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Use std:🧵:hardware_concurrency in lto-wrapper.c.

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gcc/ChangeLog:

	* lto-wrapper.c (cpuset_popcount): Remove.
	(init_num_threads): Remove and use hardware_concurrency.
This commit is contained in:
Martin Liska 2021-03-11 11:37:50 +01:00
parent 8f48ec0946
commit 0a18305ee1
1 changed files with 5 additions and 108 deletions
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113
gcc/lto-wrapper.c
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@ -49,6 +49,8 @@ along with GCC; see the file COPYING3. If not see
#include "lto-section-names.h"
#include "collect-utils.h"
#include <thread>
/* Environment variable, used for passing the names of offload targets from GCC
driver to lto-wrapper. */
#define OFFLOAD_TARGET_NAMES_ENV "OFFLOAD_TARGET_NAMES"
@ -1199,113 +1201,6 @@ cmp_priority (const void *a, const void *b)
return *((const int *)b)-*((const int *)a);
}
/* Number of CPUs that can be used for parallel LTRANS phase. */
static unsigned long nthreads_var = 0;
#ifdef HAVE_PTHREAD_AFFINITY_NP
unsigned long cpuset_size;
static unsigned long get_cpuset_size;
cpu_set_t *cpusetp;
unsigned long
static cpuset_popcount (unsigned long cpusetsize, cpu_set_t *cpusetp)
{
#ifdef CPU_COUNT_S
/* glibc 2.7 and above provide a macro for this. */
return CPU_COUNT_S (cpusetsize, cpusetp);
#else
#ifdef CPU_COUNT
if (cpusetsize == sizeof (cpu_set_t))
/* glibc 2.6 and above provide a macro for this. */
return CPU_COUNT (cpusetp);
#endif
size_t i;
unsigned long ret = 0;
STATIC_ASSERT (sizeof (cpusetp->__bits[0]) == sizeof (unsigned long int));
for (i = 0; i < cpusetsize / sizeof (cpusetp->__bits[0]); i++)
{
unsigned long int mask = cpusetp->__bits[i];
if (mask == 0)
continue;
ret += __builtin_popcountl (mask);
}
return ret;
#endif
}
#endif
/* At startup, determine the default number of threads. It would seem
this should be related to the number of cpus online. */
static void
init_num_threads (void)
{
#ifdef HAVE_PTHREAD_AFFINITY_NP
#if defined (_SC_NPROCESSORS_CONF) && defined (CPU_ALLOC_SIZE)
cpuset_size = sysconf (_SC_NPROCESSORS_CONF);
cpuset_size = CPU_ALLOC_SIZE (cpuset_size);
#else
cpuset_size = sizeof (cpu_set_t);
#endif
cpusetp = (cpu_set_t *) xmalloc (gomp_cpuset_size);
do
{
int ret = pthread_getaffinity_np (pthread_self (), gomp_cpuset_size,
cpusetp);
if (ret == 0)
{
/* Count only the CPUs this process can use. */
nthreads_var = cpuset_popcount (cpuset_size, cpusetp);
if (nthreads_var == 0)
break;
get_cpuset_size = cpuset_size;
#ifdef CPU_ALLOC_SIZE
unsigned long i;
for (i = cpuset_size * 8; i; i--)
if (CPU_ISSET_S (i - 1, cpuset_size, cpusetp))
break;
cpuset_size = CPU_ALLOC_SIZE (i);
#endif
return;
}
if (ret != EINVAL)
break;
#ifdef CPU_ALLOC_SIZE
if (cpuset_size < sizeof (cpu_set_t))
cpuset_size = sizeof (cpu_set_t);
else
cpuset_size = cpuset_size * 2;
if (cpuset_size < 8 * sizeof (cpu_set_t))
cpusetp
= (cpu_set_t *) realloc (cpusetp, cpuset_size);
else
{
/* Avoid fatal if too large memory allocation would be
requested, e.g. kernel returning EINVAL all the time. */
void *p = realloc (cpusetp, cpuset_size);
if (p == NULL)
break;
cpusetp = (cpu_set_t *) p;
}
#else
break;
#endif
}
while (1);
cpuset_size = 0;
nthreads_var = 1;
free (cpusetp);
cpusetp = NULL;
#endif
#ifdef _SC_NPROCESSORS_ONLN
nthreads_var = sysconf (_SC_NPROCESSORS_ONLN);
#endif
}
/* FIXME: once using -std=c++11, we can use std::thread::hardware_concurrency. */
/* Test and return reason why a jobserver cannot be detected. */
static const char *
@ -1389,6 +1284,9 @@ run_gcc (unsigned argc, char *argv[])
const char *incoming_dumppfx = dumppfx = NULL;
static char current_dir[] = { '.', DIR_SEPARATOR, '\0' };
/* Number of CPUs that can be used for parallel LTRANS phase. */
unsigned long nthreads_var = std::thread::hardware_concurrency ();
/* Get the driver and options. */
collect_gcc = getenv ("COLLECT_GCC");
if (!collect_gcc)
@ -1779,7 +1677,6 @@ cont1:
else if (auto_parallel)
{
char buf[256];
init_num_threads ();
if (nthreads_var == 0)
nthreads_var = 1;
if (verbose)