xref: /netbsd-src/external/gpl3/gcc.old/dist/libgomp/config/linux/sparc/futex.h (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc.
2    Contributed by Jakub Jelinek <jakub@redhat.com>.
3 
4    This file is part of the GNU OpenMP Library (libgomp).
5 
6    Libgomp is free software; you can redistribute it and/or modify it
7    under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3, or (at your option)
9    any later version.
10 
11    Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
12    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13    FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14    more details.
15 
16    Under Section 7 of GPL version 3, you are granted additional
17    permissions described in the GCC Runtime Library Exception, version
18    3.1, as published by the Free Software Foundation.
19 
20    You should have received a copy of the GNU General Public License and
21    a copy of the GCC Runtime Library Exception along with this program;
22    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23    <http://www.gnu.org/licenses/>.  */
24 
25 /* Provide target-specific access to the futex system call.  */
26 
27 #include <sys/syscall.h>
28 
29 static inline long
30 sys_futex0 (int *addr, int op, int val)
31 {
32   register long int g1  __asm__ ("g1");
33   register long int o0  __asm__ ("o0");
34   register long int o1  __asm__ ("o1");
35   register long int o2  __asm__ ("o2");
36   register long int o3  __asm__ ("o3");
37 
38   g1 = SYS_futex;
39   o0 = (long) addr;
40   o1 = op;
41   o2 = val;
42   o3 = 0;
43 
44 #ifdef __arch64__
45 # define SYSCALL_STRING "ta\t0x6d; bcs,a,pt %%xcc, 1f; sub %%g0, %%o0, %%o0; 1:"
46 #else
47 # define SYSCALL_STRING "ta\t0x10; bcs,a 1f; sub %%g0, %%o0, %%o0; 1:"
48 #endif
49 
50   __asm volatile (SYSCALL_STRING
51 		  : "=r" (g1), "=r" (o0)
52 		  : "0" (g1), "1" (o0), "r" (o1), "r" (o2), "r" (o3)
53 		  : "g2", "g3", "g4", "g5", "g6",
54 		    "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
55 		    "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
56 		    "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
57 		    "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",
58 #ifdef __arch64__
59 		    "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46",
60 		    "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62",
61 #endif
62 		    "cc", "memory");
63   return o0;
64 }
65 
66 static inline void
67 futex_wait (int *addr, int val)
68 {
69   long err = sys_futex0 (addr, gomp_futex_wait, val);
70   if (__builtin_expect (err == ENOSYS, 0))
71     {
72       gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
73       gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
74       sys_futex0 (addr, gomp_futex_wait, val);
75     }
76 }
77 
78 static inline void
79 futex_wake (int *addr, int count)
80 {
81   long err = sys_futex0 (addr, gomp_futex_wake, count);
82   if (__builtin_expect (err == ENOSYS, 0))
83     {
84       gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
85       gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
86       sys_futex0 (addr, gomp_futex_wake, count);
87     }
88 }
89 
90 static inline void
91 cpu_relax (void)
92 {
93 #if defined __arch64__ || defined  __sparc_v9__
94   __asm volatile ("membar #LoadLoad" : : : "memory");
95 #else
96   __asm volatile ("" : : : "memory");
97 #endif
98 }
99 
100 static inline void
101 atomic_write_barrier (void)
102 {
103 #if defined __arch64__ || defined __sparc_v9__
104   __asm volatile ("membar #StoreStore" : : : "memory");
105 #else
106   __sync_synchronize ();
107 #endif
108 }
109