gcc/testsuite/gcc.dg/tree-ssa/vrp98.c

   1 /* { dg-do compile } */
   2 /* { dg-require-effective-target int128 } */
   3 /* { dg-options "-Os -fdump-tree-vrp1-details" } */
   4
   5 #include <stdint.h>
   6 #include <limits.h>
   7
   8 typedef unsigned int word __attribute__((mode(word)));
   9 typedef unsigned __int128 bigger_than_word;
  10
  11 int
  12 foo (bigger_than_word a, word b, uint8_t c)
  13 {
  14   /* Must fold use of t1 into use of b, as b is no wider than word_mode. */
  15   const uint8_t t1 = b % UCHAR_MAX;
  16
  17   /* Must NOT fold use of t2 into use of a, as a is wider than word_mode. */
  18   const uint8_t t2 = a % UCHAR_MAX;
  19
  20   /* Must fold use of t3 into use of c, as c is narrower than t3. */
  21   const uint32_t t3 = (const uint32_t)(c >> 1);
  22
  23   uint16_t ret = 0;
  24
  25   if (t1 == 1)
  26     ret = 20;
  27   else if (t2 == 2)
  28     ret = 30;
  29   else if (t3 == 3)
  30     ret = 40;
  31   /* Th extra condition below is necessary to prevent a prior pass from
  32      folding away the cast. Ignored in scan-tree-dump. */
  33   else if (t3 == 4)
  34     ret = 50;
  35
  36   return ret;
  37 }
  38
  39 /* { dg-final { scan-tree-dump "Folded into: if \\(_\[0-9\]+ == 1\\)" "vrp1" } } */
  40 /* { dg-final { scan-tree-dump-not "Folded into: if \\(_\[0-9\]+ == 2\\)" "vrp1" } } */
  41 /* { dg-final { scan-tree-dump "Folded into: if \\(_\[0-9\]+ == 3\\)" "vrp1" } } */