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Re: [RFC] m68k support for libjava
Tom Tromey schrieb:
>>>>>> "Matthias" == Matthias Klose <doko@cs.tu-berlin.de> writes:
>
> Matthias> java support for m68k
> Matthias> - add m68k info to configure files
> Matthias> - add sysdep/m68k/locks.h
> Matthias> - boehm.c: don't use bitmap as gc_descr if pointer is misaligned
>
> Someone other than me should review the locks.h addition.
> The rest is ok with the appropriate ChangeLog entry.
Andreas Schwab schrieb:
> Tom Tromey <tromey@redhat.com> writes:
>
>>>>>>> "Matthias" == Matthias Klose <doko@cs.tu-berlin.de> writes:
>> Matthias> java support for m68k
>> Matthias> - add m68k info to configure files
>> Matthias> - add sysdep/m68k/locks.h
>> Matthias> - boehm.c: don't use bitmap as gc_descr if pointer is misaligned
>>
>> Someone other than me should review the locks.h addition.
>
> The m68k bits look ok to me.
committed the attached patch to the trunk.
Matthias
gcc/java/
2007-09-06 Roman Zippel <zippel@linux-m68k.org>
* boehm.c: Don't use bitmap as gc_descr if pointer is misaligned.
libjava/
2007-09-06 Roman Zippel <zippel@linux-m68k.org>
* sysdep/m68k/locks.h: New file.
* configure.host: Set sysdeps_dir and libgcj_interpreter for m68k.
* configure.ac: Set SIGNAL_HANDLER for m68*-*-linux*.
* configure: Regenerate.
Index: gcc/java/boehm.c
===================================================================
--- gcc/java/boehm.c (revision 128189)
+++ gcc/java/boehm.c (working copy)
@@ -97,6 +97,14 @@
offset = int_byte_position (field);
size_bytes = int_size_in_bytes (TREE_TYPE (field));
+
+ if (offset % (POINTER_SIZE / BITS_PER_UNIT))
+ {
+ *all_bits_set = -1;
+ *pointer_after_end = 1;
+ break;
+ }
+
if (JREFERENCE_TYPE_P (TREE_TYPE (field))
/* An `object' of type gnu.gcj.RawData is actually non-Java
data. */
Index: libjava/configure.host
===================================================================
--- libjava/configure.host (revision 128189)
+++ libjava/configure.host (working copy)
@@ -146,6 +146,10 @@
libgcj_interpreter=yes
enable_hash_synchronization_default=no
;;
+ m68k-*)
+ sysdeps_dir=m68k
+ libgcj_interpreter=yes
+ ;;
powerpc64*-*)
sysdeps_dir=powerpc
libgcj_interpreter=yes
@@ -202,6 +206,7 @@
ia64-* | \
x86_64*-linux* | \
hppa*-linux* | \
+ m68k*-linux* | \
sh-linux* | sh[34]*-linux*)
can_unwind_signal=yes
libgcj_ld_symbolic='-Wl,-Bsymbolic'
Index: libjava/configure.ac
===================================================================
--- libjava/configure.ac (revision 128189)
+++ libjava/configure.ac (working copy)
@@ -1543,6 +1543,9 @@
mips*-*-linux*)
SIGNAL_HANDLER=include/mips-signal.h
;;
+ m68*-*-linux*)
+ SIGNAL_HANDLER=include/dwarf2-signal.h
+ ;;
powerpc*-*-darwin*)
SIGNAL_HANDLER=include/darwin-signal.h
;;
Index: libjava/sysdep/m68k/locks.h
===================================================================
--- libjava/sysdep/m68k/locks.h (revision 0)
+++ libjava/sysdep/m68k/locks.h (revision 0)
@@ -0,0 +1,72 @@
+// locks.h - Thread synchronization primitives. m68k implementation.
+
+/* Copyright (C) 2006 Free Software Foundation
+
+ This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
+details. */
+
+#ifndef __SYSDEP_LOCKS_H__
+#define __SYSDEP_LOCKS_H__
+
+/* Integer type big enough for object address. */
+typedef size_t obj_addr_t __attribute__ ((aligned (4)));
+
+// Atomically replace *addr by new_val if it was initially equal to old.
+// Return true if the comparison succeeded.
+// Assumed to have acquire semantics, i.e. later memory operations
+// cannot execute before the compare_and_swap finishes.
+static inline bool
+compare_and_swap(volatile obj_addr_t *addr,
+ obj_addr_t old, obj_addr_t new_val)
+{
+ char result;
+ __asm__ __volatile__("cas.l %2,%3,%0; seq %1"
+ : "+m" (*addr), "=d" (result), "+d" (old)
+ : "d" (new_val)
+ : "memory");
+ return (bool) result;
+}
+
+// Set *addr to new_val with release semantics, i.e. making sure
+// that prior loads and stores complete before this
+// assignment.
+// On m68k, the hardware shouldn't reorder reads and writes,
+// so we just have to convince gcc not to do it either.
+static inline void
+release_set(volatile obj_addr_t *addr, obj_addr_t new_val)
+{
+ __asm__ __volatile__(" " : : : "memory");
+ *(addr) = new_val;
+}
+
+// Compare_and_swap with release semantics instead of acquire semantics.
+// On many architecture, the operation makes both guarantees, so the
+// implementation can be the same.
+static inline bool
+compare_and_swap_release(volatile obj_addr_t *addr,
+ obj_addr_t old,
+ obj_addr_t 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