8058255: Native jbyte Atomic::cmpxchg for supported x86 platforms
Summary: Use the native cmpxchgb instruction on x86.
Reviewed-by: dholmes, kbarrett, phh
Contributed-by: erik.osterlund@lnu.se
/*
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* version 2 for more details (a copy is included in the LICENSE file that
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#ifndef OS_CPU_LINUX_X86_VM_ATOMIC_LINUX_X86_INLINE_HPP
#define OS_CPU_LINUX_X86_VM_ATOMIC_LINUX_X86_INLINE_HPP
#include "runtime/atomic.hpp"
#include "runtime/os.hpp"
// 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_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_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; }
// Adding a lock prefix to an instruction on MP machine
#define LOCK_IF_MP(mp) "cmp $0, " #mp "; je 1f; lock; 1: "
inline jint Atomic::add (jint add_value, volatile jint* dest) {
jint addend = add_value;
int mp = os::is_MP();
__asm__ volatile ( LOCK_IF_MP(%3) "xaddl %0,(%2)"
: "=r" (addend)
: "0" (addend), "r" (dest), "r" (mp)
: "cc", "memory");
return addend + add_value;
}
inline void Atomic::inc (volatile jint* dest) {
int mp = os::is_MP();
__asm__ volatile (LOCK_IF_MP(%1) "addl $1,(%0)" :
: "r" (dest), "r" (mp) : "cc", "memory");
}
inline void Atomic::inc_ptr(volatile void* dest) {
inc_ptr((volatile intptr_t*)dest);
}
inline void Atomic::dec (volatile jint* dest) {
int mp = os::is_MP();
__asm__ volatile (LOCK_IF_MP(%1) "subl $1,(%0)" :
: "r" (dest), "r" (mp) : "cc", "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) {
__asm__ volatile ( "xchgl (%2),%0"
: "=r" (exchange_value)
: "0" (exchange_value), "r" (dest)
: "memory");
return exchange_value;
}
inline void* Atomic::xchg_ptr(void* exchange_value, volatile void* dest) {
return (void*)xchg_ptr((intptr_t)exchange_value, (volatile intptr_t*)dest);
}
#define VM_HAS_SPECIALIZED_CMPXCHG_BYTE
inline jbyte Atomic::cmpxchg (jbyte exchange_value, volatile jbyte* dest, jbyte compare_value) {
int mp = os::is_MP();
__asm__ volatile (LOCK_IF_MP(%4) "cmpxchgb %1,(%3)"
: "=a" (exchange_value)
: "q" (exchange_value), "a" (compare_value), "r" (dest), "r" (mp)
: "cc", "memory");
return exchange_value;
}
inline jint Atomic::cmpxchg (jint exchange_value, volatile jint* dest, jint compare_value) {
int mp = os::is_MP();
__asm__ volatile (LOCK_IF_MP(%4) "cmpxchgl %1,(%3)"
: "=a" (exchange_value)
: "r" (exchange_value), "a" (compare_value), "r" (dest), "r" (mp)
: "cc", "memory");
return exchange_value;
}
#ifdef AMD64
inline void Atomic::store (jlong store_value, jlong* dest) { *dest = store_value; }
inline void Atomic::store (jlong store_value, volatile jlong* dest) { *dest = store_value; }
inline intptr_t Atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest) {
intptr_t addend = add_value;
bool mp = os::is_MP();
__asm__ __volatile__ (LOCK_IF_MP(%3) "xaddq %0,(%2)"
: "=r" (addend)
: "0" (addend), "r" (dest), "r" (mp)
: "cc", "memory");
return addend + add_value;
}
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_ptr(volatile intptr_t* dest) {
bool mp = os::is_MP();
__asm__ __volatile__ (LOCK_IF_MP(%1) "addq $1,(%0)"
:
: "r" (dest), "r" (mp)
: "cc", "memory");
}
inline void Atomic::dec_ptr(volatile intptr_t* dest) {
bool mp = os::is_MP();
__asm__ __volatile__ (LOCK_IF_MP(%1) "subq $1,(%0)"
:
: "r" (dest), "r" (mp)
: "cc", "memory");
}
inline intptr_t Atomic::xchg_ptr(intptr_t exchange_value, volatile intptr_t* dest) {
__asm__ __volatile__ ("xchgq (%2),%0"
: "=r" (exchange_value)
: "0" (exchange_value), "r" (dest)
: "memory");
return exchange_value;
}
inline jlong Atomic::cmpxchg (jlong exchange_value, volatile jlong* dest, jlong compare_value) {
bool mp = os::is_MP();
__asm__ __volatile__ (LOCK_IF_MP(%4) "cmpxchgq %1,(%3)"
: "=a" (exchange_value)
: "r" (exchange_value), "a" (compare_value), "r" (dest), "r" (mp)
: "cc", "memory");
return exchange_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);
}
inline jlong Atomic::load(volatile jlong* src) { return *src; }
#else // !AMD64
inline intptr_t Atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest) {
return (intptr_t)Atomic::add((jint)add_value, (volatile jint*)dest);
}
inline void* Atomic::add_ptr(intptr_t add_value, volatile void* dest) {
return (void*)Atomic::add((jint)add_value, (volatile jint*)dest);
}
inline void Atomic::inc_ptr(volatile intptr_t* dest) {
inc((volatile jint*)dest);
}
inline void Atomic::dec_ptr(volatile intptr_t* dest) {
dec((volatile jint*)dest);
}
inline intptr_t Atomic::xchg_ptr(intptr_t exchange_value, volatile intptr_t* dest) {
return (intptr_t)xchg((jint)exchange_value, (volatile jint*)dest);
}
extern "C" {
// defined in linux_x86.s
jlong _Atomic_cmpxchg_long(jlong, volatile jlong*, jlong, bool);
void _Atomic_move_long(volatile jlong* src, volatile jlong* dst);
}
inline jlong Atomic::cmpxchg (jlong exchange_value, volatile jlong* dest, jlong compare_value) {
return _Atomic_cmpxchg_long(exchange_value, dest, compare_value, os::is_MP());
}
inline intptr_t Atomic::cmpxchg_ptr(intptr_t exchange_value, volatile intptr_t* dest, intptr_t compare_value) {
return (intptr_t)cmpxchg((jint)exchange_value, (volatile jint*)dest, (jint)compare_value);
}
inline void* Atomic::cmpxchg_ptr(void* exchange_value, volatile void* dest, void* compare_value) {
return (void*)cmpxchg((jint)exchange_value, (volatile jint*)dest, (jint)compare_value);
}
inline jlong Atomic::load(volatile jlong* src) {
volatile jlong dest;
_Atomic_move_long(src, &dest);
return dest;
}
inline void Atomic::store(jlong store_value, jlong* dest) {
_Atomic_move_long((volatile jlong*)&store_value, (volatile jlong*)dest);
}
inline void Atomic::store(jlong store_value, volatile jlong* dest) {
_Atomic_move_long((volatile jlong*)&store_value, dest);
}
#endif // AMD64
#endif // OS_CPU_LINUX_X86_VM_ATOMIC_LINUX_X86_INLINE_HPP