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authorjoseph <joseph@7b3dc134-2b1b-0410-93df-9e9f96275f8d>2010-10-12 20:15:00 +0000
committerjoseph <joseph@7b3dc134-2b1b-0410-93df-9e9f96275f8d>2010-10-12 20:15:00 +0000
commit9a13037b9f1354b7405124e83087b72c4c44d388 (patch)
treeada19b076406948b19b9b522f233839986f3b26f /libc/sysdeps/ieee754
parentd98e5692a730c407beffb9c2b1e31ffb14197948 (diff)
Merge changes between r11460 and r11760 from /fsf/trunk.
* sysdeps/powerpc/powerpc32/e500/fpu/feupdateenv.c (feupdateenv): Add libm_hidden_ver. * sysdeps/powerpc/powerpc32/e500/fpu/ftestexcept.c (fetestexcept): Add libm_hidden_def. git-svn-id: svn://svn.eglibc.org/trunk@11761 7b3dc134-2b1b-0410-93df-9e9f96275f8d
Diffstat (limited to 'libc/sysdeps/ieee754')
-rw-r--r--libc/sysdeps/ieee754/dbl-64/s_fmaf.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/libc/sysdeps/ieee754/dbl-64/s_fmaf.c b/libc/sysdeps/ieee754/dbl-64/s_fmaf.c
new file mode 100644
index 000000000..972187660
--- /dev/null
+++ b/libc/sysdeps/ieee754/dbl-64/s_fmaf.c
@@ -0,0 +1,50 @@
+/* Compute x * y + z as ternary operation.
+ Copyright (C) 2010 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Jakub Jelinek <jakub@redhat.com>, 2010.
+
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <math.h>
+#include <fenv.h>
+#include <ieee754.h>
+
+/* This implementation relies on double being more than twice as
+ precise as float and uses rounding to odd in order to avoid problems
+ with double rounding.
+ See a paper by Boldo and Melquiond:
+ http://www.lri.fr/~melquion/doc/08-tc.pdf */
+
+float
+__fmaf (float x, float y, float z)
+{
+ fenv_t env;
+ /* Multiplication is always exact. */
+ double temp = (double) x * (double) y;
+ union ieee754_double u;
+ feholdexcept (&env);
+ fesetround (FE_TOWARDZERO);
+ /* Perform addition with round to odd. */
+ u.d = temp + (double) z;
+ if ((u.ieee.mantissa1 & 1) == 0 && u.ieee.exponent != 0xff)
+ u.ieee.mantissa1 |= fetestexcept (FE_INEXACT) != 0;
+ feupdateenv (&env);
+ /* And finally truncation with round to nearest. */
+ return (float) u.d;
+}
+#ifndef __fmaf
+weak_alias (__fmaf, fmaf)
+#endif