C-SKY port: libgcc

2018-08-17  Jojo  <jijie_rong@c-sky.com>
	    Huibin Wang  <huibin_wang@c-sky.com>
	    Sandra Loosemore  <sandra@codesourcery.com>
	    Chung-Lin Tang  <cltang@codesourcery.com>

	C-SKY port: libgcc

	libgcc/
	* config.host: Add C-SKY support.
	* config/csky/*: New.

Co-Authored-By: Chung-Lin Tang <cltang@codesourcery.com>
Co-Authored-By: Huibin Wang <huibin_wang@c-sky.com>
Co-Authored-By: Sandra Loosemore <sandra@codesourcery.com>

From-SVN: r263631

libgcc/ChangeLog

+2018-08-17  Jojo  <jijie_rong@c-sky.com>
+	    Huibin Wang  <huibin_wang@c-sky.com>
+	    Sandra Loosemore  <sandra@codesourcery.com>
+	    Chung-Lin Tang  <cltang@codesourcery.com>
+
+	C-SKY port: libgcc
+
+	* config.host: Add C-SKY support.
+	* config/csky/*: New.
+
 2018-08-12  Chung-Ju Wu  <jasonwucj@gmail.com>
 
 	* config/nds32/t-nds32-isr: Rearrange object dependency.

libgcc/config.host

@@ -108,6 +108,9 @@ cr16-*-*)
 crisv32-*-*)
 	cpu_type=cris
 	;;
+csky*-*-*)
+	cpu_type=csky
+	;;
 fido-*-*)
 	cpu_type=m68k
 	;;
@@ -507,6 +510,15 @@ cris-*-elf)
 cris-*-linux* | crisv32-*-linux*)
 	tmake_file="$tmake_file cris/t-cris t-softfp-sfdf t-softfp cris/t-linux"
 	;;
+csky-*-elf*)
+	tmake_file="csky/t-csky t-fdpbit"
+	extra_parts="$extra_parts crti.o crtn.o"
+	;;
+csky-*-linux*)
+	tmake_file="$tmake_file csky/t-csky t-slibgcc-libgcc t-fdpbit csky/t-linux-csky"
+	extra_parts="$extra_parts crti.o crtn.o"
+	md_unwind_header=csky/linux-unwind.h
+	;;
 epiphany-*-elf* | epiphany-*-rtems*)
 	tmake_file="$tmake_file epiphany/t-epiphany t-fdpbit epiphany/t-custom-eqsf"
 	extra_parts="$extra_parts crti.o crtint.o crtrunc.o crtm1reg-r43.o crtm1reg-r63.o crtn.o"

libgcc/config/csky/crti.S

+# Define _init and _fini entry points for C-SKY.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# Contributed by C-SKY Microsystems and Mentor Graphics.
+#
+# This file is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 3, or (at your option) any
+# later version.
+#
+# This file 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
+# General Public License for more details.
+#
+# Under Section 7 of GPL version 3, you are granted additional
+# permissions described in the GCC Runtime Library Exception, version
+# 3.1, as published by the Free Software Foundation.
+#
+# You should have received a copy of the GNU General Public License and
+# a copy of the GCC Runtime Library Exception along with this program;
+# see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+
+# This file just makes a stack frame for the contents of the .fini and
+# .init sections.  Users may put any desired instructions in those
+# sections.
+
+	.file    "crti.S"
+
+/* We use more complicated versions of this code with GLIBC.  */
+#if defined(__gnu_linux__)
+
+#ifndef PREINIT_FUNCTION
+# define PREINIT_FUNCTION __gmon_start__
+#endif
+
+#ifndef PREINIT_FUNCTION_WEAK
+# define PREINIT_FUNCTION_WEAK 1
+#endif
+
+#if PREINIT_FUNCTION_WEAK
+	.global PREINIT_FUNCTION
+	.weak PREINIT_FUNCTION
+	.align 4
+	.type call_weak_fn, %function
+call_weak_fn:
+	// push  lr
+	subi    sp, 4
+	stw     lr, (sp)
+#ifdef  __PIC__
+	lrw     a2, PREINIT_FUNCTION@GOT
+	addu    a2, gb
+	ldw     a2, (a2)
+#else
+	lrw     a2, PREINIT_FUNCTION
+#endif
+	cmpnei  a2, 0
+	bf      1f
+	jsr     a2
+1:
+	// pop lr
+	ldw     lr, (sp)
+	addi    sp, 4
+	rts
+
+	.align 4
+#else
+	.hidden PREINIT_FUNCTION
+#endif /* PREINIT_FUNCTION_WEAK */
+
+	.section .init,"ax",@progbits
+	.align 4
+	.globl _init
+	.type _init, @function
+_init:
+	subi    sp, 8
+	stw     lr, (sp, 0)
+#ifdef __PIC__
+	//  stw     gb, (sp, 4)
+	bsr     .Lgetpc
+.Lgetpc:
+	lrw     gb, .Lgetpc@GOTPC
+	add     gb, lr
+#endif
+#if PREINIT_FUNCTION_WEAK
+#ifdef __PIC__
+	lrw     a2, call_weak_fn@GOTOFF
+	add     a2, gb
+	jsr     a2
+#else
+	jsri    call_weak_fn
+#endif
+#else /* !PREINIT_FUNCTION_WEAK */
+#ifdef  __PIC__
+	lrw     a2, PREINIT_FUNCTION@PLT
+	addu    a2, gb
+	ldw     a2, (a2)
+	jsr     a2
+#else
+	jsri    PREINIT_FUNCTION
+#endif
+#endif /* PREINIT_FUNCTION_WEAK */
+
+	br      2f
+	.literals
+	.align  4
+2:
+	.section .fini,"ax",@progbits
+	.align 4
+	.globl _fini
+	.type _fini, @function
+_fini:
+	subi    sp,8
+	stw     lr, (sp, 0)
+	br      2f
+	.literals
+	.align  4
+2:
+
+/* These are the non-GLIBC versions.  */
+#else  /* !defined(__gnu_linux__) */
+	.section  ".init"
+	.global  _init
+	.type  _init,@function
+	.align  2
+_init:
+	subi  sp, 16
+	st.w  lr, (sp, 12)
+	mov     r0, r0
+
+	.section  ".fini"
+	.global  _fini
+	.type  _fini,@function
+	.align  2
+_fini:
+	subi  sp, 16
+	st.w  lr, (sp, 12)
+	mov     r0, r0
+#endif /* defined(__gnu_linux__) */

libgcc/config/csky/crtn.S

+# Terminate C-SKY .init and .fini sections.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# Contributed by C-SKY Microsystems and Mentor Graphics.
+#
+# This file is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 3, or (at your option) any
+# later version.
+#
+# This file 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
+# General Public License for more details.
+#
+# Under Section 7 of GPL version 3, you are granted additional
+# permissions described in the GCC Runtime Library Exception, version
+# 3.1, as published by the Free Software Foundation.
+#
+# You should have received a copy of the GNU General Public License and
+# a copy of the GCC Runtime Library Exception along with this program;
+# see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+
+# This file just makes sure that the .fini and .init sections do in
+# fact return.  Users may put any desired instructions in those sections.
+# This file is the last thing linked into any executable.
+
+	.file    "crtn.S"
+
+# Is this the GLIBC version?
+#if defined(__gnu_linux__)
+	 .section .init,"ax",@progbits
+	 ldw     lr, (sp, 0)
+	 addi    sp, 8
+	 rts
+
+	 .section .fini,"ax",@progbits
+	 ldw     lr, (sp, 0)
+	 addi    sp, 8
+	 rts
+
+#else /* !defined(__gnu_linux__) */
+	.section  ".init"
+	ldw     lr, (sp, 12)
+	addi    sp, 16
+	jmp     lr
+
+	.section  ".fini"
+	ldw     lr, (sp, 12)
+	addi    sp, 16
+	jmp     lr
+
+# Th-th-th-that is all folks!
+#endif  /* defined(__gnu_linux__) */

libgcc/config/csky/linux-atomic.c

+/* Linux-specific atomic operations for C-SKY.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   Contributed by C-SKY Microsystems and Mentor Graphics.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it under
+   the terms of the GNU General Public License as published by the Free
+   Software Foundation; either version 3, or (at your option) any later
+   version.
+
+   GCC 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 General Public License
+   for more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.	 */
+
+/* Kernel helper for compare-and-exchange.  */
+inline int
+__kernel_cmpxchg (int oldval, int newval, volatile int *ptr)
+{
+  register int _a0 asm ("a0") = oldval;
+  register int _a1 asm ("a1") = newval;
+  register volatile int *_a2 asm ("a2") = ptr;
+  __asm__ __volatile__ ("trap	  2\n"	    \
+			:"+r" (_a0) :"r" (_a1) , "r" (_a2)	\
+			: "a3", "memory");			\
+  return _a0;
+}
+
+
+/* Kernel helper for memory barrier.  */
+inline void __kernel_dmb (void)
+{
+  asm ("sync":::"memory");
+}
+
+/* Note: we implement byte, short and int versions of atomic operations using
+   the above kernel helpers, but there is no support for "long long" (64-bit)
+   operations as yet.  */
+
+#define HIDDEN __attribute__ ((visibility ("hidden")))
+
+#ifdef __CSKYLE__
+#define INVERT_MASK_1 0
+#define INVERT_MASK_2 0
+#else
+#define INVERT_MASK_1 24
+#define INVERT_MASK_2 16
+#endif
+
+#define MASK_1 0xffu
+#define MASK_2 0xffffu
+
+#define FETCH_AND_OP_WORD(OP, PFX_OP, INF_OP)				\
+  int HIDDEN								\
+  __sync_fetch_and_##OP##_4 (int *ptr, int val)				\
+  {									\
+    int failure, tmp;							\
+									\
+    do									\
+      {									\
+	tmp = *ptr;							\
+	failure = __kernel_cmpxchg (tmp, PFX_OP (tmp INF_OP val), ptr);	\
+      }									\
+    while (failure != 0);						\
+									\
+    return tmp;								\
+  }
+
+FETCH_AND_OP_WORD (add,	  , +)
+FETCH_AND_OP_WORD (sub,	  , -)
+FETCH_AND_OP_WORD (or,	  , |)
+FETCH_AND_OP_WORD (and,	  , &)
+FETCH_AND_OP_WORD (xor,	  , ^)
+FETCH_AND_OP_WORD (nand, ~, &)
+
+#define NAME_oldval(OP, WIDTH) __sync_fetch_and_##OP##_##WIDTH
+#define NAME_newval(OP, WIDTH) __sync_##OP##_and_fetch_##WIDTH
+
+/* Implement both __sync_<op>_and_fetch and __sync_fetch_and_<op> for
+   subword-sized quantities.  */
+
+#define SUBWORD_SYNC_OP(OP, PFX_OP, INF_OP, TYPE, WIDTH, RETURN)	\
+  TYPE HIDDEN								\
+  NAME##_##RETURN (OP, WIDTH) (TYPE *ptr, TYPE val)			\
+  {									\
+    int *wordptr = (int *) ((unsigned int) ptr & ~3);			\
+    unsigned int mask, shift, oldval, newval;				\
+    int failure;							\
+									\
+    shift = (((unsigned int) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH;	\
+    mask = MASK_##WIDTH << shift;					\
+									\
+    do									\
+      {									\
+	oldval = *wordptr;						\
+	newval = ((PFX_OP (((oldval & mask) >> shift)			\
+		   INF_OP (unsigned int) val)) << shift) & mask;	\
+	newval |= oldval & ~mask;					\
+	failure = __kernel_cmpxchg (oldval, newval, wordptr);		\
+      }									\
+    while (failure != 0);						\
+									\
+    return (RETURN & mask) >> shift;					\
+  }
+
+SUBWORD_SYNC_OP (add,	, +, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (sub,	, -, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (or,	, |, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (and,	, &, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (xor,	, ^, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned short, 2, oldval)
+
+SUBWORD_SYNC_OP (add,	, +, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (sub,	, -, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (or,	, |, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (and,	, &, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (xor,	, ^, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, oldval)
+
+#define OP_AND_FETCH_WORD(OP, PFX_OP, INF_OP)				\
+  int HIDDEN								\
+  __sync_##OP##_and_fetch_4 (int *ptr, int val)				\
+  {									\
+    int tmp, failure;							\
+									\
+    do									\
+      {									\
+	tmp = *ptr;							\
+	failure = __kernel_cmpxchg (tmp, PFX_OP tmp INF_OP val, ptr);	\
+      }									\
+    while (failure != 0);						\
+									\
+    return PFX_OP tmp INF_OP val;					\
+  }
+
+OP_AND_FETCH_WORD (add,	  , +)
+OP_AND_FETCH_WORD (sub,	  , -)
+OP_AND_FETCH_WORD (or,	  , |)
+OP_AND_FETCH_WORD (and,	  , &)
+OP_AND_FETCH_WORD (xor,	  , ^)
+OP_AND_FETCH_WORD (nand, ~, &)
+
+SUBWORD_SYNC_OP (add,	, +, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (sub,	, -, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (or,	, |, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (and,	, &, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (xor,	, ^, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned short, 2, newval)
+
+SUBWORD_SYNC_OP (add,	, +, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (sub,	, -, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (or,	, |, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (and,	, &, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (xor,	, ^, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, newval)
+
+int HIDDEN
+__sync_val_compare_and_swap_4 (int *ptr, int oldval, int newval)
+{
+  int actual_oldval, fail;
+
+  while (1)
+    {
+      actual_oldval = *ptr;
+
+      if (oldval != actual_oldval)
+	return actual_oldval;
+
+      fail = __kernel_cmpxchg (actual_oldval, newval, ptr);
+
+      if (!fail)
+	return oldval;
+    }
+}
+
+#define SUBWORD_VAL_CAS(TYPE, WIDTH)					\
+  TYPE HIDDEN								\
+  __sync_val_compare_and_swap_##WIDTH (TYPE *ptr, TYPE oldval,		\
+				       TYPE newval)			\
+  {									\
+    int *wordptr = (int *)((unsigned int) ptr & ~3), fail;		\
+    unsigned int mask, shift, actual_oldval, actual_newval;		\
+									\
+    shift = (((unsigned int) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH;	\
+    mask = MASK_##WIDTH << shift;					\
+									\
+    while (1)								\
+      {									\
+	actual_oldval = *wordptr;					\
+									\
+	if (((actual_oldval & mask) >> shift) != (unsigned int) oldval)	\
+	  return (actual_oldval & mask) >> shift;			\
+									\
+	actual_newval = (actual_oldval & ~mask)				\
+			| (((unsigned int) newval << shift) & mask);	\
+									\
+	fail = __kernel_cmpxchg (actual_oldval, actual_newval,		\
+				 wordptr);				\
+									\
+	if (!fail)							\
+	  return oldval;						\
+      }									\
+  }
+
+SUBWORD_VAL_CAS (unsigned short, 2)
+SUBWORD_VAL_CAS (unsigned char,	1)
+
+typedef unsigned char bool;
+
+bool HIDDEN
+__sync_bool_compare_and_swap_4 (int *ptr, int oldval, int newval)
+{
+  int failure = __kernel_cmpxchg (oldval, newval, ptr);
+  return (failure == 0);
+}
+
+#define SUBWORD_BOOL_CAS(TYPE, WIDTH)					\
+  bool HIDDEN								\
+  __sync_bool_compare_and_swap_##WIDTH (TYPE *ptr, TYPE oldval,		\
+					TYPE newval)			\
+  {									\
+    TYPE actual_oldval							\
+      = __sync_val_compare_and_swap_##WIDTH (ptr, oldval, newval);	\
+    return (oldval == actual_oldval);					\
+  }
+
+SUBWORD_BOOL_CAS (unsigned short, 2)
+SUBWORD_BOOL_CAS (unsigned char, 1)
+
+void HIDDEN
+__sync_synchronize (void)
+{
+  __kernel_dmb ();
+}
+
+int HIDDEN
+__sync_lock_test_and_set_4 (int *ptr, int val)
+{
+  int failure, oldval;
+
+  do
+    {
+      oldval = *ptr;
+      failure = __kernel_cmpxchg (oldval, val, ptr);
+    }
+  while (failure != 0);
+
+  return oldval;
+}
+
+#define SUBWORD_TEST_AND_SET(TYPE, WIDTH)				\
+  TYPE HIDDEN								\
+  __sync_lock_test_and_set_##WIDTH (TYPE *ptr, TYPE val)		\
+  {									\
+    int failure;							\
+    unsigned int oldval, newval, shift, mask;				\
+    int *wordptr = (int *) ((unsigned int) ptr & ~3);			\
+									\
+    shift = (((unsigned int) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH;	\
+    mask = MASK_##WIDTH << shift;					\
+									\
+    do									\
+      {									\
+	oldval = *wordptr;						\
+	newval = ((oldval & ~mask)					\
+		  | (((unsigned int) val << shift) & mask));		\
+	failure = __kernel_cmpxchg (oldval, newval, wordptr);		\
+      }									\
+    while (failure != 0);						\
+									\
+    return (oldval & mask) >> shift;					\
+  }
+
+SUBWORD_TEST_AND_SET (unsigned short, 2)
+SUBWORD_TEST_AND_SET (unsigned char,  1)
+
+#define SYNC_LOCK_RELEASE(TYPE, WIDTH)					\
+  void HIDDEN								\
+  __sync_lock_release_##WIDTH (TYPE *ptr)				\
+  {									\
+    /* All writes before this point must be seen before we release	\
+       the lock itself.	 */						\
+    __kernel_dmb ();							\
+    *ptr = 0;								\
+  }
+
+SYNC_LOCK_RELEASE (int,	  4)
+SYNC_LOCK_RELEASE (short, 2)
+SYNC_LOCK_RELEASE (char,  1)

libgcc/config/csky/linux-unwind.h

+/* DWARF2 EH unwinding support for C-SKY Linux.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   Contributed by C-SKY Microsystems and Mentor Graphics.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GCC 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 General Public License for more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef inhibit_libc
+
+/* Do code reading to identify a signal frame, and set the frame
+   state data appropriately.  See unwind-dw2.c for the structs.  */
+
+#include <signal.h>
+#include <asm/unistd.h>
+
+/* The third parameter to the signal handler points to something with
+   this structure defined in asm/ucontext.h, but the name clashes with
+   struct ucontext from sys/ucontext.h so this private copy is used.  */
+typedef struct _sig_ucontext {
+  unsigned long         uc_flags;
+  struct _sig_ucontext  *uc_link;
+  stack_t               uc_stack;
+  struct sigcontext     uc_mcontext;
+  sigset_t              uc_sigmask;
+} _sig_ucontext_t;
+
+#define MD_FALLBACK_FRAME_STATE_FOR csky_fallback_frame_state
+
+static _Unwind_Reason_Code
+csky_fallback_frame_state (struct _Unwind_Context *context,
+			   _Unwind_FrameState *fs)
+{
+  u_int16_t *pc = (u_int16_t *) context->ra;
+  struct sigcontext *sc;
+  _Unwind_Ptr new_cfa;
+  int i;
+
+  /* movi r7, __NR_rt_sigreturn; trap 0  */
+  if ((*(pc+0) == 0xea07) && (*(pc+1) == 119)
+      && (*(pc+2) == 0xc000) &&  (*(pc+3) == 0x2020))
+  {
+    struct sigframe
+    {
+      int sig;
+      int code;
+      struct sigcontext *psc;
+      unsigned long extramask[2]; /* _NSIG_WORDS */
+      struct sigcontext sc;
+    } *_rt = context->cfa;
+    sc = _rt->psc; // &(_rt->sc);
+  }
+  /* movi r7, __NR_rt_sigreturn; trap 0  */
+  else if ((*(pc+0) == 0xea07) && (*(pc+1) == 173)
+	   && (*(pc+2) == 0xc000) &&  (*(pc+3) == 0x2020))
+  {
+    struct rt_sigframe
+    {
+      int sig;
+      struct siginfo *pinfo;
+      void* puc;
+      siginfo_t info;
+      struct ucontext uc;
+    } *_rt = context->cfa;
+    sc = &(_rt->uc.uc_mcontext);
+  }
+  else
+    return _URC_END_OF_STACK;
+
+  new_cfa = (_Unwind_Ptr) sc->sc_usp;
+  fs->regs.cfa_how = CFA_REG_OFFSET;
+  fs->regs.cfa_reg = STACK_POINTER_REGNUM;
+  fs->regs.cfa_offset = new_cfa - (_Unwind_Ptr) context->cfa;
+
+  fs->regs.reg[0].how = REG_SAVED_OFFSET;
+  fs->regs.reg[0].loc.offset = (_Unwind_Ptr)&(sc->sc_a0) - new_cfa;
+
+  fs->regs.reg[1].how = REG_SAVED_OFFSET;
+  fs->regs.reg[1].loc.offset = (_Unwind_Ptr)&(sc->sc_a1) - new_cfa;
+
+  fs->regs.reg[2].how = REG_SAVED_OFFSET;
+  fs->regs.reg[2].loc.offset = (_Unwind_Ptr)&(sc->sc_a2) - new_cfa;
+
+  fs->regs.reg[3].how = REG_SAVED_OFFSET;
+  fs->regs.reg[3].loc.offset = (_Unwind_Ptr)&(sc->sc_a3) - new_cfa;
+
+  for (i = 4; i < 14; i++)
+    {
+      fs->regs.reg[i].how = REG_SAVED_OFFSET;
+      fs->regs.reg[i].loc.offset = ((_Unwind_Ptr)&(sc->sc_regs[i - 4])
+				    - new_cfa);
+    }
+
+  for (i = 16; i < 32; i++)
+    {
+      fs->regs.reg[i].how = REG_SAVED_OFFSET;
+      fs->regs.reg[i].loc.offset = ((_Unwind_Ptr)&(sc->sc_exregs[i - 16])
+				    - new_cfa);
+    }
+
+  /* FIXME : hi lo ? */
+  fs->regs.reg[15].how = REG_SAVED_OFFSET;
+  fs->regs.reg[15].loc.offset = (_Unwind_Ptr)&(sc->sc_r15) - new_cfa;
+
+  fs->regs.reg[56].how = REG_SAVED_OFFSET;
+  fs->regs.reg[56].loc.offset = (_Unwind_Ptr)&(sc->sc_pc) - new_cfa;
+  fs->retaddr_column = 56;
+  fs->signal_frame = 1;
+
+  return _URC_NO_REASON;
+}
+
+
+#endif

libgcc/config/csky/t-csky

+# Makefile fragment for all C-SKY targets.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# Contributed by C-SKY Microsystems and Mentor Graphics.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+LIB1ASMSRC 	= csky/lib1funcs.S
+LIB1ASMFUNCS   = _divsi3 _udivsi3 _modsi3 _umodsi3 _unorddf2 _unordsf2 \
+    _csky_case_sqi _csky_case_uqi  _csky_case_shi _csky_case_uhi _csky_case_si
+
+LIB2FUNCS_EXCLUDE  += _unord_df
+LIB2FUNCS_EXCLUDE  += _unord_sf
+
+TARGET_LIBGCC2_CFLAGS=-O3 -DNO_FLOATLIB_FIXUNSDFSI

libgcc/config/csky/t-linux-csky

+# Makefile fragment for C-SKY targets running Linux.
+# Copyright (C) 2018 Free Software Foundation, Inc.
+# Contributed by C-SKY Microsystems and Mentor Graphics.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+LIB2ADD_ST += $(srcdir)/config/csky/linux-atomic.c