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-rw-r--r--sysdeps/alpha/fpu/s_floor.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/sysdeps/alpha/fpu/s_floor.c b/sysdeps/alpha/fpu/s_floor.c
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+++ b/sysdeps/alpha/fpu/s_floor.c
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+/* Copyright (C) 1998-2014 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 -inf rounding mode conversion instructions to implement
+   floor.  We note when the exponent is large enough that the value
+   must be integral, as this avoids unpleasant integer overflows.  */
+
+double
+__floor (double x)
+{
+  if (isless (fabs (x), 9007199254740992.0))	/* 1 << DBL_MANT_DIG */
+    {
+      double tmp1, new_x;
+
+      __asm (
+#ifdef _IEEE_FP_INEXACT
+	     "cvttq/svim %2,%1\n\t"
+#else
+	     "cvttq/svm %2,%1\n\t"
+#endif
+	     "cvtqt/m %1,%0\n\t"
+	     : "=f"(new_x), "=&f"(tmp1)
+	     : "f"(x));
+
+      /* floor(-0) == -0, and in general we'll always have the same
+	 sign as our input.  */
+      x = copysign(new_x, x);
+    }
+  return x;
+}
+
+weak_alias (__floor, floor)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__floor, __floorl)
+weak_alias (__floor, floorl)
+#endif
+#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)
+compat_symbol (libm, __floor, floorl, GLIBC_2_0);
+#endif