1 files changed, 88 insertions, 0 deletions
diff --git a/libc/dfp/sysdeps/ieee754r/d32/logbd32.c b/libc/dfp/sysdeps/ieee754r/d32/logbd32.c
new file mode 100644
index 000000000..63e28ca0f
--- /dev/null
+++ b/libc/dfp/sysdeps/ieee754r/d32/logbd32.c
@@ -0,0 +1,88 @@
+/* Returns the unbiased exponent of the passed _Decimal32 value
+   Copyright (C) 2006 IBM Corporation.
+
+   Author(s): Joseph Kerian <jkerian@us.ibm.com>
+
+   The Decimal Floating Point C Library is free software; you can
+   redistribute it and/or modify it under the terms of the GNU Lesser
+   General Public License version 2.1.
+
+   The Decimal Floating Point 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 version 2.1 for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License version 2.1 along with the Decimal Floating Point C Library;
+   if not, write to the Free Software Foundation, Inc., 59 Temple Place,
+   Suite 330, Boston, MA 02111-1307 USA.
+
+   Please see dfp/COPYING.txt for more information.  */
+
+#ifndef _DECIMAL_SIZE
+#  include <decimal32.h>
+#  define _DECIMAL_SIZE 32
+#endif
+
+#include <decContext.h>
+#include <decNumber.h>
+#include <math.h>
+#include <errno.h>
+
+#include <decNumberMath.h>
+
+#define FUNCTION_NAME logb
+
+#include <dfpmacro.h>
+
+DEC_TYPE
+IEEE_FUNCTION_NAME (DEC_TYPE x)
+{
+  decContext context;
+  decNumber dn_result;
+  DEC_TYPE result;
+  decNumber dn_x;
+  decNumber dn_x2;
+
+  FUNC_CONVERT_TO_DN (&x, &dn_x);
+  if (___decNumberIsNaN (&dn_x) || ___decNumberIsInfinite (&dn_x))
+    return x+x;
+  if (___decNumberIsZero (&dn_x))	/*  Pole Error if x==0 */
+    {
+      DFP_EXCEPT (FE_DIVBYZERO);
+      return -DFP_HUGE_VAL;
+    }
+  if (___decNumberIsInfinite (&dn_x) && ___decNumberIsNegative (&dn_x))
+    return -x;
+
+  ___decContextDefault (&context, DEFAULT_CONTEXT);
+  ___decNumberAbs (&dn_x2, &dn_x, &context);
+  /*  For DFP, we use radix 10 instead of whatever FLT_RADIX
+      happens to be */
+  ___decNumberLog10 (&dn_x, &dn_x2, &context);
+
+  /* Capture the case where truncation will return the wrong result.  */
+  if (x < DFP_CONSTANT(1.0) && x > DFP_CONSTANT(-1.0))
+    context.round = DEC_ROUND_UP; /* round away from zero  */
+  else
+    context.round = DEC_ROUND_DOWN; /*  truncate */
+  ___decNumberToIntegralValue (&dn_result, &dn_x, &context);
+
+  FUNC_CONVERT_FROM_DN (&dn_result, &result, &context);
+
+  return result;
+}
+
+DEC_TYPE
+INTERNAL_FUNCTION_NAME (DEC_TYPE x)
+{
+  DEC_TYPE z = IEEE_FUNCTION_NAME (x);
+#ifndef _IEEE_LIBDFP
+  if (_LIB_VERSION == _IEEE_) return z;
+  if (x == DFP_CONSTANT(0.0))
+    DFP_ERRNO (ERANGE);
+#endif
+  return z;
+}
+
+weak_alias (INTERNAL_FUNCTION_NAME, EXTERNAL_FUNCTION_NAME)