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-rw-r--r--math/s_log10p1_template.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/math/s_log10p1_template.c b/math/s_log10p1_template.c
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+++ b/math/s_log10p1_template.c
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+/* Return base-10 logarithm of 1 + X.
+ Copyright (C) 2024 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <math.h>
+#include <math-narrow-eval.h>
+#include <math-underflow.h>
+
+FLOAT
+M_DECL_FUNC (__log10p1) (FLOAT x)
+{
+ if (__glibc_unlikely (islessequal (x, M_LIT (-1.0))))
+ {
+ if (x == -1)
+ __set_errno (ERANGE);
+ else
+ __set_errno (EDOM);
+ }
+ if (isless (M_FABS (x), M_EPSILON / 4))
+ {
+ /* Ensure appropriate underflows (a wider range than for log1p,
+ with potential for zero results from nonzero arguments, in
+ which case errno should be set based on the result with any
+ excess range and precision removed) even if the result of
+ multiplying by M_MLIT (M_LOG10E) is exact. */
+ FLOAT ret = math_narrow_eval (M_MLIT (M_LOG10E) * x);
+ math_check_force_underflow (ret);
+ if (x != 0 && ret == 0)
+ __set_errno (ERANGE);
+ return ret;
+ }
+ return M_MLIT (M_LOG10E) * M_SUF (__log1p) (x);
+}
+declare_mgen_alias (__log10p1, log10p1);