diff options
Diffstat (limited to 'src/utils/common.h')
| -rw-r--r-- | src/utils/common.h | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/src/utils/common.h b/src/utils/common.h index 2e599f0..f75ace8 100644 --- a/src/utils/common.h +++ b/src/utils/common.h @@ -21,15 +21,17 @@ #include <intrin.h> #pragma intrinsic(_BitScanForward) #pragma intrinsic(_BitScanReverse) -#if defined(_M_X64) || defined(_M_ARM) || defined(_M_ARM64) +#if defined(_M_X64) || defined(_M_ARM64) #pragma intrinsic(_BitScanReverse64) #define HAVE_BITSCANREVERSE64 -#endif // defined(_M_X64) || defined(_M_ARM) || defined(_M_ARM64) +#endif // defined(_M_X64) || defined(_M_ARM64) #endif // defined(_MSC_VER) +#include <algorithm> #include <cassert> #include <cstddef> #include <cstdint> +#include <cstdlib> #include <cstring> #include <type_traits> @@ -40,6 +42,26 @@ namespace libgav1 { +// LIBGAV1_RESTRICT +// Declares a pointer with the restrict type qualifier if available. +// This allows code to hint to the compiler that only this pointer references a +// particular object or memory region within the scope of the block in which it +// is declared. This may allow for improved optimizations due to the lack of +// pointer aliasing. See also: +// https://en.cppreference.com/w/c/language/restrict +// Note a template alias is not used for compatibility with older compilers +// (e.g., gcc < 10) that do not expand the type when instantiating a template +// function, either explicitly or in an assignment to a function pointer as is +// done within the dsp code. RestrictPtr<T>::type is an alternative to this, +// similar to std::add_const, but for conciseness the macro is preferred. +#ifdef __GNUC__ +#define LIBGAV1_RESTRICT __restrict__ +#elif defined(_MSC_VER) +#define LIBGAV1_RESTRICT __restrict +#else +#define LIBGAV1_RESTRICT +#endif + // Aligns |value| to the desired |alignment|. |alignment| must be a power of 2. template <typename T> inline T Align(T value, T alignment) { |