Merge branch 'branchless-tweaks'

Chaos/Padding/PadderIso7816.hpp

@@ -52,8 +52,8 @@ public:
         uint8_t padSizeIncrement = 1;
         uint8_t padSize = 0;
 
-        uint8_t encountered0x80 = 0x00;
+        uint8_t encountered0x80 = Branchless::FalseMask;
-        uint8_t onlyZerosPast0x80 = 0xFF;
+        uint8_t onlyZerosPast0x80 = Branchless::TrueMask;
 
         InputIt it = end;
         while (it != begin && padSize < std::numeric_limits<uint8_t>::max())
@@ -73,7 +73,7 @@ public:
 
         return
         {
-            .IsOkay_ = static_cast<bool>(isOkay),
+            .IsOkay_ = Branchless::ToBool(isOkay),
             .PadSize_ = Branchless::Sel<uint8_t>(isOkay, padSize, 0)
         };
     }

Chaos/Padding/PadderPkcs7.hpp

@@ -66,7 +66,7 @@ public:
 
         return
         {
-            .IsOkay_ = static_cast<bool>(isOkay),
+            .IsOkay_ = Branchless::ToBool(isOkay),
             .PadSize_ = Branchless::Sel<uint8_t>(isOkay, padSize, 0)
         };
     }

Chaos/Service/Branchless.hpp

@@ -10,6 +10,9 @@ namespace Chaos::Service
 
 struct Branchless
 {
+    static constexpr uint8_t FalseMask = 0x00;
+    static constexpr uint8_t TrueMask = 0xFF;
+
     template<typename OutUInt, typename InUInt>
     static constexpr OutUInt MsbMask(InUInt in) noexcept
     {
@@ -79,6 +82,14 @@ struct Branchless
 
         return (mask & onTrue) | (~mask & onFalse);
     }
+
+    template<typename UInt>
+    static constexpr bool ToBool(UInt mask) noexcept
+    {
+        static_assert(std::is_unsigned_v<UInt>);
+
+        return Sel<UInt>(mask, 1, 0);
+    }
 };
 
 } // namespace Chaos::Service