AK: Add AK::ceil(float) and AK::ceil_log2(integer)

Co-authored-by: Leon Albrecht <leon2002.la@gmail.com>
This commit is contained in:
MacDue 2022-06-29 18:56:39 +01:00 committed by Andreas Kling
parent 1e36224321
commit 072a78b958
Notes: sideshowbarker 2024-07-17 09:52:05 +09:00
2 changed files with 25 additions and 0 deletions

View file

@ -24,6 +24,17 @@ constexpr T log2(T x)
return x ? (8 * sizeof(T) - 1) - count_leading_zeroes(static_cast<MakeUnsigned<T>>(x)) : 0; return x ? (8 * sizeof(T) - 1) - count_leading_zeroes(static_cast<MakeUnsigned<T>>(x)) : 0;
} }
template<Integral T>
constexpr T ceil_log2(T x)
{
if (!x)
return 0;
T log = AK::log2(x);
log += (x & ((1 << (log - 1)) - 1)) != 0;
return log;
}
template<Integral I> template<Integral I>
constexpr I pow(I base, I exponent) constexpr I pow(I base, I exponent)
{ {

View file

@ -8,6 +8,7 @@
#include <AK/BuiltinWrappers.h> #include <AK/BuiltinWrappers.h>
#include <AK/Concepts.h> #include <AK/Concepts.h>
#include <AK/NumericLimits.h>
#include <AK/StdLibExtraDetails.h> #include <AK/StdLibExtraDetails.h>
#include <AK/Types.h> #include <AK/Types.h>
@ -665,6 +666,19 @@ constexpr T pow(T x, T y)
return exp2<T>(y * log2<T>(x)); return exp2<T>(y * log2<T>(x));
} }
template<FloatingPoint T>
constexpr T ceil(T num)
{
if (is_constant_evaluated()) {
if (num < NumericLimits<i64>::min() || num > NumericLimits<i64>::max())
return num;
return (static_cast<double>(static_cast<i64>(num)) == num)
? static_cast<i64>(num)
: static_cast<i64>(num) + ((num > 0) ? 1 : 0);
}
return __builtin_ceil(num);
}
#undef CONSTEXPR_STATE #undef CONSTEXPR_STATE
} }