gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-5.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fdump-tree-optimized" } */
   3
   4 int x;
   5
   6 int
   7 f1 (int i, int j, int k)
   8 {
   9   int *p = k ? &i : &j;
  10   i = 3;
  11   *p = 5;
  12   x = j;
  13 }
  14
  15 /* The assignment "i = 3" is partially dead.  Our DSE pass doesn't handle
  16    detection of partially dead assignments.
  17
  18    There's two outputs which would indicate that the optimization was
  19    performed.
  20
  21    If we used block copying to detect and eliminate the partially dead
  22    store, then we should see an assignment "i = 5" somewhere in the
  23    dump file.
  24
  25    Another approach would be to redirect the path from the true arm
  26    of the first conditional so that it reaches the statement *p = 5
  27    rather than i = 3.  */
  28
  29 /* { dg-final { scan-tree-dump-times "i = 5" 1 "optimized" { xfail *-*-* }} } */
  30 /* { dg-final { scan-tree-dump-times "<L.*>:;\[\n\t \]*\\*p = 5" 1 "optimized" { xfail *-*-*}} } */
  31
  32