From d40807681d3df9b7cc3ab8c33f3c78a880d81d30 Mon Sep 17 00:00:00 2001
From: ronak69 <ronak69@danwin1210.de>
Date: Sat, 12 Aug 2023 13:39:06 +0000
Subject: [PATCH] AK: Cast lhs of left shifts to FixedPoint's underlying
 integer type

By default, `1` is of the type `int` which is 32-bits wide at max.
Because of that, if `precision` of a `FixedPoint` is greater than 32,
the expression `1 << precision` will get clamped at 32-bits and the
result will always be zero. Casting `1` to the wider underlying type
will make the expression not overflow.
---
 AK/FixedPoint.h | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/AK/FixedPoint.h b/AK/FixedPoint.h
index f5747415a3..9815931f18 100644
--- a/AK/FixedPoint.h
+++ b/AK/FixedPoint.h
@@ -109,7 +109,7 @@ public:
         //       add 1 when we see a fract values behind the `.5`s place set,
         //       because that means they are smaller than .5
         // fract(m_value) >= .5?
-        if (m_value & (1u << (precision - 1))) {
+        if (m_value & (static_cast<Underlying>(1) << (precision - 1))) {
             // fract(m_value) > .5?
             if (m_value & (radix_mask >> 1)) {
                 // yes: round "up";
@@ -128,13 +128,13 @@ public:
     constexpr This ceil() const
     {
         return create_raw((m_value & ~radix_mask)
-            + (m_value & radix_mask ? 1 << precision : 0));
+            + (m_value & radix_mask ? static_cast<Underlying>(1) << precision : 0));
     }
     constexpr This trunc() const
     {
         return create_raw((m_value & ~radix_mask)
             + ((m_value & radix_mask)
-                    ? (m_value > 0 ? 0 : (1 << precision))
+                    ? (m_value > 0 ? 0 : (static_cast<Underlying>(1) << precision))
                     : 0));
     }
 
@@ -157,7 +157,7 @@ public:
     constexpr This log2() const
     {
         // 0.5
-        This b = create_raw(1 << (precision - 1));
+        This b = create_raw(static_cast<Underlying>(1) << (precision - 1));
         This y = 0;
         This x = *this;
 
@@ -217,7 +217,7 @@ public:
         This ret = create_raw(value >> precision);
         // Rounding:
         // If last bit cut off is 1:
-        if (value & (1u << (precision - 1))) {
+        if (value & (static_cast<Underlying>(1) << (precision - 1))) {
             // If the bit after is 1 as well
             if (value & (radix_mask >> 1)) {
                 // We round away from 0
@@ -245,12 +245,12 @@ public:
     template<Integral I>
     constexpr This operator+(I other) const
     {
-        return create_raw(m_value + (other << precision));
+        return create_raw(m_value + (static_cast<Underlying>(other) << precision));
     }
     template<Integral I>
     constexpr This operator-(I other) const
     {
-        return create_raw(m_value - (other << precision));
+        return create_raw(m_value - (static_cast<Underlying>(other) << precision));
     }
     template<Integral I>
     constexpr This operator*(I other) const
@@ -297,13 +297,13 @@ public:
     template<Integral I>
     This& operator+=(I other)
     {
-        m_value += other << precision;
+        m_value += static_cast<Underlying>(other) << precision;
         return *this;
     }
     template<Integral I>
     This& operator-=(I other)
     {
-        m_value -= other << precision;
+        m_value -= static_cast<Underlying>(other) << precision;
         return *this;
     }
     template<Integral I>
@@ -362,7 +362,7 @@ public:
     template<Integral I>
     bool operator<(I other) const
     {
-        return (m_value >> precision) < other || m_value < (other << precision);
+        return (m_value >> precision) < other || m_value < (static_cast<Underlying>(other) << precision);
     }
     template<Integral I>
     bool operator<=(I other) const