREE_TYPE (lhs)) >= bitint_prec_large)
    {
      int p = var_to_partition (m_map, lhs);
      gcc_assert (m_vars[p] != NULL_TREE);
      m_lhs = lhs = m_vars[p];
    }
  unsigned cnt, rem = 0, end = 0, prec = TYPE_PRECISION (type);
  bool sext = false;
  tree ext = NULL_TREE, store_operand = NULL_TREE;
  bool eh = false;
  basic_block eh_pad = NULL;
  tree nlhs = NULL_TREE;
  unsigned HOST_WIDE_INT bo_idx = 0;
  unsigned HOST_WIDE_INT bo_bit = 0;
  tree bf_cur = NULL_TREE, bf_next = NULL_TREE;
  if (gimple_store_p (stmt))
    {
      store_operand = gimple_assign_rhs1 (stmt);
      eh = stmt_ends_bb_p (stmt);
      if (eh)
	{
	  edge e;
	  edge_iterator ei;
	  basic_block bb = gimple_bb (stmt);

	  FOR_EACH_EDGE (e, ei, bb->succs)
	    if (e->flags & EDGE_EH)
	      {
		eh_pad = e->dest;
		break;
	      }
	}
      if (TREE_CODE (lhs) == COMPONENT_REF
	  && DECL_BIT_FIELD_TYPE (TREE_OPERAND (lhs, 1)))
	{
	  tree fld = TREE_OPERAND (lhs, 1);
	  gcc_assert (tree_fits_uhwi_p (DECL_FIELD_BIT_OFFSET (fld)));
	  tree repr = DECL_BIT_FIELD_REPRESENTATIVE (fld);
	  poly_int64 bitoffset;
	  poly_uint64 field_offset, repr_offset;
	  if ((tree_to_uhwi (DECL_FIELD_BIT_OFFSET (fld)) % BITS_PER_UNIT) == 0)
	    nlhs = lhs;
	  else
	    {
	      bool var_field_off = false;
	      if (poly_int_tree_p (DECL_FIELD_OFFSET (fld), &field_offset)
		  && poly_int_tree_p (DECL_FIELD_OFFSET (repr), &repr_offset))
		bitoffset = (field_offset - repr_offset) * BITS_PER_UNIT;
	      else
		{
		  bitoffset = 0;
		  var_field_off = true;
		}
	      bitoffset += (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (fld))
			    - tree_to_uhwi (DECL_FIELD_BIT_OFFSET (repr)));
	      nlhs = build3 (COMPONENT_REF, TREE_TYPE (repr),
			     TREE_OPERAND (lhs, 0), repr,
			     var_field_off
			     ? TREE_OPERAND (lhs, 2) : NULL_TREE);
	      HOST_WIDE_INT bo = bitoffset.to_constant ();
	      bo_idx = (unsigned HOST_WIDE_INT) bo / limb_prec;
	      bo_bit = (unsigned HOST_WIDE_INT) bo % limb_prec;
	    }
	}
    }
  if ((store_operand
       && TREE_CODE (store_operand) == SSA_NAME
       && (m_names == NULL
	   || !bitmap_bit_p (m_names, SSA_NAME_VERSION (store_operand)))
       && gimple_assign_cast_p (SSA_NAME_DEF_STMT (store_operand)))
      || gimple_assign_cast_p (stmt))
    {
      rhs1 = gimple_assign_rhs1 (store_operand
				 ? SSA_NAME_DEF_STMT (store_operand)
				 : stmt);
      /* Optimize mergeable ops ending with widening cast to _BitInt
	 (or followed by store).  We can lower just the limbs of the
	 cast operand and widen afterwards.  */
      if (TREE_CODE (rhs1) == SSA_NAME
	  && (m_names == NULL
	      || !bitmap_bit_p (m_names, SSA_NAME_VERSION (rhs1)))
	  && TREE_CODE (TREE_TYPE (rhs1)) == BITINT_TYPE
	  && bitint_precision_kind (TREE_TYPE (rhs1)) >= bitint_prec_large
	  && (CEIL ((unsigned) TYPE_PRECISION (TREE_TYPE (rhs1)),
		    limb_prec) < CEIL (prec, limb_prec)
	      || (kind == bitint_prec_huge
		  && TYPE_PRECISION (TREE_TYPE (rhs1)) < prec)))
	{
	  store_operand = rhs1;
	  prec = TYPE_PRECISION (TREE_TYPE (rhs1));
	  kind = bitint_precision_kind (TREE_TYPE (rhs1));
	  if (!TYPE_UNSIGNED (TREE_TYPE (rhs1)))
	    sext = true;
	}
    }
  tree idx = NULL_TREE, idx_first = NULL_TREE, idx_next = NULL_TREE;
  if (kind == bitint_prec_large)
    cnt = CEIL (prec, limb_prec);
  else
    {
      rem = (prec % (2 * limb_prec));
      end = (prec - rem) / limb_prec;
      cnt = 2 + CEIL (rem, limb_prec);
      idx = idx_first = create_loop (size_zero_node, &idx_next);
    }

  basic_block edge_bb = NULL;
  if (eq_p)
    {
      gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
      gsi_prev (&gsi);
      edge e = split_block (gsi_bb (gsi), gsi_stmt (gsi));
      edge_bb = e->src;
      if (kind == bitint_prec_large)
	m_gsi = gsi_end_bb (edge_bb);
    }
  else
    m_after_stmt = stmt;
  if (kind != bitint_prec_large)
    m_upwards_2limb = end;
  m_upwards = true;

  bool separate_ext
    = (prec != (unsigned) TYPE_PRECISION (type)
       && (CEIL ((unsigned) TYPE_PRECISION (type), limb_prec)
	   > CEIL (prec, limb_prec)));

  for (unsigned i = 0; i < cnt; i++)
    {
      m_data_cnt = 0;
      if (kind == bitint_prec_large)
	idx = size_int (i);
      else if (i >= 2)
	idx = size_int (end + (i > 2));
      if (eq_p)
	{
	  rhs1 = handle_operand (cmp_op1, idx);
	  tree rhs2 = handle_operand (cmp_op2, idx);
	  g = gimple_build_cond (NE_EXPR, rhs1, rhs2, NULL_TREE, NULL_TREE);
	  insert_before (g);
	  edge e1 = split_block (gsi_bb (m_gsi), g);
	  e1->flags = EDGE_FALSE_VALUE;
	  edge e2 = make_edge (e1->src, gimple_bb (stmt), EDGE_TRUE_VALUE);
	  e1->probability = profile_probability::unlikely ();
	  e2->probability = e1->probability.invert ();
	  if (i == 0)
	    set_immediate_dominator (CDI_DOMINATORS, e2->dest, e2->src);
	  m_gsi = gsi_after_labels (e1->dest);
	}
      else
	{
	  if (store_operand)
	    rhs1 = handle_operand (store_operand, idx);
	  else
	    rhs1 = handle_stmt (stmt, idx);
	  if (!useless_type_conversion_p (m_limb_type, TREE_TYPE (rhs1)))
	    rhs1 = add_cast (m_limb_type, rhs1);
	  if (sext && i == cnt - 1)
	    ext = rhs1;
	  tree nidx = idx;
	  if (bo_idx)
	    {
	      if (tree_fits_uhwi_p (idx))
		nidx = size_int (tree_to_uhwi (idx) + bo_idx);
	      else
		{
		  nidx = make_ssa_name (sizetype);
		  g = gimple_build_assign (nidx, PLUS_EXPR, idx,
					   size_int (bo_idx));
		  insert_before (g);
		}
	    }
	  bool done = false;
	  basic_block new_bb = NULL;
	  /* Handle stores into bit-fields.  */
	  if (bo_bit)
	    {
	      if (i == 0)
		{
		  edge e2 = NULL;
		  if (kind != bitint_prec_large)
		    {
		      prepare_data_in_out (build_zero_cst (m_limb_type),
					   idx, &bf_next);
		      bf_next = m_data.pop ();
		      bf_cur = m_data.pop ();
		      g = gimple_build_cond (EQ_EXPR, idx, size_zero_node,
					     NULL_TREE, NULL_TREE);
		      edge edge_true;
		      if_then_else (g, profile_probability::unlikely (),
				    edge_true, e2);
		      new_bb = e2->dest;
		    }
		  tree ftype
		    = build_nonstandard_integer_type (limb_prec - bo_bit, 1);
		  tree bfr = build3 (BIT_FIELD_REF, ftype, unshare_expr (nlhs),
				     bitsize_int (limb_prec - bo_bit),
				     bitsize_int (bo_idx * limb_prec + bo_bit));
		  tree t = add_cast (ftype, rhs1);
		  g = gimple_build_assign (bfr, t);
		  insert_before (g);
		  if (eh)
		    {
		      maybe_duplicate_eh_stmt (g, stmt);
		      if (eh_pad)
			{
			  edge e = split_block (gsi_bb (m_gsi), g);
			  m_gsi = gsi_after_labels (e->dest);
			  make_edge (e->src, eh_pad, EDGE_EH)->probability
			    = profile_probability::very_unlikely ();
			}
		    }
		  if (kind == bitint_prec_large)
		    {
		      bf_cur = rhs1;
		      done = true;
		    }
		  else if (e2)
		    m_gsi = gsi_after_labels (e2->src);
		}
	      if (!done)
		{
		  tree t1 = make_ssa_name (m_limb_type);
		  tree t2 = make_ssa_name (m_limb_type);
		  tree t3 = make_ssa_name (m_limb_type);
		  g = gimple_build_assign (t1, RSHIFT_EXPR, bf_cur,
					   build_int_cst (unsigned_type_node,
							  limb_prec - bo_bit));
		  insert_before (g);
		  g = gimple_build_assign (t2, LSHIFT_EXPR, rhs1,
					   build_int_cst (unsigned_type_node,
							  bo_bit));
		  insert_before (g);
		  bf_cur = rhs1;
		  g = gimple_build_assign (t3, BIT_IOR_EXPR, t1, t2);
		  insert_before (g);
		  rhs1 = t3;
		  if (bf_next && i == 1)
		    {
		      g = gimple_build_assign (bf_next, bf_cur);
		      insert_before (g);
		    }
		}
	    }
	  if (!done)
	    {
	      /* Handle bit-field access to partial last limb if needed.  */
	      if (nlhs
		  && i == cnt - 1
		  && !separate_ext
		  && tree_fits_uhwi_p (idx))
		{
		  unsigned int tprec = TYPE_PRECISION (type);
		  unsigned int rprec = tprec % limb_prec;
		  if (rprec + bo_bit < (unsigned) limb_prec)
		    {
		      tree ftype
			= build_nonstandard_integer_type (rprec + bo_bit, 1);
		      tree bfr = build3 (BIT_FIELD_REF, ftype,
					 unshare_expr (nlhs),
					 bitsize_int (rprec + bo_bit),
					 bitsize_int ((bo_idx
						       + tprec / limb_prec)
						      * limb_prec));
		      tree t = add_cast (ftype, rhs1);
		      g = gimple_build_assign (bfr, t);
		      done = true;
		      bf_cur = NULL_TREE;
		    }
		  else if (rprec + bo_bit == (unsigned) limb_prec)
		    bf_cur = NULL_TREE;
		}
	      /* Otherwise, stores to any other lhs.  */
	      if (!done)
		{
		  tree l = limb_access (lhs_type, nlhs ? nlhs : lhs,
					nidx, true);
		  g = gimple_build_assign (l, rhs1);
		}
	      insert_before (g);
	      if (eh)
		{
		  maybe_duplicate_eh_stmt (g, stmt);
		  if (eh_pad)
		    {
		      edge e = split_block (gsi_bb (m_gsi), g);
		      m_gsi = gsi_after_labels (e->dest);
		      make_edge (e->src, eh_pad, EDGE_EH)->probability
			= profile_probability::very_unlikely ();
		    }
		}
	      if (new_bb)
		m_gsi = gsi_after_labels (new_bb);
	    }
	}
      m_first = false;
      if (kind == bitint_prec_huge && i <= 1)
	{
	  if (i == 0)
	    {
	      idx = make_ssa_name (sizetype);
	      g = gimple_build_assign (idx, PLUS_EXPR, idx_first,
				       size_one_node);
	      insert_before (g);
	    }
	  else
	    {
	      g = gimple_build_assign (idx_next, PLUS_EXPR, idx_first,
				       size_int (2));
	      insert_before (g);
	      g = gimple_build_cond (NE_EXPR, idx_next, size_int (end),
				     NULL_TREE, NULL_TREE);
	      insert_before (g);
	      if (eq_p)
		m_gsi = gsi_after_labels (edge_bb);
	      else
		m_gsi = gsi_for_stmt (stmt);
	    }
	}
    }

  if (separate_ext)
    {
      if (sext)
	{
	  ext = add_cast (signed_type_for (m_limb_type), ext);
	  tree lpm1 = build_int_cst (unsigned_type_node,
				     limb_prec - 1);
	  tree n = make_ssa_name (TREE_TYPE (ext));
	  g = gimple_build_assign (n, RSHIFT_EXPR, ext, lpm1);
	  insert_before (g);
	  ext = add_cast (m_limb_type, n);
	}
      else
	ext = build_zero_cst (m_limb_type);
      kind = bitint_precision_kind (type);
      unsigned start = CEIL (prec, limb_prec);
      prec = TYPE_PRECISION (type);
      idx = idx_first = idx_next = NULL_TREE;
      if (prec <= (start + 2 + (bo_bit != 0)) * limb_prec)
	kind = bitint_prec_large;
      if (kind == bitint_prec_large)
	cnt = CEIL (prec, limb_prec) - start;
      else
	{
	  rem = prec % limb_prec;
	  end = (prec - rem) / limb_prec;
	  cnt = (bo_bit != 0) + 1 + (rem != 0);
	}
      for (unsigned i = 0; i < cnt; i++)
	{
	  if (kind == bitint_prec_large || (i == 0 && bo_bit != 0))
	    idx = size_int (start + i);
	  else if (i == cnt - 1 && (rem != 0))
	    idx = size_int (end);
	  else if (i == (bo_bit != 0))
	    idx = create_loop (size_int (start + i), &idx_next);
	  rhs1 = ext;
	  if (bf_cur != NULL_TREE && bf_cur != ext)
	    {
	      tree t1 = make_ssa_name (m_limb_type);
	      g = gimple_build_assign (t1, RSHIFT_EXPR, bf_cur,
				       build_int_cst (unsigned_type_node,
						      limb_prec - bo_bit));
	      insert_before (g);
	      if (integer_zerop (ext))
		rhs1 = t1;
	      else
		{
		  tree t2 = make_ssa_name (m_limb_type);
		  rhs1 = make_ssa_name (m_limb_type);
		  g = gimple_build_assign (t2, LSHIFT_EXPR, ext,
					   build_int_cst (unsigned_type_node,
							  bo_bit));
		  insert_before (g);
		  g = gimple_build_assign (rhs1, BIT_IOR_EXPR, t1, t2);
		  insert_before (g);
		}
	      bf_cur = ext;
	    }
	  tree nidx = idx;
	  if (bo_idx)
	    {
	      if (tree_fits_uhwi_p (idx))
		nidx = size_int (tree_to_uhwi (idx) + bo_idx);
	      else
		{
		  nidx = make_ssa_name (sizetype);
		  g = gimple_build_assign (nidx, PLUS_EXPR, idx,
					   size_int (bo_idx));
		  insert_before (g);
		}
	    }
	  bool done = false;
	  /* Handle bit-field access to partial last limb if needed.  */
	  if (nlhs && i == cnt - 1)
	    {
	      unsigned int tprec = TYPE_PRECISION (type);
	      unsigned int rprec = tprec % limb_prec;
	      if (rprec + bo_bit < (unsigned) limb_prec)
		{
		  tree ftype
		    = build_nonstandard_integer_type (rprec + bo_bit, 1);
		  tree bfr = build3 (BIT_FIELD_REF, ftype,
				     unshare_expr (nlhs),
				     bitsize_int (rprec + bo_bit),
				     bitsize_int ((bo_idx + tprec / limb_prec)
						  * limb_prec));
		  tree t = add_cast (ftype, rhs1);
		  g = gimple_build_assign (bfr, t);
		  done = true;
		  bf_cur = NULL_TREE;
		}
	      else if (rprec + bo_bit == (unsigned) limb_prec)
		bf_cur = NULL_TREE;
	    }
	  /* Otherwise, stores to any other lhs.  */
	  if (!done)
	    {
	      tree l = limb_access (lhs_type, nlhs ? nlhs : lhs, nidx, true);
	      g = gimple_build_assign (l, rhs1);
	    }
	  insert_before (g);
	  if (eh)
	    {
	      maybe_duplicate_eh_stmt (g, stmt);
	      if (eh_pad)
		{
		  edge e = split_block (gsi_bb (m_gsi), g);
		  m_gsi = gsi_after_labels (e->dest);
		  make_edge (e->src, eh_pad, EDGE_EH)->probability
		    = profile_probability::very_unlikely ();
		}
	    }
	  if (kind == bitint_prec_huge && i == (bo_bit != 0))
	    {
	      g = gimple_build_assign (idx_next, PLUS_EXPR, idx,
				       size_one_node);
	      insert_before (g);
	      g = gimple_build_cond (NE_EXPR, idx_next, size_int (end),
				     NULL_TREE, NULL_TREE);
	      insert_before (g);
	      m_gsi = gsi_for_stmt (stmt);
	    }
	}
    }
  if (bf_cur != NULL_TREE)
    {
      unsigned int tprec = TYPE_PRECISION (type);
      unsigned int rprec = tprec % limb_prec;
      tree ftype = build_nonstandard_integer_type (rprec + bo_bit, 1);
      tree bfr = build3 (BIT_FIELD_REF, ftype, unshare_expr (nlhs),
			 bitsize_int (rprec + bo_bit),
			 bitsize_int ((bo_idx + tprec / limb_prec)
				      * limb_prec));
      rhs1 = bf_cur;
      if (bf_cur != ext)
	{
	  rhs1 = make_ssa_name (TREE_TYPE (rhs1));
	  g = gimple_build_assign (rhs1, RSHIFT_EXPR, bf_cur,
				   build_int_cst (unsigned_type_node,
						  limb_prec - bo_bit));
	  insert_before (g);
	}
      rhs1 = add_cast (ftype, rhs1);
      g = gimple_build_assign (bfr, rhs1);
      insert_before (g);
      if (eh)
	{
	  maybe_duplicate_eh_stmt (g, stmt);
	  if (eh_pad)
	    {
	      edge e = split_block (gsi_bb (m_gsi), g);
	      m_gsi = gsi_after_labels (e->dest);
	      make_edge (e->src, eh_pad, EDGE_EH)->probability
		= profile_probability::very_unlikely ();
	    }
	}
    }

  if (gimple_store_p (stmt))
    {
      unlink_stmt_vdef (stmt);
      release_ssa_name (gimple_vdef (stmt));
      gsi_remove (&m_gsi, true);
    }
  if (eq_p)
    {
      lhs = make_ssa_name (boolean_type_node);
      basic_block bb = gimple_bb (stmt);
      gphi *phi = create_phi_node (lhs, bb);
      edge e = find_edge (gsi_bb (m_gsi), bb);
      unsigned int n = EDGE_COUNT (bb->preds);
      for (unsigned int i = 0; i < n; i++)
	{
	  edge e2 = EDGE_PRED (bb, i);
	  add_phi_arg (phi, e == e2 ? boolean_true_node : boolean_false_node,
		       e2, UNKNOWN_LOCATION);
	}
      cmp_code = cmp_code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
      return lhs;
    }
  else
    return NULL_TREE;
}

/* Handle a large/huge _BitInt comparison statement STMT other than
   EQ_EXPR/NE_EXPR.  CMP_CODE, CMP_OP1 and CMP_OP2 meaning is like in
   lower_mergeable_stmt.  The {GT,GE,LT,LE}_EXPR comparisons are
   lowered by iteration from the most significant limb downwards to
   the least significant one, for large _BitInt in straight line code,
   otherwise with most significant limb handled in
   straight line code followed by a loop handling one limb at a time.
   Comparisons with unsigned huge _BitInt with precisions which are
   multiples of limb precision can use just the loop and don't need to
   handle most significant limb before the loop.  The loop or straight
   line code jumps to final basic block if a particular pair of limbs
   is not equal.  */

tree
bitint_large_huge::lower_comparison_stmt (gimple *stmt, tree_code &cmp_code,
					  tree cmp_op1, tree cmp_op2)
{
  tree type = TREE_TYPE (cmp_op1);
  gcc_assert (TREE_CODE (type) == BITINT_TYPE);
  bitint_prec_kind kind = bitint_precision_kind (type);
  gcc_assert (kind >= bitint_prec_large);
  gimple *g;
  if (!TYPE_UNSIGNED (type)
      && integer_zerop (cmp_op2)
      && (cmp_code == GE_EXPR || cmp_code == LT_EXPR))
    {
      unsigned end = CEIL ((unsigned) TYPE_PRECISION (type), limb_prec) - 1;
      tree idx = size_int (end);
      m_data_cnt = 0;
      tree rhs1 = handle_operand (cmp_op1, idx);
      if (TYPE_UNSIGNED (TREE_TYPE (rhs1)))
	{
	  tree stype = signed_type_for (TREE_TYPE (rhs1));
	  rhs1 = add_cast (stype, rhs1);
	}
      tree lhs = make_ssa_name (boolean_type_node);
      g = gimple_build_assign (lhs, cmp_code, rhs1,
			       build_zero_cst (TREE_TYPE (rhs1)));
      insert_before (g);
      cmp_code = NE_EXPR;
      return lhs;
    }

  unsigned cnt, rem = 0, end = 0;
  tree idx = NULL_TREE, idx_next = NULL_TREE;
  if (kind == bitint_prec_large)
    cnt = CEIL ((unsigned) TYPE_PRECISION (type), limb_prec);
  else
    {
      rem = ((unsigned) TYPE_PRECISION (type) % limb_prec);
      if (rem == 0 && !TYPE_UNSIGNED (type))
	rem = limb_prec;
      end = ((unsigned) TYPE_PRECISION (type) - rem) / limb_prec;
      cnt = 1 + (rem != 0);
    }

  basic_block edge_bb = NULL;
  gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
  gsi_prev (&gsi);
  edge e = split_block (gsi_bb (gsi), gsi_stmt (gsi));
  edge_bb = e->src;
  m_gsi = gsi_end_bb (edge_bb);

  edge *edges = XALLOCAVEC (edge, cnt * 2);
  for (unsigned i = 0; i < cnt; i++)
    {
      m_data_cnt = 0;
      if (kind == bitint_prec_large)
	idx = size_int (cnt - i - 1);
      else if (i == cnt - 1)
	idx = create_loop (size_int (end - 1), &idx_next);
      else
	idx = size_int (end);
      tree rhs1 = handle_operand (cmp_op1, idx);
      tree rhs2 = handle_operand (cmp_op2, idx);
      if (i == 0
	  && !TYPE_UNSIGNED (type)
	  && TYPE_UNSIGNED (TREE_TYPE (rhs1)))
	{
	  tree stype = signed_type_for (TREE_TYPE (rhs1));
	  rhs1 = add_cast (stype, rhs1);
	  rhs2 = add_cast (stype, rhs2);
	}
      g = gimple_build_cond (GT_EXPR, rhs1, rhs2, NULL_TREE, NULL_TREE);
      insert_before (g);
      edge e1 = split_block (gsi_bb (m_gsi), g);
      e1->flags = EDGE_FALSE_VALUE;
      edge e2 = make_edge (e1->src, gimple_bb (stmt), EDGE_TRUE_VALUE);
      e1->probability = profile_probability::likely ();
      e2->probability = e1->probability.invert ();
      if (i == 0)
	set_immediate_dominator (CDI_DOMINATORS, e2->dest, e2->src);
      m_gsi = gsi_after_labels (e1->dest);
      edges[2 * i] = e2;
      g = gimple_build_cond (LT_EXPR, rhs1, rhs2, NULL_TREE, NULL_TREE);
      insert_before (g);
      e1 = split_block (gsi_bb (m_gsi), g);
      e1->flags = EDGE_FALSE_VALUE;
      e2 = make_edge (e1->src, gimple_bb (stmt), EDGE_TRUE_VALUE);
      e1->probability = profile_probability::unlikely ();
      e2->probability = e1->probability.invert ();
      m_gsi = gsi_after_labels (e1->dest);
      edges[2 * i + 1] = e2;
      m_first = false;
      if (kind == bitint_prec_huge && i == cnt - 1)
	{
	  g = gimple_build_assign (idx_next, PLUS_EXPR, idx, size_int (-1));
	  insert_before (g);
	  g = gimple_build_cond (NE_EXPR, idx, size_zero_node,
				 NULL_TREE, NULL_TREE);
	  insert_before (g);
	  edge true_edge, false_edge;
	  extract_true_false_edges_from_block (gsi_bb (m_gsi),
					       &true_edge, &false_edge);
	  m_gsi = gsi_after_labels (false_edge->dest);
	}
    }

  tree lhs = make_ssa_name (boolean_type_node);
  basic_block bb = gimple_bb (stmt);
  gphi *phi = create_phi_node (lhs, bb);
  for (unsigned int i = 0; i < cnt * 2; i++)
    {
      tree val = ((cmp_code == GT_EXPR || cmp_code == GE_EXPR)
		  ^ (i & 1)) ? boolean_true_node : boolean_false_node;
      add_phi_arg (phi, val, edges[i], UNKNOWN_LOCATION);
    }
  add_phi_arg (phi, (cmp_code == GE_EXPR || cmp_code == LE_EXPR)
		    ? boolean_true_node : boolean_false_node,
	       find_edge (gsi_bb (m_gsi), bb), UNKNOWN_LOCATION);
  cmp_code = NE_EXPR;
  return lhs;
}

/* Lower large/huge _BitInt left and right shift except for left
   shift by < limb_prec constant.  */

void
bitint_large_huge::lower_shift_stmt (tree o