flodavid/suyu
1
0
Fork 0
forked from suyu/suyu
Code Pull requests Activity

Common: remove a mod from AlignUp (#5441)

Browse source 
In cases where the size is not a known constant when inlining, AlignUp<std::size_t> currently generates two 64-bit div instructions.
This generates one div and a cmov which is significantly cheaper.
This commit is contained in:
Marshall Mohror 2020-07-07 16:39:23 -05:00 committed by FearlessTobi
parent a0ee597b19
commit a4306b9e56
1 changed files with 3 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
src/common/alignment.h
View file

@ -11,7 +11,9 @@ namespace Common {
template <typename T> template <typename T>
constexpr T AlignUp(T value, std::size_t size) { constexpr T AlignUp(T value, std::size_t size) {
static_assert(std::is_unsigned_v<T>, "T must be an unsigned value."); static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
return static_cast<T>(value + (size - value % size) % size); auto mod{value % size};
value -= mod;
return static_cast<T>(mod == T{0} ? value : value + size);
} }
template <typename T> template <typename T>