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authorRich Felker <dalias@aerifal.cx>2012-03-13 01:17:53 -0400
committerRich Felker <dalias@aerifal.cx>2012-03-13 01:17:53 -0400
commitb69f695acedd4ce2798ef9ea28d834ceccc789bd (patch)
treeeafd98b9b75160210f3295ac074d699f863d958e /src/math/lround.c
parentd46cf2e14cc4df7cc75e77d7009fcb6df1f48a33 (diff)
downloadmusl-b69f695acedd4ce2798ef9ea28d834ceccc789bd.tar.gz
first commit of the new libm!
thanks to the hard work of Szabolcs Nagy (nsz), identifying the best (from correctness and license standpoint) implementations from freebsd and openbsd and cleaning them up! musl should now fully support c99 float and long double math functions, and has near-complete complex math support. tgmath should also work (fully on gcc-compatible compilers, and mostly on any c99 compiler). based largely on commit 0376d44a890fea261506f1fc63833e7a686dca19 from nsz's libm git repo, with some additions (dummy versions of a few missing long double complex functions, etc.) by me. various cleanups still need to be made, including re-adding (if they're correct) some asm functions that were dropped.
Diffstat (limited to 'src/math/lround.c')
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diff --git a/src/math/lround.c b/src/math/lround.c
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+/* origin: FreeBSD /usr/src/lib/msun/src/s_lround.c */
+/*-
+ * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <limits.h>
+#include <fenv.h>
+#include "libm.h"
+
+#ifndef type
+#define type double
+#define roundit round
+#define dtype long
+#define DTYPE_MIN LONG_MIN
+#define DTYPE_MAX LONG_MAX
+#define fn lround
+#endif
+
+/*
+ * If type has more precision than dtype, the endpoints dtype_(min|max) are
+ * of the form xxx.5; they are "out of range" because lround() rounds away
+ * from 0. On the other hand, if type has less precision than dtype, then
+ * all values that are out of range are integral, so we might as well assume
+ * that everything is in range. At compile time, INRANGE(x) should reduce to
+ * two floating-point comparisons in the former case, or TRUE otherwise.
+ */
+static const type dtype_min = DTYPE_MIN - 0.5;
+static const type dtype_max = DTYPE_MAX + 0.5;
+#define INRANGE(x) \
+ (dtype_max - DTYPE_MAX != 0.5 || ((x) > dtype_min && (x) < dtype_max))
+
+dtype fn(type x)
+{
+
+ if (INRANGE(x)) {
+ x = roundit(x);
+ return (dtype)x;
+ } else {
+ feraiseexcept(FE_INVALID);
+ return DTYPE_MAX;
+ }
+}