Add support for div() to the C library. From OrbitalFox

Documentation @ ce750c08

-Subproject commit 8cc114a79fd2b9b61aa4dd6185feafd9b4acf805
+Subproject commit ce750c0899c2138b37b52a48d020a3eceb92fd04

include/stdlib.h

 /****************************************************************************
  * include/stdlib.h
  *
- *   Copyright (C) 2007-2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -95,6 +95,16 @@ struct mallinfo
                  * by free (not in use) chunks.*/
 };
 
+/* Structure type returned by the div() function. */
+
+struct div_s
+{
+  int quot;     /* Quotient */
+  int rem;      /* Remainder */
+};
+
+typedef struct div_s div_t;
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
@@ -170,13 +180,19 @@ FAR void *memalign(size_t, size_t);
 FAR void *zalloc(size_t);
 FAR void *calloc(size_t, size_t);
 
-/* Misc */
+/* Arithmetic */
 
 int      abs(int j);
+#ifdef CONFIG_CAN_PASS_STRUCTS
+div_t    div(int numer, int denom);
+#endif
 long int labs(long int j);
 #ifdef CONFIG_HAVE_LONG_LONG
 long long int llabs(long long int j);
 #endif
+
+/* Temporary files */
+
 int      mktemp(FAR char *path_template);
 int      mkstemp(FAR char *path_template);
 

libc/stdlib/Make.defs

 ############################################################################
 # libc/stdlib/Make.defs
 #
-#   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2012, 2015 Gregory Nutt. All rights reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
@@ -35,7 +35,7 @@
 
 # Add the stdlib C files to the build
 
-CSRCS += lib_abs.c lib_abort.c lib_imaxabs.c lib_itoa.c lib_labs.c
+CSRCS += lib_abs.c lib_abort.c lib_div.c lib_imaxabs.c lib_itoa.c lib_labs.c
 CSRCS += lib_llabs.c lib_rand.c lib_qsort.c
 CSRCS += lib_strtol.c lib_strtoll.c lib_strtoul.c lib_strtoull.c
 CSRCS += lib_strtod.c lib_checkbase.c

libc/stdlib/lib_div.c

+/****************************************************************************
+ * libc/stdlib/lib_div.c
+ *
+ *   Copyright (C) 2015 Stavros Polymenis. All rights reserved.
+ *   Author: Stavros Polymenis <sp@orbitalfox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <stdlib.h>
+
+#ifdef CONFIG_CAN_PASS_STRUCTS
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: div
+ *
+ * Description:
+ *   The div() function computes the quotient and remainder of the division
+ *   of the numerator 'numer' by the denominator 'denom". If the division is
+ *   inexact, the resulting quotient is the integer of lesser magnitude that
+ *   is the nearest to the algebraic quotient. If the result cannot be
+ *   represented, the behavior is undefined; otherwise, quot * denom + rem
+ *   will equal 'numer'.
+ *
+ * Input Parameters:
+ *   numer - Numerator of the Division
+ *   denom - Denominator of the division
+ *
+ * Returned Value:
+ *   The result of the devision represent as values of type div_t
+ *
+ ****************************************************************************/
+
+div_t div(int numer, int denom)
+{
+  div_t f;
+
+  f.quot = numer / denom;
+  f.rem  = numer % denom;
+  return f;
+}
+
+#endif /* CONFIG_CAN_PASS_STRUCTS */
\ No newline at end of file