gnss-sdr/src/algorithms/libs/volk_gnsssdr/lib/volk_gnsssdr_rank_archs.c

120 lines
3.9 KiB
C

/*
* Copyright 2011-2012 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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.
*
* GNU Radio 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.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include <volk_gnsssdr_rank_archs.h>
#include <volk_gnsssdr/volk_gnsssdr_prefs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if __GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 4
#define __popcnt __builtin_popcount
#else
inline unsigned __popcnt(unsigned num)
{
unsigned pop = 0;
while(num)
{
if (num & 0x1) pop++;
num >>= 1;
}
return pop;
}
#endif
int volk_gnsssdr_get_index(
const char *impl_names[], //list of implementations by name
const size_t n_impls, //number of implementations available
const char *impl_name //the implementation name to find
){
unsigned int i;
for (i = 0; i < n_impls; i++) {
if(!strncmp(impl_names[i], impl_name, 20)) {
return i;
}
}
//TODO return -1;
//something terrible should happen here
printf("Volk warning: no arch found, returning generic impl\n");
return volk_gnsssdr_get_index(impl_names, n_impls, "generic"); //but we'll fake it for now
}
int volk_gnsssdr_rank_archs(
const char *kern_name, //name of the kernel to rank
const char *impl_names[], //list of implementations by name
const int* impl_deps, //requirement mask per implementation
const bool* alignment, //alignment status of each implementation
size_t n_impls, //number of implementations available
const bool align //if false, filter aligned implementations
){
size_t i;
static volk_gnsssdr_arch_pref_t *volk_gnsssdr_arch_prefs;
static size_t n_arch_prefs = 0;
static int prefs_loaded = 0;
if(!prefs_loaded) {
n_arch_prefs = volk_gnsssdr_load_preferences(&volk_gnsssdr_arch_prefs);
prefs_loaded = 1;
}
// If we've defined VOLK_GENERIC to be anything, always return the
// 'generic' kernel. Used in GR's QA code.
char *gen_env = getenv("VOLK_GENERIC");
if(gen_env) {
return volk_gnsssdr_get_index(impl_names, n_impls, "generic");
}
//now look for the function name in the prefs list
for(i = 0; i < n_arch_prefs; i++)
{
if(!strncmp(kern_name, volk_gnsssdr_arch_prefs[i].name, sizeof(volk_gnsssdr_arch_prefs[i].name))) //found it
{
const char *impl_name = align? volk_gnsssdr_arch_prefs[i].impl_a : volk_gnsssdr_arch_prefs[i].impl_u;
return volk_gnsssdr_get_index(impl_names, n_impls, impl_name);
}
}
//return the best index with the largest deps
size_t best_index_a = 0;
size_t best_index_u = 0;
int best_value_a = -1;
int best_value_u = -1;
for(i = 0; i < n_impls; i++)
{
const signed val = __popcnt(impl_deps[i]);
if (alignment[i] && val > best_value_a)
{
best_index_a = i;
best_value_a = val;
}
if (!alignment[i] && val > best_value_u)
{
best_index_u = i;
best_value_u = val;
}
}
//when align and we found a best aligned, use it
if (align && best_value_a != -1) return best_index_a;
//otherwise return the best unaligned
return best_index_u;
}