/*
 * See what happens when we try to load Maverick doublewords from
 * a boundary not aligned to 8 bytes (or not to 4 bytes)
 *
 * Usage: alignment n
 * where n is the offset in bytes to use from an 8-byte-aligned address
 *
 * non-4-aligned maverick double loads with /proc/cpu/alignment = 
 * 5 (signal+warn) cause bus errors and increment field "User"
 * 3 (fixup+warn)  cause illegal instruction and increment User and Skipped
 * 1 (warn) hangs giving 100 User faults a second until something else runs,
 * then returns the value at the pointer & ~3.
 * 0 (ignore) immediately returns the value at pointer & ~3.
 */

#include <stdio.h>

char __attribute__((aligned(8))) buf[16];

main(int argc, char **argv)
{
	register volatile double df asm("mvd4");
	register double *dp asm("r3");
	int offset;

	if (argc != 2 || (offset = atoi(argv[1])) < 0 || offset > 8) {
		fputs("Usage: aligment n (0-8)\n", stderr);
		exit(1);
	}

	buf[7] = 1;

	dp = (double *)(buf + offset);

	asm volatile("cfldrd	mvd4, [r3]" : "=v" (df) : "m" (*dp));
	/* df = *dp;  /* Boom! :) */

	printf("Got %g\n", df);

	exit(0);
}