2.5-18.1

1 files changed, 32 insertions, 0 deletions

diff --git a/math/w_exp2f.c b/math/w_exp2f.c
new file mode 100644
index 0000000000..9120c88b60
--- /dev/null
+++ b/math/w_exp2f.c
@@ -0,0 +1,32 @@
+/*
+ * wrapper exp2f(x)
+ */
+
+#include <float.h>
+#include <math.h>
+#include "math_private.h"
+
+static const float o_threshold= (float) FLT_MAX_EXP;
+static const float u_threshold= (float) (FLT_MIN_EXP - FLT_MANT_DIG - 1);
+
+float
+__exp2f (float x)		/* wrapper exp2f */
+{
+#ifdef _IEEE_LIBM
+  return __ieee754_exp2f (x);
+#else
+  float z;
+  z = __ieee754_exp2f (x);
+  if (_LIB_VERSION != _IEEE_ && __finitef (x))
+    {
+      if (x > o_threshold)
+	/* exp2 overflow */
+	return (float) __kernel_standard ((double) x, (double) x, 144);
+      else if (x <= u_threshold)
+	/* exp2 underflow */
+	return (float) __kernel_standard ((double) x, (double) x, 145);
+    }
+  return z;
+#endif
+}
+weak_alias (__exp2f, exp2f)