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-require-effective-target mmap } */
  10 #include <sys/mman.h>
  11 #include <stdio.h>
  12 #include "tree-vect.h"
  13
  14 #define MMAP_SIZE 0x20000
  15 #define ADDRESS 0x1122000000
  16
  17 #define MB_BLOCK_SIZE 16
  18 #define VERT_PRED_16 0
  19 #define HOR_PRED_16 1
  20 #define DC_PRED_16 2
  21 int *sptr;
  22 extern void intrapred_luma_16x16();
  23 unsigned short mprr_2[5][16][16];
  24 void initialise_s(int *s) { }
  25 int main() {
  26     void *s_mapping;
  27     void *end_s;
  28     check_vect ();
  29     s_mapping = mmap ((void *)ADDRESS, MMAP_SIZE, PROT_READ | PROT_WRITE,
  30                       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  31     if (s_mapping == MAP_FAILED)
  32       {
  33         perror ("mmap");
  34         return 1;
  35       }
  36     end_s = (s_mapping + MMAP_SIZE);
  37     sptr = (int*)(end_s - sizeof(int[31]));
  38     intrapred_luma_16x16(sptr);
  39     return 0;
  40 }
  41
  42 void intrapred_luma_16x16(int * restrict sp) {
  43     for (int j=0; j < MB_BLOCK_SIZE; j++)
  44       {
  45         mprr_2[VERT_PRED_16][j][0]=sp[j*2];
  46         mprr_2[VERT_PRED_16][j][1]=sp[j*2];
  47         mprr_2[VERT_PRED_16][j][2]=sp[j*2];
  48         mprr_2[VERT_PRED_16][j][3]=sp[j*2];
  49         mprr_2[VERT_PRED_16][j][4]=sp[j*2];
  50         mprr_2[VERT_PRED_16][j][5]=sp[j*2];
  51         mprr_2[VERT_PRED_16][j][6]=sp[j*2];
  52         mprr_2[VERT_PRED_16][j][7]=sp[j*2];
  53         mprr_2[VERT_PRED_16][j][8]=sp[j*2];
  54         mprr_2[VERT_PRED_16][j][9]=sp[j*2];
  55         mprr_2[VERT_PRED_16][j][10]=sp[j*2];
  56         mprr_2[VERT_PRED_16][j][11]=sp[j*2];
  57         mprr_2[VERT_PRED_16][j][12]=sp[j*2];
  58         mprr_2[VERT_PRED_16][j][13]=sp[j*2];
  59         mprr_2[VERT_PRED_16][j][14]=sp[j*2];
  60         mprr_2[VERT_PRED_16][j][15]=sp[j*2];
  61       }
  62 }
  63 /* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" {target { vect_int && vect_perm } } } } */