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

1 files changed, 299 insertions, 0 deletions

diff --git a/libgcc/config/csky/linux-atomic.c b/libgcc/config/csky/linux-atomic.c
new file mode 100644
index 0000000..03cf2c0
--- /dev/null
+++ b/libgcc/config/csky/linux-atomic.c
@@ -0,0 +1,299 @@
+/* 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)