gcc/testsuite/gcc.dg/vect/vect-multi-peel-gaps.c

   1 /* For some targets we end up vectorizing the below loop such that the `sp`
   2    single integer is loaded into a 4 integer vector.
   3    While the writes are all safe, without 2 scalar loops being peeled into the
   4    epilogue we would read past the end of the 31 integer array.  This happens
   5    because we load a 4 integer chunk to only use the first integer and
   6    increment by 2 integers at a time, hence the last load needs s[30-33] and
   7    the penultimate load needs s[28-31].
   8    This testcase ensures that we do not crash due to that behaviour.  */
   9 /* { dg-additional-options "-std=gnu17" } */
  10 /* { dg-require-effective-target mmap } */
  11 #include <sys/mman.h>
  12 #include <stdio.h>
  13 #include "tree-vect.h"
  14
  15 #define MMAP_SIZE 0x20000
  16 #define ADDRESS 0x1122000000
  17
  18 #define MB_BLOCK_SIZE 16
  19 #define VERT_PRED_16 0
  20 #define HOR_PRED_16 1
  21 #define DC_PRED_16 2
  22 int *sptr;
  23 extern void intrapred_luma_16x16();
  24 unsigned short mprr_2[5][16][16];
  25 void initialise_s(int *s) { }
  26 int main() {
  27     void *s_mapping;
  28     void *end_s;
  29     check_vect ();
  30     s_mapping = mmap ((void *)ADDRESS, MMAP_SIZE, PROT_READ | PROT_WRITE,
  31                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  32     if (s_mapping == MAP_FAILED)
  33       {
  34         perror ("mmap");
  35         return 1;
  36       }
  37     end_s = (s_mapping + MMAP_SIZE);
  38     sptr = (int*)(end_s - sizeof(int[31]));
  39     intrapred_luma_16x16(sptr);
  40     return 0;
  41 }
  42
  43 void intrapred_luma_16x16(int * restrict sp) {
  44     for (int j=0; j < MB_BLOCK_SIZE; j++)
  45       {
  46         mprr_2[VERT_PRED_16][j][0]=sp[j*2];
  47         mprr_2[VERT_PRED_16][j][1]=sp[j*2];
  48         mprr_2[VERT_PRED_16][j][2]=sp[j*2];
  49         mprr_2[VERT_PRED_16][j][3]=sp[j*2];
  50         mprr_2[VERT_PRED_16][j][4]=sp[j*2];
  51         mprr_2[VERT_PRED_16][j][5]=sp[j*2];
  52         mprr_2[VERT_PRED_16][j][6]=sp[j*2];
  53         mprr_2[VERT_PRED_16][j][7]=sp[j*2];
  54         mprr_2[VERT_PRED_16][j][8]=sp[j*2];
  55         mprr_2[VERT_PRED_16][j][9]=sp[j*2];
  56         mprr_2[VERT_PRED_16][j][10]=sp[j*2];
  57         mprr_2[VERT_PRED_16][j][11]=sp[j*2];
  58         mprr_2[VERT_PRED_16][j][12]=sp[j*2];
  59         mprr_2[VERT_PRED_16][j][13]=sp[j*2];
  60         mprr_2[VERT_PRED_16][j][14]=sp[j*2];
  61         mprr_2[VERT_PRED_16][j][15]=sp[j*2];
  62       }
  63 }
  64 /* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" {target { vect_int && vect_perm } } } } */