From 0aea6467d5022e3858bfed5ce5d24aa877bfed1a Mon Sep 17 00:00:00 2001
From: Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz>
Date: Wed, 19 May 2004 19:53:45 +0200
Subject: Multiple fixes: PRs 14692, 15274 and 15463

	PR c++/15463
	* loop-iv.c (iv_number_of_iterations):  Use trunc_int_for_mode on
	result of inverse.

	PR rtl-optimization/15274
	* loop-iv.c (determine_max_iter, shorten_into_mode,
	iv_number_of_iterations): Handle constants correctly.
	* rtl.h (get_mode_bounds): Declaration changed.
	* stor-layout.c (get_mode_bounds): Return a constant suitable for
	the target mode.

	PR rtl-optimization/14692
	* loop-unswitch.c (may_unswitch_on): Try folding the result.
	(unswitch_single_loop): Work correctly when may_unswitch_on
	returns a folded constant.

	* loop-iv.c (implies_p): Handle A < B ==> A + 1 <= B.
	* simplify-rtx.c (simplify_const_relational_operation): Optimize
	comparisons with mode bounds.

	* function.c (struct temp_slot): Add new field prev.
	(free_after_compilation, init_temp_slots): Free new fields.
	(cut_slot_from_list, insert_slot_to_list,
	temp_slots_at_level, max_slot_level, move_slot_to_level,
	make_slot_available): New functions.
	(assign_stack_temp_for_type, combine_temp_slots,
	find_temp_slot_from_address, preserve_temp_slots,
	preserve_rtl_expr_result, free_temp_slots,
	free_temps_for_rtl_expr, pop_temp_slots): Work with
	the new structure of lists.
	(mark_all_temps_used): Removed.
	* function.h (struct function): Field x_temp_slots
	replaced by x_used_temp_slots and x_avail_temp_slots.
	(temp_slots): Replaced by ...
	(used_temp_slots, avail_temp_slots): New.
	* tree.h (mark_all_temps_used): Declaration removed.

	* loop-iv.c (mark_single_set, get_biv_step_1, iv_analyze,
	simplify_using_assignment): Take the expression out of
	the expr_list wrapper.

	* loop-iv.c (iv_number_of_iterations): Improve clasification of
	infinite loops.

From-SVN: r82028
---
 gcc/simplify-rtx.c | 84 ++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 57 insertions(+), 27 deletions(-)

(limited to 'gcc/simplify-rtx.c')

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 680ecaf..0bef69e 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -2892,6 +2892,63 @@ simplify_const_relational_operation (enum rtx_code code,
   /* Otherwise, there are some code-specific tests we can make.  */
   else
     {
+      /* Optimize comparisons with upper and lower bounds.  */
+      if (INTEGRAL_MODE_P (mode)
+	  && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
+	{
+	  rtx mmin, mmax;
+	  int sign;
+
+	  if (code == GEU
+	      || code == LEU
+	      || code == GTU
+	      || code == LTU)
+	    sign = 0;
+	  else
+	    sign = 1;
+
+	  get_mode_bounds (mode, sign, mode, &mmin, &mmax);
+
+	  tem = NULL_RTX;
+	  switch (code)
+	    {
+	    case GEU:
+	    case GE:
+	      /* x >= min is always true.  */
+	      if (rtx_equal_p (trueop1, mmin))
+		tem = const_true_rtx;
+	      else 
+	      break;
+
+	    case LEU:
+	    case LE:
+	      /* x <= max is always true.  */
+	      if (rtx_equal_p (trueop1, mmax))
+		tem = const_true_rtx;
+	      break;
+
+	    case GTU:
+	    case GT:
+	      /* x > max is always false.  */
+	      if (rtx_equal_p (trueop1, mmax))
+		tem = const0_rtx;
+	      break;
+
+	    case LTU:
+	    case LT:
+	      /* x < min is always false.  */
+	      if (rtx_equal_p (trueop1, mmin))
+		tem = const0_rtx;
+	      break;
+
+	    default:
+	      break;
+	    }
+	  if (tem == const0_rtx
+	      || tem == const_true_rtx)
+	    return tem;
+	}
+
       switch (code)
 	{
 	case EQ:
@@ -2904,33 +2961,6 @@ simplify_const_relational_operation (enum rtx_code code,
 	    return const_true_rtx;
 	  break;
 
-	case GEU:
-	  /* Unsigned values are never negative.  */
-	  if (trueop1 == const0_rtx)
-	    return const_true_rtx;
-	  break;
-
-	case LTU:
-	  if (trueop1 == const0_rtx)
-	    return const0_rtx;
-	  break;
-
-	case LEU:
-	  /* Unsigned values are never greater than the largest
-	     unsigned value.  */
-	  if (GET_CODE (trueop1) == CONST_INT
-	      && (unsigned HOST_WIDE_INT) INTVAL (trueop1) == GET_MODE_MASK (mode)
-	    && INTEGRAL_MODE_P (mode))
-	  return const_true_rtx;
-	  break;
-
-	case GTU:
-	  if (GET_CODE (trueop1) == CONST_INT
-	      && (unsigned HOST_WIDE_INT) INTVAL (trueop1) == GET_MODE_MASK (mode)
-	      && INTEGRAL_MODE_P (mode))
-	    return const0_rtx;
-	  break;
-
 	case LT:
 	  /* Optimize abs(x) < 0.0.  */
 	  if (trueop1 == CONST0_RTX (mode) && !HONOR_SNANS (mode))
-- 
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