From: Aldy Hernandez <aldyh@redhat.com>
Date: Wed, 21 Sep 2022 09:18:48 +0000 (+0200)
Subject: [PR106967] Set known NANs to undefined for flag_finite_math_only.
X-Git-Tag: basepoints/gcc-14~4446
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dc829c7613ddf562d1aecaf22eda965e87108ac8;p=thirdparty%2Fgcc.git

[PR106967] Set known NANs to undefined for flag_finite_math_only.

Explicit NANs in the IL can be treated as undefined for
flag_finite_math_only.  This causes all the right things to happen wrt
threading, folding, etc.  It also saves us special casing throughout.

	PR tree-optimization/106967

gcc/ChangeLog:

	* value-range.cc (frange::set): Set known NANs to undefined for
	flag_finite_math_only.
---

diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index 505eb9211a79..7e8028eced2a 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -313,8 +313,13 @@ frange::set (tree min, tree max, value_range_kind kind)
       gcc_checking_assert (real_identical (TREE_REAL_CST_PTR (min),
 					   TREE_REAL_CST_PTR (max)));
       tree type = TREE_TYPE (min);
-      bool sign = real_isneg (TREE_REAL_CST_PTR (min));
-      set_nan (type, sign);
+      if (HONOR_NANS (type))
+	{
+	  bool sign = real_isneg (TREE_REAL_CST_PTR (min));
+	  set_nan (type, sign);
+	}
+      else
+	set_undefined ();
       return;
     }