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+/* Test of <float.h> substitute.
+ Copyright (C) 2011-2015 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 <http://www.gnu.org/licenses/>. */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2011. */
+
+#include <config.h>
+
+#include <float.h>
+
+#include "fpucw.h"
+#include "macros.h"
+
+/* Check that FLT_RADIX is a constant expression. */
+int a[] = { FLT_RADIX };
+
+#if FLT_RADIX == 2
+
+/* Return 2^n. */
+static float
+pow2f (int n)
+{
+ int k = n;
+ volatile float x = 1;
+ volatile float y = 2;
+ /* Invariant: 2^n == x * y^k. */
+ if (k < 0)
+ {
+ y = 0.5f;
+ k = - k;
+ }
+ while (k > 0)
+ {
+ if (k != 2 * (k / 2))
+ {
+ x = x * y;
+ k = k - 1;
+ }
+ if (k == 0)
+ break;
+ y = y * y;
+ k = k / 2;
+ }
+ /* Now k == 0, hence x == 2^n. */
+ return x;
+}
+
+/* Return 2^n. */
+static double
+pow2d (int n)
+{
+ int k = n;
+ volatile double x = 1;
+ volatile double y = 2;
+ /* Invariant: 2^n == x * y^k. */
+ if (k < 0)
+ {
+ y = 0.5;
+ k = - k;
+ }
+ while (k > 0)
+ {
+ if (k != 2 * (k / 2))
+ {
+ x = x * y;
+ k = k - 1;
+ }
+ if (k == 0)
+ break;
+ y = y * y;
+ k = k / 2;
+ }
+ /* Now k == 0, hence x == 2^n. */
+ return x;
+}
+
+/* Return 2^n. */
+static long double
+pow2l (int n)
+{
+ int k = n;
+ volatile long double x = 1;
+ volatile long double y = 2;
+ /* Invariant: 2^n == x * y^k. */
+ if (k < 0)
+ {
+ y = 0.5L;
+ k = - k;
+ }
+ while (k > 0)
+ {
+ if (k != 2 * (k / 2))
+ {
+ x = x * y;
+ k = k - 1;
+ }
+ if (k == 0)
+ break;
+ y = y * y;
+ k = k / 2;
+ }
+ /* Now k == 0, hence x == 2^n. */
+ return x;
+}
+
+/* ----------------------- Check macros for 'float' ----------------------- */
+
+/* Check that the FLT_* macros expand to constant expressions. */
+int fb[] =
+ {
+ FLT_MANT_DIG, FLT_MIN_EXP, FLT_MAX_EXP,
+ FLT_DIG, FLT_MIN_10_EXP, FLT_MAX_10_EXP
+ };
+float fc[] = { FLT_EPSILON, FLT_MIN, FLT_MAX };
+
+static void
+test_float (void)
+{
+ /* Check that the value of FLT_MIN_EXP is well parenthesized. */
+ ASSERT ((FLT_MIN_EXP % 101111) == (FLT_MIN_EXP) % 101111);
+
+ /* Check that the value of DBL_MIN_10_EXP is well parenthesized. */
+ ASSERT ((FLT_MIN_10_EXP % 101111) == (FLT_MIN_10_EXP) % 101111);
+
+ /* Check that 'float' is as specified in IEEE 754. */
+ ASSERT (FLT_MANT_DIG == 24);
+ ASSERT (FLT_MIN_EXP == -125);
+ ASSERT (FLT_MAX_EXP == 128);
+
+ /* Check the value of FLT_MIN_10_EXP. */
+ ASSERT (FLT_MIN_10_EXP == - (int) (- (FLT_MIN_EXP - 1) * 0.30103));
+
+ /* Check the value of FLT_DIG. */
+ ASSERT (FLT_DIG == (int) ((FLT_MANT_DIG - 1) * 0.30103));
+
+ /* Check the value of FLT_MIN_10_EXP. */
+ ASSERT (FLT_MIN_10_EXP == - (int) (- (FLT_MIN_EXP - 1) * 0.30103));
+
+ /* Check the value of FLT_MAX_10_EXP. */
+ ASSERT (FLT_MAX_10_EXP == (int) (FLT_MAX_EXP * 0.30103));
+
+ /* Check the value of FLT_MAX. */
+ {
+ volatile float m = FLT_MAX;
+ int n;
+
+ ASSERT (m + m > m);
+ for (n = 0; n <= 2 * FLT_MANT_DIG; n++)
+ {
+ volatile float pow2_n = pow2f (n); /* 2^n */
+ volatile float x = m + (m / pow2_n);
+ if (x > m)
+ ASSERT (x + x == x);
+ else
+ ASSERT (!(x + x == x));
+ }
+ }
+
+ /* Check the value of FLT_MIN. */
+ {
+ volatile float m = FLT_MIN;
+ volatile float x = pow2f (FLT_MIN_EXP - 1);
+ ASSERT (m == x);
+ }
+
+ /* Check the value of FLT_EPSILON. */
+ {
+ volatile float e = FLT_EPSILON;
+ volatile float me;
+ int n;
+
+ me = 1.0f + e;
+ ASSERT (me > 1.0f);
+ ASSERT (me - 1.0f == e);
+ for (n = 0; n <= 2 * FLT_MANT_DIG; n++)
+ {
+ volatile float half_n = pow2f (- n); /* 2^-n */
+ volatile float x = me - half_n;
+ if (x < me)
+ ASSERT (x <= 1.0f);
+ }
+ }
+}
+
+/* ----------------------- Check macros for 'double' ----------------------- */
+
+/* Check that the DBL_* macros expand to constant expressions. */
+int db[] =
+ {
+ DBL_MANT_DIG, DBL_MIN_EXP, DBL_MAX_EXP,
+ DBL_DIG, DBL_MIN_10_EXP, DBL_MAX_10_EXP
+ };
+double dc[] = { DBL_EPSILON, DBL_MIN, DBL_MAX };
+
+static void
+test_double (void)
+{
+ /* Check that the value of DBL_MIN_EXP is well parenthesized. */
+ ASSERT ((DBL_MIN_EXP % 101111) == (DBL_MIN_EXP) % 101111);
+
+ /* Check that the value of DBL_MIN_10_EXP is well parenthesized. */
+ ASSERT ((DBL_MIN_10_EXP % 101111) == (DBL_MIN_10_EXP) % 101111);
+
+ /* Check that 'double' is as specified in IEEE 754. */
+ ASSERT (DBL_MANT_DIG == 53);
+ ASSERT (DBL_MIN_EXP == -1021);
+ ASSERT (DBL_MAX_EXP == 1024);
+
+ /* Check the value of DBL_MIN_10_EXP. */
+ ASSERT (DBL_MIN_10_EXP == - (int) (- (DBL_MIN_EXP - 1) * 0.30103));
+
+ /* Check the value of DBL_DIG. */
+ ASSERT (DBL_DIG == (int) ((DBL_MANT_DIG - 1) * 0.30103));
+
+ /* Check the value of DBL_MIN_10_EXP. */
+ ASSERT (DBL_MIN_10_EXP == - (int) (- (DBL_MIN_EXP - 1) * 0.30103));
+
+ /* Check the value of DBL_MAX_10_EXP. */
+ ASSERT (DBL_MAX_10_EXP == (int) (DBL_MAX_EXP * 0.30103));
+
+ /* Check the value of DBL_MAX. */
+ {
+ volatile double m = DBL_MAX;
+ int n;
+
+ ASSERT (m + m > m);
+ for (n = 0; n <= 2 * DBL_MANT_DIG; n++)
+ {
+ volatile double pow2_n = pow2d (n); /* 2^n */
+ volatile double x = m + (m / pow2_n);
+ if (x > m)
+ ASSERT (x + x == x);
+ else
+ ASSERT (!(x + x == x));
+ }
+ }
+
+ /* Check the value of DBL_MIN. */
+ {
+ volatile double m = DBL_MIN;
+ volatile double x = pow2d (DBL_MIN_EXP - 1);
+ ASSERT (m == x);
+ }
+
+ /* Check the value of DBL_EPSILON. */
+ {
+ volatile double e = DBL_EPSILON;
+ volatile double me;
+ int n;
+
+ me = 1.0 + e;
+ ASSERT (me > 1.0);
+ ASSERT (me - 1.0 == e);
+ for (n = 0; n <= 2 * DBL_MANT_DIG; n++)
+ {
+ volatile double half_n = pow2d (- n); /* 2^-n */
+ volatile double x = me - half_n;
+ if (x < me)
+ ASSERT (x <= 1.0);
+ }
+ }
+}
+
+/* -------------------- Check macros for 'long double' -------------------- */
+
+/* Check that the LDBL_* macros expand to constant expressions. */
+int lb[] =
+ {
+ LDBL_MANT_DIG, LDBL_MIN_EXP, LDBL_MAX_EXP,
+ LDBL_DIG, LDBL_MIN_10_EXP, LDBL_MAX_10_EXP
+ };
+long double lc1 = LDBL_EPSILON;
+long double lc2 = LDBL_MIN;
+#if 0 /* LDBL_MAX is not a constant expression on some platforms. */
+long double lc3 = LDBL_MAX;
+#endif
+
+static void
+test_long_double (void)
+{
+ /* Check that the value of LDBL_MIN_EXP is well parenthesized. */
+ ASSERT ((LDBL_MIN_EXP % 101111) == (LDBL_MIN_EXP) % 101111);
+
+ /* Check that the value of LDBL_MIN_10_EXP is well parenthesized. */
+ ASSERT ((LDBL_MIN_10_EXP % 101111) == (LDBL_MIN_10_EXP) % 101111);
+
+ /* Check that 'long double' is at least as wide as 'double'. */
+ ASSERT (LDBL_MANT_DIG >= DBL_MANT_DIG);
+ ASSERT (LDBL_MIN_EXP - LDBL_MANT_DIG <= DBL_MIN_EXP - DBL_MANT_DIG);
+ ASSERT (LDBL_MAX_EXP >= DBL_MAX_EXP);
+
+ /* Check the value of LDBL_DIG. */
+ ASSERT (LDBL_DIG == (int)((LDBL_MANT_DIG - 1) * 0.30103));
+
+ /* Check the value of LDBL_MIN_10_EXP. */
+ ASSERT (LDBL_MIN_10_EXP == - (int) (- (LDBL_MIN_EXP - 1) * 0.30103));
+
+ /* Check the value of LDBL_MAX_10_EXP. */
+ ASSERT (LDBL_MAX_10_EXP == (int) (LDBL_MAX_EXP * 0.30103));
+
+ /* Check the value of LDBL_MAX. */
+ {
+ volatile long double m = LDBL_MAX;
+ int n;
+
+ ASSERT (m + m > m);
+ for (n = 0; n <= 2 * LDBL_MANT_DIG; n++)
+ {
+ volatile long double pow2_n = pow2l (n); /* 2^n */
+ volatile long double x = m + (m / pow2_n);
+ if (x > m)
+ ASSERT (x + x == x);
+ else
+ ASSERT (!(x + x == x));
+ }
+ }
+
+ /* Check the value of LDBL_MIN. */
+ {
+ volatile long double m = LDBL_MIN;
+ volatile long double x = pow2l (LDBL_MIN_EXP - 1);
+ ASSERT (m == x);
+ }
+
+ /* Check the value of LDBL_EPSILON. */
+ {
+ volatile long double e = LDBL_EPSILON;
+ volatile long double me;
+ int n;
+
+ me = 1.0L + e;
+ ASSERT (me > 1.0L);
+ ASSERT (me - 1.0L == e);
+ for (n = 0; n <= 2 * LDBL_MANT_DIG; n++)
+ {
+ volatile long double half_n = pow2l (- n); /* 2^-n */
+ volatile long double x = me - half_n;
+ if (x < me)
+ ASSERT (x <= 1.0L);
+ }
+ }
+}
+
+int
+main ()
+{
+ test_float ();
+ test_double ();
+
+ {
+ DECL_LONG_DOUBLE_ROUNDING
+
+ BEGIN_LONG_DOUBLE_ROUNDING ();
+
+ test_long_double ();
+
+ END_LONG_DOUBLE_ROUNDING ();
+ }
+
+ return 0;
+}
+
+#else
+
+int
+main ()
+{
+ fprintf (stderr, "Skipping test: FLT_RADIX is not 2.\n");
+ return 77;
+}
+
+#endif
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