Commit 6724292e by Andreas Schwab Committed by Andreas Schwab

locks.h (compare_and_swap): Use __sync_bool_compare_and_swap.

* sysdep/m68k/locks.h (compare_and_swap): Use
__sync_bool_compare_and_swap.
(release_set): Use write_barrier instead of inlining it.

From-SVN: r188650
parent 6d017004
2012-06-15 Andreas Schwab <schwab@linux-m68k.org>
* sysdep/m68k/locks.h (compare_and_swap): Use
__sync_bool_compare_and_swap.
(release_set): Use write_barrier instead of inlining it.
2012-06-15 Andreas Krebbel <Andreas.Krebbel@de.ibm.com> 2012-06-15 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
* sysdep/s390/locks.h (compare_and_swap, release_set) * sysdep/s390/locks.h (compare_and_swap, release_set)
......
// locks.h - Thread synchronization primitives. m68k implementation. // locks.h - Thread synchronization primitives. m68k implementation.
/* Copyright (C) 2006 Free Software Foundation /* Copyright (C) 2006, 2012 Free Software Foundation
This file is part of libgcj. This file is part of libgcj.
...@@ -22,12 +22,24 @@ static inline bool ...@@ -22,12 +22,24 @@ static inline bool
compare_and_swap(volatile obj_addr_t *addr, compare_and_swap(volatile obj_addr_t *addr,
obj_addr_t old, obj_addr_t new_val) obj_addr_t old, obj_addr_t new_val)
{ {
char result; return __sync_bool_compare_and_swap (addr, old, new_val);
__asm__ __volatile__("cas.l %2,%3,%0; seq %1" }
: "+m" (*addr), "=d" (result), "+d" (old)
: "d" (new_val) // Ensure that subsequent instructions do not execute on stale
: "memory"); // data that was loaded from memory before the barrier.
return (bool) result; // On m68k, the hardware ensures that reads are properly ordered.
static inline void
read_barrier(void)
{
}
// Ensure that prior stores to memory are completed with respect to other
// processors.
static inline void
write_barrier(void)
{
// m68k does not reorder writes. We just need to ensure that gcc also doesn't.
__asm__ __volatile__(" " : : : "memory");
} }
// Set *addr to new_val with release semantics, i.e. making sure // Set *addr to new_val with release semantics, i.e. making sure
...@@ -38,8 +50,8 @@ compare_and_swap(volatile obj_addr_t *addr, ...@@ -38,8 +50,8 @@ compare_and_swap(volatile obj_addr_t *addr,
static inline void static inline void
release_set(volatile obj_addr_t *addr, obj_addr_t new_val) release_set(volatile obj_addr_t *addr, obj_addr_t new_val)
{ {
__asm__ __volatile__(" " : : : "memory"); write_barrier ();
*(addr) = new_val; *addr = new_val;
} }
// Compare_and_swap with release semantics instead of acquire semantics. // Compare_and_swap with release semantics instead of acquire semantics.
...@@ -53,20 +65,4 @@ compare_and_swap_release(volatile obj_addr_t *addr, ...@@ -53,20 +65,4 @@ compare_and_swap_release(volatile obj_addr_t *addr,
return compare_and_swap(addr, old, new_val); return compare_and_swap(addr, old, new_val);
} }
// Ensure that subsequent instructions do not execute on stale
// data that was loaded from memory before the barrier.
// On m68k, the hardware ensures that reads are properly ordered.
static inline void
read_barrier(void)
{
}
// Ensure that prior stores to memory are completed with respect to other
// processors.
static inline void
write_barrier(void)
{
// m68k does not reorder writes. We just need to ensure that gcc also doesn't.
__asm__ __volatile__(" " : : : "memory");
}
#endif #endif
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