math: Add test to check if floor raise inexact floating-point exception

It is not allowed anymore on ISO C23.

math/Makefile

@@ -241,7 +241,7 @@ tests = test-matherr-3 test-fenv basic-test \
 	test-fenv-tls test-fenv-preserve test-fenv-return \
 	test-nearbyint-except test-fenv-clear \
 	test-nearbyint-except-2 test-signgam-uchar test-signgam-uchar-init \
-	test-ceil-except-2 \
+	test-ceil-except-2 test-floor-except-2 \
 	test-signgam-uint test-signgam-uint-init test-signgam-ullong \
 	test-signgam-ullong-init test-nan-overflow test-nan-payload \
 	test-fexcept test-fexcept-traps test-fesetexcept \
@@ -465,6 +465,7 @@ CFLAGS-test-fe-snans-always-signal.c += $(config-cflags-signaling-nans)
 CFLAGS-test-nan-const.c += -fno-builtin
 
 CFLAGS-test-ceil-except-2.c += -fno-builtin
+CFLAGS-test-floor-except-2.c += -fno-builtin
 
 include ../Rules
 

math/test-floor-except-2.c

@@ -0,0 +1,67 @@
+/* Test floor functions do not disable exception traps.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <fenv.h>
+#include <math.h>
+#include <stdio.h>
+
+#ifndef FE_INEXACT
+# define FE_INEXACT 0
+#endif
+
+#define TEST_FUNC(NAME, FLOAT, SUFFIX)					\
+static int								\
+NAME (void)								\
+{									\
+  int result = 0;							\
+  volatile FLOAT a, b __attribute__ ((unused));				\
+  a = 1.5;								\
+  /* floor must work when traps on "inexact" are enabled.  */	\
+  b = floor ## SUFFIX (a);						\
+  /* And it must have left those traps enabled.  */			\
+  if (fegetexcept () == FE_INEXACT)					\
+    puts ("PASS: " #FLOAT);						\
+  else									\
+    {									\
+      puts ("FAIL: " #FLOAT);						\
+      result = 1;							\
+    }									\
+  return result;							\
+}
+
+TEST_FUNC (float_test, float, f)
+TEST_FUNC (double_test, double, )
+TEST_FUNC (ldouble_test, long double, l)
+
+static int
+do_test (void)
+{
+  if (feenableexcept (FE_INEXACT) == -1)
+    {
+      puts ("enabling FE_INEXACT traps failed, cannot test");
+      return 77;
+    }
+  int result = float_test ();
+  feenableexcept (FE_INEXACT);
+  result |= double_test ();
+  feenableexcept (FE_INEXACT);
+  result |= ldouble_test ();
+  return result;
+}
+
+#include <support/test-driver.c>