/* rbtest.c - how fast can the 604e read a frame out of the Mystique's VRAM?
 * Claude Opus 5.5, 2026-10-14. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mga.h"
#define N (640 * 480 * 2)
static int cmpd(const void *a, const void *b)
{ double x = *(const double *) a, y = *(const double *) b; return x < y ? -1 : x > y; }
int main(void)
{
    static double buf[N / 8];
    double t[15];
    int m, k, i;
    static char *name[] = { "32-bit loads", "64-bit (lfd) loads", "memcpy", "16-bit loads" };
    if (mga_open()) return 1;
    for (m = 0; m < 4; m++) {
        for (k = 0; k < 15; k++) {
            double t0 = mga_now();
            if (m == 0) { volatile unsigned int *s = (volatile unsigned int *) mga_fb; unsigned int *d = (unsigned int *) buf;
                for (i = 0; i < N / 4; i++) d[i] = s[i]; }
            if (m == 1) { volatile double *s = (volatile double *) mga_fb;
                for (i = 0; i < N / 8; i++) buf[i] = s[i]; }
            if (m == 2) memcpy(buf, (void *) mga_fb, N);
            if (m == 3) { volatile unsigned short *s = (volatile unsigned short *) mga_fb; unsigned short *d = (unsigned short *) buf;
                for (i = 0; i < N / 2; i++) d[i] = s[i]; }
            t[k] = mga_now() - t0;
        }
        qsort(t, 15, sizeof(double), cmpd);
        printf("%-20s min %6.1f ms  median %6.1f ms  %5.1f MB/s\n", name[m], t[0] * 1e3, t[7] * 1e3, N / t[7] / 1e6);
    }
    /* for scale: writing the same frame into VRAM */
    for (k = 0; k < 15; k++) { double t0 = mga_now(); volatile double *d = (volatile double *) mga_fb;
        for (i = 0; i < N / 8; i++) d[i] = buf[i]; t[k] = mga_now() - t0; }
    qsort(t, 15, sizeof(double), cmpd);
    printf("%-20s min %6.1f ms  median %6.1f ms  %5.1f MB/s\n", "64-bit stores", t[0] * 1e3, t[7] * 1e3, N / t[7] / 1e6);
    mga_close();
    return 0;
}