From b9f328eeef0039579d11f4c02ed73fdd7bb885ca Mon Sep 17 00:00:00 2001
From: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>
Date: Sat, 9 Oct 2010 20:46:14 +0000
Subject: [PATCH] add abs()

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2984 42af7a65-404d-4744-a932-0658087f49c3
---
 include/stdlib.h |  4 ++++
 lib/Makefile     |  2 +-
 lib/lib_abs.c    | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 lib/lib_abs.c

diff --git a/include/stdlib.h b/include/stdlib.h
index 19ed91ec4a..c30d07ee39 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -144,6 +144,10 @@ EXTERN FAR void  *memalign(size_t, size_t);
 EXTERN FAR void  *zalloc(size_t);
 EXTERN FAR void  *calloc(size_t, size_t);
 
+/* Misc */
+
+EXTERN int        abs(int i);
+
 /* Sorting */
 
 EXTERN void       qsort(void *base, size_t nmemb, size_t size,
diff --git a/lib/Makefile b/lib/Makefile
index 4ca4735c14..b8897d842f 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -75,7 +75,7 @@ ifeq ($(CONFIG_LIBC_FLOATINGPOINT),y)
 STDIO_SRCS	+= lib_dtoa.c
 endif
 
-STDLIB_SRCS	= lib_rand.c lib_qsort.c
+STDLIB_SRCS	= lib_abs.c lib_rand.c lib_qsort.c
 
 MATH_SRCS	= lib_rint.c lib_fixedmath.c lib_b16sin.c lib_b16cos.c
 
diff --git a/lib/lib_abs.c b/lib/lib_abs.c
new file mode 100644
index 0000000000..8ef131b875
--- /dev/null
+++ b/lib/lib_abs.c
@@ -0,0 +1,54 @@
+/************************************************************************
+ * lib/lib_abs.c
+ *
+ *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <stdlib.h>
+
+/************************************************************************
+ * Global Functions
+ ************************************************************************/
+
+int abs(int i)
+{
+  if (i < 0)
+    {
+      i = -i;
+    }
+  return i;
+}