// SPDX-License-Identifier: GPL-2.0
// Carsten Haitzler <carsten.haitzler@arm.com>, 2021
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>

struct args {
        pthread_t th;
        unsigned int in;
        void *ret;
};

static void *thrfn(void *arg)
{
        struct args *a = arg;
        unsigned int i, in = a->in;

        for (i = 0; i < 10000; i++) {
                asm volatile (
// force an unroll of thia add instruction so we can test long runs of code
#define SNIP1 "add %w[in], %w[in], #1\n"
// 10
#define SNIP2 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1 SNIP1
// 100
#define SNIP3 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2 SNIP2
// 1000
#define SNIP4 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3 SNIP3
// 10000
#define SNIP5 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4 SNIP4
// 100000
                        SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5 SNIP5
                        : /* out */
                        : /* in */ [in] "r" (in)
                        : /* clobber */
                );
        }

        return NULL;
}

static pthread_t new_thr(void *(*fn) (void *arg), void *arg)
{
        pthread_t t;
        pthread_attr_t attr;

        pthread_attr_init(&attr);
        pthread_create(&t, &attr, fn, arg);
        return t;
}

int main(int argc, char **argv)
{
        unsigned int i, thr;
        struct args args[256];

        if (argc < 2) {
                printf("ERR: %s [numthreads]\n", argv[0]);
                exit(1);
        }

        thr = atoi(argv[1]);
        if ((thr > 256) || (thr < 1)) {
                printf("ERR: threads 1-256\n");
                exit(1);
        }
        for (i = 0; i < thr; i++) {
                args[i].in = rand();
                args[i].th = new_thr(thrfn, &(args[i]));
        }
        for (i = 0; i < thr; i++)
                pthread_join(args[i].th, &(args[i].ret));
        return 0;
}