gcc/testsuite/gcc.dg/vect/pr20122.c

/* { dg-require-effective-target vect_int } */

#include <stdarg.h>
#include "tree-vect.h"

short Kernshort[24] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
static void VecBug(short Kernel[8][24]) __attribute__((noinline));
static void VecBug2(short Kernel[8][24]) __attribute__((noinline));

/* Kernel may alias Kernshort - a global array.
   Use versioning for aliasing.  */
static void VecBug(short Kernel[8][24])
{
  int k,i;
    for (k = 0; k<8; k++)
        for (i = 0; i<24; i++)
            Kernshort[i] = Kernel[k][i];
}

/* Vectorizable: Kernshort2 is local.  */
static void VecBug2(short Kernel[8][24])
{
  int k,i;
  short Kernshort2[24] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
    for (k = 0; k<8; k++)
        for (i = 0; i<24; i++)
            Kernshort2[i] = Kernel[k][i];

    for (k = 0; k<8; k++)
        for (i = 0; i<24; i++)
            if (Kernshort2[i] != Kernel[k][i])
                abort ();
}

int main (int argc, char **argv)
{
    check_vect ();

    short Kernel[8][24];
    int k,i;

    for (k = 0; k<8; k++)
      for (i = 0; i<24; i++)
	{
	  Kernel[k][i] = 0;
	  /* Don't get into the game of versioning vs. peeling.  */
	  __asm__ volatile ("" : : : "memory");
	}

    VecBug(Kernel);
    VecBug2(Kernel);

    return 0;
}

/* The loops in VecBug and VecBug2 require versioning for alignment.  */
/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 2 "vect" } } */
/*  { dg-final { scan-tree-dump-times "Alignment of access forced using versioning" 2 "vect" { target { vect_no_align && { ! vect_hw_misalign } } } } } */