[Feature][ZXW-33]merge ZXW 0428 version
Change-Id: I11f167edfea428d9fab198ff00ff1364932d1b0b
diff --git a/ap/libc/glibc/glibc-2.23/math/e_exp2l.c b/ap/libc/glibc/glibc-2.23/math/e_exp2l.c
new file mode 100644
index 0000000..b1ea7c7
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/math/e_exp2l.c
@@ -0,0 +1,62 @@
+/* Compute 2^x.
+ Copyright (C) 2012-2016 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <math.h>
+#include <math_private.h>
+#include <float.h>
+
+/* To avoid spurious underflows, use this definition to treat IBM long
+ double as approximating an IEEE-style format. */
+#if LDBL_MANT_DIG == 106
+# undef LDBL_EPSILON
+# define LDBL_EPSILON 0x1p-106L
+#endif
+
+long double
+__ieee754_exp2l (long double x)
+{
+ if (__glibc_likely (isless (x, (long double) LDBL_MAX_EXP)))
+ {
+ if (__builtin_expect (isgreaterequal (x, (long double) (LDBL_MIN_EXP
+ - LDBL_MANT_DIG
+ - 1)), 1))
+ {
+ int intx = (int) x;
+ long double fractx = x - intx;
+ long double result;
+ if (fabsl (fractx) < LDBL_EPSILON / 4.0L)
+ result = __scalbnl (1.0L + fractx, intx);
+ else
+ result = __scalbnl (__ieee754_expl (M_LN2l * fractx), intx);
+ math_check_force_underflow_nonneg (result);
+ return result;
+ }
+ else
+ {
+ /* Underflow or exact zero. */
+ if (isinf (x))
+ return 0;
+ else
+ return LDBL_MIN * LDBL_MIN;
+ }
+ }
+ else
+ /* Infinity, NaN or overflow. */
+ return LDBL_MAX * x;
+}
+strong_alias (__ieee754_exp2l, __exp2l_finite)