[patch tree-optimization]: [3 of 3]: Boolify compares & more

[Kai Tietz <ktietz70 at googlemail dot com>]

Hello,

This patch - third of series - fixes vrp to handle bitwise one-bit
precision typed operations.
And it introduces a second - limitted to non-switch-statement range - vrp pass.

Bootstrapped and regression tested for all standard-languages (plus
Ada and Obj-C++) on host x86_64-pc-linux-gnu.

Ok for apply?

Regards,
Kai

ChangeLog

2011-07-07  Kai Tietz  <ktietz@redhat.com>

	* tree-vrp.c (in_second_pass): New static variable.
	(extract_range_from_binary_expr): Add handling for
	BIT_IOR_EXPR, BIT_AND_EXPR, and BIT_NOT_EXPR.
	(register_edge_assert_for_1): Add handling for 1-bit
	BIT_IOR_EXPR and BIT_NOT_EXPR.
	(register_edge_assert_for): Add handling for 1-bit
	BIT_IOR_EXPR.
	(ssa_name_get_inner_ssa_name_p): New helper function.
	(ssa_name_get_cast_to_p): New helper function.
	(simplify_truth_ops_using_ranges): Handle prefixed
	cast instruction for result, and add support for one
	bit precision BIT_IOR_EXPR, BIT_AND_EXPR, BIT_XOR_EXPR,
	, and BIT_NOT_EXPR.
	(simplify_stmt_using_ranges): Add handling for one bit
	precision BIT_IOR_EXPR, BIT_AND_EXPR, BIT_XOR_EXPR,
	and BIT_NOT_EXPR.
	(vrp_finalize): Do substitute and fold pass a second
	time for vrp_stmt and preserve switch-edge simplification
	on second run.
	(simplify_switch_using_ranges): Preserve rerun of function
	in second pass.

Index: gcc-head/gcc/tree-vrp.c
===================================================================
--- gcc-head.orig/gcc/tree-vrp.c
+++ gcc-head/gcc/tree-vrp.c
@@ -74,6 +74,9 @@ struct value_range_d

 typedef struct value_range_d value_range_t;

+/* This flag indicates that we are doing a second pass of VRP.  */
+static bool in_second_pass = false;
+
 /* Set of SSA names found live during the RPO traversal of the function
    for still active basic-blocks.  */
 static sbitmap *live;
@@ -2232,6 +2235,7 @@ extract_range_from_binary_expr (value_ra
      some cases.  */
   if (code != BIT_AND_EXPR
       && code != TRUTH_AND_EXPR
+      && code != BIT_IOR_EXPR
       && code != TRUTH_OR_EXPR
       && code != TRUNC_DIV_EXPR
       && code != FLOOR_DIV_EXPR
@@ -2291,6 +2295,8 @@ extract_range_from_binary_expr (value_ra
 	  else
 	    set_value_range_to_varying (vr);
 	}
+      else if (code == BIT_IOR_EXPR)
+        set_value_range_to_varying (vr);
       else
 	gcc_unreachable ();

@@ -2300,11 +2306,13 @@ extract_range_from_binary_expr (value_ra
   /* For integer ranges, apply the operation to each end of the
      range and see what we end up with.  */
   if (code == TRUTH_AND_EXPR
-      || code == TRUTH_OR_EXPR)
+      || code == TRUTH_OR_EXPR
+      || ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR)
+          && TYPE_PRECISION (TREE_TYPE (op1)) == 1))
     {
       /* If one of the operands is zero, we know that the whole
 	 expression evaluates zero.  */
-      if (code == TRUTH_AND_EXPR
+      if ((code == TRUTH_AND_EXPR || code == BIT_AND_EXPR)
 	  && ((vr0.type == VR_RANGE
 	       && integer_zerop (vr0.min)
 	       && integer_zerop (vr0.max))
@@ -2317,7 +2325,7 @@ extract_range_from_binary_expr (value_ra
 	}
       /* If one of the operands is one, we know that the whole
 	 expression evaluates one.  */
-      else if (code == TRUTH_OR_EXPR
+      else if ((code == TRUTH_OR_EXPR || code == BIT_IOR_EXPR)
 	       && ((vr0.type == VR_RANGE
 		    && integer_onep (vr0.min)
 		    && integer_onep (vr0.max))
@@ -2809,7 +2817,7 @@ extract_range_from_unary_expr (value_ran
      cannot easily determine a resulting range.  */
   if (code == FIX_TRUNC_EXPR
       || code == FLOAT_EXPR
-      || code == BIT_NOT_EXPR
+      || (code == BIT_NOT_EXPR && TYPE_PRECISION (type) != 1)
       || code == CONJ_EXPR)
     {
       /* We can still do constant propagation here.  */
@@ -3976,7 +3984,9 @@ build_assert_expr_for (tree cond, tree v
       tree a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
       assertion = gimple_build_assign (n, a);
     }
-  else if (TREE_CODE (cond) == TRUTH_NOT_EXPR)
+  else if (TREE_CODE (cond) == TRUTH_NOT_EXPR
+  	   || (TREE_CODE (cond) == BIT_NOT_EXPR
+  	       && TYPE_PRECISION (TREE_TYPE (cond)) == 1))
     {
       /* Given !V, build the assignment N = false.  */
       tree op0 = TREE_OPERAND (cond, 0);
@@ -4531,7 +4541,9 @@ register_edge_assert_for_1 (tree op, enu
       retval |= register_edge_assert_for_1 (gimple_assign_rhs2 (op_def),
 					    code, e, bsi);
     }
-  else if (gimple_assign_rhs_code (op_def) == TRUTH_NOT_EXPR)
+  else if (gimple_assign_rhs_code (op_def) == TRUTH_NOT_EXPR
+  	   || (gimple_assign_rhs_code (op_def) == BIT_NOT_EXPR
+  	       && TYPE_PRECISION (TREE_TYPE (op)) == 1))
     {
       /* Recurse, flipping CODE.  */
       code = invert_tree_comparison (code, false);
@@ -4617,6 +4629,9 @@ register_edge_assert_for (tree name, edg

       if (is_gimple_assign (def_stmt)
 	  && (gimple_assign_rhs_code (def_stmt) == TRUTH_OR_EXPR
+	      || (gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR
+		  && INTEGRAL_TYPE_P (TREE_TYPE (name))
+		  && TYPE_PRECISION (TREE_TYPE (name)) == 1)
 	      /* For BIT_IOR_EXPR only if NAME == 0 both operands have
 		 necessarily zero value.  */
 	      || (comp_code == EQ_EXPR
@@ -6747,19 +6762,96 @@ varying:
   return SSA_PROP_VARYING;
 }

+/* Returns operand1 of ssa-name with SSA_NAME as code, Otherwise it
+   returns NULL_TREE.  */
+static tree
+ssa_name_get_inner_ssa_name_p (tree op)
+{
+  gimple stmt;
+
+  if (TREE_CODE (op) != SSA_NAME
+      || !is_gimple_assign (SSA_NAME_DEF_STMT (op)))
+    return NULL_TREE;
+  stmt = SSA_NAME_DEF_STMT (op);
+  if (gimple_assign_rhs_code (stmt) != SSA_NAME)
+    return NULL_TREE;
+  return gimple_assign_rhs1 (stmt);
+}
+
+/* Returns operand of cast operation, if OP is a type-conversion. Otherwise
+   return NULL_TREE.  */
+static tree
+ssa_name_get_cast_to_p (tree op)
+{
+  gimple stmt;
+
+  if (TREE_CODE (op) != SSA_NAME
+      || !is_gimple_assign (SSA_NAME_DEF_STMT (op)))
+    return NULL_TREE;
+  stmt = SSA_NAME_DEF_STMT (op);
+  if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt)))
+    return NULL_TREE;
+  return gimple_assign_rhs1 (stmt);
+}
+
 /* Simplify boolean operations if the source is known
    to be already a boolean.  */
 static bool
 simplify_truth_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
 {
   enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
+  gimple stmt2 = stmt;
   tree val = NULL;
-  tree op0, op1;
+  tree op0, op1, cop0, cop1;
   value_range_t *vr;
   bool sop = false;
   bool need_conversion;
+  location_t loc = gimple_location (stmt);

   op0 = gimple_assign_rhs1 (stmt);
+  op1 = NULL_TREE;
+
+  /* Handle cases with prefixed type-cast.  */
+  if (CONVERT_EXPR_CODE_P (rhs_code)
+      && INTEGRAL_TYPE_P (TREE_TYPE (op0))
+      && TREE_CODE (op0) == SSA_NAME
+      && is_gimple_assign (SSA_NAME_DEF_STMT (op0))
+      && INTEGRAL_TYPE_P (TREE_TYPE (gimple_assign_lhs (stmt))))
+    {
+      stmt2 = SSA_NAME_DEF_STMT (op0);
+      op0 = gimple_assign_rhs1 (stmt2);
+      if (!INTEGRAL_TYPE_P (TREE_TYPE (op0)))
+	return false;
+      rhs_code = gimple_assign_rhs_code (stmt2);
+      if (rhs_code != BIT_NOT_EXPR && rhs_code != TRUTH_NOT_EXPR
+	  && rhs_code != TRUTH_AND_EXPR && rhs_code != BIT_AND_EXPR
+	  && rhs_code != TRUTH_OR_EXPR && rhs_code != BIT_IOR_EXPR
+	  && rhs_code != TRUTH_XOR_EXPR && rhs_code != BIT_XOR_EXPR
+	  && rhs_code != NE_EXPR && rhs_code != EQ_EXPR)
+	return false;
+      if (rhs_code == BIT_AND_EXPR || rhs_code == BIT_IOR_EXPR
+	  || rhs_code == BIT_XOR_EXPR || rhs_code == TRUTH_AND_EXPR
+	  || rhs_code == TRUTH_OR_EXPR || rhs_code == TRUTH_XOR_EXPR
+	  || rhs_code == NE_EXPR || rhs_code == EQ_EXPR)
+	op1 = gimple_assign_rhs2 (stmt2);
+      if (gimple_has_location (stmt2))
+        loc = gimple_location (stmt2);
+    }
+  else if (CONVERT_EXPR_CODE_P (rhs_code))
+    return false;
+  else if (rhs_code == BIT_AND_EXPR || rhs_code == BIT_IOR_EXPR
+      || rhs_code == BIT_XOR_EXPR || rhs_code == TRUTH_AND_EXPR
+      || rhs_code == TRUTH_OR_EXPR || rhs_code == TRUTH_XOR_EXPR
+      || rhs_code == NE_EXPR || rhs_code == EQ_EXPR)
+    op1 = gimple_assign_rhs2 (stmt);
+
+  /* ~X is only equivalent of !X, if type-precision is one and X has
+     an integral type.  */
+  if (rhs_code == BIT_NOT_EXPR
+      && (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
+	  || TYPE_PRECISION (TREE_TYPE (op0)) != 1))
+    return false;
+
   if (TYPE_PRECISION (TREE_TYPE (op0)) != 1)
     {
       if (TREE_CODE (op0) != SSA_NAME)
@@ -6775,22 +6867,100 @@ simplify_truth_ops_using_ranges (gimple_
         return false;
     }

-  if (rhs_code == TRUTH_NOT_EXPR)
+  if (op1 && TREE_CODE (op1) != INTEGER_CST
+      && TYPE_PRECISION (TREE_TYPE (op1)) != 1)
+    {
+      vr = get_value_range (op1);
+      val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
+      if (!val || !integer_onep (val))
+	return false;
+
+      val = compare_range_with_value (LE_EXPR, vr, integer_one_node, &sop);
+      if (!val || !integer_onep (val))
+	return false;
+    }
+
+  need_conversion =
+    !useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (stmt)),
+			        TREE_TYPE (op0));
+
+  /* As comparisons X != 0 getting folded by prior pass to (bool) X,
+     but X == 0 might be not folded for none boolean type of X
+     to (bool) (X ^ 1).
+     So for bitwise-binary operations we have three cases to handle:
+     a) ((bool) X) op ((bool) Y)
+     b) ((bool) X) op (Y == 0) OR (X == 0) op ((bool) Y)
+     c) (X == 0) op (Y == 0)
+     The later two cases can't be handled for now, as vr tables
+     would need to be adjusted.  */
+  if (need_conversion
+      && (rhs_code == BIT_XOR_EXPR
+	  || rhs_code == BIT_AND_EXPR
+	  || rhs_code == BIT_IOR_EXPR)
+      && TREE_CODE (op1) == SSA_NAME && TREE_CODE (op0) == SSA_NAME)
+    {
+      cop0 = ssa_name_get_cast_to_p (op0);
+      cop1 = ssa_name_get_cast_to_p (op1);
+      if (!cop0 || !cop1)
+        /* We would need an new statment for cases b and c, and we can't
+           due vr table, so bail out.  */
+        return false;
+
+      if (!INTEGRAL_TYPE_P (TREE_TYPE (cop0))
+	  || !types_compatible_p (TREE_TYPE (cop0), TREE_TYPE (cop1)))
+	return false;
+      need_conversion =
+	!useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (stmt)),
+				    TREE_TYPE (cop0));
+      if (need_conversion)
+	return false;
+      op0 = cop0;
+      op1 = cop1;
+
+      /* We need to re-check if value ranges for new operands
+         for 1-bit precision/range.  */
+      if (TYPE_PRECISION (TREE_TYPE (op0)) != 1)
+	{
+	  if (TREE_CODE (op0) != SSA_NAME)
+	    return false;
+	  vr = get_value_range (op0);
+
+	  val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
+	  if (!val || !integer_onep (val))
+	    return false;
+
+	  val = compare_range_with_value (LE_EXPR, vr, integer_one_node, &sop);
+	  if (!val || !integer_onep (val))
+	    return false;
+	}
+
+      if (op1 && TYPE_PRECISION (TREE_TYPE (op1)) != 1)
+	{
+	  vr = get_value_range (op1);
+	  val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
+	  if (!val || !integer_onep (val))
+	    return false;
+
+	  val = compare_range_with_value (LE_EXPR, vr, integer_one_node, &sop);
+	  if (!val || !integer_onep (val))
+	    return false;
+	}
+    }
+  else if (rhs_code == TRUTH_NOT_EXPR || rhs_code == BIT_NOT_EXPR)
     {
       rhs_code = NE_EXPR;
       op1 = build_int_cst (TREE_TYPE (op0), 1);
     }
   else
     {
-      op1 = gimple_assign_rhs2 (stmt);
-
       /* Reduce number of cases to handle.  */
       if (is_gimple_min_invariant (op1))
 	{
           /* Exclude anything that should have been already folded.  */
 	  if (rhs_code != EQ_EXPR
 	      && rhs_code != NE_EXPR
-	      && rhs_code != TRUTH_XOR_EXPR)
+	      && rhs_code != TRUTH_XOR_EXPR
+	      && rhs_code != BIT_XOR_EXPR)
 	    return false;

 	  if (!integer_zerop (op1)
@@ -6810,18 +6980,6 @@ simplify_truth_ops_using_ranges (gimple_
 	  /* Punt on A == B as there is no BIT_XNOR_EXPR.  */
 	  if (rhs_code == EQ_EXPR)
 	    return false;
-
-	  if (TYPE_PRECISION (TREE_TYPE (op1)) != 1)
-	    {
-	      vr = get_value_range (op1);
-	      val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
-	      if (!val || !integer_onep (val))
-	        return false;
-
-	      val = compare_range_with_value (LE_EXPR, vr, integer_one_node, &sop);
-	      if (!val || !integer_onep (val))
-	        return false;
-	    }
 	}
     }

@@ -6838,7 +6996,8 @@ simplify_truth_ops_using_ranges (gimple_
         warning_at (location, OPT_Wstrict_overflow,
 	            _("assuming signed overflow does not occur when "
 		      "simplifying && or || to & or |"));
-      else
+      else if (rhs_code != BIT_AND_EXPR && rhs_code != BIT_IOR_EXPR
+	       && rhs_code != BIT_XOR_EXPR)
         warning_at (location, OPT_Wstrict_overflow,
 	            _("assuming signed overflow does not occur when "
 		      "simplifying ==, != or ! to identity or ^"));
@@ -6859,16 +7018,21 @@ simplify_truth_ops_using_ranges (gimple_
     case TRUTH_AND_EXPR:
       rhs_code = BIT_AND_EXPR;
       break;
+    case BIT_AND_EXPR:
+      break;
     case TRUTH_OR_EXPR:
       rhs_code = BIT_IOR_EXPR;
+    case BIT_IOR_EXPR:
       break;
     case TRUTH_XOR_EXPR:
+    case BIT_XOR_EXPR:
     case NE_EXPR:
       if (integer_zerop (op1))
 	{
 	  gimple_assign_set_rhs_with_ops (gsi,
 					  need_conversion ? NOP_EXPR : SSA_NAME,
 					  op0, NULL);
+	  gimple_set_location (stmt, loc);
 	  update_stmt (gsi_stmt (*gsi));
 	  return true;
 	}
@@ -6879,10 +7043,20 @@ simplify_truth_ops_using_ranges (gimple_
       gcc_unreachable ();
     }

+  /* We can't insert here new expression as otherwise
+     tracked vr tables getting out of bounds.  */
   if (need_conversion)
     return false;

+  /* Reduce here SSA_NAME -> SSA_NAME.  */
+  while ((cop0 = ssa_name_get_inner_ssa_name_p (op0)) != NULL_TREE)
+    op0 = cop0;
+
+  while ((cop1 = ssa_name_get_inner_ssa_name_p (op1)) != NULL_TREE)
+    op1 = cop1;
+
   gimple_assign_set_rhs_with_ops (gsi, rhs_code, op0, op1);
+  gimple_set_location (stmt, loc);
   update_stmt (gsi_stmt (*gsi));
   return true;
 }
@@ -7263,6 +7437,9 @@ simplify_switch_using_ranges (gimple stm
   tree vec2;
   switch_update su;

+  if (in_second_pass)
+    return false;
+
   if (TREE_CODE (op) == SSA_NAME)
     {
       vr = get_value_range (op);
@@ -7390,6 +7567,7 @@ simplify_stmt_using_ranges (gimple_stmt_
 	{
 	case EQ_EXPR:
 	case NE_EXPR:
+	case BIT_NOT_EXPR:
 	case TRUTH_NOT_EXPR:
 	case TRUTH_AND_EXPR:
 	case TRUTH_OR_EXPR:
@@ -7425,13 +7603,21 @@ simplify_stmt_using_ranges (gimple_stmt_
 	     if all the bits being cleared are already cleared or
 	     all the bits being set are already set.  */
 	  if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
-	    return simplify_bit_ops_using_ranges (gsi, stmt);
+	    {
+	      if (simplify_truth_ops_using_ranges (gsi, stmt))
+		return true;
+	      return simplify_bit_ops_using_ranges (gsi, stmt);
+	    }
 	  break;

 	CASE_CONVERT:
 	  if (TREE_CODE (rhs1) == SSA_NAME
 	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
-	    return simplify_conversion_using_ranges (stmt);
+	    {
+	      if (simplify_truth_ops_using_ranges (gsi, stmt))
+		return true;
+	      return simplify_conversion_using_ranges (stmt);
+	    }
 	  break;

 	default:
@@ -7685,8 +7870,16 @@ vrp_finalize (void)
       fprintf (dump_file, "\n");
     }

+  /* We redo folding here one time for allowing to inspect more
+     complex reductions.  */
+  substitute_and_fold (op_with_constant_singleton_value_range,
+		       vrp_fold_stmt, false);
+  /* We need to mark this second pass to avoid re-entering of same
+     edges for switch statments.  */
+  in_second_pass = true;
   substitute_and_fold (op_with_constant_singleton_value_range,
 		       vrp_fold_stmt, false);
+  in_second_pass = false;

   if (warn_array_bounds)
     check_all_array_refs ();