1 files changed, 179 insertions, 0 deletions
diff --git a/gnulib-tests/test-frexp.h b/gnulib-tests/test-frexp.h
new file mode 100644
index 0000000..ead73d7
--- /dev/null
+++ b/gnulib-tests/test-frexp.h
@@ -0,0 +1,179 @@
+/* Test of splitting a double into fraction and mantissa.
+   Copyright (C) 2012-2023 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+static DOUBLE
+my_ldexp (DOUBLE x, int d)
+{
+  for (; d > 0; d--)
+    x *= L_(2.0);
+  for (; d < 0; d++)
+    x *= L_(0.5);
+  return x;
+}
+
+static void
+test_function (void)
+{
+  int i;
+  VOLATILE DOUBLE x;
+
+  { /* NaN.  */
+    int exp = -9999;
+    DOUBLE mantissa;
+    x = NAN;
+    mantissa = FREXP (x, &exp);
+    ASSERT (ISNAN (mantissa));
+  }
+
+  { /* Positive infinity.  */
+    int exp = -9999;
+    DOUBLE mantissa;
+    x = INFINITY;
+    mantissa = FREXP (x, &exp);
+    ASSERT (mantissa == x);
+  }
+
+  { /* Negative infinity.  */
+    int exp = -9999;
+    DOUBLE mantissa;
+    x = - INFINITY;
+    mantissa = FREXP (x, &exp);
+    ASSERT (mantissa == x);
+  }
+
+  { /* Positive zero.  */
+    int exp = -9999;
+    DOUBLE mantissa;
+    x = L_(0.0);
+    mantissa = FREXP (x, &exp);
+    ASSERT (exp == 0);
+    ASSERT (mantissa == x);
+    ASSERT (!signbit (mantissa));
+  }
+
+  { /* Negative zero.  */
+    int exp = -9999;
+    DOUBLE mantissa;
+    x = MINUS_ZERO;
+    mantissa = FREXP (x, &exp);
+    ASSERT (exp == 0);
+    ASSERT (mantissa == x);
+    ASSERT (signbit (mantissa));
+  }
+
+  for (i = 1, x = L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == L_(0.5));
+    }
+  for (i = 1, x = L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == L_(0.5));
+    }
+  for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == L_(0.5));
+    }
+
+  for (i = 1, x = - L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == - L_(0.5));
+    }
+  for (i = 1, x = - L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == - L_(0.5));
+    }
+  for (; i >= MIN_EXP - 100 && x < L_(0.0); i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == - L_(0.5));
+    }
+
+  for (i = 1, x = L_(1.01); i <= MAX_EXP; i++, x *= L_(2.0))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == L_(0.505));
+    }
+  for (i = 1, x = L_(1.01); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == L_(0.505));
+    }
+  for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa >= L_(0.5));
+      ASSERT (mantissa < L_(1.0));
+      ASSERT (mantissa == my_ldexp (x, - exp));
+    }
+
+  for (i = 1, x = L_(1.73205); i <= MAX_EXP; i++, x *= L_(2.0))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == L_(0.866025));
+    }
+  for (i = 1, x = L_(1.73205); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i);
+      ASSERT (mantissa == L_(0.866025));
+    }
+  for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5))
+    {
+      int exp = -9999;
+      DOUBLE mantissa = FREXP (x, &exp);
+      ASSERT (exp == i || exp == i + 1);
+      ASSERT (mantissa >= L_(0.5));
+      ASSERT (mantissa < L_(1.0));
+      ASSERT (mantissa == my_ldexp (x, - exp));
+    }
+
+  /* Randomized tests.  */
+  for (i = 0; i < SIZEOF (RANDOM); i++)
+    {
+      x = L_(20.0) * RANDOM[i] - L_(10.0); /* -10.0 <= x <= 10.0 */
+      {
+        int exp = -9999;
+        DOUBLE mantissa = FREXP (x, &exp);
+        ASSERT (x == my_ldexp (mantissa, exp));
+      }
+    }
+}