gcc/testsuite/c-c++-common/Wtautological-compare-5.c

   1 /* PR c/81783 */
   2 /* { dg-do compile } */
   3 /* { dg-options "-Wtautological-compare" } */
   4
   5 enum E { FOO = 128 };
   6
   7 int
   8 f (int a)
   9 {
  10   if ((a & 16) == 10) /* { dg-warning "bitwise comparison always evaluates to false" } */
  11     return 1;
  12   if ((16 & a) == 10) /* { dg-warning "bitwise comparison always evaluates to false" } */
  13     return 1;
  14   if (10 == (a & 16)) /* { dg-warning "bitwise comparison always evaluates to false" } */
  15     return 1;
  16   if (10 == (16 & a)) /* { dg-warning "bitwise comparison always evaluates to false" } */
  17     return 1;
  18
  19   if ((a & 16) != 10) /* { dg-warning "bitwise comparison always evaluates to true" } */
  20     return 1;
  21   if ((16 & a) != 10) /* { dg-warning "bitwise comparison always evaluates to true" } */
  22     return 1;
  23   if (10 != (a & 16)) /* { dg-warning "bitwise comparison always evaluates to true" } */
  24     return 1;
  25   if (10 != (16 & a)) /* { dg-warning "bitwise comparison always evaluates to true" } */
  26     return 1;
  27
  28   if ((a & 9) == 8)
  29     return 1;
  30   if ((9 & a) == 8)
  31     return 1;
  32   if (8 == (a & 9))
  33     return 1;
  34   if (8 == (9 & a))
  35     return 1;
  36
  37   if ((a & 9) != 8)
  38     return 1;
  39   if ((9 & a) != 8)
  40     return 1;
  41   if (8 != (a & 9))
  42     return 1;
  43   if (8 != (9 & a))
  44     return 1;
  45
  46   if ((a | 16) == 10) /* { dg-warning "bitwise comparison always evaluates to false" } */
  47     return 1;
  48   if ((16 | a) == 10) /* { dg-warning "bitwise comparison always evaluates to false" } */
  49     return 1;
  50   if (10 == (a | 16)) /* { dg-warning "bitwise comparison always evaluates to false" } */
  51     return 1;
  52   if (10 == (16 | a)) /* { dg-warning "bitwise comparison always evaluates to false" } */
  53     return 1;
  54
  55   if ((a | 16) != 10) /* { dg-warning "bitwise comparison always evaluates to true" } */
  56     return 1;
  57   if ((16 | a) != 10) /* { dg-warning "bitwise comparison always evaluates to true" } */
  58     return 1;
  59   if (10 != (a | 16)) /* { dg-warning "bitwise comparison always evaluates to true" } */
  60     return 1;
  61   if (10 != (16 | a)) /* { dg-warning "bitwise comparison always evaluates to true" } */
  62     return 1;
  63
  64   if ((a | 9) == 8) /* { dg-warning "bitwise comparison always evaluates to false" } */
  65     return 1;
  66   if ((9 | a) == 8) /* { dg-warning "bitwise comparison always evaluates to false" } */
  67     return 1;
  68   if (8 == (a | 9)) /* { dg-warning "bitwise comparison always evaluates to false" } */
  69     return 1;
  70   if (8 == (9 | a)) /* { dg-warning "bitwise comparison always evaluates to false" } */
  71     return 1;
  72
  73   if ((a | 9) != 8) /* { dg-warning "bitwise comparison always evaluates to true" } */
  74     return 1;
  75   if ((9 | a) != 8) /* { dg-warning "bitwise comparison always evaluates to true" } */
  76     return 1;
  77   if (8 != (a | 9)) /* { dg-warning "bitwise comparison always evaluates to true" } */
  78     return 1;
  79   if (8 != (9 | a)) /* { dg-warning "bitwise comparison always evaluates to true" } */
  80     return 1;
  81
  82   if ((a & 128) != 1) /* { dg-warning "bitwise comparison always evaluates to true" } */
  83     return 1;
  84   if ((128 & a) != 1) /* { dg-warning "bitwise comparison always evaluates to true" } */
  85     return 1;
  86   if ((a & FOO) != 1) /* { dg-warning "bitwise comparison always evaluates to true" } */
  87     return 1;
  88   if ((FOO & a) != 1) /* { dg-warning "bitwise comparison always evaluates to true" } */
  89     return 1;
  90   if ((a & 128) == 1) /* { dg-warning "bitwise comparison always evaluates to false" } */
  91     return 1;
  92   if ((128 & a) == 1) /* { dg-warning "bitwise comparison always evaluates to false" } */
  93     return 1;
  94   if ((a & FOO) == 1) /* { dg-warning "bitwise comparison always evaluates to false" } */
  95     return 1;
  96   if ((FOO & a) == 1) /* { dg-warning "bitwise comparison always evaluates to false" } */
  97     return 1;
  98
  99 #define N 0x10
 100   if ((a & N) == 10) /* { dg-bogus "bitwise comparison always evaluates to false" "" { xfail *-*-* } } */
 101     return 1;
 102   if ((a | N) == 10) /* { dg-bogus "bitwise comparison always evaluates to false" "" { xfail *-*-* } } */
 103     return 1;
 104
 105   return 0;
 106 }