gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fdump-tree-dom2-stats -fdump-tree-thread2-stats -fdump-tree-dom3-stats -fno-guess-branch-probability" } */
   3
   4 /* { dg-final { scan-tree-dump-not "Jumps threaded"  "dom2" } } */
   5
   6 /* We were previously checking for no threads in vrp-thread2, but now
   7    that we have merged the post and pre threaders, we get a dozen
   8    threads before VRP2.  */
   9
  10 /* aarch64 has the highest CASE_VALUES_THRESHOLD in GCC.  It's high enough
  11    to change decisions in switch expansion which in turn can expose new
  12    jump threading opportunities.  Skip the later tests on aarch64.  */
  13 /* { dg-final { scan-tree-dump-not "Jumps threaded"  "dom3" { target { ! aarch64*-*-* } } } } */
  14 /* { dg-final { scan-tree-dump "Jumps threaded: 9"  "thread2" { target { ! aarch64*-*-* } } } } */
  15 /* { dg-final { scan-tree-dump "Jumps threaded: 17"  "thread2" { target { aarch64*-*-* } } } } */
  16
  17 enum STATE {
  18   S0=0,
  19   SI,
  20   S1,
  21   S2,
  22   S3,
  23   S4,
  24   S5,
  25   S6
  26 };
  27
  28 int bar (enum STATE s);
  29
  30 enum STATE foo (unsigned char **y, unsigned *c)
  31 {
  32   unsigned char *x = *y;
  33   unsigned char n;
  34   enum STATE s = S0;
  35
  36   for( ; *x && s != SI; x++ )
  37     {
  38       n = *x;
  39       if (n == 'x')
  40         {
  41           x++;
  42           break;
  43         }
  44       switch(s)
  45         {
  46         case S0:
  47           if(bar(n))
  48             s = S3;
  49           else if( n == 'a' || n == 'b' )
  50             s = S1;
  51           else if( n == 'c' )
  52             s = S4;
  53           else
  54             {
  55               s = SI;
  56               c[SI]++;
  57             }
  58           c[S0]++;
  59           break;
  60         case S1:
  61           if(bar(n))
  62             {
  63               s = S3;
  64               c[S1]++;
  65             }
  66           else if( n == 'c' )
  67             {
  68               s = S4;
  69               c[S1]++;
  70             }
  71           else
  72             {
  73               s = SI;
  74               c[S1]++;
  75             }
  76           break;
  77         case S3:
  78           if( n == 'c' )
  79             {
  80               s = S4;
  81               c[S3]++;
  82             }
  83           else if(!bar(n))
  84             {
  85               s = SI;
  86               c[S3]++;
  87             }
  88           break;
  89         case S4:
  90           if( n == 'E' || n == 'e' )
  91             {
  92               s = S2;
  93               c[S4]++;
  94             }
  95           else if(!bar(n))
  96             {
  97               s = SI;
  98               c[S4]++;
  99             }
 100           break;
 101         case S2:
 102           if( n == 'a' || n == 'b' )
 103             {
 104               s = S5;
 105               c[S2]++;
 106             }
 107           else
 108             {
 109               s = SI;
 110               c[S2]++;
 111             }
 112           break;
 113         case S5:
 114           if(bar(n))
 115             {
 116               s = S6;
 117               c[S5]++;
 118             }
 119           else
 120             {
 121               s = SI;
 122               c[S5]++;
 123             }
 124           break;
 125         case S6:
 126           if(!bar(n))
 127             {
 128               s = SI;
 129               c[SI]++;
 130             }
 131           break;
 132         default:
 133           break;
 134         }
 135     }
 136   *y=x;
 137   return s;
 138 }