gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-4.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fdump-tree-vrp1-details -fdump-tree-dom2-details -std=gnu89" } */
   3 struct bitmap_head_def;
   4 typedef struct bitmap_head_def *bitmap;
   5 typedef const struct bitmap_head_def *const_bitmap;
   6 typedef unsigned long BITMAP_WORD;
   7 typedef struct bitmap_element_def
   8 {
   9   struct bitmap_element_def *next;
  10   unsigned int indx;
  11 } bitmap_element;
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21 unsigned char
  22 bitmap_ior_and_compl (bitmap dst, const_bitmap a, const_bitmap b,
  23                       const_bitmap kill)
  24 {
  25   unsigned char changed = 0;
  26
  27   bitmap_element *dst_elt;
  28   const bitmap_element *a_elt, *b_elt, *kill_elt, *dst_prev;
  29
  30   while (a_elt || b_elt)
  31     {
  32       unsigned char new_element = 0;
  33
  34       if (b_elt)
  35         while (kill_elt && kill_elt->indx < b_elt->indx)
  36           kill_elt = kill_elt->next;
  37
  38       if (b_elt && kill_elt && kill_elt->indx == b_elt->indx
  39           && (!a_elt || a_elt->indx >= b_elt->indx))
  40         {
  41           bitmap_element tmp_elt;
  42           unsigned ix;
  43
  44           BITMAP_WORD ior = 0;
  45
  46               changed = bitmap_elt_ior (dst, dst_elt, dst_prev,
  47                                         a_elt, &tmp_elt, changed);
  48
  49         }
  50
  51     }
  52
  53
  54   return changed;
  55 }
  56 /* The block starting the second conditional has  3 incoming edges,
  57    we should thread all three, but due to a bug in the threading
  58    code we missed the edge when the first conditional is false
  59    (b_elt is zero, which means the second conditional is always
  60    zero.  VRP1 catches all three.  */
  61 /* { dg-final { scan-tree-dump-times "Threaded" 3 "vrp1" { target { ! logical_op_short_circuit } } } } */
  62
  63 /* On targets that define LOGICAL_OP_NON_SHORT_CIRCUIT to 0, we split both
  64    "a_elt || b_elt" and "b_elt && kill_elt" into two conditions each,
  65    rather than using "(var1 != 0) op (var2 != 0)".  Also, as on other targets,
  66    we duplicate the header of the inner "while" loop.  There are then
  67    4 threading opportunities:
  68
  69    1x "!a_elt && b_elt" in the outer "while" loop
  70       -> the start of the inner "while" loop,
  71          skipping the known-true "b_elt" in the first condition.
  72    1x "!b_elt" in the first condition
  73       -> the outer "while" loop's continuation point,
  74          skipping the known-false "b_elt" in the second condition.
  75    2x "kill_elt->indx >= b_elt->indx" in the first "while" loop
  76       -> "kill_elt->indx == b_elt->indx" in the second condition,
  77          skipping the known-true "b_elt && kill_elt" in the second
  78          condition.
  79
  80    All the cases are picked up by VRP1 as jump threads.  */
  81 /* { dg-final { scan-tree-dump-times "Threaded" 4 "vrp1" { target logical_op_short_circuit } } } */
  82