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>

17 files changed, 783 insertions, 0 deletions

diff --git a/libm/nds32/Makefile.arch b/libm/nds32/Makefile.arch
new file mode 100644
index 000000000..bd38690be
--- /dev/null
+++ b/libm/nds32/Makefile.arch
@@ -0,0 +1,16 @@
+# Makefile for uClibc-ng
+# Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+
+ifeq ($(UCLIBC_HAS_FENV),y)
+libm_ARCH_SRC:=$(wildcard $(libm_ARCH_DIR)/*.c)
+libm_ARCH_OBJ:=$(patsubst $(libm_ARCH_DIR)/%.c,$(libm_ARCH_OUT)/%.o,$(libm_ARCH_SRC))
+endif
+
+libm_ARCH_OBJS:=$(libm_ARCH_OBJ)
+
+ifeq ($(DOPIC),y)
+libm-a-y+=$(libm_ARCH_OBJS:.o=.os)
+else
+libm-a-y+=$(libm_ARCH_OBJS)
+endif
+libm-so-y+=$(libm_ARCH_OBJS:.o=.os)
diff --git a/libm/nds32/e_sqrt.c b/libm/nds32/e_sqrt.c
new file mode 100644
index 000000000..c737e10c6
--- /dev/null
+++ b/libm/nds32/e_sqrt.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Copyright (C) 2002-2013 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/>.  */
+
+#if defined(__NDS32_ABI_2FP_PLUS__) && defined(__NDS32_EXT_FPU_DP__)
+
+double __ieee754_sqrt (double x)
+{
+  double z;
+  __asm__ ("fsqrtd %0,%1" : "=f" (z) : "f" (x));
+  return z;
+}
+strong_alias(__ieee754_sqrt, sqrt)
+libm_hidden_def(sqrt)
+#else
+#include <libm/e_sqrt.c>
+#endif
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
+}
diff --git a/libm/nds32/fedisblxcpt.c b/libm/nds32/fedisblxcpt.c
new file mode 100644
index 000000000..bbb6d54e4
--- /dev/null
+++ b/libm/nds32/fedisblxcpt.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Disable floating-point exceptions.
+   Copyright (C) 2001-2013 Free Software Foundation, Inc.
+   Contributed by Philip Blundell <philb@gnu.org>, 2001.
+
+   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
+fedisableexcept (int excepts)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	unsigned long int new_exc, old_exc;
+
+	_FPU_GETCW(new_exc);
+
+	old_exc = (new_exc & ENABLE_MASK) >> ENABLE_SHIFT;
+
+	excepts &= FE_ALL_EXCEPT;
+
+	new_exc &= ~(excepts << ENABLE_SHIFT);
+	new_exc &= ~_FPU_RESERVED;
+	_FPU_SETCW (new_exc);
+
+	return old_exc;
+#else
+	/* Unsupported, so return -1 for failure.  */
+	return -1;
+#endif
+}
diff --git a/libm/nds32/feenablxcpt.c b/libm/nds32/feenablxcpt.c
new file mode 100644
index 000000000..14aef9850
--- /dev/null
+++ b/libm/nds32/feenablxcpt.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Enable floating-point exceptions.
+   Copyright (C) 2001-2013 Free Software Foundation, Inc.
+   Contributed by Philip Blundell <philb@gnu.org>, 2001.
+
+   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
+feenableexcept (int excepts)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	unsigned long int new_exc, old_exc;
+
+	_FPU_GETCW(new_exc);
+
+	old_exc = (new_exc & ENABLE_MASK) >> ENABLE_SHIFT;
+
+	excepts &= FE_ALL_EXCEPT;
+
+	new_exc |= (excepts << ENABLE_SHIFT);
+	new_exc &= ~_FPU_RESERVED;
+
+	_FPU_SETCW(new_exc);
+
+	return old_exc;
+#else
+  /* Unsupported, so return -1 for failure.  */
+  return -1;
+#endif
+}
diff --git a/libm/nds32/fegetenv.c b/libm/nds32/fegetenv.c
new file mode 100644
index 000000000..782cf793e
--- /dev/null
+++ b/libm/nds32/fegetenv.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Store 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 <fpu_control.h>
+
+int
+fegetenv (fenv_t *envp)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+      unsigned long int temp;
+      _FPU_GETCW (temp);
+      envp->__fpcsr = temp;
+
+      /* Success.  */
+      return 0;
+#else
+  /* Unsupported, so fail.  */
+  return 1;
+#endif
+}
diff --git a/libm/nds32/fegetexcept.c b/libm/nds32/fegetexcept.c
new file mode 100644
index 000000000..1ffe361cc
--- /dev/null
+++ b/libm/nds32/fegetexcept.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Get floating-point exceptions.
+   Copyright (C) 2001-2013 Free Software Foundation, Inc.
+   Contributed by Philip Blundell <philb@gnu.org>, 2001
+
+   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
+fegetexcept (void)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	unsigned long temp;
+
+	_FPU_GETCW (temp);
+
+	return (temp & ENABLE_MASK) >> ENABLE_SHIFT;
+#else
+	/* Unsupported. Return all exceptions disabled.  */
+	return 0;
+#endif
+}
diff --git a/libm/nds32/fegetround.c b/libm/nds32/fegetround.c
new file mode 100644
index 000000000..e4e70eaad
--- /dev/null
+++ b/libm/nds32/fegetround.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Return current rounding direction.
+   Copyright (C) 2004-2013 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 <fpu_control.h>
+
+int
+fegetround (void)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	unsigned int temp;
+
+	/* Get the current environment.  */
+	_FPU_GETCW (temp);
+
+	return temp & 0x3;
+#else
+	/* The current soft-float implementation only handles TONEAREST.  */
+	return FE_TONEAREST;
+#endif
+}
diff --git a/libm/nds32/feholdexcpt.c b/libm/nds32/feholdexcpt.c
new file mode 100644
index 000000000..4ea3679f5
--- /dev/null
+++ b/libm/nds32/feholdexcpt.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Store current floating-point environment and clear exceptions.
+   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 <fpu_control.h>
+#include "fenv_libc.h"
+
+int
+feholdexcept (fenv_t *envp)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	unsigned long int temp;
+
+	/* Store the environment.  */
+	_FPU_GETCW(temp);
+	envp->__fpcsr = temp;
+
+	/* Now set all exceptions to non-stop.  */
+	temp &= ~(FE_ALL_EXCEPT << ENABLE_SHIFT);
+
+	/* And clear all exception flags.  */
+	temp &= ~FE_ALL_EXCEPT;
+
+	_FPU_SETCW(temp);
+
+	return 0;
+#else
+	/* Unsupported, so fail.  */
+	return 1;
+#endif
+}
+
diff --git a/libm/nds32/fenv_libc.h b/libm/nds32/fenv_libc.h
new file mode 100644
index 000000000..a76f131e4
--- /dev/null
+++ b/libm/nds32/fenv_libc.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Copyright (C) 2000-2013 Free Software Foundation, Inc.
+   Contributed by Alexandre Oliva <aoliva@redhat.com>
+   based on the corresponding file in the mips port.
+
+   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/>.  */
+
+#ifndef _FENV_LIBC_H
+#define _FENV_LIBC_H
+
+/* Mask for enabling exceptions and for the CAUSE bits.  */
+#define ENABLE_MASK	0x00F80U
+
+/* Shift for FE_* flags to get up to the ENABLE bits.  */
+#define	ENABLE_SHIFT	5
+
+#endif /* _FENV_LIBC_H */
diff --git a/libm/nds32/fesetenv.c b/libm/nds32/fesetenv.c
new file mode 100644
index 000000000..4682d3c8e
--- /dev/null
+++ b/libm/nds32/fesetenv.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Install given floating-point environment.
+   Copyright (C) 2004-2013 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 <fpu_control.h>
+
+int
+fesetenv (const fenv_t *envp)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	unsigned int temp;
+
+	_FPU_GETCW (temp);
+	temp &= _FPU_RESERVED;
+
+	if (envp == FE_DFL_ENV)
+	  temp |= _FPU_DEFAULT;
+	else if (envp == FE_NOMASK_ENV)
+	  temp |= _FPU_IEEE;
+	else
+	  temp |= envp->__fpcsr & ~_FPU_RESERVED;
+
+	_FPU_SETCW (temp);
+
+	/* Success.  */
+	return 0;
+#else
+
+	/* Unsupported, so fail.  */
+	return 1;
+#endif
+}
diff --git a/libm/nds32/fesetround.c b/libm/nds32/fesetround.c
new file mode 100644
index 000000000..012a5bfff
--- /dev/null
+++ b/libm/nds32/fesetround.c
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Set current rounding direction.
+   Copyright (C) 2004-2013 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 <fpu_control.h>
+
+int
+fesetround (int round)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	fpu_control_t temp;
+	if ((round & ~0x3) != 0)
+	  /* ROUND is no valid rounding mode.  */
+		return 1;
+
+	_FPU_GETCW (temp);
+	temp = (temp & ~0x3) | round;
+	_FPU_SETCW (temp);
+	return 0;
+#else
+	return (round != FE_TONEAREST);
+#endif
+}
diff --git a/libm/nds32/feupdateenv.c b/libm/nds32/feupdateenv.c
new file mode 100644
index 000000000..d58c9004b
--- /dev/null
+++ b/libm/nds32/feupdateenv.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Install given floating-point environment and raise exceptions.
+   Copyright (C) 1997-2013 Free Software Foundation, Inc.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   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 <fpu_control.h>
+
+int
+feupdateenv (const fenv_t *envp)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	unsigned int temp;
+
+	/* Get the current exception state.  */
+	_FPU_GETCW (temp);
+
+	/* Install new environment.  */
+	fesetenv (envp);
+
+	/* Raise the saved exceptions.  */
+	feraiseexcept (temp & FE_ALL_EXCEPT);
+
+	/* Success.  */
+	return 0;
+#else
+	/* Unsupported, so fail.  */
+	return 1;
+#endif
+}
diff --git a/libm/nds32/fgetexcptflg.c b/libm/nds32/fgetexcptflg.c
new file mode 100644
index 000000000..e446c429c
--- /dev/null
+++ b/libm/nds32/fgetexcptflg.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Store current representation for exceptions.
+   Copyright (C) 1997-2013 Free Software Foundation, Inc.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   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 <fpu_control.h>
+
+int
+fegetexceptflag (fexcept_t *flagp, int excepts)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	fpu_control_t temp;
+
+	/* Get the current exceptions.  */
+	_FPU_GETCW (temp);
+
+	*flagp = temp & excepts & FE_ALL_EXCEPT;
+
+	/* Success.  */
+	return 0;
+#else
+	/* Unsupported, so fail.  */
+	return 1;
+#endif
+}
diff --git a/libm/nds32/fraiseexcpt.c b/libm/nds32/fraiseexcpt.c
new file mode 100644
index 000000000..d1942110c
--- /dev/null
+++ b/libm/nds32/fraiseexcpt.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Raise given exceptions.
+   Copyright (C) 2004-2013 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 <fpu_control.h>
+#include <fenv.h>
+#include <float.h>
+#include "fenv_libc.h"
+
+int
+feraiseexcept (int excepts)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	float temp1 = 0.0, temp2 = 1.0;
+	if (FE_INVALID & excepts)
+	{
+		__asm__ volatile(
+			"fmtsr\t %0, $fs0\n\t"
+			"fdivs\t $fs0, $fs0, $fs0\n\t"
+			:
+			:"r"(temp1)
+			:"$fs0"
+			);
+	}
+	if (FE_DIVBYZERO & excepts)
+	{
+		__asm__ volatile(
+			"fmtsr\t %0, $fs0\n\t"
+			"fmtsr\t %1, $fs1\n\t"
+			"fdivs\t $fs0, $fs1, $fs0\n\t"
+			:
+			:"r"(temp1),"r"(temp2)
+			:"$fs0"
+			);
+	}
+	if (FE_OVERFLOW & excepts)
+	{
+	/* There's no way to raise overflow without also raising inexact.
+	*/
+		unsigned int fpcsr;
+		temp1 = FLT_MAX;
+		__asm__ volatile(
+			"fmfcsr\t %0\n\t"
+			"fmtsr\t %1, $fs0\n\t"
+			"fadds\t $fs0, $fs0, $fs0\n\t"
+			"ori\t %0,%0,0x10\n\t"
+			"fmtcsr\t %0\n\t"
+			:"=&r"(fpcsr)
+			:"r"(temp1)
+			:"$fs0"
+			);
+	}
+	if (FE_UNDERFLOW & excepts)
+	{
+	/* There's no way to raise overflow without also raising inexact.
+	*/
+		temp1 = FLT_MIN;
+		temp2 = 2.0;
+		__asm__ volatile(
+			"fmtsr\t %0, $fs0\n\t"
+			"fmtsr\t %1, $fs1\n\t"
+			"fdivs\t $fs1, $fs0, $fs1\n\t"
+			:
+			:"r"(temp1),"r"(temp2)
+			:"$fs0","$fs1"
+			);
+	}
+	if (FE_INEXACT & excepts)
+	{
+		temp1 = 3.0;
+		__asm__ volatile(
+			"fmtsr\t %0, $fs1\n\t"
+			"fmtsr\t %1, $fs0\n\t"
+			"fdivs\t $fs1, $fs0, $fs1\n\t"
+			:
+			:"r"(temp1),"r"(temp2)
+			:"$fs0","$fs1"
+			);
+	}
+
+	return 0;
+
+#endif
+	/* Unsupported, so fail unless nothing needs to be done.  */
+	return (excepts != 0);
+}
diff --git a/libm/nds32/fsetexcptflg.c b/libm/nds32/fsetexcptflg.c
new file mode 100644
index 000000000..7da943b9d
--- /dev/null
+++ b/libm/nds32/fsetexcptflg.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Set floating-point environment exception handling.
+   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 <fpu_control.h>
+
+int
+fesetexceptflag (const fexcept_t *flagp, int excepts)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	fexcept_t temp;
+
+	/* Get the current environment.  */
+	_FPU_GETCW (temp);
+
+	/* Set the desired exception mask.  */
+	temp &= ~(excepts & FE_ALL_EXCEPT);
+	temp |= (*flagp & excepts & FE_ALL_EXCEPT);
+
+	/* Save state back to the FPU.  */
+	_FPU_SETCW (temp);
+
+	/* Success.  */
+	return 0;
+#else
+	/* Unsupported, so fail unless nothing needs to be done.  */
+	return (excepts != 0);
+#endif
+}
diff --git a/libm/nds32/ftestexcept.c b/libm/nds32/ftestexcept.c
new file mode 100644
index 000000000..8257b6f45
--- /dev/null
+++ b/libm/nds32/ftestexcept.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+/* Test exception in current 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 <fpu_control.h>
+
+int
+fetestexcept (int excepts)
+{
+#ifdef __NDS32_ABI_2FP_PLUS__
+	fexcept_t temp;
+
+	/* Get current exceptions.  */
+	_FPU_GETCW(temp);
+
+	return temp & excepts & FE_ALL_EXCEPT;
+#else
+	/* Unsupported, return 0.  */
+	return 0;
+#endif
+}