From: Aldy Hernandez <aldyh@redhat.com>
Date: Thu, 26 Jan 2023 03:46:54 +0000 (+0100)
Subject: Return true from operator== for two identical ranges containing NAN.
X-Git-Tag: basepoints/gcc-15~10107
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10e481b154c5fc63e6ce4b449ce86cecb87a6015;p=thirdparty%2Fgcc.git

Return true from operator== for two identical ranges containing NAN.

The == operator for ranges signifies that two ranges contain the same
thing, not that they are ultimately equal.  So [2,4] == [2,4], even
though one may be a 2 and the other may be a 3.  Similarly with two
VARYING ranges.

There is an oversight in frange::operator== where we are returning
false for two identical NANs.  This is causing us to never cache NANs
in sbr_sparse_bitmap::set_bb_range.

gcc/ChangeLog:

	* value-range.cc (frange::operator==): Adjust for NAN.
	(range_tests_nan): Remove some NAN tests.
---

diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index c14a27e23af9..8b5d0cb53e46 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -681,9 +681,6 @@ frange::operator== (const frange &src) const
       if (varying_p ())
 	return types_compatible_p (m_type, src.m_type);
 
-      if (known_isnan () || src.known_isnan ())
-	return false;
-
       return (real_identical (&m_min, &src.m_min)
 	      && real_identical (&m_max, &src.m_max)
 	      && m_pos_nan == src.m_pos_nan
@@ -3801,13 +3798,6 @@ range_tests_nan ()
       ASSERT_TRUE (r0.maybe_isnan ());
     }
 
-  // NAN ranges are not equal to each other.
-  r0.set_nan (float_type_node);
-  r1 = r0;
-  ASSERT_FALSE (r0 == r1);
-  ASSERT_FALSE (r0 == r0);
-  ASSERT_TRUE (r0 != r0);
-
   // [5,6] U NAN = [5,6] NAN.
   r0 = frange_float ("5", "6");
   r0.clear_nan ();