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-rw-r--r--math/w_exp2.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/math/w_exp2.c b/math/w_exp2.c
new file mode 100644
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--- /dev/null
+++ b/math/w_exp2.c
@@ -0,0 +1,36 @@
+/*
+ * wrapper exp2(x)
+ */
+
+#include <float.h>
+#include <math.h>
+#include "math_private.h"
+
+static const double o_threshold= (double) DBL_MAX_EXP;
+static const double u_threshold= (double) (DBL_MIN_EXP - DBL_MANT_DIG - 1);
+
+double
+__exp2 (double x) /* wrapper exp2 */
+{
+#ifdef _IEEE_LIBM
+ return __ieee754_exp2 (x);
+#else
+ double z;
+ z = __ieee754_exp2 (x);
+ if (_LIB_VERSION != _IEEE_ && __finite (x))
+ {
+ if (x > o_threshold)
+ /* exp2 overflow */
+ return __kernel_standard (x, x, 44);
+ else if (x <= u_threshold)
+ /* exp2 underflow */
+ return __kernel_standard (x, x, 45);
+ }
+ return z;
+#endif
+}
+weak_alias (__exp2, exp2)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__exp2, __exp2l)
+weak_alias (__exp2, exp2l)
+#endif