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Merge pull request #8649 from awlauria/force_ppc_assembly_atomics
Powerpc atomics: Force usage of powerpc assembly.
2 parents cc32d74 + 136213d commit d440c13

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4 files changed

+266
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‎config/opal_config_asm.m4

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@@ -1192,6 +1192,18 @@ AC_DEFUN([OPAL_CONFIG_ASM],[
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AC_MSG_ERROR([Could not determine PowerPC word size: $ac_cv_sizeof_long])
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fi
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OPAL_GCC_INLINE_ASSIGN='"1: li %0,0" : "=&r"(ret)'
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# See the following github PR and some performance numbers/discussion:
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# https://github.com/open-mpi/ompi/pull/8649
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AC_MSG_CHECKING([$opal_cv_asm_arch: Checking if force gcc atomics requested])
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if test $force_gcc_atomics_ppc = 0 ; then
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AC_MSG_RESULT([no])
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opal_cv_asm_builtin="BUILTIN_NO"
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else
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AC_MSG_RESULT([Yes])
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AC_MSG_WARN([$opal_cv_asm_arch: gcc atomics have been known to perform poorly on powerpc.])
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fi
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;;
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*)
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if test $opal_cv_have___atomic = "yes" ; then

‎config/opal_configure_options.m4

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@@ -84,6 +84,13 @@ else
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WANT_BRANCH_PROBABILITIES=0
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fi
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AC_ARG_ENABLE([builtin-atomics-for-ppc],[AS_HELP_STRING([--enable-builtin-atomics-for-ppc],
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[POWER architectures only: Force use of builtin atomics if available. This could either be gcc builtins or C11 atomics, depending on what is available on your system. Enabling this is known to cause poor performance in atomic operations on Power machines. (default: disabled)])])
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if test "x$enable_builtin_atomics_for_ppc" = "xyes" ; then
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force_gcc_atomics_ppc=1
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else
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force_gcc_atomics_ppc=0
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fi
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#
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# Memory debugging

‎test/threads/Makefile.am

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@@ -10,7 +10,8 @@
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# University of Stuttgart. All rights reserved.
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# Copyright (c) 2004-2005 The Regents of the University of California.
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# All rights reserved.
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# Copyright (c) 2016 Cisco Systems, Inc. All rights reserved.
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# Copyright (c) 2016 Cisco Systems, Inc. All rights reserved.
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# Copyright (c) 2021 IBM Corporation. All rights reserved.
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# $COPYRIGHT$
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#
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# Additional copyrights may follow
@@ -24,7 +25,8 @@ AM_LDFLAGS = -lpthread
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check_PROGRAMS = \
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opal_thread \
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opal_condition
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opal_condition \
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opal_atomic_thread_bench
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# JMS possibly to be re-added when #1232 is fixed
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#TESTS = $(check_PROGRAMS)
@@ -42,5 +44,11 @@ opal_condition_LDADD = \
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$(top_builddir)/opal/lib@[email protected]
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opal_condition_DEPENDENCIES = $(opal_condition_LDADD)
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opal_atomic_thread_bench_SOURCES = opal_atomic_thread_bench.c
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opal_atomic_thread_bench_LDADD = \
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$(top_builddir)/test/support/libsupport.a \
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$(top_builddir)/opal/lib@[email protected]
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opal_atomic_thread_bench_DEPENDENCIES = $(opal_atomic_thread_bench_LDADD)
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distclean:
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rm -rf *.dSYM .deps .libs *.log *.o *.trs $(check_PROGRAMS) Makefile

‎test/threads/opal_atomic_thread_bench.c

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@@ -0,0 +1,237 @@
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/*
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* Copyright (c) 2021 IBM Corporation. All rights reserved.
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* Additional copyrights may follow
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*
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* $HEADER$
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*/
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#include "opal_config.h"
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#include <stdio.h>
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#include <time.h>
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#include "support.h"
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#include "opal/runtime/opal.h"
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#include "opal/constants.h"
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#include "opal/mca/threads/threads.h"
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#include "opal/mca/threads/condition.h"
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#include "opal/sys/atomic.h"
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#define OPAL_TEST_THREAD_COUNT 8
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#define ITERATIONS 1000000
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#define ITEM_COUNT 100
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static opal_atomic_int64_t var_64 = 0;
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static opal_atomic_int32_t var_32 = 0;
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static pthread_barrier_t barrier;
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#if !defined(timersub)
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#define timersub(a, b, r) \
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do { \
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(r)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
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if ((a)->tv_usec < (b)->tv_usec) { \
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(r)->tv_sec--; \
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(a)->tv_usec += 1000000; \
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} \
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(r)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
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} while (0)
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#endif
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#if !defined(OPAL_TEST_DONE)
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#define OPAL_TEST_DONE(func, val) { \
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gettimeofday (&stop, NULL); \
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timersub(&stop, &start, &total); \
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timing = ((double) total.tv_sec + (double) total.tv_usec * 1e-6) / (double) ITERATIONS; \
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printf ("%s() thread finished. Time: %d s %d us %d nsec/per\n", func, (int) total.tv_sec, \
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(int)total.tv_usec, (int)(timing / 1e-9)); \
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memset(&stop, 0, sizeof(struct timeval)); \
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memset(&start, 0, sizeof(struct timeval)); \
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memset(&total, 0, sizeof(struct timeval)); \
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/* printf("%ld\n", val); */ \
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fflush(stdout); \
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pthread_barrier_wait (&barrier); \
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}
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#endif
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#if !defined(OPAL_RESET_VAR)
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#define OPAL_RESET_VAR(var) { \
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var = 0; \
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pthread_barrier_wait (&barrier); \
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}
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#endif
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static void *thread_test (void *arg) {
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struct timeval start, stop, total;
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double timing;
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_compare_exchange_strong_64(&var_64, &i, i+1);
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}
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OPAL_TEST_DONE("opal_atomic_compare_exchange_strong_64", var_64);
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OPAL_RESET_VAR(var_64);
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_compare_exchange_strong_rel_64(&var_64, &i, i+1);
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}
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OPAL_TEST_DONE("opal_atomic_compare_exchange_strong_rel_64", var_64);
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OPAL_RESET_VAR(var_64);
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_compare_exchange_strong_acq_64(&var_64, &i, i+1);
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}
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OPAL_TEST_DONE("opal_atomic_compare_exchange_strong_acq_64", var_64);
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OPAL_RESET_VAR(var_64);
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_fetch_add_64(&var_64, 1);
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}
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OPAL_TEST_DONE("opal_atomic_fetch_add_64", var_64);
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OPAL_RESET_VAR(var_64);
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_fetch_sub_64(&var_64, 1);
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}
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OPAL_TEST_DONE("opal_atomic_fetch_sub_64", var_64);
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OPAL_RESET_VAR(var_64);
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_fetch_xor_64(&var_64, i);
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}
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OPAL_TEST_DONE("opal_atomic_fetch_xor_64", var_64);
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OPAL_RESET_VAR(var_64);
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
119+
opal_atomic_swap_64(&var_64, i);
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}
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OPAL_TEST_DONE("opal_atomic_swap_64", var_64);
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OPAL_RESET_VAR(var_64);
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#if OPAL_HAVE_ATOMIC_LLSC_64
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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int ret;
129+
opal_atomic_sc_64(&var_64, i, ret);
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}
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OPAL_TEST_DONE("opal_atomic_sc_64", var_64);
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OPAL_RESET_VAR(var_64);
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gettimeofday (&start, NULL);
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for (int64_t i = 0 ; i < ITERATIONS ; ++i) {
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int ret;
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opal_atomic_sc_64(&var_64, i, ret);
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}
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OPAL_TEST_DONE("opal_atomic_ll_64", var_64);
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OPAL_RESET_VAR(var_64);
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#endif
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_compare_exchange_strong_32(&var_32, &i, i+1);
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}
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OPAL_TEST_DONE("opal_atomic_compare_exchange_strong_32", var_32);
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OPAL_RESET_VAR(var_32);
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_compare_exchange_strong_rel_32(&var_32, &i, i+1);
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}
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OPAL_TEST_DONE("opal_atomic_compare_exchange_strong_rel_32", var_32);
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OPAL_RESET_VAR(var_32);
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_compare_exchange_strong_acq_32(&var_32, &i, i+1);
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}
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OPAL_TEST_DONE("opal_atomic_compare_exchange_strong_acq_32", var_32);
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OPAL_RESET_VAR(var_32);
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_fetch_add_32(&var_32, 1);
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}
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OPAL_TEST_DONE("opal_atomic_fetch_add_32", var_32);
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OPAL_RESET_VAR(var_32);
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_fetch_sub_32(&var_32, 1);
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}
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OPAL_TEST_DONE("opal_atomic_fetch_sub_32", var_32);
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OPAL_RESET_VAR(var_32);
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_fetch_xor_32(&var_32, i);
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}
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OPAL_TEST_DONE("opal_atomic_fetch_xor_32", var_32);
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OPAL_RESET_VAR(var_32);
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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opal_atomic_swap_32(&var_32, i);
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}
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OPAL_TEST_DONE("opal_atomic_swap_32", var_32);
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OPAL_RESET_VAR(var_32);
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#if OPAL_HAVE_ATOMIC_LLSC_32
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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int ret;
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opal_atomic_sc_32(&var_32, i, ret);
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}
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OPAL_TEST_DONE("opal_atomic_sc_32", var_32);
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OPAL_RESET_VAR(var_32);
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gettimeofday (&start, NULL);
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for (int32_t i = 0 ; i < ITERATIONS ; ++i) {
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int ret;
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opal_atomic_sc_32(&var_32, i, ret);
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}
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OPAL_TEST_DONE("opal_atomic_ll_32", var_32);
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OPAL_RESET_VAR(var_32);
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#endif
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return NULL;
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}
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int main(void) {
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pthread_barrier_init (&barrier, NULL, OPAL_TEST_THREAD_COUNT);
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pthread_t ts[OPAL_TEST_THREAD_COUNT];
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for(int i = 0; i < OPAL_TEST_THREAD_COUNT; i++) {
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pthread_create(&ts[i], NULL, &thread_test, NULL);
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}
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for(int i = 0; i < OPAL_TEST_THREAD_COUNT; i++) {
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pthread_join(ts[i], NULL);
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}
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return 0;
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}

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