[PATCH v2 5/5] x86 long double: Add tests for pseudo normal numbers

[Siddhesh Poyarekar]

Add some tests for fpclassify, isnanl, isinfl and issignaling.
---
 sysdeps/x86/fpu/Makefile        |   3 +-
 sysdeps/x86/fpu/test-unnormal.c | 132 ++++++++++++++++++++++++++++++++
 2 files changed, 134 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/x86/fpu/test-unnormal.c

diff --git a/sysdeps/x86/fpu/Makefile b/sysdeps/x86/fpu/Makefile
index 600e42c3db..e77de56d14 100644
--- a/sysdeps/x86/fpu/Makefile
+++ b/sysdeps/x86/fpu/Makefile
@@ -4,11 +4,12 @@ CPPFLAGS += -I../soft-fp
 
 libm-support += powl_helper
 tests += test-fenv-sse test-fenv-clear-sse test-fenv-x87 test-fenv-sse-2 \
-	 test-flt-eval-method-387 test-flt-eval-method-sse
+	 test-flt-eval-method-387 test-flt-eval-method-sse test-unnormal
 CFLAGS-test-fenv-sse.c += -msse2 -mfpmath=sse
 CFLAGS-test-fenv-clear-sse.c += -msse2 -mfpmath=sse
 CFLAGS-test-fenv-sse-2.c += -msse2 -mfpmath=sse
 CFLAGS-test-flt-eval-method-387.c += -fexcess-precision=standard -mfpmath=387
 CFLAGS-test-flt-eval-method-sse.c += -fexcess-precision=standard -msse2 \
 				     -mfpmath=sse
+CFLAGS-test-unnormal.c += -fsignaling-nans -std=c2x
 endif
diff --git a/sysdeps/x86/fpu/test-unnormal.c b/sysdeps/x86/fpu/test-unnormal.c
new file mode 100644
index 0000000000..a6baa01802
--- /dev/null
+++ b/sysdeps/x86/fpu/test-unnormal.c
@@ -0,0 +1,132 @@
+/* Test long double classification with x86 pseudo normal numbers.
+   Copyright (C) 2020 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 <math.h>
+#include <stdio.h>
+#include <string.h>
+#include <math_ldbl.h>
+#include <support/test-driver.h>
+#include <support/check.h>
+
+/* If we need to add regular NaNs here then we need another member specifying
+   whether the NaN is signaling and then issignaling test should be updated to
+   use it.  Additionally, all pseudo-numbers should be classified as
+   signaling.  */
+struct tests
+{
+  ieee_long_double_shape_type d;
+  int class;
+} inputs[] = {
+      /* Normal.  */
+      {
+	.d.parts.lsw = 0x00000400,
+	.d.parts.msw = 0x00000000,
+	.d.parts.sign_exponent = 0x0400,
+	.class = FP_NAN
+      },
+      {
+	.d.parts.lsw = 0x00000400,
+	.d.parts.msw = 0xf0000000,
+	.d.parts.sign_exponent = 0x0400,
+	.class = FP_NORMAL
+      },
+      /* Pseudo-infinite.  */
+      {
+	.d.parts.lsw = 0x00000000,
+	.d.parts.msw = 0x00000000,
+	.d.parts.sign_exponent = 0x7fff,
+	.class = FP_NAN
+      },
+      {
+	.d.parts.lsw = 0x00000000,
+	.d.parts.msw = 0x80000000,
+	.d.parts.sign_exponent = 0x7fff,
+	.class = FP_INFINITE
+      },
+      /* Pseudo-zero.  */
+      {
+	.d.parts.lsw = 0x00000000,
+	.d.parts.msw = 0x00000000,
+	.d.parts.sign_exponent = 0x0100,
+	.class = FP_NAN
+      },
+      {
+	.d.parts.lsw = 0x00000000,
+	.d.parts.msw = 0x00000000,
+	.d.parts.sign_exponent = 0x0000,
+	.class = FP_ZERO
+      },
+};
+
+typedef void (*testfunc_t) (long double, int);
+
+static int
+test_func (const char *testname, testfunc_t testfunc)
+{
+  verbose_printf ("* %s:\n", testname);
+
+  for (int i = 0; i < sizeof (inputs)/sizeof (struct tests); i++)
+    {
+      verbose_printf ("Testing 0x%04x %08x %08x\n",
+		      inputs[i].d.parts.sign_exponent, inputs[i].d.parts.msw,
+		      inputs[i].d.parts.lsw);
+      testfunc (inputs[i].d.value, inputs[i].class);
+    }
+
+  return 0;
+}
+
+static void
+test_fpclassify (long double value, int class)
+{
+  TEST_COMPARE (fpclassify (value), class);
+}
+
+static void
+test_isinf (long double value, int class)
+{
+  TEST_COMPARE ((isinf (value) != 0), (class == FP_INFINITE));
+}
+
+static void
+test_isnan (long double value, int class)
+{
+  TEST_COMPARE ((isnan (value) != 0), (class == FP_NAN));
+}
+
+static void
+test_issignaling (long double value, int class)
+{
+  TEST_COMPARE ((issignaling (value) != 0), (class == FP_NAN));
+}
+
+int
+do_test (void)
+{
+  int ret = 0;
+
+  test_func ("fpclassify", test_fpclassify);
+  test_func ("isinf", test_isinf);
+  test_func ("isnan", test_isnan);
+  test_func ("issignaling", test_issignaling);
+
+  return ret;
+}
+
+#include <support/test-driver.c>
-- 
2.29.2