* cfgloop.h (struct loop_desc): Removed.

	(struct loop): Fields simple, desc and has_desc removed.
	(simple_loop_p, count_loop_iterations): Declaration removed.
	* cfgloopanal.c (struct unmark_altered_insn_data): Removed.
	(unmark_altered, blocks_invariant_registers, unmark_altered_insn
	blocks_single_set_registers, invariant_rtx_wrto_regs_p_helper,
	invariant_rtx_wrto_regs_p, test_for_iteration, constant_iterations,
	simple_loop_exit_p, variable_initial_value, variable_initial_values,
	simple_condition_p, simple_increment, count_strange_loop_iterations,
	inverse, fits_in_mode_p, simple_loop_p, count_loop_iterations):
	Removed.
	* loop-iv.c (check_simple_exit, find_simple_exit): Update comments.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@78777 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 20 insertions, 1098 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7cd729097c0..31cafc8e44b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2004-03-02  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
+
+	* cfgloop.h (struct loop_desc): Removed.
+	(struct loop): Fields simple, desc and has_desc removed.
+	(simple_loop_p, count_loop_iterations): Declaration removed.
+	* cfgloopanal.c (struct unmark_altered_insn_data): Removed.
+	(unmark_altered, blocks_invariant_registers, unmark_altered_insn
+	blocks_single_set_registers, invariant_rtx_wrto_regs_p_helper,
+	invariant_rtx_wrto_regs_p, test_for_iteration, constant_iterations,
+	simple_loop_exit_p, variable_initial_value, variable_initial_values,
+	simple_condition_p, simple_increment, count_strange_loop_iterations,
+	inverse, fits_in_mode_p, simple_loop_p, count_loop_iterations):
+	Removed.
+	* loop-iv.c (check_simple_exit, find_simple_exit): Update comments.
+
 2004-03-02  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* genattrtab.c: Don't handle MATCH_INSN.
diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
index 4226592a750..8a24c15f271 100644
--- a/gcc/cfgloop.h
+++ b/gcc/cfgloop.h
@@ -36,29 +36,6 @@ struct lpt_decision
   unsigned times;
 };
 
-/* Description of loop for simple loop unrolling.  */
-struct loop_desc
-{
-  int postincr;		/* 1 if increment/decrement is done after loop exit condition.  */
-  rtx stride;		/* Value added to VAR in each iteration.  */
-  rtx var;		/* Loop control variable.  */
-  enum machine_mode inner_mode;
-			/* The mode from that it is extended.  */
-  enum rtx_code extend;	/* With this extend.  */
-  rtx var_alts;		/* List of definitions of its initial value.  */
-  rtx lim;		/* Expression var is compared with.  */
-  rtx lim_alts;		/* List of definitions of its initial value.  */
-  bool const_iter;      /* True if it iterates constant number of times.  */
-  unsigned HOST_WIDE_INT niter;
-			/* Number of iterations if it is constant.  */
-  bool may_be_zero;     /* If we cannot determine that the first iteration will pass.  */
-  enum rtx_code cond;	/* Exit condition.  */
-  int neg;		/* Set to 1 if loop ends when condition is satisfied.  */
-  edge out_edge;	/* The exit edge.  */
-  edge in_edge;		/* And the other one.  */
-  int n_branches;	/* Number of branches inside the loop.  */
-};
-
 /* Structure to hold information for each natural loop.  */
 struct loop
 {
@@ -77,11 +54,6 @@ struct loop
   /* For loop unrolling/peeling decision.  */
   struct lpt_decision lpt_decision;
 
-  /* Simple loop description.  */
-  int simple;
-  struct loop_desc desc;
-  int has_desc;
-
   /* Number of loop insns.  */
   unsigned ninsns;
 
@@ -305,8 +277,6 @@ extern void force_single_succ_latches (struct loops *);
 extern void verify_loop_structure (struct loops *);
 
 /* Loop analysis.  */
-extern bool simple_loop_p (struct loop *, struct loop_desc *);
-extern rtx count_loop_iterations (struct loop_desc *, rtx, rtx);
 extern bool just_once_each_iteration_p (struct loop *, basic_block);
 extern unsigned expected_loop_iterations (const struct loop *);
 
@@ -370,8 +340,8 @@ struct rtx_iv
   unsigned first_special : 1;
 };
 
-/* This should replace struct loop_desc.  We keep this just so that we are
-   able to compare the results.  */
+/* The description of an exit from the loop and of the number of iterations
+   till we take the exit.  */
 
 struct niter_desc
 {
diff --git a/gcc/cfgloopanal.c b/gcc/cfgloopanal.c
index 6ca4cb454c1..9b3ffa0c8ae 100644
--- a/gcc/cfgloopanal.c
+++ b/gcc/cfgloopanal.c
@@ -29,48 +29,8 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "expr.h"
 #include "output.h"
 
-struct unmark_altered_insn_data;
-static void unmark_altered (rtx, rtx, regset);
-static void blocks_invariant_registers (basic_block *, int, regset);
-static void unmark_altered_insn (rtx, rtx, struct unmark_altered_insn_data *);
-static void blocks_single_set_registers (basic_block *, int, rtx *);
-static int invariant_rtx_wrto_regs_p_helper (rtx *, regset);
-static bool invariant_rtx_wrto_regs_p (rtx, regset);
-static rtx test_for_iteration (struct loop_desc *desc, unsigned HOST_WIDE_INT);
-static bool constant_iterations (struct loop_desc *, unsigned HOST_WIDE_INT *,
-				 bool *);
-static bool simple_loop_exit_p (struct loop *, edge, regset,
-				rtx *, struct loop_desc *);
-static rtx variable_initial_value (rtx, regset, rtx, rtx *, enum machine_mode);
-static rtx variable_initial_values (edge, rtx, enum machine_mode);
-static bool simple_condition_p (struct loop *, rtx, regset,
-				struct loop_desc *);
-static basic_block simple_increment (struct loop *, rtx *, struct loop_desc *);
-static rtx count_strange_loop_iterations (rtx, rtx, enum rtx_code,
-					  int, rtx, enum machine_mode,
-					  enum machine_mode);
-static unsigned HOST_WIDEST_INT inverse (unsigned HOST_WIDEST_INT, int);
-static bool fits_in_mode_p (enum machine_mode mode, rtx expr);
-
-/* Computes inverse to X modulo (1 << MOD).  */
-static unsigned HOST_WIDEST_INT
-inverse (unsigned HOST_WIDEST_INT x, int mod)
-{
-  unsigned HOST_WIDEST_INT mask =
-	  ((unsigned HOST_WIDEST_INT) 1 << (mod - 1) << 1) - 1;
-  unsigned HOST_WIDEST_INT rslt = 1;
-  int i;
-
-  for (i = 0; i < mod - 1; i++)
-    {
-      rslt = (rslt * x) & mask;
-      x = (x * x) & mask;
-    }
-
-  return rslt;
-}
-
 /* Checks whether BB is executed exactly once in each LOOP iteration.  */
+
 bool
 just_once_each_iteration_p (struct loop *loop, basic_block bb)
 {
@@ -89,1028 +49,6 @@ just_once_each_iteration_p (struct loop *loop, basic_block bb)
   return true;
 }
 
-
-/* Unmarks modified registers; helper to blocks_invariant_registers.  */
-static void
-unmark_altered (rtx what, rtx by ATTRIBUTE_UNUSED, regset regs)
-{
-  if (GET_CODE (what) == SUBREG)
-    what = SUBREG_REG (what);
-  if (!REG_P (what))
-    return;
-  CLEAR_REGNO_REG_SET (regs, REGNO (what));
-}
-
-/* Marks registers that are invariant inside blocks BBS.  */
-static void
-blocks_invariant_registers (basic_block *bbs, int nbbs, regset regs)
-{
-  rtx insn;
-  int i;
-
-  for (i = 0; i < max_reg_num (); i++)
-    SET_REGNO_REG_SET (regs, i);
-  for (i = 0; i < nbbs; i++)
-    for (insn = BB_HEAD (bbs[i]);
-	 insn != NEXT_INSN (BB_END (bbs[i]));
-	 insn = NEXT_INSN (insn))
-      if (INSN_P (insn))
-	note_stores (PATTERN (insn),
-		     (void (*) (rtx, rtx, void *)) unmark_altered,
-		     regs);
-}
-
-/* Unmarks modified registers; helper to blocks_single_set_registers.  */
-struct unmark_altered_insn_data
-{
-  rtx *regs;
-  rtx insn;
-};
-
-static void
-unmark_altered_insn (rtx what, rtx by ATTRIBUTE_UNUSED,
-		     struct unmark_altered_insn_data *data)
-{
-  int rn;
-
-  if (GET_CODE (what) == SUBREG)
-    what = SUBREG_REG (what);
-  if (!REG_P (what))
-    return;
-  rn = REGNO (what);
-  if (data->regs[rn] == data->insn)
-    return;
-  data->regs[rn] = NULL;
-}
-
-/* Marks registers that have just single simple set in BBS; the relevant
-   insn is returned in REGS.  */
-static void
-blocks_single_set_registers (basic_block *bbs, int nbbs, rtx *regs)
-{
-  rtx insn;
-  int i;
-  struct unmark_altered_insn_data data;
-
-  for (i = 0; i < max_reg_num (); i++)
-    regs[i] = NULL;
-
-  for (i = 0; i < nbbs; i++)
-    for (insn = BB_HEAD (bbs[i]);
-	 insn != NEXT_INSN (BB_END (bbs[i]));
-	 insn = NEXT_INSN (insn))
-      {
-	rtx set = single_set (insn);
-	if (!set)
-	  continue;
-	if (!REG_P (SET_DEST (set)))
-	  continue;
-	regs[REGNO (SET_DEST (set))] = insn;
-      }
-
-  data.regs = regs;
-  for (i = 0; i < nbbs; i++)
-    for (insn = BB_HEAD (bbs[i]);
-	 insn != NEXT_INSN (BB_END (bbs[i]));
-	 insn = NEXT_INSN (insn))
-      {
-        if (!INSN_P (insn))
-	  continue;
-	data.insn = insn;
-	note_stores (PATTERN (insn),
-	    (void (*) (rtx, rtx, void *)) unmark_altered_insn,
-	    &data);
-      }
-}
-
-/* Helper for invariant_rtx_wrto_regs_p.  */
-static int
-invariant_rtx_wrto_regs_p_helper (rtx *expr, regset invariant_regs)
-{
-  switch (GET_CODE (*expr))
-    {
-    case CC0:
-    case PC:
-    case UNSPEC_VOLATILE:
-      return 1;
-
-    case CONST_INT:
-    case CONST_DOUBLE:
-    case CONST:
-    case SYMBOL_REF:
-    case LABEL_REF:
-      return 0;
-
-    case ASM_OPERANDS:
-      return MEM_VOLATILE_P (*expr);
-
-    case MEM:
-      /* If the memory is not constant, assume it is modified.  If it is
-	 constant, we still have to check the address.  */
-      return !RTX_UNCHANGING_P (*expr);
-
-    case REG:
-      return !REGNO_REG_SET_P (invariant_regs, REGNO (*expr));
-
-    default:
-      return 0;
-    }
-}
-
-/* Checks that EXPR is invariant provided that INVARIANT_REGS are invariant.  */
-static bool
-invariant_rtx_wrto_regs_p (rtx expr, regset invariant_regs)
-{
-  return !for_each_rtx (&expr, (rtx_function) invariant_rtx_wrto_regs_p_helper,
-			invariant_regs);
-}
-
-/* Checks whether CONDITION is a simple comparison in that one of operands
-   is register and the other one is invariant in the LOOP. Fills var, lim
-   and cond fields in DESC.  */
-static bool
-simple_condition_p (struct loop *loop ATTRIBUTE_UNUSED, rtx condition,
-		    regset invariant_regs, struct loop_desc *desc)
-{
-  rtx op0, op1;
-
-  /* Check condition.  */
-  switch (GET_CODE (condition))
-    {
-      case EQ:
-      case NE:
-      case LE:
-      case LT:
-      case GE:
-      case GT:
-      case GEU:
-      case GTU:
-      case LEU:
-      case LTU:
-	break;
-      default:
-	return false;
-    }
-
-  /* Of integers or pointers.  */
-  if (GET_MODE_CLASS (GET_MODE (XEXP (condition, 0))) != MODE_INT
-      && GET_MODE_CLASS (GET_MODE (XEXP (condition, 0))) != MODE_PARTIAL_INT)
-    return false;
-
-  /* One of operands must be a simple register.  */
-  op0 = XEXP (condition, 0);
-  op1 = XEXP (condition, 1);
-
-  /* One of operands must be invariant.  */
-  if (invariant_rtx_wrto_regs_p (op0, invariant_regs))
-    {
-      /* And the other one must be a register.  */
-      if (!REG_P (op1))
-	return false;
-      desc->var = op1;
-      desc->lim = op0;
-
-      desc->cond = swap_condition (GET_CODE (condition));
-      if (desc->cond == UNKNOWN)
-	return false;
-      return true;
-    }
-
-  /* Check the other operand.  */
-  if (!invariant_rtx_wrto_regs_p (op1, invariant_regs))
-    return false;
-  if (!REG_P (op0))
-    return false;
-
-  desc->var = op0;
-  desc->lim = op1;
-
-  desc->cond = GET_CODE (condition);
-
-  return true;
-}
-
-/* Checks whether DESC->var is incremented/decremented exactly once each
-   iteration.  Fills in DESC->stride and returns block in that DESC->var is
-   modified.  */
-static basic_block
-simple_increment (struct loop *loop, rtx *simple_increment_regs,
-		  struct loop_desc *desc)
-{
-  rtx mod_insn, mod_insn1, set, set_src, set_add;
-  basic_block mod_bb, mod_bb1;
-
-  /* Find insn that modifies var.  */
-  mod_insn = simple_increment_regs[REGNO (desc->var)];
-  if (!mod_insn)
-    return NULL;
-  mod_bb = BLOCK_FOR_INSN (mod_insn);
-
-  /* Check that it is executed exactly once each iteration.  */
-  if (!just_once_each_iteration_p (loop, mod_bb))
-    return NULL;
-
-  /* mod_insn must be a simple increment/decrement.  */
-  set = single_set (mod_insn);
-  if (!set)
-    abort ();
-  if (!rtx_equal_p (SET_DEST (set), desc->var))
-    abort ();
-
-  set_src = find_reg_equal_equiv_note (mod_insn);
-  if (!set_src)
-    set_src = SET_SRC (set);
-
-  /* Check for variables that iterate in narrower mode.  */
-  if (GET_CODE (set_src) == SIGN_EXTEND
-      || GET_CODE (set_src) == ZERO_EXTEND)
-    {
-      /* If we are sign extending variable that is then compared unsigned
-	 or vice versa, there is something weird happening.  */
-      if (desc->cond != EQ
-	  && desc->cond != NE
-	  && ((desc->cond == LEU
-	       || desc->cond == LTU
-	       || desc->cond == GEU
-	       || desc->cond == GTU)
-	      ^ (GET_CODE (set_src) == ZERO_EXTEND)))
-	return NULL;
-
-      if (GET_CODE (XEXP (set_src, 0)) != SUBREG
-	  || SUBREG_BYTE (XEXP (set_src, 0)) != 0
-	  || GET_MODE (SUBREG_REG (XEXP (set_src, 0))) != GET_MODE (desc->var))
-	return NULL;
-
-      desc->inner_mode = GET_MODE (XEXP (set_src, 0));
-      desc->extend = GET_CODE (set_src);
-      set_src = SUBREG_REG (XEXP (set_src, 0));
-
-      if (GET_CODE (set_src) != REG)
-	return NULL;
-
-      /* Find where the reg is set.  */
-      mod_insn1 = simple_increment_regs[REGNO (set_src)];
-      if (!mod_insn1)
-	return NULL;
-
-      mod_bb1 = BLOCK_FOR_INSN (mod_insn1);
-      if (!dominated_by_p (CDI_DOMINATORS, mod_bb, mod_bb1))
-	return NULL;
-      if (mod_bb1 == mod_bb)
-	{
-	  for (;
-	       mod_insn != PREV_INSN (BB_HEAD (mod_bb));
-	       mod_insn = PREV_INSN (mod_insn))
-	    if (mod_insn == mod_insn1)
-	      break;
-
-	  if (mod_insn == PREV_INSN (BB_HEAD (mod_bb)))
-	    return NULL;
-	}
-
-      /* Replace the source with the possible place of increment.  */
-      set = single_set (mod_insn1);
-      if (!set)
-	abort ();
-      if (!rtx_equal_p (SET_DEST (set), set_src))
-	abort ();
-
-      set_src = find_reg_equal_equiv_note (mod_insn1);
-      if (!set_src)
-	set_src = SET_SRC (set);
-    }
-  else
-    {
-      desc->inner_mode = GET_MODE (desc->var);
-      desc->extend = NIL;
-    }
-
-  if (GET_CODE (set_src) != PLUS)
-    return NULL;
-  if (!rtx_equal_p (XEXP (set_src, 0), desc->var))
-    return NULL;
-
-  /* Set desc->stride.  */
-  set_add = XEXP (set_src, 1);
-  if (CONSTANT_P (set_add))
-    desc->stride = set_add;
-  else
-    return NULL;
-
-  return mod_bb;
-}
-
-/* Tries to find initial value of VAR in INSN.  This value must be invariant
-   wrto INVARIANT_REGS.  If SET_INSN is not NULL, insn in that var is set is
-   placed here.  INNER_MODE is mode in that induction variable VAR iterates.  */
-static rtx
-variable_initial_value (rtx insn, regset invariant_regs,
-			rtx var, rtx *set_insn, enum machine_mode inner_mode)
-{
-  basic_block bb;
-  rtx set;
-  rtx ret = NULL;
-
-  /* Go back through cfg.  */
-  bb = BLOCK_FOR_INSN (insn);
-  while (1)
-    {
-      for (; insn != BB_HEAD (bb); insn = PREV_INSN (insn))
-	{
-	  if (INSN_P (insn))
-	    note_stores (PATTERN (insn),
-		(void (*) (rtx, rtx, void *)) unmark_altered,
-		invariant_regs);
-	  if (modified_between_p (var, PREV_INSN (insn), NEXT_INSN (insn)))
-	    break;
-	}
-
-      if (insn != BB_HEAD (bb))
-	{
-	  /* We found place where var is set.  */
-	  rtx set_dest;
-	  rtx val;
-	  rtx note;
-
-	  set = single_set (insn);
-	  if (!set)
-	    return NULL;
-	  set_dest = SET_DEST (set);
-	  if (!rtx_equal_p (set_dest, var))
-	    return NULL;
-
-	  note = find_reg_equal_equiv_note (insn);
-	  if (note && GET_CODE (XEXP (note, 0)) != EXPR_LIST)
-	    val = XEXP (note, 0);
-	  else
-	    val = SET_SRC (set);
-
-	  /* If we know that the initial value is indeed in range of
-	     the inner mode, record the fact even in case the value itself
-	     is useless.  */
-	  if ((GET_CODE (val) == SIGN_EXTEND
-	       || GET_CODE (val) == ZERO_EXTEND)
-	      && GET_MODE (XEXP (val, 0)) == inner_mode)
-	    ret = gen_rtx_fmt_e (GET_CODE (val),
-				 GET_MODE (var),
-				 gen_rtx_fmt_ei (SUBREG,
-						 inner_mode,
-						 var, 0));
-
-	  if (!invariant_rtx_wrto_regs_p (val, invariant_regs))
-	    return ret;
-
-	  if (set_insn)
-	    *set_insn = insn;
-	  return val;
-	}
-
-
-      if (bb->pred->pred_next || bb->pred->src == ENTRY_BLOCK_PTR)
-	return NULL;
-
-      bb = bb->pred->src;
-      insn = BB_END (bb);
-    }
-
-  return NULL;
-}
-
-/* Returns list of definitions of initial value of VAR at edge E.  INNER_MODE
-   is mode in that induction variable VAR really iterates.  */
-static rtx
-variable_initial_values (edge e, rtx var, enum machine_mode inner_mode)
-{
-  rtx set_insn, list;
-  regset invariant_regs;
-  regset_head invariant_regs_head;
-  int i;
-
-  invariant_regs = INITIALIZE_REG_SET (invariant_regs_head);
-  for (i = 0; i < max_reg_num (); i++)
-    SET_REGNO_REG_SET (invariant_regs, i);
-
-  list = alloc_EXPR_LIST (0, copy_rtx (var), NULL);
-
-  if (e->src == ENTRY_BLOCK_PTR)
-    return list;
-
-  set_insn = BB_END (e->src);
-  while (REG_P (var)
-	 && (var = variable_initial_value (set_insn, invariant_regs, var,
-					   &set_insn, inner_mode)))
-    list = alloc_EXPR_LIST (0, copy_rtx (var), list);
-
-  FREE_REG_SET (invariant_regs);
-  return list;
-}
-
-/* Counts constant number of iterations of the loop described by DESC;
-   returns false if impossible.  */
-static bool
-constant_iterations (struct loop_desc *desc, unsigned HOST_WIDE_INT *niter,
-		     bool *may_be_zero)
-{
-  rtx test, expr;
-  rtx ainit, alim;
-
-  test = test_for_iteration (desc, 0);
-  if (test == const0_rtx)
-    {
-      *niter = 0;
-      *may_be_zero = false;
-      return true;
-    }
-
-  *may_be_zero = (test != const_true_rtx);
-
-  /* It would make a little sense to check every with every when we
-     know that all but the first alternative are simply registers.  */
-  for (ainit = desc->var_alts; ainit; ainit = XEXP (ainit, 1))
-    {
-      alim = XEXP (desc->lim_alts, 0);
-      if (!(expr = count_loop_iterations (desc, XEXP (ainit, 0), alim)))
-	continue;
-      if (GET_CODE (expr) == CONST_INT)
-	{
-	  *niter = INTVAL (expr);
-	  return true;
-	}
-    }
-  for (alim = XEXP (desc->lim_alts, 1); alim; alim = XEXP (alim, 1))
-    {
-      ainit = XEXP (desc->var_alts, 0);
-      if (!(expr = count_loop_iterations (desc, ainit, XEXP (alim, 0))))
-	continue;
-      if (GET_CODE (expr) == CONST_INT)
-	{
-	  *niter = INTVAL (expr);
-	  return true;
-	}
-    }
-
-  return false;
-}
-
-/* Attempts to determine a number of iterations of a "strange" loop.
-   Its induction variable starts with value INIT, is compared by COND
-   with LIM.  If POSTINCR, it is incremented after the test.  It is incremented
-   by STRIDE each iteration, has mode MODE but iterates in INNER_MODE.
-
-   By "strange" we mean loops where induction variable increases in the wrong
-   direction wrto comparison, i.e. for (i = 6; i > 5; i++).  */
-static rtx
-count_strange_loop_iterations (rtx init, rtx lim, enum rtx_code cond,
-			       int postincr, rtx stride, enum machine_mode mode,
-			       enum machine_mode inner_mode)
-{
-  rtx rqmt, n_to_wrap, before_wrap, after_wrap;
-  rtx mode_min, mode_max;
-  int size;
-
-  /* This could be handled, but it is not important enough to lose time with
-     it just now.  */
-  if (mode != inner_mode)
-    return NULL_RTX;
-
-  if (!postincr)
-    init = simplify_gen_binary (PLUS, mode, init, stride);
-
-  /* If we are able to prove that we don't pass the first test, we are
-     done.  */
-  rqmt = simplify_relational_operation (cond, mode, init, lim);
-  if (rqmt == const0_rtx)
-    return const0_rtx;
-
-  /* And if we don't know we pass it, the things are too complicated for us.  */
-  if (rqmt != const_true_rtx)
-    return NULL_RTX;
-
-  switch (cond)
-    {
-    case GE:
-    case GT:
-    case LE:
-    case LT:
-      size = GET_MODE_BITSIZE (mode);
-      mode_min = GEN_INT (-((unsigned HOST_WIDEST_INT) 1 << (size - 1)));
-      mode_max = GEN_INT (((unsigned HOST_WIDEST_INT) 1 << (size - 1)) - 1);
-			      
-      break;
-
-    case GEU:
-    case GTU:
-    case LEU:
-    case LTU:
-    case EQ:
-      mode_min = const0_rtx;
-      mode_max = simplify_gen_binary (MINUS, mode, const0_rtx, const1_rtx);
-      break;
-
-    default:
-      abort ();
-    }
-
-  switch (cond)
-    {
-    case EQ:
-      /* This iterates once, as init == lim.  */
-      return const1_rtx;
-
-      /* The behavior is undefined in signed cases.  Never mind, we still
-	 try to behave sanely.  */
-    case GE:
-    case GT:
-    case GEU:
-    case GTU:
-      if (INTVAL (stride) <= 0)
-	abort ();
-      n_to_wrap = simplify_gen_binary (MINUS, mode, mode_max, copy_rtx (init));
-      n_to_wrap = simplify_gen_binary (UDIV, mode, n_to_wrap, stride);
-      before_wrap = simplify_gen_binary (MULT, mode,
-					 copy_rtx (n_to_wrap), stride);
-      before_wrap = simplify_gen_binary (PLUS, mode,
-					 before_wrap, copy_rtx (init));
-      after_wrap = simplify_gen_binary (PLUS, mode,
-					before_wrap, stride);
-      if (GET_CODE (after_wrap) != CONST_INT)
-	{
-	  after_wrap = simplify_gen_binary (PLUS, mode, mode_min, stride);
-	  after_wrap = simplify_gen_binary (MINUS, mode, after_wrap, const1_rtx);
-	}
-      break;
-
-    case LE:
-    case LT:
-    case LEU:
-    case LTU:
-      if (INTVAL (stride) >= 0)
-	abort ();
-      stride = simplify_gen_unary (NEG, mode, stride, mode);
-      n_to_wrap = simplify_gen_binary (MINUS, mode, copy_rtx (init), mode_min);
-      n_to_wrap = simplify_gen_binary (UDIV, mode, n_to_wrap, stride);
-      before_wrap = simplify_gen_binary (MULT, mode,
-					 copy_rtx (n_to_wrap), stride);
-      before_wrap = simplify_gen_binary (MINUS, mode,
-					 copy_rtx (init), before_wrap);
-      after_wrap = simplify_gen_binary (MINUS, mode,
-					before_wrap, stride);
-      if (GET_CODE (after_wrap) != CONST_INT)
-	{
-	  after_wrap = simplify_gen_binary (MINUS, mode, mode_max, stride);
-	  after_wrap = simplify_gen_binary (PLUS, mode, after_wrap, const1_rtx);
-	}
-      break;
-    default:
-      abort ();
-    }
-
-  /* If this is const_true_rtx and we did not take a conservative approximation
-     of after_wrap above, we might iterate the calculation (but of course we
-     would have to take care about infinite cases).  Ignore this for now.  */
-  rqmt = simplify_relational_operation (cond, mode, after_wrap, lim);
-  if (rqmt != const0_rtx)
-    return NULL_RTX;
-
-  return simplify_gen_binary (PLUS, mode, n_to_wrap, const1_rtx);
-}
-
-/* Checks whether value of EXPR fits into range of MODE.  */
-static bool
-fits_in_mode_p (enum machine_mode mode, rtx expr)
-{
-  unsigned HOST_WIDEST_INT val;
-  int n_bits = 0;
-
-  if (GET_CODE (expr) == CONST_INT)
-    {
-      for (val = INTVAL (expr); val; val >>= 1)
-	n_bits++;
-
-      return n_bits <= GET_MODE_BITSIZE (mode);
-    }
-
-  if (GET_CODE (expr) == SIGN_EXTEND
-      || GET_CODE (expr) == ZERO_EXTEND)
-    return GET_MODE (XEXP (expr, 0)) == mode;
-
-  return false;
-}
-
-/* Return RTX expression representing number of iterations of loop as bounded
-   by test described by DESC (in the case loop really has multiple exit
-   edges, fewer iterations may happen in the practice).
-
-   Return NULL if it is unknown.  Additionally the value may be invalid for
-   paradoxical loop (lets define paradoxical loops as loops whose test is
-   failing at -1th iteration, for instance "for (i=5;i<1;i++);").
-
-   These cases needs to be either cared by copying the loop test in the front
-   of loop or keeping the test in first iteration of loop.
-
-   When INIT/LIM are set, they are used instead of var/lim of DESC.  */
-rtx
-count_loop_iterations (struct loop_desc *desc, rtx init, rtx lim)
-{
-  enum rtx_code cond = desc->cond;
-  rtx stride = desc->stride;
-  rtx mod, exp, ainit, bound;
-  rtx overflow_check, mx, mxp;
-  enum machine_mode mode = GET_MODE (desc->var);
-  unsigned HOST_WIDEST_INT s, size, d;
-
-  /* Give up on floating point modes and friends.  It can be possible to do
-     the job for constant loop bounds, but it is probably not worthwhile.  */
-  if (!INTEGRAL_MODE_P (mode))
-    return NULL;
-
-  init = copy_rtx (init ? init : desc->var);
-  lim = copy_rtx (lim ? lim : desc->lim);
-
-  /* Ensure that we always handle the condition to stay inside loop.  */
-  if (desc->neg)
-    cond = reverse_condition (cond);
-
-  if (desc->inner_mode != mode)
-    {
-      /* We have a case when the variable in fact iterates in the narrower
-	 mode.  This has following consequences:
-	 
-	 For induction variable itself, if !desc->postincr, it does not mean
-	 anything too special, since we know the variable is already in range
-	 of the inner mode when we compare it (so it is just needed to shorten
-	 it into the mode before calculations are done, so that we don't risk
-	 wrong results).  More complicated case is when desc->postincr; then
-	 the first two iterations are special (the first one because the value
-	 may be out of range, the second one because after shortening it to the
-	 range it may have absolutely any value), and we do not handle this in
-	 unrolling.  So if we aren't able to prove that the initial value is in
-	 the range, we fail in this case.
-	 
-	 Step is just moduled to fit into inner mode.
-
-	 If lim is out of range, then either the loop is infinite (and then
-	 we may unroll however we like to), or exits in the first iteration
-	 (this is also ok, since we handle it specially for this case anyway).
-	 So we may safely assume that it fits into the inner mode.  */
-
-      for (ainit = desc->var_alts; ainit; ainit = XEXP (ainit, 1))
-	if (fits_in_mode_p (desc->inner_mode, XEXP (ainit, 0)))
-	  break;
-
-      if (!ainit)
-	{
-	  if (desc->postincr)
-	    return NULL_RTX;
-
-	  init = simplify_gen_unary (desc->extend,
-				     mode,
-				     simplify_gen_subreg (desc->inner_mode,
-							  init,
-							  mode,
-							  0),
-				     desc->inner_mode);
-	}
-
-      stride = simplify_gen_subreg (desc->inner_mode, stride, mode, 0);
-      if (stride == const0_rtx)
-	return NULL_RTX;
-    }
-
-  /* Prepare condition to verify that we do not risk overflow.  */
-  if (stride == const1_rtx
-      || stride == constm1_rtx
-      || cond == NE
-      || cond == EQ)
-    {
-      /* Overflow at NE conditions does not occur.  EQ condition
-	 is weird and is handled in count_strange_loop_iterations.
-	 If stride is 1, overflow may occur only for <= and >= conditions,
-	 and then they are infinite, so it does not bother us.  */
-      overflow_check = const0_rtx;
-    }
-  else
-    {
-      if (cond == LT || cond == LTU)
-	mx = simplify_gen_binary (MINUS, mode, lim, const1_rtx);
-      else if (cond == GT || cond == GTU)
-	mx = simplify_gen_binary (PLUS, mode, lim, const1_rtx);
-      else
-	mx = lim;
-      if (mode != desc->inner_mode)
-	mxp = simplify_gen_subreg (desc->inner_mode, mx, mode, 0);
-      else
-	mxp = mx;
-      mxp = simplify_gen_binary (PLUS, desc->inner_mode, mxp, stride);
-      if (mode != desc->inner_mode)
-	mxp = simplify_gen_unary (desc->extend, mode, mxp, desc->inner_mode);
-      overflow_check = simplify_gen_relational (cond, SImode, mode, mx, mxp);
-    }
-    
-  /* Compute absolute value of the difference of initial and final value.  */
-  if (INTVAL (stride) > 0)
-    {
-      /* Handle strange tests specially.  */
-      if (cond == EQ || cond == GE || cond == GT || cond == GEU
-	  || cond == GTU)
-	return count_strange_loop_iterations (init, lim, cond, desc->postincr,
-					      stride, mode, desc->inner_mode);
-      exp = simplify_gen_binary (MINUS, mode, lim, init);
-    }
-  else
-    {
-      if (cond == EQ || cond == LE || cond == LT || cond == LEU
-	  || cond == LTU)
-	return count_strange_loop_iterations (init, lim, cond, desc->postincr,
-					      stride, mode, desc->inner_mode);
-      exp = simplify_gen_binary (MINUS, mode, init, lim);
-      stride = simplify_gen_unary (NEG, mode, stride, mode);
-    }
-
-  /* If there is a risk of overflow (i.e. when we increment value satisfying
-     a condition, we may again obtain a value satisfying the condition),
-     fail.  */
-  if (overflow_check != const0_rtx)
-    return NULL_RTX;
-
-  /* Normalize difference so the value is always first examined
-     and later incremented.  */
-  if (!desc->postincr)
-    exp = simplify_gen_binary (MINUS, mode, exp, stride);
-
-  /* Determine delta caused by exit condition.  */
-  switch (cond)
-    {
-    case NE:
-      /* NE tests are easy to handle, because we just perform simple
-	 arithmetics modulo power of 2.  Let's use the fact to compute the
-	 number of iterations exactly.  We are now in situation when we want to
-	 solve an equation stride * i = c (mod size of inner_mode).
-	 Let nsd (stride, size of mode) = d.  If d does not divide c, the
-	 loop is infinite.  Otherwise, the number of iterations is
-	 (inverse(s/d) * (c/d)) mod (size of mode/d).  */
-      size = GET_MODE_BITSIZE (desc->inner_mode);
-      s = INTVAL (stride);
-      d = 1;
-      while (s % 2 != 1)
-	{
-	  s /= 2;
-	  d *= 2;
-	  size--;
-	}
-      bound = GEN_INT (((unsigned HOST_WIDEST_INT) 1 << (size - 1 ) << 1) - 1);
-      exp = simplify_gen_binary (UDIV, mode, exp, GEN_INT (d));
-      exp = simplify_gen_binary (MULT, mode,
-				 exp, GEN_INT (inverse (s, size)));
-      exp = simplify_gen_binary (AND, mode, exp, bound);
-      break;
-
-    case LT:
-    case GT:
-    case LTU:
-    case GTU:
-      break;
-    case LE:
-    case GE:
-    case LEU:
-    case GEU:
-      exp = simplify_gen_binary (PLUS, mode, exp, const1_rtx);
-      break;
-    default:
-      abort ();
-    }
-
-  if (cond != NE && stride != const1_rtx)
-    {
-      /* Number of iterations is now (EXP + STRIDE - 1 / STRIDE),
-	 but we need to take care for overflows.  */
-
-      mod = simplify_gen_binary (UMOD, mode, exp, stride);
-
-      /* This is dirty trick.  When we can't compute number of iterations
-	 to be constant, we simply ignore the possible overflow, as
-	 runtime unroller always use power of 2 amounts and does not
-	 care about possible lost bits.  */
-
-      if (GET_CODE (mod) != CONST_INT)
-	{
-	  rtx stridem1 = simplify_gen_binary (PLUS, mode, stride, constm1_rtx);
-	  exp = simplify_gen_binary (PLUS, mode, exp, stridem1);
-	  exp = simplify_gen_binary (UDIV, mode, exp, stride);
-	}
-      else
-	{
-	  exp = simplify_gen_binary (UDIV, mode, exp, stride);
-	  if (mod != const0_rtx)
-	    exp = simplify_gen_binary (PLUS, mode, exp, const1_rtx);
-	}
-    }
-
-  if (dump_file)
-    {
-      fprintf (dump_file, ";  Number of iterations: ");
-      print_simple_rtl (dump_file, exp);
-      fprintf (dump_file, "\n");
-    }
-
-  return exp;
-}
-
-/* Return simplified RTX expression representing the value of test
-   described of DESC at given iteration of loop.  */
-
-static rtx
-test_for_iteration (struct loop_desc *desc, unsigned HOST_WIDE_INT iter)
-{
-  enum rtx_code cond = desc->cond;
-  rtx exp = XEXP (desc->var_alts, 0);
-  rtx addval;
-
-  /* Give up on floating point modes and friends.  It can be possible to do
-     the job for constant loop bounds, but it is probably not worthwhile.  */
-  if (!INTEGRAL_MODE_P (GET_MODE (desc->var)))
-    return NULL;
-
-  /* Ensure that we always handle the condition to stay inside loop.  */
-  if (desc->neg)
-    cond = reverse_condition (cond);
-
-  /* Compute the value of induction variable.  */
-  addval = simplify_gen_binary (MULT, GET_MODE (desc->var),
-				desc->stride,
-				gen_int_mode (desc->postincr
-					      ? iter : iter + 1,
-					      GET_MODE (desc->var)));
-  exp = simplify_gen_binary (PLUS, GET_MODE (desc->var), exp, addval);
-  /* Test at given condition.  */
-  exp = simplify_gen_relational (cond, SImode,
-				 GET_MODE (desc->var), exp, desc->lim);
-
-  if (dump_file)
-    {
-      fprintf (dump_file, ";  Conditional to continue loop at "
-	       HOST_WIDE_INT_PRINT_UNSIGNED "th iteration: ", iter);
-      print_simple_rtl (dump_file, exp);
-      fprintf (dump_file, "\n");
-    }
-  return exp;
-}
-
-
-/* Tests whether exit at EXIT_EDGE from LOOP is simple.  Returns simple loop
-   description joined to it in in DESC.  INVARIANT_REGS and SINGLE_SET_REGS
-   are results of blocks_{invariant,single_set}_regs over BODY.  */
-static bool
-simple_loop_exit_p (struct loop *loop, edge exit_edge,
-		    regset invariant_regs, rtx *single_set_regs,
-		    struct loop_desc *desc)
-{
-  basic_block mod_bb, exit_bb;
-  int fallthru_out;
-  rtx condition;
-  edge ei, e;
-
-  exit_bb = exit_edge->src;
-
-  fallthru_out = (exit_edge->flags & EDGE_FALLTHRU);
-
-  if (!exit_bb)
-    return false;
-
-  /* It must be tested (at least) once during any iteration.  */
-  if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit_bb))
-    return false;
-
-  /* It must end in a simple conditional jump.  */
-  if (!any_condjump_p (BB_END (exit_bb)))
-    return false;
-
-  ei = exit_bb->succ;
-  if (ei == exit_edge)
-    ei = ei->succ_next;
-
-  desc->out_edge = exit_edge;
-  desc->in_edge = ei;
-
-  /* Condition must be a simple comparison in that one of operands
-     is register and the other one is invariant.  */
-  if (!(condition = get_condition (BB_END (exit_bb), NULL, false)))
-    return false;
-
-  if (!simple_condition_p (loop, condition, invariant_regs, desc))
-    return false;
-
-  /*  Var must be simply incremented or decremented in exactly one insn that
-     is executed just once every iteration.  */
-  if (!(mod_bb = simple_increment (loop, single_set_regs, desc)))
-    return false;
-
-  /* OK, it is simple loop.  Now just fill in remaining info.  */
-  desc->postincr = !dominated_by_p (CDI_DOMINATORS, exit_bb, mod_bb);
-  desc->neg = !fallthru_out;
-
-  /* Find initial value of var and alternative values for lim.  */
-  e = loop_preheader_edge (loop);
-  desc->var_alts = variable_initial_values (e, desc->var, desc->inner_mode);
-  desc->lim_alts = variable_initial_values (e, desc->lim, desc->inner_mode);
-
-  /* Number of iterations.  */
-  desc->const_iter =
-    constant_iterations (desc, &desc->niter, &desc->may_be_zero);
-  if (!desc->const_iter && !count_loop_iterations (desc, NULL, NULL))
-    return false;
-  return true;
-}
-
-/* Tests whether LOOP is simple for loop.  Returns simple loop description
-   in DESC.  */
-bool
-simple_loop_p (struct loop *loop, struct loop_desc *desc)
-{
-  unsigned i;
-  basic_block *body;
-  edge e;
-  struct loop_desc act;
-  bool any = false;
-  regset invariant_regs;
-  regset_head invariant_regs_head;
-  rtx *single_set_regs;
-  int n_branches;
-
-  body = get_loop_body (loop);
-
-  invariant_regs = INITIALIZE_REG_SET (invariant_regs_head);
-  single_set_regs = xmalloc (max_reg_num () * sizeof (rtx));
-
-  blocks_invariant_registers (body, loop->num_nodes, invariant_regs);
-  blocks_single_set_registers (body, loop->num_nodes, single_set_regs);
-
-  n_branches = 0;
-  for (i = 0; i < loop->num_nodes; i++)
-    {
-      for (e = body[i]->succ; e; e = e->succ_next)
-	if (!flow_bb_inside_loop_p (loop, e->dest)
-	    && simple_loop_exit_p (loop, e,
-		   invariant_regs, single_set_regs, &act))
-	  {
-	    /* Prefer constant iterations; the less the better.  */
-	    if (!any)
-	      any = true;
-	    else if (!act.const_iter
-		     || (desc->const_iter && act.niter >= desc->niter))
-	      continue;
-	    *desc = act;
-	  }
-
-      if (body[i]->succ && body[i]->succ->succ_next)
-	n_branches++;
-    }
-  desc->n_branches = n_branches;
-
-  if (dump_file && any)
-    {
-      fprintf (dump_file, "; Simple loop %i\n", loop->num);
-      if (desc->postincr)
-	fprintf (dump_file,
-		 ";  does postincrement after loop exit condition\n");
-
-      fprintf (dump_file, ";  Induction variable:");
-      print_simple_rtl (dump_file, desc->var);
-      fputc ('\n', dump_file);
-
-      fprintf (dump_file, ";  Initial values:");
-      print_simple_rtl (dump_file, desc->var_alts);
-      fputc ('\n', dump_file);
-
-      fprintf (dump_file, ";  Stride:");
-      print_simple_rtl (dump_file, desc->stride);
-      fputc ('\n', dump_file);
-
-      fprintf (dump_file, ";  Compared with:");
-      print_simple_rtl (dump_file, desc->lim);
-      fputc ('\n', dump_file);
-
-      fprintf (dump_file, ";  Alternative values:");
-      print_simple_rtl (dump_file, desc->lim_alts);
-      fputc ('\n', dump_file);
-
-      fprintf (dump_file, ";  Exit condition:");
-      if (desc->neg)
-	fprintf (dump_file, "(negated)");
-      fprintf (dump_file, "%s\n", GET_RTX_NAME (desc->cond));
-
-      fprintf (dump_file, ";  Number of branches:");
-      fprintf (dump_file, "%d\n", desc->n_branches);
-
-      fputc ('\n', dump_file);
-    }
-
-  free (body);
-  FREE_REG_SET (invariant_regs);
-  free (single_set_regs);
-  return any;
-}
-
 /* Structure representing edge of a graph.  */
 
 struct edge
diff --git a/gcc/loop-iv.c b/gcc/loop-iv.c
index 9c170dec2ec..ccc239a3652 100644
--- a/gcc/loop-iv.c
+++ b/gcc/loop-iv.c
@@ -2306,7 +2306,7 @@ zero_iter:
 }
 
 /* Checks whether E is a simple exit from LOOP and stores its description
-   into DESC.  TODO Should replace cfgloopanal.c:simple_loop_exit_p.  */
+   into DESC.  */
 
 static void
 check_simple_exit (struct loop *loop, edge e, struct niter_desc *desc)
@@ -2353,8 +2353,7 @@ check_simple_exit (struct loop *loop, edge e, struct niter_desc *desc)
   iv_number_of_iterations (loop, at, condition, desc);
 }
 
-/* Finds a simple exit of LOOP and stores its description into DESC.
-   TODO Should replace cfgloopanal.c:simple_loop_p.  */
+/* Finds a simple exit of LOOP and stores its description into DESC.  */
 
 void
 find_simple_exit (struct loop *loop, struct niter_desc *desc)