hotspot/src/os_cpu/aix_ppc/vm/atomic_aix_ppc.inline.hpp

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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#ifndef OS_CPU_AIX_OJDKPPC_VM_ATOMIC_AIX_PPC_INLINE_HPP
#define OS_CPU_AIX_OJDKPPC_VM_ATOMIC_AIX_PPC_INLINE_HPP

#include "orderAccess_aix_ppc.inline.hpp"
#include "runtime/atomic.hpp"
#include "runtime/os.hpp"
#include "vm_version_ppc.hpp"

#ifndef _LP64
#error "Atomic currently only impleneted for PPC64"
#endif

// Implementation of class atomic

inline void Atomic::store    (jbyte    store_value, jbyte*    dest) { *dest = store_value; }
inline void Atomic::store    (jshort   store_value, jshort*   dest) { *dest = store_value; }
inline void Atomic::store    (jint     store_value, jint*     dest) { *dest = store_value; }
inline void Atomic::store    (jlong    store_value, jlong*    dest) { *dest = store_value; }
inline void Atomic::store_ptr(intptr_t store_value, intptr_t* dest) { *dest = store_value; }
inline void Atomic::store_ptr(void*    store_value, void*     dest) { *(void**)dest = store_value; }

inline void Atomic::store    (jbyte    store_value, volatile jbyte*    dest) { *dest = store_value; }
inline void Atomic::store    (jshort   store_value, volatile jshort*   dest) { *dest = store_value; }
inline void Atomic::store    (jint     store_value, volatile jint*     dest) { *dest = store_value; }
inline void Atomic::store    (jlong    store_value, volatile jlong*    dest) { *dest = store_value; }
inline void Atomic::store_ptr(intptr_t store_value, volatile intptr_t* dest) { *dest = store_value; }
inline void Atomic::store_ptr(void*    store_value, volatile void*     dest) { *(void* volatile *)dest = store_value; }

inline jlong Atomic::load(volatile jlong* src) { return *src; }

/*
  machine barrier instructions:

  - ppc_sync            two-way memory barrier, aka fence
  - ppc_lwsync          orders  Store|Store,
                                 Load|Store,
                                 Load|Load,
                        but not Store|Load
  - ppc_eieio           orders memory accesses for device memory (only)
  - ppc_isync           invalidates speculatively executed instructions
                        From the POWER ISA 2.06 documentation:
                         "[...] an isync instruction prevents the execution of
                        instructions following the isync until instructions
                        preceding the isync have completed, [...]"
                        From IBM's AIX assembler reference:
                         "The isync [...] instructions causes the processor to
                        refetch any instructions that might have been fetched
                        prior to the isync instruction. The instruction isync
                        causes the processor to wait for all previous instructions
                        to complete. Then any instructions already fetched are
                        discarded and instruction processing continues in the
                        environment established by the previous instructions."

  semantic barrier instructions:
  (as defined in orderAccess.hpp)

  - ppc_release         orders Store|Store,       (maps to ppc_lwsync)
                                Load|Store
  - ppc_acquire         orders  Load|Store,       (maps to ppc_lwsync)
                                Load|Load
  - ppc_fence           orders Store|Store,       (maps to ppc_sync)
                                Load|Store,
                                Load|Load,
                               Store|Load
*/

#define strasm_ppc_sync                       "\n  sync    \n"
#define strasm_ppc_lwsync                     "\n  lwsync  \n"
#define strasm_ppc_isync                      "\n  isync   \n"
#define strasm_ppc_release                    strasm_ppc_lwsync
#define strasm_ppc_acquire                    strasm_ppc_lwsync
#define strasm_ppc_fence                      strasm_ppc_sync
#define strasm_ppc_nobarrier                  ""
#define strasm_ppc_nobarrier_clobber_memory   ""

inline jint     Atomic::add    (jint     add_value, volatile jint*     dest) {

  unsigned int result;

  __asm__ __volatile__ (
    strasm_ppc_lwsync
    "1: lwarx   %0,  0, %2    \n"
    "   add     %0, %0, %1    \n"
    "   stwcx.  %0,  0, %2    \n"
    "   bne-    1b            \n"
    strasm_ppc_isync
    : /*%0*/"=&r" (result)
    : /*%1*/"r" (add_value), /*%2*/"r" (dest)
    : "cc", "memory" );

  return (jint) result;
}


inline intptr_t Atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest) {

  long result;

  __asm__ __volatile__ (
    strasm_ppc_lwsync
    "1: ldarx   %0,  0, %2    \n"
    "   add     %0, %0, %1    \n"
    "   stdcx.  %0,  0, %2    \n"
    "   bne-    1b            \n"
    strasm_ppc_isync
    : /*%0*/"=&r" (result)
    : /*%1*/"r" (add_value), /*%2*/"r" (dest)
    : "cc", "memory" );

  return (intptr_t) result;
}

inline void*    Atomic::add_ptr(intptr_t add_value, volatile void*     dest) {
  return (void*)add_ptr(add_value, (volatile intptr_t*)dest);
}


inline void Atomic::inc    (volatile jint*     dest) {

  unsigned int temp;

  __asm__ __volatile__ (
    strasm_ppc_nobarrier
    "1: lwarx   %0,  0, %2    \n"
    "   addic   %0, %0,  1    \n"
    "   stwcx.  %0,  0, %2    \n"
    "   bne-    1b            \n"
    strasm_ppc_nobarrier
    : /*%0*/"=&r" (temp), "=m" (*dest)
    : /*%2*/"r" (dest), "m" (*dest)
    : "cc" strasm_ppc_nobarrier_clobber_memory);

}

inline void Atomic::inc_ptr(volatile intptr_t* dest) {

  long temp;

  __asm__ __volatile__ (
    strasm_ppc_nobarrier
    "1: ldarx   %0,  0, %2    \n"
    "   addic   %0, %0,  1    \n"
    "   stdcx.  %0,  0, %2    \n"
    "   bne-    1b            \n"
    strasm_ppc_nobarrier
    : /*%0*/"=&r" (temp), "=m" (*dest)
    : /*%2*/"r" (dest), "m" (*dest)
    : "cc" strasm_ppc_nobarrier_clobber_memory);

}

inline void Atomic::inc_ptr(volatile void*     dest) {
  inc_ptr((volatile intptr_t*)dest);
}


inline void Atomic::dec    (volatile jint*     dest) {

  unsigned int temp;

  __asm__ __volatile__ (
    strasm_ppc_nobarrier
    "1: lwarx   %0,  0, %2    \n"
    "   addic   %0, %0, -1    \n"
    "   stwcx.  %0,  0, %2    \n"
    "   bne-    1b            \n"
    strasm_ppc_nobarrier
    : /*%0*/"=&r" (temp), "=m" (*dest)
    : /*%2*/"r" (dest), "m" (*dest)
    : "cc" strasm_ppc_nobarrier_clobber_memory);

}

inline void Atomic::dec_ptr(volatile intptr_t* dest) {

  long temp;

  __asm__ __volatile__ (
    strasm_ppc_nobarrier
    "1: ldarx   %0,  0, %2    \n"
    "   addic   %0, %0, -1    \n"
    "   stdcx.  %0,  0, %2    \n"
    "   bne-    1b            \n"
    strasm_ppc_nobarrier
    : /*%0*/"=&r" (temp), "=m" (*dest)
    : /*%2*/"r" (dest), "m" (*dest)
    : "cc" strasm_ppc_nobarrier_clobber_memory);

}

inline void Atomic::dec_ptr(volatile void*     dest) {
  dec_ptr((volatile intptr_t*)dest);
}

inline jint Atomic::xchg(jint exchange_value, volatile jint* dest) {

  // Note that xchg_ptr doesn't necessarily do an acquire
  // (see synchronizer.cpp).

  unsigned int old_value;
  const uint64_t zero = 0;

  __asm__ __volatile__ (
    /* lwsync */
    strasm_ppc_lwsync
    /* atomic loop */
    "1:                                                 \n"
    "   lwarx   %[old_value], %[dest], %[zero]          \n"
    "   stwcx.  %[exchange_value], %[dest], %[zero]     \n"
    "   bne-    1b                                      \n"
    /* isync */
    strasm_ppc_sync
    /* exit */
    "2:                                                 \n"
    /* out */
    : [old_value]       "=&r"   (old_value),
                        "=m"    (*dest)
    /* in */
    : [dest]            "b"     (dest),
      [zero]            "r"     (zero),
      [exchange_value]  "r"     (exchange_value),
                        "m"     (*dest)
    /* clobber */
    : "cc",
      "memory"
    );

  return (jint) old_value;
}

inline intptr_t Atomic::xchg_ptr(intptr_t exchange_value, volatile intptr_t* dest) {

  // Note that xchg_ptr doesn't necessarily do an acquire
  // (see synchronizer.cpp).

  long old_value;
  const uint64_t zero = 0;

  __asm__ __volatile__ (
    /* lwsync */
    strasm_ppc_lwsync
    /* atomic loop */
    "1:                                                 \n"
    "   ldarx   %[old_value], %[dest], %[zero]          \n"
    "   stdcx.  %[exchange_value], %[dest], %[zero]     \n"
    "   bne-    1b                                      \n"
    /* isync */
    strasm_ppc_sync
    /* exit */
    "2:                                                 \n"
    /* out */
    : [old_value]       "=&r"   (old_value),
                        "=m"    (*dest)
    /* in */
    : [dest]            "b"     (dest),
      [zero]            "r"     (zero),
      [exchange_value]  "r"     (exchange_value),
                        "m"     (*dest)
    /* clobber */
    : "cc",
      "memory"
    );

  return (intptr_t) old_value;
}

inline void* Atomic::xchg_ptr(void* exchange_value, volatile void* dest) {
  return (void*)xchg_ptr((intptr_t)exchange_value, (volatile intptr_t*)dest);
}

inline jint Atomic::cmpxchg(jint exchange_value, volatile jint* dest, jint compare_value) {

  // Note that cmpxchg guarantees a two-way memory barrier across
  // the cmpxchg, so it's really a a 'fence_cmpxchg_acquire'
  // (see atomic.hpp).

  unsigned int old_value;
  const uint64_t zero = 0;

  __asm__ __volatile__ (
    /* fence */
    strasm_ppc_sync
    /* simple guard */
    "   lwz     %[old_value], 0(%[dest])                \n"
    "   cmpw    %[compare_value], %[old_value]          \n"
    "   bne-    2f                                      \n"
    /* atomic loop */
    "1:                                                 \n"
    "   lwarx   %[old_value], %[dest], %[zero]          \n"
    "   cmpw    %[compare_value], %[old_value]          \n"
    "   bne-    2f                                      \n"
    "   stwcx.  %[exchange_value], %[dest], %[zero]     \n"
    "   bne-    1b                                      \n"
    /* acquire */
    strasm_ppc_sync
    /* exit */
    "2:                                                 \n"
    /* out */
    : [old_value]       "=&r"   (old_value),
                        "=m"    (*dest)
    /* in */
    : [dest]            "b"     (dest),
      [zero]            "r"     (zero),
      [compare_value]   "r"     (compare_value),
      [exchange_value]  "r"     (exchange_value),
                        "m"     (*dest)
    /* clobber */
    : "cc",
      "memory"
    );

  return (jint) old_value;
}

inline jlong Atomic::cmpxchg(jlong exchange_value, volatile jlong* dest, jlong compare_value) {

  // Note that cmpxchg guarantees a two-way memory barrier across
  // the cmpxchg, so it's really a a 'fence_cmpxchg_acquire'
  // (see atomic.hpp).

  long old_value;
  const uint64_t zero = 0;

  __asm__ __volatile__ (
    /* fence */
    strasm_ppc_sync
    /* simple guard */
    "   ld      %[old_value], 0(%[dest])                \n"
    "   cmpd    %[compare_value], %[old_value]          \n"
    "   bne-    2f                                      \n"
    /* atomic loop */
    "1:                                                 \n"
    "   ldarx   %[old_value], %[dest], %[zero]          \n"
    "   cmpd    %[compare_value], %[old_value]          \n"
    "   bne-    2f                                      \n"
    "   stdcx.  %[exchange_value], %[dest], %[zero]     \n"
    "   bne-    1b                                      \n"
    /* acquire */
    strasm_ppc_sync
    /* exit */
    "2:                                                 \n"
    /* out */
    : [old_value]       "=&r"   (old_value),
                        "=m"    (*dest)
    /* in */
    : [dest]            "b"     (dest),
      [zero]            "r"     (zero),
      [compare_value]   "r"     (compare_value),
      [exchange_value]  "r"     (exchange_value),
                        "m"     (*dest)
    /* clobber */
    : "cc",
      "memory"
    );

  return (jlong) old_value;
}

inline intptr_t Atomic::cmpxchg_ptr(intptr_t exchange_value, volatile intptr_t* dest, intptr_t compare_value) {
  return (intptr_t)cmpxchg((jlong)exchange_value, (volatile jlong*)dest, (jlong)compare_value);
}

inline void* Atomic::cmpxchg_ptr(void* exchange_value, volatile void* dest, void* compare_value) {
  return (void*)cmpxchg((jlong)exchange_value, (volatile jlong*)dest, (jlong)compare_value);
}

#undef strasm_ppc_sync
#undef strasm_ppc_lwsync
#undef strasm_ppc_isync
#undef strasm_ppc_release
#undef strasm_ppc_acquire
#undef strasm_ppc_fence
#undef strasm_ppc_nobarrier
#undef strasm_ppc_nobarrier_clobber_memory

#endif // OS_CPU_AIX_OJDKPPC_VM_ATOMIC_AIX_PPC_INLINE_HPP