/usr/src/gcc-4.4/debian/patches/libjava-atomic-builtins-eabi.diff is in gcc-4.4-source 4.4.7-1ubuntu2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 | # DP: libjava: Use atomic builtins For Linux ARM/EABI.
libjava/
2009-08-12 Andrew Haley <aph@redhat.com>
* sysdep/arm/locks.h: Use atomic builtins For Linux EABI.
* configure.ac: Add ATOMICSPEC.
* libgcj.spec.in: Likewise.
* configure.host (arm*-linux*): Add -Wno-abi to cxxflags.
(testsuite/libjava.jvmti/jvmti-interp.exp): Likewise.
(testsuite/libjava.jvmti/jvmti.exp): Likewise.
(testsuite/libjava.jni/jni.exp): Likewise.
Set ATOMICSPEC.
Index: libjava/configure.host
===================================================================
--- a/src/libjava/configure.host (revision 150701)
+++ b/src/libjava/configure.host (revision 150702)
@@ -69,6 +69,7 @@
EXCEPTIONSPEC=-fnon-call-exceptions
CHECKREFSPEC=
BACKTRACESPEC=
+ATOMICSPEC=
# This case statement supports per-CPU defaults.
case "${host}" in
@@ -87,6 +88,7 @@
sysdeps_dir=arm
fallback_backtrace_h=sysdep/arm/backtrace.h
libgcj_cxxflags=-Wno-abi
+ ATOMICSPEC=-fuse-atomic-builtins
;;
mips-tx39-*|mipstx39-unknown-*)
libgcj_flags="${libgcj_flags} -G 0"
Index: libjava/configure.ac
===================================================================
--- a/src/libjava/configure.ac (revision 150701)
+++ b/src/libjava/configure.ac (revision 150702)
@@ -1447,6 +1447,7 @@
AC_SUBST(EXCEPTIONSPEC)
AC_SUBST(BACKTRACESPEC)
AC_SUBST(IEEESPEC)
+AC_SUBST(ATOMICSPEC)
AM_CONDITIONAL(NATIVE, test "$NATIVE" = yes)
AM_CONDITIONAL(ENABLE_SHARED, test "$enable_shared" = yes)
Index: libjava/sysdep/arm/locks.h
===================================================================
--- a/src/libjava/sysdep/arm/locks.h (revision 150701)
+++ b/src/libjava/sysdep/arm/locks.h (revision 150702)
@@ -13,7 +13,60 @@
typedef size_t obj_addr_t; /* Integer type big enough for object */
/* address. */
+#if (__ARM_EABI__ && __linux)
+// 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.
+inline static bool
+compare_and_swap(volatile obj_addr_t *addr,
+ obj_addr_t old,
+ obj_addr_t new_val)
+{
+ return __sync_bool_compare_and_swap(addr, old, new_val);
+}
+
+// Set *addr to new_val with release semantics, i.e. making sure
+// that prior loads and stores complete before this
+// assignment.
+inline static void
+release_set(volatile obj_addr_t *addr, obj_addr_t new_val)
+{
+ __sync_synchronize();
+ *(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.
+inline static bool
+compare_and_swap_release(volatile obj_addr_t *addr,
+ obj_addr_t old,
+ obj_addr_t new_val)
+{
+ return __sync_bool_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 X86, the hardware ensures that reads are properly ordered.
+inline static void
+read_barrier()
+{
+ __sync_synchronize();
+}
+
+// Ensure that prior stores to memory are completed with respect to other
+// processors.
+inline static void
+write_barrier()
+{
+ __sync_synchronize();
+}
+
+#else
+
/* Atomic compare and exchange. These sequences are not actually
atomic; there is a race if *ADDR != OLD_VAL and we are preempted
between the two swaps. However, they are very close to atomic, and
@@ -54,8 +107,8 @@
inline static bool
compare_and_swap_release(volatile obj_addr_t *addr,
- obj_addr_t old,
- obj_addr_t new_val)
+ obj_addr_t old,
+ obj_addr_t new_val)
{
return compare_and_swap(addr, old, new_val);
}
@@ -77,3 +130,4 @@
}
#endif
+#endif
Index: libjava/libgcj.spec.in
===================================================================
--- a/src/libjava/libgcj.spec.in (revision 150701)
+++ b/src/libjava/libgcj.spec.in (revision 150702)
@@ -9,4 +9,4 @@
%rename lib liborig
*lib: @LD_START_STATIC_SPEC@ @LIBGCJ_SPEC@ @LD_FINISH_STATIC_SPEC@ -lm @LIBICONV@ @GCSPEC@ @THREADSPEC@ @ZLIBSPEC@ @SYSTEMSPEC@ %(libgcc) @LIBSTDCXXSPEC@ %(liborig)
-*jc1: @HASH_SYNC_SPEC@ @DIVIDESPEC@ @CHECKREFSPEC@ @JC1GCSPEC@ @EXCEPTIONSPEC@ @BACKTRACESPEC@ @IEEESPEC@ -fkeep-inline-functions
+*jc1: @HASH_SYNC_SPEC@ @DIVIDESPEC@ @CHECKREFSPEC@ @JC1GCSPEC@ @EXCEPTIONSPEC@ @BACKTRACESPEC@ @IEEESPEC@ @ATOMICSPEC@ -fkeep-inline-functions
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