diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/sh/pthread_barrier_wait.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/sh/pthread_barrier_wait.S | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/sh/pthread_barrier_wait.S b/sysdeps/unix/sysv/linux/sh/pthread_barrier_wait.S new file mode 100644 index 0000000000..946b1d746f --- /dev/null +++ b/sysdeps/unix/sysv/linux/sh/pthread_barrier_wait.S @@ -0,0 +1,239 @@ +/* Copyright (C) 2003-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include <lowlevellock.h> +#include <lowlevelbarrier.h> +#include "lowlevel-atomic.h" + + .text + + .globl pthread_barrier_wait + .type pthread_barrier_wait,@function + .align 5 + cfi_startproc +pthread_barrier_wait: + mov.l r9, @-r15 + cfi_adjust_cfa_offset (4) + cfi_rel_offset (r9, 0) + mov.l r8, @-r15 + cfi_adjust_cfa_offset (4) + cfi_rel_offset (r8, 0) + sts.l pr, @-r15 + cfi_adjust_cfa_offset (4) + cfi_rel_offset (pr, 0) + mov r4, r8 + + /* Get the mutex. */ + mov #0, r3 + mov #1, r4 + CMPXCHG (r3, @(MUTEX,r8), r4, r2) + bf 1f + + /* One less waiter. If this was the last one needed wake + everybody. */ +2: + mov.l @(LEFT,r8), r0 + add #-1, r0 + mov.l r0, @(LEFT,r8) + tst r0, r0 + bt 3f + + /* There are more threads to come. */ + mov.l @(CURR_EVENT,r8), r6 + + /* Release the mutex. */ + DEC (@(MUTEX,r8), r2) + tst r2, r2 + bf 6f +7: + /* Wait for the remaining threads. The call will return immediately + if the CURR_EVENT memory has meanwhile been changed. */ + mov r8, r4 +#if CURR_EVENT != 0 + add #CURR_EVENT, r4 +#endif +#if FUTEX_WAIT == 0 + mov.l @(PRIVATE,r8), r5 +#else + mov #FUTEX_WAIT, r5 + mov.l @(PRIVATE,r8), r0 + or r0, r5 +#endif + mov #0, r7 +8: + mov #SYS_futex, r3 + extu.b r3, r3 + trapa #0x14 + SYSCALL_INST_PAD + + /* Don't return on spurious wakeups. The syscall does not change + any register except r0 so there is no need to reload any of + them. */ + mov.l @(CURR_EVENT,r8), r0 + cmp/eq r0, r6 + bt 8b + + /* Increment LEFT. If this brings the count back to the + initial count unlock the object. */ + mov #1, r3 + mov.l @(INIT_COUNT,r8), r4 + XADD (r3, @(LEFT,r8), r2, r5) + add #-1, r4 + cmp/eq r2, r4 + bf 10f + + /* Release the mutex. We cannot release the lock before + waking the waiting threads since otherwise a new thread might + arrive and gets waken up, too. */ + DEC (@(MUTEX,r8), r2) + tst r2, r2 + bf 9f + +10: + cfi_remember_state + lds.l @r15+, pr + cfi_adjust_cfa_offset (-4) + cfi_restore (pr) + mov.l @r15+, r8 + cfi_adjust_cfa_offset (-4) + cfi_restore (r8) + mov.l @r15+, r9 + cfi_adjust_cfa_offset (-4) + cfi_restore (r9) + rts + mov #0, r0 /* != PTHREAD_BARRIER_SERIAL_THREAD */ + cfi_restore_state + +3: + /* The necessary number of threads arrived. */ + mov.l @(CURR_EVENT,r8), r1 + add #1, r1 + mov.l r1, @(CURR_EVENT,r8) + + /* Wake up all waiters. The count is a signed number in the kernel + so 0x7fffffff is the highest value. */ + mov.l .Lall, r6 + mov r8, r4 +#if CURR_EVENT != 0 + add #CURR_EVENT, r4 +#endif + mov #0, r7 + mov #FUTEX_WAKE, r5 + mov.l @(PRIVATE,r8), r0 + or r0, r5 + mov #SYS_futex, r3 + extu.b r3, r3 + trapa #0x14 + SYSCALL_INST_PAD + + /* Increment LEFT. If this brings the count back to the + initial count unlock the object. */ + mov #1, r3 + mov.l @(INIT_COUNT,r8), r4 + XADD (r3, @(LEFT,r8), r2, r5) + add #-1, r4 + cmp/eq r2, r4 + bf 5f + + /* Release the mutex. */ + DEC (@(MUTEX,r8), r2) + tst r2, r2 + bf 4f +5: + cfi_remember_state + lds.l @r15+, pr + cfi_adjust_cfa_offset (-4) + cfi_restore (pr) + mov.l @r15+, r8 + cfi_adjust_cfa_offset (-4) + cfi_restore (r8) + mov.l @r15+, r9 + cfi_adjust_cfa_offset (-4) + cfi_restore (r9) + rts + mov #-1, r0 /* == PTHREAD_BARRIER_SERIAL_THREAD */ + cfi_restore_state + +1: + mov.l @(PRIVATE,r8), r6 + mov #LLL_SHARED, r0 + extu.b r0, r0 + xor r0, r6 + mov r2, r4 + mov r8, r5 + mov.l .Lwait0, r1 + bsrf r1 + add #MUTEX, r5 +.Lwait0b: + bra 2b + nop + +4: + mov.l @(PRIVATE,r8), r5 + mov #LLL_SHARED, r0 + extu.b r0, r0 + xor r0, r5 + mov r8, r4 + mov.l .Lwake0, r1 + bsrf r1 + add #MUTEX, r4 +.Lwake0b: + bra 5b + nop + +6: + mov r6, r9 + mov.l @(PRIVATE,r8), r5 + mov #LLL_SHARED, r0 + extu.b r0, r0 + xor r0, r5 + mov r8, r4 + mov.l .Lwake1, r1 + bsrf r1 + add #MUTEX, r4 +.Lwake1b: + bra 7b + mov r9, r6 + +9: + mov r6, r9 + mov.l @(PRIVATE,r8), r5 + mov #LLL_SHARED, r0 + extu.b r0, r0 + xor r0, r5 + mov r8, r4 + mov.l .Lwake2, r1 + bsrf r1 + add #MUTEX, r4 +.Lwake2b: + bra 10b + mov r9, r6 + cfi_endproc + + .align 2 +.Lall: + .long 0x7fffffff +.Lwait0: + .long __lll_lock_wait-.Lwait0b +.Lwake0: + .long __lll_unlock_wake-.Lwake0b +.Lwake1: + .long __lll_unlock_wake-.Lwake1b +.Lwake2: + .long __lll_unlock_wake-.Lwake2b + .size pthread_barrier_wait,.-pthread_barrier_wait |