[gcc r13-3453] Check HONOR_NANS instead of flag_finite_math_only in frange:verify_range.

[gcc r13-3453] Check HONOR_NANS instead of flag_finite_math_only in frange:verify_range.

[Aldy Hernandez]

https://gcc.gnu.org/g:1e9d9ed095df3d064cf9d91d46f3e5426c2a05a7

commit r13-3453-g1e9d9ed095df3d064cf9d91d46f3e5426c2a05a7
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Sun Oct 23 16:51:17 2022 +0200

    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:
---
 gcc/value-range.cc | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index d779e9819e2..d8ee6ec0d0f 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 ();
 }