builtin-expect-with-probability.cpp
2.85 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
// RUN: %clang_cc1 -fsyntax-only -verify %s
__attribute__((noreturn)) extern void bar();
int test_no_warn(int x) {
if (x) {
if (__builtin_expect_with_probability(1, 1, 1))
bar();
} else {
return 0;
}
} // 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
template <int b> void tempf() {
static_assert(b == 1, "should be evaluated as 1"); // should not have error here
}
constexpr int constf() {
return __builtin_expect_with_probability(1, 1, 1);
}
void foo() {
tempf<__builtin_expect_with_probability(1, 1, 1)>();
constexpr int f = constf();
static_assert(f == 1, "should be evaluated as 1"); // should not have error here
}
extern int global;
struct S {
static constexpr float prob = 0.7;
};
template<typename T>
void expect_taken(int x) {
if (__builtin_expect_with_probability(x > 0, 1, T::prob)) {
global++;
}
}
void test(int x, double p) { // expected-note {{declared here}}
bool dummy;
dummy = __builtin_expect_with_probability(x > 0, 1, 0.9);
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]}}
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]}}
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 {{read of non-constexpr variable 'p' is not allowed in a constant expression}}
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]'}}
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]}}
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]}}
dummy = __builtin_expect_with_probability(x > 0, 1, -0.0);
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]}}
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]}}
constexpr double pd = 0.7;
dummy = __builtin_expect_with_probability(x > 0, 1, pd);
constexpr int pi = 1;
dummy = __builtin_expect_with_probability(x > 0, 1, pi);
expect_taken<S>(x);
}