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/* TILE atomics.
Copyright (C) 2011, 2012
Free Software Foundation, Inc.
Contributed by Walter Lee (walt@tilera.com)
This file 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, or (at your option) any
later version.
This file 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
<http://www.gnu.org/licenses/>. */
#include "system.h"
#include "coretypes.h"
#include "atomic.h"
/* This code should be inlined by the compiler, but for now support
it as out-of-line methods in libgcc. */
static void
pre_atomic_barrier (int model)
{
switch ((enum memmodel) model)
{
case MEMMODEL_RELEASE:
case MEMMODEL_ACQ_REL:
case MEMMODEL_SEQ_CST:
__atomic_thread_fence (model);
break;
default:
break;
}
return;
}
static void
post_atomic_barrier (int model)
{
switch ((enum memmodel) model)
{
case MEMMODEL_ACQUIRE:
case MEMMODEL_ACQ_REL:
case MEMMODEL_SEQ_CST:
__atomic_thread_fence (model);
break;
default:
break;
}
return;
}
#define __unused __attribute__((unused))
#define __atomic_fetch_and_do(type, size, opname) \
type \
__atomic_fetch_##opname##_##size(type* p, type i, int model) \
{ \
pre_atomic_barrier(model); \
type rv = arch_atomic_##opname(p, i); \
post_atomic_barrier(model); \
return rv; \
}
__atomic_fetch_and_do (int, 4, add)
__atomic_fetch_and_do (int, 4, sub)
__atomic_fetch_and_do (int, 4, or)
__atomic_fetch_and_do (int, 4, and)
__atomic_fetch_and_do (int, 4, xor)
__atomic_fetch_and_do (int, 4, nand)
__atomic_fetch_and_do (long long, 8, add)
__atomic_fetch_and_do (long long, 8, sub)
__atomic_fetch_and_do (long long, 8, or)
__atomic_fetch_and_do (long long, 8, and)
__atomic_fetch_and_do (long long, 8, xor)
__atomic_fetch_and_do (long long, 8, nand)
#define __atomic_do_and_fetch(type, size, opname, op) \
type \
__atomic_##opname##_fetch_##size(type* p, type i, int model) \
{ \
pre_atomic_barrier(model); \
type rv = arch_atomic_##opname(p, i) op i; \
post_atomic_barrier(model); \
return rv; \
}
__atomic_do_and_fetch (int, 4, add, +)
__atomic_do_and_fetch (int, 4, sub, -)
__atomic_do_and_fetch (int, 4, or, |)
__atomic_do_and_fetch (int, 4, and, &)
__atomic_do_and_fetch (int, 4, xor, |)
__atomic_do_and_fetch (int, 4, nand, &)
__atomic_do_and_fetch (long long, 8, add, +)
__atomic_do_and_fetch (long long, 8, sub, -)
__atomic_do_and_fetch (long long, 8, or, |)
__atomic_do_and_fetch (long long, 8, and, &)
__atomic_do_and_fetch (long long, 8, xor, |)
__atomic_do_and_fetch (long long, 8, nand, &)
#define __atomic_exchange_methods(type, size) \
bool \
__atomic_compare_exchange_##size(volatile type* ptr, type* oldvalp, \
type newval, bool weak __unused, \
int models, int modelf __unused) \
{ \
type oldval = *oldvalp; \
pre_atomic_barrier(models); \
type retval = arch_atomic_val_compare_and_exchange(ptr, oldval, newval); \
post_atomic_barrier(models); \
bool success = (retval == oldval); \
*oldvalp = retval; \
return success; \
} \
\
type \
__atomic_exchange_##size(volatile type* ptr, type val, int model) \
{ \
pre_atomic_barrier(model); \
type retval = arch_atomic_exchange(ptr, val); \
post_atomic_barrier(model); \
return retval; \
}
__atomic_exchange_methods (int, 4)
__atomic_exchange_methods (long long, 8)
/* Subword methods require the same approach for both TILEPro and
TILE-Gx. We load the background data for the word, insert the
desired subword piece, then compare-and-exchange it into place. */
#define u8 unsigned char
#define u16 unsigned short
#define __atomic_subword_cmpxchg(type, size) \
\
bool \
__atomic_compare_exchange_##size(volatile type* ptr, type* guess, \
type val, bool weak __unused, int models, \
int modelf __unused) \
{ \
pre_atomic_barrier(models); \
unsigned int *p = (unsigned int *)((unsigned long)ptr & ~3UL); \
const int shift = ((unsigned long)ptr & 3UL) * 8; \
const unsigned int valmask = (1 << (sizeof(type) * 8)) - 1; \
const unsigned int bgmask = ~(valmask << shift); \
unsigned int oldword = *p; \
type oldval = (oldword >> shift) & valmask; \
if (__builtin_expect((oldval == *guess), 1)) { \
unsigned int word = (oldword & bgmask) | ((val & valmask) << shift); \
oldword = arch_atomic_val_compare_and_exchange(p, oldword, word); \
oldval = (oldword >> shift) & valmask; \
} \
post_atomic_barrier(models); \
bool success = (oldval == *guess); \
*guess = oldval; \
return success; \
}
__atomic_subword_cmpxchg (u8, 1)
__atomic_subword_cmpxchg (u16, 2)
/* For the atomic-update subword methods, we use the same approach as
above, but we retry until we succeed if the compare-and-exchange
fails. */
#define __atomic_subword(type, proto, top, expr, bottom) \
proto \
{ \
top \
unsigned int *p = (unsigned int *)((unsigned long)ptr & ~3UL); \
const int shift = ((unsigned long)ptr & 3UL) * 8; \
const unsigned int valmask = (1 << (sizeof(type) * 8)) - 1; \
const unsigned int bgmask = ~(valmask << shift); \
unsigned int oldword, xword = *p; \
type val, oldval; \
do { \
oldword = xword; \
oldval = (oldword >> shift) & valmask; \
val = expr; \
unsigned int word = (oldword & bgmask) | ((val & valmask) << shift); \
xword = arch_atomic_val_compare_and_exchange(p, oldword, word); \
} while (__builtin_expect(xword != oldword, 0)); \
bottom \
}
#define __atomic_subword_fetch(type, funcname, expr, retval) \
__atomic_subword(type, \
type __atomic_ ## funcname(volatile type *ptr, type i, int model), \
pre_atomic_barrier(model);, \
expr, \
post_atomic_barrier(model); return retval;)
__atomic_subword_fetch (u8, fetch_add_1, oldval + i, oldval)
__atomic_subword_fetch (u8, fetch_sub_1, oldval - i, oldval)
__atomic_subword_fetch (u8, fetch_or_1, oldval | i, oldval)
__atomic_subword_fetch (u8, fetch_and_1, oldval & i, oldval)
__atomic_subword_fetch (u8, fetch_xor_1, oldval ^ i, oldval)
__atomic_subword_fetch (u8, fetch_nand_1, ~(oldval & i), oldval)
__atomic_subword_fetch (u16, fetch_add_2, oldval + i, oldval)
__atomic_subword_fetch (u16, fetch_sub_2, oldval - i, oldval)
__atomic_subword_fetch (u16, fetch_or_2, oldval | i, oldval)
__atomic_subword_fetch (u16, fetch_and_2, oldval & i, oldval)
__atomic_subword_fetch (u16, fetch_xor_2, oldval ^ i, oldval)
__atomic_subword_fetch (u16, fetch_nand_2, ~(oldval & i), oldval)
__atomic_subword_fetch (u8, add_fetch_1, oldval + i, val)
__atomic_subword_fetch (u8, sub_fetch_1, oldval - i, val)
__atomic_subword_fetch (u8, or_fetch_1, oldval | i, val)
__atomic_subword_fetch (u8, and_fetch_1, oldval & i, val)
__atomic_subword_fetch (u8, xor_fetch_1, oldval ^ i, val)
__atomic_subword_fetch (u8, nand_fetch_1, ~(oldval & i), val)
__atomic_subword_fetch (u16, add_fetch_2, oldval + i, val)
__atomic_subword_fetch (u16, sub_fetch_2, oldval - i, val)
__atomic_subword_fetch (u16, or_fetch_2, oldval | i, val)
__atomic_subword_fetch (u16, and_fetch_2, oldval & i, val)
__atomic_subword_fetch (u16, xor_fetch_2, oldval ^ i, val)
__atomic_subword_fetch (u16, nand_fetch_2, ~(oldval & i), val)
#define __atomic_subword_lock(type, size) \
\
__atomic_subword(type, \
type __atomic_exchange_##size(volatile type* ptr, type nval, int model), \
pre_atomic_barrier(model);, \
nval, \
post_atomic_barrier(model); return oldval;)
__atomic_subword_lock (u8, 1)
__atomic_subword_lock (u16, 2)
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