about summary refs log tree commit diff
path: root/sysdeps/m68k/m680x0/fpu/s_frexpl.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/m68k/m680x0/fpu/s_frexpl.c')
-rw-r--r--sysdeps/m68k/m680x0/fpu/s_frexpl.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/sysdeps/m68k/m680x0/fpu/s_frexpl.c b/sysdeps/m68k/m680x0/fpu/s_frexpl.c
new file mode 100644
index 0000000000..7fdfe2cf7d
--- /dev/null
+++ b/sysdeps/m68k/m680x0/fpu/s_frexpl.c
@@ -0,0 +1,58 @@
+/* Copyright (C) 2003-2014 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+
+long double
+__frexpl (long double value, int *expptr)
+{
+  long double mantissa, exponent;
+  int iexponent;
+  unsigned long fpsr;
+
+  __asm ("ftst%.x %1\n"
+	 "fmove%.l %/fpsr, %0"
+	 : "=dm" (fpsr) : "f" (value));
+  if (fpsr & (7 << 24))
+    {
+      /* Not finite or zero.  */
+      *expptr = 0;
+      return value;
+    }
+  __asm ("fgetexp%.x %1, %0" : "=f" (exponent) : "f" (value));
+  iexponent = (int) exponent + 1;
+  *expptr = iexponent;
+  /* Unnormalized numbers must be handled specially, otherwise fscale
+     results in overflow.  */
+  if (iexponent <= -16384)
+    {
+      value *= 0x1p16383L;
+      iexponent += 16383;
+    }
+  else if (iexponent >= 16384)
+    {
+      value *= 0x1p-16383L;
+      iexponent -= 16383;
+    }
+
+  __asm ("fscale%.l %2, %0"
+	 : "=f" (mantissa)
+	 : "0" (value), "dmi" (-iexponent));
+  return mantissa;
+}
+
+weak_alias (__frexpl, frexpl)