Add bit pattern early exit

Author: Genbox

Docs/Optimizations.md

@@ -58,6 +58,12 @@ Input: `stable softice sophisticated santa`
 
 It generates this early exit: `if ((4208UL & (1UL << (value.Length - 1))) == 0) return false;`
 
+### Value bitmask early exit
+For integer keys, FastData can build a bitmask of all bits that appear in the dataset. If an input has any bit set that never appears in any key, it cannot be in the dataset.
+Input: `2 4 6 8`
+
+It generates this early exit: `if ((key & 1) != 0) return false;`
+
 ## Structure specializations
 
 ### Hash table

Src/FastData.Cli.Tests/CommandOutputs/cpp_-k UInt8_Files_Integers.input.verified.txt

@@ -12,7 +12,7 @@ class MyData final {
 public:
     [[nodiscard]]
     static constexpr bool contains(const uint8_t key) noexcept {
-        if (key < 42 || key > 100)
+        if ((static_cast<uint8_t>(key) & 129) != 0)
             return false;
         if (key == 42 || key == 62 || key == 80 || key == 100)
             return true;

Src/FastData.Cli.Tests/CommandOutputs/csharp_-k UInt8_Files_Integers.input.verified.txt

@@ -13,7 +13,7 @@ internal static class MyData
 
     public static bool Contains(byte key)
     {
-        if (key < 42 || key > 100)
+        if (((byte)key & 129) != 0)
             return false;
 
         switch (key)

Src/FastData.Cli.Tests/CommandOutputs/rust_-k UInt8_Files_Integers.input.verified.txt

@@ -13,7 +13,7 @@ pub struct MyData;
 impl MyData {
     #[must_use]
     pub fn contains(key: u8) -> bool {
-        if key < 42 || key > 100 {
+        if (key as u8 & 129) != 0 {
             return false;
         }
 

Src/FastData.Generator.CPlusPlus.Tests/Features/ObjectSupportTest-ArrayStructure_Int32_3_complex.verified.txt

@@ -24,7 +24,7 @@ class ArrayStructure_Int32_3_complex final {
 public:
     [[nodiscard]]
     static constexpr bool contains(const int32_t key) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             return false;
 
         for (size_t i = 0; i < 3; i++)
@@ -36,7 +36,7 @@ public:
     }
     [[nodiscard]]
     static bool try_lookup(const int32_t key, const Person*& value) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             {
     value = nullptr;
     return false;

Src/FastData.Generator.CPlusPlus.Tests/Features/ObjectSupportTest-ArrayStructure_Int32_3_simple.verified.txt

@@ -17,7 +17,7 @@ class ArrayStructure_Int32_3_simple final {
 public:
     [[nodiscard]]
     static constexpr bool contains(const int32_t key) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             return false;
 
         for (size_t i = 0; i < 3; i++)
@@ -29,7 +29,7 @@ public:
     }
     [[nodiscard]]
     static bool try_lookup(const int32_t key, const int32_t*& value) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             {
     value = nullptr;
     return false;

Src/FastData.Generator.CPlusPlus.Tests/Features/ObjectSupportTest-BinarySearchStructure_Int32_3_complex.verified.txt

@@ -24,7 +24,7 @@ class BinarySearchStructure_Int32_3_complex final {
 public:
     [[nodiscard]]
     static constexpr bool contains(const int32_t key) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             return false;
 
         int32_t lo = 0;
@@ -46,7 +46,7 @@ public:
     }
     [[nodiscard]]
     static bool try_lookup(const int32_t key, const Person*& value) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             {
     value = nullptr;
     return false;

Src/FastData.Generator.CPlusPlus.Tests/Features/ObjectSupportTest-BinarySearchStructure_Int32_3_simple.verified.txt

@@ -17,7 +17,7 @@ class BinarySearchStructure_Int32_3_simple final {
 public:
     [[nodiscard]]
     static constexpr bool contains(const int32_t key) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             return false;
 
         int32_t lo = 0;
@@ -39,7 +39,7 @@ public:
     }
     [[nodiscard]]
     static bool try_lookup(const int32_t key, const int32_t*& value) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             {
     value = nullptr;
     return false;

Src/FastData.Generator.CPlusPlus.Tests/Features/ObjectSupportTest-BitSetStructure_Int32_3_complex.verified.txt

@@ -23,7 +23,7 @@ class BitSetStructure_Int32_3_complex final {
 public:
     [[nodiscard]]
     static constexpr bool contains(const int32_t key) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             return false;
 
         const uint64_t offset = static_cast<uint64_t>(key - min_key);
@@ -32,7 +32,7 @@ public:
     }
     [[nodiscard]]
     static bool try_lookup(const int32_t key, const Person*& value) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             {
     value = nullptr;
     return false;

Src/FastData.Generator.CPlusPlus.Tests/Features/ObjectSupportTest-HashTablePerfectStructure_Int32_3_complex.verified.txt

@@ -34,7 +34,7 @@ class HashTablePerfectStructure_Int32_3_complex final {
 public:
     [[nodiscard]]
     static constexpr bool contains(const int32_t key) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             return false;
 
         const uint64_t hash = get_hash(key);
@@ -45,7 +45,7 @@ public:
     }
     [[nodiscard]]
     static bool try_lookup(const int32_t key, const Person*& value) noexcept {
-        if (key < 1 || key > 3)
+        if ((static_cast<uint32_t>(key) & 4294967292u) != 0)
             {
     value = nullptr;
     return false;