FEXCore: Adds DividePow2 helper

FEXCore/include/FEXCore/Utils/MathUtils.h

@@ -25,4 +25,12 @@ requires(std::is_unsigned_v<T>)
   return std::countr_zero(Value);
 }
 
+// Divide a number by a power-of-2 by avoiding integer division.
+// Can be a faster implementation than regular integer divide.
+// Divisor requires to be power-of-2, is enforced in ilog2 helper.
+template<typename T, typename TT>
+requires(std::is_unsigned_v<T> && std::is_unsigned_v<TT>)
+[[nodiscard]] constexpr T DividePow2(T Dividend, TT Divisor) {
+  return Dividend >> ilog2(Divisor);
+}
 } // namespace FEXCore

FEXCore/unittests/APITests/ILog2.cpp

@@ -5,3 +5,9 @@ TEST_CASE("ILog2") {
   auto i = GENERATE(range(0, 64));
   REQUIRE(FEXCore::ilog2(1ull << i) == i);
 }
+
+TEST_CASE("DividePow2") {
+  auto j = GENERATE(range(0, 64));
+  auto i = GENERATE(range(0, 64));
+  REQUIRE(FEXCore::DividePow2(1ull << j, 1ull << i) == ((1ull << j) / (1ull << i)));
+}