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authorJoseph Myers <joseph@codesourcery.com>2012-07-01 13:08:59 +0000
committerJoseph Myers <joseph@codesourcery.com>2012-07-01 13:08:59 +0000
commite84eabb3871c9b39e59323bf3f6b98c2ca9d1cd0 (patch)
treedff3f1b79454b518d15a7b9bbedeb57ff156bbe8 /ports/sysdeps/alpha/fpu/s_trunc.c
parent75f0d3040a2c2de8842bfa7a09e11da1a73e17d0 (diff)
parente64ac02c24b43659048622714afdc92fedf561fa (diff)
downloadglibc-2.16.90.tar.gz
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Merge glibc-ports into ports/ directory. glibc-2.16.90 glibc-2.16-ports-merge
Diffstat (limited to 'ports/sysdeps/alpha/fpu/s_trunc.c')
-rw-r--r--ports/sysdeps/alpha/fpu/s_trunc.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/ports/sysdeps/alpha/fpu/s_trunc.c b/ports/sysdeps/alpha/fpu/s_trunc.c
new file mode 100644
index 0000000000..876330c0fe
--- /dev/null
+++ b/ports/sysdeps/alpha/fpu/s_trunc.c
@@ -0,0 +1,52 @@
+/* Copyright (C) 2007 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Richard Henderson.
+
+   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_ldbl_opt.h>
+
+
+/* Use the chopped rounding mode conversion instructions to implement trunc. */
+
+double
+__trunc (double x)
+{
+  double two52 = copysign (0x1.0p52, x);
+  double r, tmp;
+  
+  __asm (
+#ifdef _IEEE_FP_INEXACT
+	 "addt/suic %2, %3, %1\n\tsubt/suic %1, %3, %0"
+#else
+	 "addt/suc %2, %3, %1\n\tsubt/suc %1, %3, %0"
+#endif
+	 : "=&f"(r), "=&f"(tmp)
+	 : "f"(x), "f"(two52));
+
+  /* trunc(-0) == -0, and in general we'll always have the same
+     sign as our input.  */
+  return copysign (r, x);
+}
+
+weak_alias (__trunc, trunc)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__trunc, __truncl)
+weak_alias (__trunc, truncl)
+#endif
+#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_1)
+compat_symbol (libm, __trunc, truncl, GLIBC_2_1);
+#endif