From 363dbb9e44d0101f29ec34cadd001893daab3fc6 Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito@andestech.com>
Date: Thu, 27 Jul 2017 16:44:22 +0800
Subject: Add RISC-V port for newlib

  Contributor list:
    - Andrew Waterman  <andrew@sifive.com>
    - Palmer Dabbelt  <palmer@dabbelt.com>
    - Kito Cheng  <kito.cheng@gmail.com>
    - Scott Beamer  <sbeamer@eecs.berkeley.edu>
---
 newlib/libc/machine/riscv/ffs.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 newlib/libc/machine/riscv/ffs.c

(limited to 'newlib/libc/machine/riscv/ffs.c')

diff --git a/newlib/libc/machine/riscv/ffs.c b/newlib/libc/machine/riscv/ffs.c
new file mode 100644
index 000000000..652207722
--- /dev/null
+++ b/newlib/libc/machine/riscv/ffs.c
@@ -0,0 +1,32 @@
+/* Copyright (c) 2017  SiFive Inc. All rights reserved.
+
+   This copyrighted material is made available to anyone wishing to use,
+   modify, copy, or redistribute it subject to the terms and conditions
+   of the BSD License.   This program is distributed in the hope that
+   it will be useful, but WITHOUT ANY WARRANTY expressed or implied,
+   including the implied warranties of MERCHANTABILITY or FITNESS FOR
+   A PARTICULAR PURPOSE.  A copy of this license is available at
+   http://www.opensource.org/licenses.
+*/
+#include <strings.h>
+
+int
+ffs (int word)
+{
+#if __riscv_xlen == 32
+  return (__builtin_ffs (word));
+#else
+  int i;
+
+  if (!word)
+    return 0;
+
+  i = 0;
+  for (;;)
+    {
+      if (((1 << i++) & word) != 0)
+       return i;
+    }
+  return 0;
+#endif
+}
-- 
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