lk/app/tests/float.c

/*
 * Copyright (c) 2013-2015 Travis Geiselbrecht
 *
 * Use of this source code is governed by a MIT-style
 * license that can be found in the LICENSE file or at
 * https://opensource.org/licenses/MIT
 */
#if !WITH_NO_FP

#include <stdio.h>
#include <inttypes.h>
#include <rand.h>
#include <string.h>
#include <lk/err.h>
#include <lk/console_cmd.h>
#include <app/tests.h>
#include <kernel/thread.h>
#include <kernel/mutex.h>
#include <kernel/semaphore.h>
#include <kernel/event.h>
#include <platform.h>

#if ARM_WITH_VFP_SP_ONLY
#define FLOAT float
#else
#define FLOAT double
#endif

/* optimize this function to cause it to try to use a lot of registers */
__OPTIMIZE("O3")
static int float_thread(void *arg) {
    FLOAT *val = arg;

    FLOAT a[16];

    /* do a bunch of work with floating point to test context switching */
    a[0] = *val;
    for (size_t i = 1; i < countof(a); i++) {
        a[i] = a[i-1] * (FLOAT)1.01f;
    }

    for (size_t i = 0; i < 1000000; i++) {
        a[0] += (FLOAT)0.001f;
        for (size_t j = 1; j < countof(a); j++) {
            a[j] += a[j-1] * (FLOAT)0.00001f;
        }
    }

    *val = a[countof(a) - 1];

    return 1;
}

#if ARCH_ARM && !ARM_ISA_ARMV7M
extern void float_vfp_arm_instruction_test(void);
extern void float_vfp_thumb_instruction_test(void);
extern void float_neon_arm_instruction_test(void);
extern void float_neon_thumb_instruction_test(void);

static void arm_float_instruction_trap_test(void) {
    printf("testing fpu trap\n");

#if !ARM_ONLY_THUMB
    float_vfp_arm_instruction_test();
    float_neon_arm_instruction_test();
#endif
    float_vfp_thumb_instruction_test();
    float_neon_thumb_instruction_test();

    printf("if we got here, we probably decoded everything properly\n");
}
#endif

static void float_test(void) {
    /* test lazy fpu load on separate thread */
    thread_t *t[8];
    volatile FLOAT val[countof(t)];
    const uint32_t test_results_32[8] = {
        0x473aced4,
        0x4788973e,
        0x47b3c703,
        0x47def6ab,
        0x48051399,
        0x481aaab3,
        0x48304325,
        0x4845da0c,
    };
    const uint64_t test_results_64[8] = {
        0x40e7570fc8092db9,
        0x40f1117b2a41e1dc,
        0x40f6776e707f2b8a,
        0x40fbdd61b6bc75cf,
        0x4100a1aa7e7cdfa2,
        0x410354a4219b8561,
        0x4106079dc4ba29ff,
        0x4108ba9767d8cf09,
    };


    printf("creating %zu floating point threads\n", countof(t));
    for (uint i = 0; i < countof(t); i++) {
        val[i] = i;
        char name[32];
        snprintf(name, sizeof(name), "float %u", i);
        t[i] = thread_create(name, &float_thread, (void *)&val[i], LOW_PRIORITY, DEFAULT_STACK_SIZE);
        thread_resume(t[i]);
    }

    int res;
    for (uint i = 0; i < countof(t); i++) {
        thread_join(t[i], &res, INFINITE_TIME);

        if (sizeof(FLOAT) == 4) {
            float result = val[i];
            uint32_t result_u32;
            memcpy(&result_u32, &result, sizeof(result_u32));
            printf_float("float thread %u returns %d, hex val %a, uint32 %#" PRIx32, i, res, (double)result, result_u32);
            if (result_u32 != test_results_32[i]) {
                printf("\nfloat thread %u failed, expected %#" PRIx32 "\n", i, test_results_32[i]);
            } else {
                printf(" (ok)\n");
            }
        } else {
            double result = val[i];
            uint64_t result_u64;
            memcpy(&result_u64, &result, sizeof(result_u64));
            printf_float("float thread %u returns %d, hex val %a, uint64 %#" PRIx64, i, res, result, result_u64);
            if (result_u64 != test_results_64[i]) {
                printf("\nfloat thread %u failed, expected %#" PRIx64 "\n", i, test_results_64[i]);
            } else {
                printf(" (ok)\n");
            }
            //hexdump8(&result, 8);
        }
    }
}

static int float_tests(int argc, const console_cmd_args *argv) {
    printf("floating point test:\n");

    float_test();

#if ARCH_ARM && !ARM_ISA_ARMV7M
    /* test all the instruction traps */
    arm_float_instruction_trap_test();
#endif

    return 0;
}

STATIC_COMMAND_START
STATIC_COMMAND("float_tests", "floating point test", &float_tests)
STATIC_COMMAND_END(float_tests);

#endif // !WITH_NO_FP