[PATCH] Remove follow_assert_exprs from overflow_comparison.

[Aldy Hernandez <aldyh@redhat.com>]

OK pending tests?

gcc/ChangeLog:

	* tree-vrp.cc (overflow_comparison_p_1): Remove follow_assert_exprs.
	(overflow_comparison_p): Remove use_equiv_p.
	* tree-vrp.h (overflow_comparison_p): Same.
	* vr-values.cc (vrp_evaluate_conditional_warnv_with_ops): Remove
	use_equiv_p argument to overflow_comparison_p.
---
 gcc/tree-vrp.cc  | 40 ++++------------------------------------
 gcc/tree-vrp.h   |  2 +-
 gcc/vr-values.cc |  2 +-
 3 files changed, 6 insertions(+), 38 deletions(-)

diff --git a/gcc/tree-vrp.cc b/gcc/tree-vrp.cc
index d29941d0f2d..3846dc1d849 100644
--- a/gcc/tree-vrp.cc
+++ b/gcc/tree-vrp.cc
@@ -679,7 +679,7 @@ range_fold_unary_expr (value_range *vr,
 
 static bool
 overflow_comparison_p_1 (enum tree_code code, tree op0, tree op1,
-			 bool follow_assert_exprs, bool reversed, tree *new_cst)
+			 bool reversed, tree *new_cst)
 {
   /* See if this is a relational operation between two SSA_NAMES with
      unsigned, overflow wrapping values.  If so, check it more deeply.  */
@@ -693,19 +693,6 @@ overflow_comparison_p_1 (enum tree_code code, tree op0, tree op1,
     {
       gimple *op1_def = SSA_NAME_DEF_STMT (op1);
 
-      /* If requested, follow any ASSERT_EXPRs backwards for OP1.  */
-      if (follow_assert_exprs)
-	{
-	  while (gimple_assign_single_p (op1_def)
-		 && TREE_CODE (gimple_assign_rhs1 (op1_def)) == ASSERT_EXPR)
-	    {
-	      op1 = TREE_OPERAND (gimple_assign_rhs1 (op1_def), 0);
-	      if (TREE_CODE (op1) != SSA_NAME)
-		break;
-	      op1_def = SSA_NAME_DEF_STMT (op1);
-	    }
-	}
-
       /* Now look at the defining statement of OP1 to see if it adds
 	 or subtracts a nonzero constant from another operand.  */
       if (op1_def
@@ -716,24 +703,6 @@ overflow_comparison_p_1 (enum tree_code code, tree op0, tree op1,
 	{
 	  tree target = gimple_assign_rhs1 (op1_def);
 
-	  /* If requested, follow ASSERT_EXPRs backwards for op0 looking
-	     for one where TARGET appears on the RHS.  */
-	  if (follow_assert_exprs)
-	    {
-	      /* Now see if that "other operand" is op0, following the chain
-		 of ASSERT_EXPRs if necessary.  */
-	      gimple *op0_def = SSA_NAME_DEF_STMT (op0);
-	      while (op0 != target
-		     && gimple_assign_single_p (op0_def)
-		     && TREE_CODE (gimple_assign_rhs1 (op0_def)) == ASSERT_EXPR)
-		{
-		  op0 = TREE_OPERAND (gimple_assign_rhs1 (op0_def), 0);
-		  if (TREE_CODE (op0) != SSA_NAME)
-		    break;
-		  op0_def = SSA_NAME_DEF_STMT (op0);
-		}
-	    }
-
 	  /* If we did not find our target SSA_NAME, then this is not
 	     an overflow test.  */
 	  if (op0 != target)
@@ -764,13 +733,12 @@ overflow_comparison_p_1 (enum tree_code code, tree op0, tree op1,
    the alternate range representation is often useful within VRP.  */
 
 bool
-overflow_comparison_p (tree_code code, tree name, tree val,
-		       bool use_equiv_p, tree *new_cst)
+overflow_comparison_p (tree_code code, tree name, tree val, tree *new_cst)
 {
-  if (overflow_comparison_p_1 (code, name, val, use_equiv_p, false, new_cst))
+  if (overflow_comparison_p_1 (code, name, val, false, new_cst))
     return true;
   return overflow_comparison_p_1 (swap_tree_comparison (code), val, name,
-				  use_equiv_p, true, new_cst);
+				  true, new_cst);
 }
 
 /* Handle
diff --git a/gcc/tree-vrp.h b/gcc/tree-vrp.h
index 07630b5b1ca..127909604f0 100644
--- a/gcc/tree-vrp.h
+++ b/gcc/tree-vrp.h
@@ -39,7 +39,7 @@ extern enum value_range_kind intersect_range_with_nonzero_bits
 extern bool find_case_label_range (gswitch *, tree, tree, size_t *, size_t *);
 extern tree find_case_label_range (gswitch *, const irange *vr);
 extern bool find_case_label_index (gswitch *, size_t, tree, size_t *);
-extern bool overflow_comparison_p (tree_code, tree, tree, bool, tree *);
+extern bool overflow_comparison_p (tree_code, tree, tree, tree *);
 extern void maybe_set_nonzero_bits (edge, tree);
 
 #endif /* GCC_TREE_VRP_H */
diff --git a/gcc/vr-values.cc b/gcc/vr-values.cc
index 0347c29b216..b0dd30260ae 100644
--- a/gcc/vr-values.cc
+++ b/gcc/vr-values.cc
@@ -837,7 +837,7 @@ simplify_using_ranges::vrp_evaluate_conditional_warnv_with_ops
      occurs when the chosen argument is zero and does not occur if the
      chosen argument is not zero.  */
   tree x;
-  if (overflow_comparison_p (code, op0, op1, use_equiv_p, &x))
+  if (overflow_comparison_p (code, op0, op1, &x))
     {
       wide_int max = wi::max_value (TYPE_PRECISION (TREE_TYPE (op0)), UNSIGNED);
       /* B = A - 1; if (A < B) -> B = A - 1; if (A == 0)
-- 
2.38.1