From: Aldy Hernandez <aldyh@redhat.com>
Date: Sun, 23 Oct 2022 14:51:17 +0000 (+0200)
Subject: Check HONOR_NANS instead of flag_finite_math_only in frange:verify_range.
X-Git-Tag: basepoints/gcc-14~3754
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1e9d9ed095df3d064cf9d91d46f3e5426c2a05a7;p=thirdparty%2Fgcc.git

Check HONOR_NANS instead of flag_finite_math_only in frange:verify_range.

[Jakub and other FP experts, would this be OK, or am I missing
something?]

Vax does not seem to have !flag_finite_math_only, but float_type_node
does not HONOR_NANS.  The check in frange::verify_range dependend on
flag_finite_math_only, which is technically not correct since
frange::set_varying() checks HONOR_NANS instead of
flag_finite_math_only.

I'm actually getting tired of flag_finite_math_only and
!flag_finite_math_only discrepancies in the selftests (Vax and rx-elf
come to mind).  I think we should just test both alternatives in the
selftests as in this patch.

We could also check flag_finite_math_only=0 with a float_type_node
that does not HONOR_NANs, but I have no idea how to twiddle
FLOAT_MODE_FORMAT temporarily, and that may be over thinking it.

	PR tree-optimization/107365

gcc/ChangeLog:

	* value-range.cc (frange::verify_range): Predicate NAN check in
	VARYING range on HONOR_NANS instead of flag_finite_math_only.
	(range_tests_floats): Same.
	(range_tests_floats_various): New.
	(range_tests): Call range_tests_floats_various.
---

diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index d779e9819e2e..d8ee6ec0d0f8 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -720,13 +720,13 @@ frange::verify_range ()
       gcc_checking_assert (!m_type);
       return;
     case VR_VARYING:
-      if (flag_finite_math_only)
-	gcc_checking_assert (!m_pos_nan && !m_neg_nan);
-      else
-	gcc_checking_assert (m_pos_nan && m_neg_nan);
       gcc_checking_assert (m_type);
       gcc_checking_assert (frange_val_is_min (m_min, m_type));
       gcc_checking_assert (frange_val_is_max (m_max, m_type));
+      if (HONOR_NANS (m_type))
+	gcc_checking_assert (m_pos_nan && m_neg_nan);
+      else
+	gcc_checking_assert (!m_pos_nan && !m_neg_nan);
       return;
     case VR_RANGE:
       gcc_checking_assert (m_type);
@@ -3957,10 +3957,9 @@ range_tests_floats ()
   // A range of [-INF,+INF] is actually VARYING if no other properties
   // are set.
   r0 = frange_float ("-Inf", "+Inf");
-  if (r0.maybe_isnan ())
-    ASSERT_TRUE (r0.varying_p ());
+  ASSERT_TRUE (r0.varying_p ());
   // ...unless it has some special property...
-  if (!flag_finite_math_only)
+  if (HONOR_NANS (r0.type ()))
     {
       r0.clear_nan ();
       ASSERT_FALSE (r0.varying_p ());
@@ -4041,6 +4040,24 @@ range_tests_floats ()
     }
 }
 
+// Run floating range tests for various combinations of NAN and INF
+// support.
+
+static void
+range_tests_floats_various ()
+{
+  int save_finite_math_only = flag_finite_math_only;
+
+  // Test -ffinite-math-only.
+  flag_finite_math_only = 1;
+  range_tests_floats ();
+  // Test -fno-finite-math-only.
+  flag_finite_math_only = 0;
+  range_tests_floats ();
+
+  flag_finite_math_only = save_finite_math_only;
+}
+
 void
 range_tests ()
 {
@@ -4049,7 +4066,7 @@ range_tests ()
   range_tests_int_range_max ();
   range_tests_strict_enum ();
   range_tests_nonzero_bits ();
-  range_tests_floats ();
+  range_tests_floats_various ();
   range_tests_misc ();
 }