xref: /llvm-project/clang/test/SemaCXX/rounding-math.cpp (revision 7e801ca0efa99f7cec7a2aea30513ad282030b51)
1 // RUN: %clang_cc1 -triple x86_64-linux -verify=norounding %s
2 // RUN: %clang_cc1 -triple x86_64-linux -verify=rounding %s -frounding-math
3 // rounding-no-diagnostics
4 
5 #define fold(x) (__builtin_constant_p(x) ? (x) : (x))
6 
7 constexpr double a = 1.0 / 3.0;
8 
9 constexpr int f(int n) { return int(n * (1.0 / 3.0)); }
10 
11 using T = int[f(3)];
12 using T = int[1];
13 
14 enum Enum { enum_a = f(3) };
15 
16 struct Bitfield {
17   unsigned int n : 1;
18   unsigned int m : f(3);
19 };
20 
21 void f(Bitfield &b) {
22   b.n = int(6 * (1.0 / 3.0)); // norounding-warning {{changes value from 2 to 0}}
23 }
24 
25 const int k = 3 * (1.0 / 3.0);
26 static_assert(k == 1, "");
27 
28 void g() {
29   // FIXME: Constant-evaluating this initializer is surprising, and violates
30   // the recommended practice in C++ [expr.const]p12:
31   //
32   //   Implementations should provide consistent results of floating-point
33   //   evaluations, irrespective of whether the evaluation is performed during
34   //   translation or during program execution.
35   const int k = 3 * (1.0 / 3.0);
36   static_assert(k == 1, "");
37 }
38 
39 int *h() {
40   return new int[int(-3 * (1.0 / 3.0))]; // norounding-error {{too large}}
41 }
42