nds32: add NPTL/TLS, *context function, libm changes and code cleanup

This commit includes following features.
1. Support NPTL/TLS
2. Add libm function which is used to handle FP rounding and excpetions
   (ex: fclrexcpt,fedisblxcpti,feenablxcpt... )
3. Add *context function for operating user context
   (ex: setcontext,getcontext,makecontext... )
4. Change the return flow from signal handler
5. Cleanup of old code

The testsuite only has 2 errors, tst-cpuclock1 and tst-cputimer1,
which are related to timing accuracy. (math and locale tests are disabled)

Signed-off-by: Vincent Ren-Wei Chen <vincentc@andestech.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/libm/nds32/fclrexcpt.c b/libm/nds32/fclrexcpt.c
new file mode 100644
index 000000000..938f15a25
--- /dev/null
+++ b/libm/nds32/fclrexcpt.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Clear given exceptions in current floating-point environment.
+   Copyright (C) 1997-2013 Free Software Foundation, Inc.
+
+   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 <fenv.h>
+#include "fenv_libc.h"
+#include <fpu_control.h>
+
+
+int
+feclearexcept (int excepts)
+{
+#ifdef  __NDS32_ABI_2FP_PLUS__
+      unsigned long int temp;
+
+      /* Mask out unsupported bits/exceptions.  */
+      excepts &= FE_ALL_EXCEPT;
+
+      /* Get the current floating point status. */
+      _FPU_GETCW (temp);
+
+      /* Clear the relevant bits.  */
+      temp &= ~excepts;
+
+      /* Put the new data in effect.  */
+      _FPU_SETCW (temp);
+
+      /* Success.  */
+      return 0;
+#else
+      /* Unsupported, so fail unless nothing needs to be done.  */
+      return (excepts != 0);
+#endif
+}