From 072a78b958de7510cadf174b73eaa1b1584f5c00 Mon Sep 17 00:00:00 2001
From: MacDue <macdue@dueutil.tech>
Date: Wed, 29 Jun 2022 18:56:39 +0100
Subject: [PATCH] AK: Add AK::ceil(float) and AK::ceil_log2(integer)

Co-authored-by: Leon Albrecht <leon2002.la@gmail.com>
---
 AK/IntegralMath.h | 11 +++++++++++
 AK/Math.h         | 14 ++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/AK/IntegralMath.h b/AK/IntegralMath.h
index 916d9b70cc8..415e485bf9d 100644
--- a/AK/IntegralMath.h
+++ b/AK/IntegralMath.h
@@ -24,6 +24,17 @@ constexpr T log2(T x)
     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>
 constexpr I pow(I base, I exponent)
 {
diff --git a/AK/Math.h b/AK/Math.h
index 1dd4e3c6ed8..ebf9856f933 100644
--- a/AK/Math.h
+++ b/AK/Math.h
@@ -8,6 +8,7 @@
 
 #include <AK/BuiltinWrappers.h>
 #include <AK/Concepts.h>
+#include <AK/NumericLimits.h>
 #include <AK/StdLibExtraDetails.h>
 #include <AK/Types.h>
 
@@ -665,6 +666,19 @@ constexpr T pow(T x, T y)
     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
 }