From 483104922ad93037381da8f37a8b2bb471799650 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 1 May 2012 08:48:28 -0700 Subject: Add libatomic as a target library. From-SVN: r187018 --- libatomic/fop_n.c | 200 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 200 insertions(+) create mode 100644 libatomic/fop_n.c (limited to 'libatomic/fop_n.c') diff --git a/libatomic/fop_n.c b/libatomic/fop_n.c new file mode 100644 index 0000000..251e3c9 --- /dev/null +++ b/libatomic/fop_n.c @@ -0,0 +1,200 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + Contributed by Richard Henderson . + + This file is part of the GNU Atomic Library (libatomic). + + Libatomic is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + Libatomic 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 General Public License for + more details. + + Under Section 7 of GPL version 3, you are granted additional + permissions described in the GCC Runtime Library Exception, version + 3.1, as published by the Free Software Foundation. + + You should have received a copy of the GNU General Public License and + a copy of the GCC Runtime Library Exception along with this program; + see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + . */ + +#include + + +/* This file is included multiple times with required defines: + NAME the name of the operation that we're implementing; + OP a two-operand functional macro the implements the operation. +*/ + + +/* If we support the builtin, just use it. */ +#if !DONE && SIZE(HAVE_ATOMIC_FETCH_OP) +UTYPE +SIZE(C2(libat_fetch_,NAME)) (UTYPE *mptr, UTYPE opval, int smodel) +{ + if (maybe_specialcase_relaxed(smodel)) + return C2(__atomic_fetch_,NAME) (mptr, opval, __ATOMIC_RELAXED); + else if (maybe_specialcase_acqrel(smodel)) + return C2(__atomic_fetch_,NAME) (mptr, opval, __ATOMIC_ACQ_REL); + else + return C2(__atomic_fetch_,NAME) (mptr, opval, __ATOMIC_SEQ_CST); +} + +UTYPE +SIZE(C3(libat_,NAME,_fetch)) (UTYPE *mptr, UTYPE opval, int smodel) +{ + if (maybe_specialcase_relaxed(smodel)) + return C3(__atomic_,NAME,_fetch) (mptr, opval, __ATOMIC_RELAXED); + else if (maybe_specialcase_acqrel(smodel)) + return C3(__atomic_,NAME,_fetch) (mptr, opval, __ATOMIC_ACQ_REL); + else + return C3(__atomic_,NAME,_fetch) (mptr, opval, __ATOMIC_SEQ_CST); +} + +#define DONE 1 +#endif /* HAVE_ATOMIC_FETCH_OP */ + + +#if !DONE && defined(atomic_compare_exchange_n) +UTYPE +SIZE(C2(libat_fetch_,NAME)) (UTYPE *mptr, UTYPE opval, int smodel) +{ + UTYPE oldval, t; + + pre_barrier (smodel); + + oldval = *mptr; + do + { + t = OP(oldval, opval); + } + while (!atomic_compare_exchange_n (mptr, &oldval, t, true, + __ATOMIC_RELAXED, __ATOMIC_RELAXED)); + + post_barrier (smodel); + return oldval; +} + +UTYPE +SIZE(C3(libat_,NAME,_fetch)) (UTYPE *mptr, UTYPE opval, int smodel) +{ + UTYPE oldval, t; + + pre_barrier (smodel); + + oldval = *mptr; + do + { + t = OP(oldval, opval); + } + while (!atomic_compare_exchange_n (mptr, &oldval, t, true, + __ATOMIC_RELAXED, __ATOMIC_RELAXED)); + + post_barrier (smodel); + return t; +} + +#define DONE 1 +#endif /* atomic_compare_exchange_n */ + + +/* If this type is no larger than word-sized, fall back to a word-sized + compare-and-swap loop. */ +#if !DONE && N < WORDSIZE && defined(atomic_compare_exchange_w) +UTYPE +SIZE(C2(libat_fetch_,NAME)) (UTYPE *mptr, UTYPE opval, int smodel) +{ + UWORD mask, shift, woldval, wopval, t, *wptr; + + pre_barrier (smodel); + + wptr = (UWORD *)mptr; + shift = 0; + mask = -1; + + wopval = (UWORD)opval << shift; + woldval = __atomic_load_n (wptr, __ATOMIC_RELAXED); + do + { + t = (woldval & ~mask) | (OP(woldval, wopval) & mask); + } + while (!atomic_compare_exchange_w (wptr, &woldval, t, true, + __ATOMIC_RELAXED, __ATOMIC_RELAXED)); + + post_barrier (smodel); + return woldval >> shift; +} + +UTYPE +SIZE(C3(libat_,NAME,_fetch)) (UTYPE *mptr, UTYPE opval, int smodel) +{ + UWORD mask, shift, woldval, wopval, t, *wptr; + + pre_barrier (smodel); + + wptr = (UWORD *)mptr; + shift = 0; + mask = -1; + + wopval = (UWORD)opval << shift; + woldval = __atomic_load_n (wptr, __ATOMIC_RELAXED); + do + { + t = (woldval & ~mask) | (OP(woldval, wopval) & mask); + } + while (!atomic_compare_exchange_w (wptr, &woldval, t, true, + __ATOMIC_RELAXED, __ATOMIC_RELAXED)); + + post_barrier (smodel); + return t >> shift; +} + +#define DONE 1 +#endif /* atomic_compare_exchange_w */ + + +/* Otherwise, fall back to some sort of protection mechanism. */ +#if !DONE +UTYPE +SIZE(C2(libat_fetch_,NAME)) (UTYPE *mptr, UTYPE opval, int smodel UNUSED) +{ + UTYPE ret; + UWORD magic; + + pre_seq_barrier (smodel); + magic = protect_start (mptr); + + ret = *mptr; + *mptr = OP(ret, opval); + + protect_end (mptr, magic); + post_seq_barrier (smodel); + + return ret; +} + +UTYPE +SIZE(C3(libat_,NAME,_fetch)) (UTYPE *mptr, UTYPE opval, int smodel UNUSED) +{ + UTYPE ret; + UWORD magic; + + pre_seq_barrier (smodel); + magic = protect_start (mptr); + + ret = OP (*mptr, opval); + *mptr = ret; + + protect_end (mptr, magic); + post_seq_barrier (smodel); + + return ret; +} +#endif + +EXPORT_ALIAS (SIZE(C2(fetch_,NAME))); +EXPORT_ALIAS (SIZE(C2(NAME,_fetch))); -- cgit v1.1