clang/test/Sema/builtin-expect-with-probability.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -fexperimental-new-constant-interpreter %s
   3
   4 __attribute__((noreturn)) extern void bar();
   5
   6 int test_no_warn(int x) {
   7   if (x) {
   8     if (__builtin_expect_with_probability(1, 1, 1))
   9       bar();
  10   } else {
  11     return 0;
  12   }
  13 } // should not emit warn "control may reach end of non-void function" here since expr is constantly true, so the "if(__bui..)" should be constantly true condition and be ignored
  14
  15 template <int b> void tempf() {
  16   static_assert(b == 1, "should be evaluated as 1"); // should not have error here
  17 }
  18
  19 constexpr int constf() {
  20   return __builtin_expect_with_probability(1, 1, 1);
  21 }
  22
  23 void foo() {
  24   tempf<__builtin_expect_with_probability(1, 1, 1)>();
  25   constexpr int f = constf();
  26   static_assert(f == 1, "should be evaluated as 1"); // should not have error here
  27 }
  28
  29 extern int global;
  30
  31 struct S {
  32   static constexpr float prob = 0.7;
  33 };
  34
  35 template<typename T>
  36 void expect_taken(int x) {
  37   if (__builtin_expect_with_probability(x > 0, 1, T::prob)) {
  38     global++;
  39   }
  40 }
  41
  42 void test(int x, double p) { // expected-note {{declared here}}
  43   bool dummy;
  44   dummy = __builtin_expect_with_probability(x > 0, 1, 0.9);
  45   dummy = __builtin_expect_with_probability(x > 0, 1, 1.1); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
  46   dummy = __builtin_expect_with_probability(x > 0, 1, -1); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
  47   dummy = __builtin_expect_with_probability(x > 0, 1, p); // expected-error {{probability argument to __builtin_expect_with_probability must be constant floating-point expression}} expected-note {{function parameter 'p'}}
  48   dummy = __builtin_expect_with_probability(x > 0, 1, "aa"); // expected-error {{cannot initialize a parameter of type 'double' with an lvalue of type 'const char[3]'}}
  49   dummy = __builtin_expect_with_probability(x > 0, 1, __builtin_nan("")); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
  50   dummy = __builtin_expect_with_probability(x > 0, 1, __builtin_inf()); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
  51   dummy = __builtin_expect_with_probability(x > 0, 1, -0.0);
  52   dummy = __builtin_expect_with_probability(x > 0, 1, 1.0 + __DBL_EPSILON__); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
  53   dummy = __builtin_expect_with_probability(x > 0, 1, -__DBL_DENORM_MIN__); // expected-error {{probability argument to __builtin_expect_with_probability is outside the range [0.0, 1.0]}}
  54   constexpr double pd = 0.7;
  55   dummy = __builtin_expect_with_probability(x > 0, 1, pd);
  56   constexpr int pi = 1;
  57   dummy = __builtin_expect_with_probability(x > 0, 1, pi);
  58   expect_taken<S>(x);
  59 }