332ac18e31
According to [P0533R9](https://wg21.link/P0533R9), the C++ standard library functions corresponding to the C macros in `[c.math.abs]` are now `constexpr`. To implement this feature in libc++, we must make the built-in abs function `constexpr`. This patch adds the implementation of a `constexpr` abs function for the current constant evaluator and the new bytecode interpreter. It is important to note that in 2's complement systems, the absolute value of the most negative value is out of range. In gcc, it will result in an out-of-range error and will not be evaluated as constants. We follow the same approach here.
80 lines
2.1 KiB
C++
80 lines
2.1 KiB
C++
// RUN: %clang_cc1 -triple=x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s
|
|
|
|
// Builtins inside a namespace inside an extern "C" must be considered builtins.
|
|
extern "C" {
|
|
namespace X {
|
|
double __builtin_fabs(double);
|
|
float __builtin_fabsf(float) noexcept;
|
|
} // namespace X
|
|
}
|
|
|
|
int o = X::__builtin_fabs(-2.0);
|
|
// CHECK: @o ={{.*}} global i32 2, align 4
|
|
|
|
long p = X::__builtin_fabsf(-3.0f);
|
|
// CHECK: @p ={{.*}} global i64 3, align 8
|
|
|
|
int x = __builtin_abs(-2);
|
|
// CHECK: @x ={{.*}} global i32 2, align 4
|
|
|
|
long y = __builtin_abs(-2l);
|
|
// CHECK: @y ={{.*}} global i64 2, align 8
|
|
|
|
// PR8839
|
|
extern "C" char memmove();
|
|
|
|
int main() {
|
|
// CHECK: call {{signext i8|i8}} @memmove()
|
|
return memmove();
|
|
}
|
|
|
|
struct S;
|
|
// CHECK: define {{.*}} @_Z9addressofbR1SS0_(
|
|
S *addressof(bool b, S &s, S &t) {
|
|
// CHECK: %[[LVALUE:.*]] = phi
|
|
// CHECK: ret ptr %[[LVALUE]]
|
|
return __builtin_addressof(b ? s : t);
|
|
}
|
|
|
|
namespace std { template<typename T> T *addressof(T &); }
|
|
|
|
// CHECK: define {{.*}} @_Z13std_addressofbR1SS0_(
|
|
S *std_addressof(bool b, S &s, S &t) {
|
|
// CHECK: %[[LVALUE:.*]] = phi
|
|
// CHECK: ret ptr %[[LVALUE]]
|
|
return std::addressof(b ? s : t);
|
|
}
|
|
|
|
namespace std { template<typename T> T *__addressof(T &); }
|
|
|
|
// CHECK: define {{.*}} @_Z15std___addressofbR1SS0_(
|
|
S *std___addressof(bool b, S &s, S &t) {
|
|
// CHECK: %[[LVALUE:.*]] = phi
|
|
// CHECK: ret ptr %[[LVALUE]]
|
|
return std::__addressof(b ? s : t);
|
|
}
|
|
|
|
extern "C" int __builtin_abs(int); // #1
|
|
long __builtin_abs(long); // #2
|
|
extern "C" int __builtin_abs(int); // #3
|
|
|
|
extern const char char_memchr_arg[32];
|
|
char *memchr_result = __builtin_char_memchr(char_memchr_arg, 123, 32);
|
|
// CHECK: call ptr @memchr(ptr noundef @char_memchr_arg, i32 noundef 123, i64 noundef 32)
|
|
|
|
int constexpr_overflow_result() {
|
|
constexpr int x = 1;
|
|
// CHECK: alloca i32
|
|
constexpr int y = 2;
|
|
// CHECK: alloca i32
|
|
int z;
|
|
// CHECK: [[Z:%.+]] = alloca i32
|
|
|
|
__builtin_sadd_overflow(x, y, &z);
|
|
return z;
|
|
// CHECK: [[RET_PTR:%.+]] = extractvalue { i32, i1 } %0, 0
|
|
// CHECK: store i32 [[RET_PTR]], ptr [[Z]]
|
|
// CHECK: [[RET_VAL:%.+]] = load i32, ptr [[Z]]
|
|
// CHECK: ret i32 [[RET_VAL]]
|
|
}
|