Naive attempt to reduce branching

README.md

@@ -34,34 +34,49 @@ WhiteRabbit.exe < wordlist
 Performance
 ===========
 
-Memory usage is minimal (for that kind of task), less than 10MB (25MB for MaxNumberOfWords = 8).
+Memory usage is minimal (for that kind of task), less than 10MB.
 
 It is also somewhat optimized for likely intended phrases, as anagrams consisting of longer words are generated first.
 That's why the given hashes are solved much sooner than it takes to check all anagrams.
 
 Anagrams generation is not parallelized, as even single-threaded performance for 4-word anagrams is high enough; and 5-word (or larger) anagrams are frequent enough for most of the time being spent on computing hashes, with full CPU load.
 
-Multi-threaded performance with RyuJIT (.NET 4.6, 64-bit system) on i5-6500 is as follows (excluding initialization time of 0.2 seconds), for different maximum allowed words in an anagram:
-
-Number of words|Time to check all anagrams no longer than that|Time to solve "easy" hash|Time to solve "more difficult" hash|Time to solve "hard" hash|Number of unique anagrams no longer than that
----------------|----------------------------------------------|-------------------------|-----------------------------------|-------------------------|---------------------------------------------
-3|0.04s||||4560
-4|0.45s|||0.08s|7,431,984
-5|9.6s|0.15s|0.06s|0.27s|1,347,437,484
-6|4.5 minutes|0.85s|0.17s|2.05s|58,405,904,844
-7|83 minutes|4.7s|0.6s|13.3s|1,070,307,744,114
-8|14 hours|17.6s|1.8s|55s|10,893,594,396,594
-9||45s|4s|2.5 minutes|70,596,864,409,954
-10||80s|5.8s|4.8 minutes|314,972,701,475,754
+Multi-threaded performance with RyuJIT (.NET 4.6, 64-bit system) on quad-core Sandy Bridge @2.8GHz (without AVX2 support) is as follows (excluding initialization time of 0.2 seconds), for different maximum allowed words in an anagram:
+
+Number of words|Time to check all anagrams no longer than that|Time to solve "easy" hash|Time to solve "more difficult" hash|Time to solve "hard" hash|Number of anagrams no longer than that (see note below)
+---------------|----------------------------------------------|-------------------------|-----------------------------------|-------------------------|-------------------------------------------------------
+3|Fractions of a second||||4560
+4|0.6s|||0.1s|7,433,016
+5|60s|||1.5s|1,348,876,896
+6|45 minutes|||21s|58,837,302,096
+7|10 hours (?)|1.5 minutes|8s|4.5 minutes|1,108,328,708,976
+8|||||12,089,249,231,856
+9|||||88,977,349,731,696
+10|||||482,627,715,786,096
+11|||||2,030,917,440,675,696
+12|||||6,813,402,098,518,896
+13|||||18,437,325,782,691,696
+14|||||40,367,286,468,925,296
+15|||||71,561,858,517,565,296
+16|||||103,280,807,987,773,296
+17|||||123,910,678,817,341,296
+18|||||130,313,052,523,069,296
 
 Note that all measurements were done on a Release build; Debug build is significantly slower.
 
 For comparison, certain other solutions available on GitHub seem to require 3 hours to find all 3-word anagrams. This solution is faster by 6-7 orders of magnitude (it finds and checks all 4-word anagrams in 1/10000th fraction of time required for other solution just to find all 3-word anagrams, with no MD5 calculations).
 
+Also, note that anagram counts are inflated for the sake of code simplicity.
+E.g. for phrase "aabbc" and dictionary [ab, ba, c] there are four possible set of words adding up to the source phrase: [ab, ab, c], [ab, ba, c], [ba, ab, c], [ba, ba, c].
+My implementation regards these sets as sets of different words, and applies all possible permutations to the every set, even if it will result in the same set.
+For the example above, my application would produce 24 anagrams (with six permutations for every of the four sets), although actually there are only 12 different anagrams.
+
 Conditional compilation symbols
 ===============================
 
-* Define `DEBUG`, or build in debug mode, to get the total number of anagrams (not optimized).
+* Define `SINGLE_THREADED` to use standard enumerables instead of ParallelEnumerable (useful for profiling).
+
+* Define `DEBUG`, or build in debug mode, to get the total number of anagrams (not optimized, memory-hogging).
 
 Implementation notes
 ====================

dotnet/TrustPilotChallenge.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 15
-VisualStudioVersion = 15.0.26403.3
+# Visual Studio 14
+VisualStudioVersion = 14.0.25420.1
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WhiteRabbit", "WhiteRabbit\WhiteRabbit.csproj", "{3A4E69F0-7A8E-4B92-BA02-A231D75CB3E4}"
 EndProject

dotnet/WhiteRabbit.UnmanagedBridge/WhiteRabbit.UnmanagedBridge.cpp

@@ -4,29 +4,22 @@
 
 #include "WhiteRabbit.UnmanagedBridge.h"
 #include "md5.h"
-#include "phraseset.h"
 
-void WhiteRabbitUnmanagedBridge::MD5Unmanaged::ComputeMD5(unsigned __int32 * input, unsigned __int32 * expected)
+void WhiteRabbitUnmanagedBridge::MD5Unmanaged::ComputeMD5(unsigned __int32 * input, unsigned __int32 * output)
 {
 #if AVX2
-    md5(input + 0 * 8 * 8, expected);
+    md5(input + 0 * 8 * 8, output + 0 * 8);
 #elif SIMD
-    md5(input + 0 * 8 * 4);
-    md5(input + 1 * 8 * 4);
-    if (input[2 * 8 * 4] != 0)
-    {
-        md5(input + 2 * 8 * 4);
-        md5(input + 3 * 8 * 4);
-    }
+    md5(input + 0 * 8 * 4, output + 0 * 4);
+    md5(input + 1 * 8 * 4, output + 1 * 4);
 #else
-    for (int i = 0; i < 16; i++)
-    {
-        md5(input + i * 8);
-    }
+    md5(input + 0 * 8, output + 0);
+    md5(input + 1 * 8, output + 1);
+    md5(input + 2 * 8, output + 2);
+    md5(input + 3 * 8, output + 3);
+    md5(input + 4 * 8, output + 4);
+    md5(input + 5 * 8, output + 5);
+    md5(input + 6 * 8, output + 6);
+    md5(input + 7 * 8, output + 7);
 #endif
 }
-
-void WhiteRabbitUnmanagedBridge::MD5Unmanaged::FillPhraseSet(unsigned __int64* initialBufferPointer, unsigned __int64* bufferPointer, unsigned __int64* allWordsPointer, __int32* wordIndexes, unsigned __int64* permutationsPointer, int numberOfWords)
-{
-    fillPhraseSet(initialBufferPointer, bufferPointer, allWordsPointer, wordIndexes, permutationsPointer, numberOfWords);
-}

dotnet/WhiteRabbit.UnmanagedBridge/WhiteRabbit.UnmanagedBridge.h

@@ -2,8 +2,6 @@
 
 #pragma once
 
-#include "constants.h"
-
 using namespace System;
 
 namespace WhiteRabbitUnmanagedBridge {
@@ -11,8 +9,6 @@ namespace WhiteRabbitUnmanagedBridge {
 	public ref class MD5Unmanaged
 	{
         public:
-            literal int PhrasesPerSet = PHRASES_PER_SET;
-            static void ComputeMD5(unsigned int* input, unsigned __int32 * expected);
-            static void FillPhraseSet(unsigned __int64* initialBufferPointer, unsigned __int64* bufferPointer, unsigned __int64* allWordsPointer, __int32* wordIndexes, unsigned __int64* permutationsPointer, int numberOfWords);
+            static void ComputeMD5(unsigned int* input, unsigned int* output);
 	};
 }

dotnet/WhiteRabbit.UnmanagedBridge/WhiteRabbit.UnmanagedBridge.vcxproj

@@ -20,37 +20,37 @@
   </ItemGroup>
   <PropertyGroup Label="Globals">
     <ProjectGuid>{039F03A0-7E8F-415D-8180-969D24479B44}</ProjectGuid>
-    <TargetFrameworkVersion>v4.7</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <Keyword>ManagedCProj</Keyword>
     <RootNamespace>WhiteRabbitUnmanagedBridge</RootNamespace>
-    <WindowsTargetPlatformVersion>10.0.10586.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion>8.1</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
-    <PlatformToolset>v141</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <CLRSupport>true</CLRSupport>
     <CharacterSet>Unicode</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <UseDebugLibraries>false</UseDebugLibraries>
-    <PlatformToolset>v141</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <CLRSupport>true</CLRSupport>
     <CharacterSet>Unicode</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
-    <PlatformToolset>v141</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <CLRSupport>true</CLRSupport>
     <CharacterSet>Unicode</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <UseDebugLibraries>false</UseDebugLibraries>
-    <PlatformToolset>v141</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <CLRSupport>true</CLRSupport>
     <CharacterSet>Unicode</CharacterSet>
   </PropertyGroup>
@@ -133,9 +133,7 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClInclude Include="constants.h" />
     <ClInclude Include="md5.h" />
-    <ClInclude Include="phraseset.h" />
     <ClInclude Include="resource.h" />
     <ClInclude Include="Stdafx.h" />
     <ClInclude Include="WhiteRabbit.UnmanagedBridge.h" />
@@ -143,7 +141,6 @@
   <ItemGroup>
     <ClCompile Include="AssemblyInfo.cpp" />
     <ClCompile Include="md5.cpp" />
-    <ClCompile Include="phraseset.cpp" />
     <ClCompile Include="Stdafx.cpp">
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Create</PrecompiledHeader>
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">Create</PrecompiledHeader>

dotnet/WhiteRabbit.UnmanagedBridge/WhiteRabbit.UnmanagedBridge.vcxproj.filters

@@ -23,12 +23,6 @@
     <ClInclude Include="md5.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="constants.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
-    <ClInclude Include="phraseset.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="AssemblyInfo.cpp">
@@ -43,8 +37,5 @@
     <ClCompile Include="md5.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="phraseset.cpp">
-      <Filter>Source Files</Filter>
-    </ClCompile>
   </ItemGroup>
 </Project>

dotnet/WhiteRabbit.UnmanagedBridge/constants.h

@@ -1,3 +0,0 @@
-#pragma once
-
-#define PHRASES_PER_SET 16

dotnet/WhiteRabbit.UnmanagedBridge/md5.cpp

@@ -5,155 +5,186 @@
 
 #pragma unmanaged
 
-struct MD5Vector
+#if AVX2
+
+typedef __m256i MD5Vector;
+
+#define OP_XOR(a, b) _mm256_xor_si256(a, b)
+#define OP_AND(a, b) _mm256_and_si256(a, b)
+#define OP_ANDNOT(a, b) _mm256_andnot_si256(a, b)
+#define OP_OR(a, b) _mm256_or_si256(a, b)
+#define OP_ADD(a, b) _mm256_add_epi32(a, b)
+#define OP_ROT(a, r) OP_OR(_mm256_slli_epi32(a, r), _mm256_srli_epi32(a, 32 - (r)))
+#define OP_BLEND(a, b, x) OP_OR(OP_AND(x, b), OP_ANDNOT(x, a))
+
+#define CREATE_VECTOR(a) _mm256_set1_epi32(a)
+#define CREATE_VECTOR_FROM_INPUT(input, offset) _mm256_set_epi32( \
+    input[offset + 0 * 8], \
+    input[offset + 1 * 8], \
+    input[offset + 2 * 8], \
+    input[offset + 3 * 8], \
+    input[offset + 4 * 8], \
+    input[offset + 5 * 8], \
+    input[offset + 6 * 8], \
+    input[offset + 7 * 8])
+
+#define WRITE_TO_OUTPUT(a, output) \
+    ((unsigned __int64*)output)[0] = a.m256i_u64[0]; \
+    ((unsigned __int64*)output)[1] = a.m256i_u64[1]; \
+    ((unsigned __int64*)output)[2] = a.m256i_u64[2]; \
+    ((unsigned __int64*)output)[3] = a.m256i_u64[3];
+
+#elif SIMD
+
+typedef __m128i MD5Vector;
+
+#define OP_XOR(a, b) _mm_xor_si128(a, b)
+#define OP_AND(a, b) _mm_and_si128(a, b)
+#define OP_ANDNOT(a, b) _mm_andnot_si128(a, b)
+#define OP_OR(a, b) _mm_or_si128(a, b)
+#define OP_ADD(a, b) _mm_add_epi32(a, b)
+#define OP_ROT(a, r) OP_OR(_mm_slli_epi32(a, r), _mm_srli_epi32(a, 32 - (r)))
+#define OP_BLEND(a, b, x) OP_OR(OP_AND(x, b), OP_ANDNOT(x, a))
+//#define OP_BLEND(a, b, x) OP_XOR(a, OP_AND(x, OP_XOR(b, a)))
+
+#define CREATE_VECTOR(a) _mm_set1_epi32(a)
+#define CREATE_VECTOR_FROM_INPUT(input, offset) _mm_set_epi32( \
+    input[offset + 3 * 8], \
+    input[offset + 2 * 8], \
+    input[offset + 1 * 8], \
+    input[offset + 0 * 8])
+
+#define WRITE_TO_OUTPUT(a, output) \
+    ((unsigned __int64*)output)[0] = a.m128i_u64[0]; \
+    ((unsigned __int64*)output)[1] = a.m128i_u64[1];
+
+#else
+
+typedef unsigned int MD5Vector;
+
+#define OP_XOR(a, b) (a) ^ (b)
+#define OP_AND(a, b) (a) & (b)
+#define OP_ANDNOT(a, b) ~(a) & (b)
+#define OP_OR(a, b) (a) | (b)
+#define OP_ADD(a, b) (a) + (b)
+#define OP_ROT(a, r) _rotl(a, r)
+#define OP_BLEND(a, b, x) ((x) & (b)) | (~(x) & (a))
+
+#define CREATE_VECTOR(a) a
+#define CREATE_VECTOR_FROM_INPUT(input, offset) (input[offset])
+
+#define WRITE_TO_OUTPUT(a, output) \
+    output[0] = a;
+#endif
+
+#define OP_NEG(a) OP_ANDNOT(a, CREATE_VECTOR(0xffffffff))
+
+typedef struct {
+    unsigned int K[64];
+    unsigned int Init[4];
+} MD5Parameters;
+
+static const MD5Parameters Parameters = {
     {
-    __m256i m_V0;
-    __m256i m_V1;
-    __forceinline MD5Vector() {}
-    __forceinline MD5Vector(__m256i C0, __m256i C1) :m_V0(C0), m_V1(C1) {}
-
-    __forceinline MD5Vector MXor(MD5Vector R) const
-    {
-        return MD5Vector(_mm256_xor_si256(m_V0, R.m_V0), _mm256_xor_si256(m_V1, R.m_V1));
-    }
-
-    __forceinline MD5Vector MAnd(MD5Vector R) const
-    {
-        return MD5Vector(_mm256_and_si256(m_V0, R.m_V0), _mm256_and_si256(m_V1, R.m_V1));
-    }
-
-    __forceinline MD5Vector MAndNot(MD5Vector R) const
-    {
-        return MD5Vector(_mm256_andnot_si256(m_V0, R.m_V0), _mm256_andnot_si256(m_V1, R.m_V1));
-    }
-
-    __forceinline const MD5Vector MOr(const MD5Vector R) const
-    {
-        return MD5Vector(_mm256_or_si256(m_V0, R.m_V0), _mm256_or_si256(m_V1, R.m_V1));
-    }
-
-    __forceinline const MD5Vector MAdd(const MD5Vector R) const
-    {
-        return MD5Vector(_mm256_add_epi32(m_V0, R.m_V0), _mm256_add_epi32(m_V1, R.m_V1));
-    }
-
-    __forceinline const MD5Vector MShiftLeft(const int shift) const
-    {
-        return MD5Vector(_mm256_slli_epi32(m_V0, shift), _mm256_slli_epi32(m_V1, shift));
-    }
-
-    __forceinline const MD5Vector MShiftRight(const int shift) const
-    {
-        return MD5Vector(_mm256_srli_epi32(m_V0, shift), _mm256_srli_epi32(m_V1, shift));
-    }
-
-    template<int imm8>
-    __forceinline const MD5Vector Permute() const
-    {
-        return MD5Vector(_mm256_permute4x64_epi64(m_V0, imm8), _mm256_permute4x64_epi64(m_V1, imm8));
-    }
-
-    __forceinline const MD5Vector CompareEquality32(const __m256i other) const
+        0xd76aa478,
+        0xe8c7b756,
+        0x242070db,
+        0xc1bdceee,
+        0xf57c0faf,
+        0x4787c62a,
+        0xa8304613,
+        0xfd469501,
+        0x698098d8,
+        0x8b44f7af,
+        0xffff5bb1,
+        0x895cd7be,
+        0x6b901122,
+        0xfd987193,
+        0xa679438e,
+        0x49b40821,
+        0xf61e2562,
+        0xc040b340,
+        0x265e5a51,
+        0xe9b6c7aa,
+        0xd62f105d,
+        0x02441453,
+        0xd8a1e681,
+        0xe7d3fbc8,
+        0x21e1cde6,
+        0xc33707d6,
+        0xf4d50d87,
+        0x455a14ed,
+        0xa9e3e905,
+        0xfcefa3f8,
+        0x676f02d9,
+        0x8d2a4c8a,
+        0xfffa3942,
+        0x8771f681,
+        0x6d9d6122,
+        0xfde5380c,
+        0xa4beea44,
+        0x4bdecfa9,
+        0xf6bb4b60,
+        0xbebfbc70,
+        0x289b7ec6,
+        0xeaa127fa,
+        0xd4ef3085,
+        0x04881d05,
+        0xd9d4d039,
+        0xe6db99e5,
+        0x1fa27cf8,
+        0xc4ac5665,
+        0xf4292244,
+        0x432aff97,
+        0xab9423a7,
+        0xfc93a039,
+        0x655b59c3,
+        0x8f0ccc92,
+        0xffeff47d,
+        0x85845dd1,
+        0x6fa87e4f,
+        0xfe2ce6e0,
+        0xa3014314,
+        0x4e0811a1,
+        0xf7537e82,
+        0xbd3af235,
+        0x2ad7d2bb,
+        0xeb86d391,
+    },
     {
-        return MD5Vector(_mm256_cmpeq_epi32(m_V0, other), _mm256_cmpeq_epi32(m_V1, other));
-    }
-
-    __forceinline void WriteMoveMask8(__int32 * output) const
-    {
-        output[0] = _mm256_movemask_epi8(m_V0);
-        output[1] = _mm256_movemask_epi8(m_V1);
-    }
+        0x67452301,
+        0xefcdab89,
+        0x98badcfe,
+        0x10325476,
+    },
 };
 
-__forceinline const MD5Vector OP_XOR(const MD5Vector a, const MD5Vector b) { return a.MXor(b); }
-__forceinline const MD5Vector OP_AND(const MD5Vector a, const MD5Vector b) { return a.MAnd(b); }
-__forceinline const MD5Vector OP_ANDNOT(const MD5Vector a, const MD5Vector b) { return a.MAndNot(b); }
-__forceinline const MD5Vector OP_OR(const MD5Vector a, const MD5Vector b) { return a.MOr(b); }
-__forceinline const MD5Vector OP_ADD(const MD5Vector a, const MD5Vector b) { return a.MAdd(b); }
-template<int r>
-__forceinline const MD5Vector OP_ROT(const MD5Vector a) { return OP_OR(a.MShiftLeft(r), a.MShiftRight(32 - (r))); }
-__forceinline const MD5Vector OP_BLEND(const MD5Vector a, const MD5Vector b, const MD5Vector x) { return OP_OR(OP_AND(x, b), OP_ANDNOT(x, a)); }
-
-__forceinline const MD5Vector CREATE_VECTOR(const int a) { return MD5Vector(_mm256_set1_epi32(a), _mm256_set1_epi32(a)); }
-__forceinline const MD5Vector CREATE_VECTOR_FROM_INPUT(const unsigned __int32* input, const size_t offset)
-{
-    return MD5Vector(
-        _mm256_i32gather_epi32((int*)(input + offset), _mm256_set_epi32(7 * 8, 6 * 8, 5 * 8, 4 * 8, 3 * 8, 2 * 8, 1 * 8, 0 * 8), 4),
-        _mm256_i32gather_epi32((int*)(input + offset), _mm256_set_epi32(15 * 8, 14 * 8, 13 * 8, 12 * 8, 11 * 8, 10 * 8, 9 * 8, 8 * 8), 4));
-}
-
-#define WRITE_TO_OUTPUT(a, output, expected) \
-    a.Permute<0 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output); \
-    a.Permute<1 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output + 2); \
-    a.Permute<2 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output + 4); \
-    a.Permute<3 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output + 6); \
-    output[8] = _mm256_movemask_epi8(_mm256_cmpeq_epi8(*((__m256i*)output), _mm256_setzero_si256()));
-
-__forceinline void WriteToOutput(const MD5Vector a, __int32 * output, __m256i * expected)
-{
-    a.Permute<0 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output);
-    a.Permute<1 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output);
-    a.Permute<2 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output);
-    a.Permute<3 * 0x55>().CompareEquality32(*expected).WriteMoveMask8(output);
-    output[8] = _mm256_movemask_epi8(_mm256_cmpeq_epi8(*((__m256i*)output), _mm256_setzero_si256()));
-}
-
-const MD5Vector Ones = CREATE_VECTOR(0xffffffff);
-__forceinline const MD5Vector OP_NEG(const MD5Vector a) { return OP_ANDNOT(a, Ones); }
-
-__forceinline const MD5Vector Blend(const MD5Vector a, const MD5Vector b, const MD5Vector x) { return OP_BLEND(a, b, x); }
-__forceinline const MD5Vector Xor(const MD5Vector a, const MD5Vector b, const MD5Vector c) { return OP_XOR(a, OP_XOR(b, c)); }
-__forceinline const MD5Vector I(const MD5Vector a, const MD5Vector b, const MD5Vector c) { return OP_XOR(a, OP_OR(b, OP_NEG(c))); }
+#define Blend(a, b, x) OP_BLEND(a, b, x)
+#define Xor(a, b, c) OP_XOR(a, OP_XOR(b, c))
+#define I(a, b, c) OP_XOR(a, OP_OR(b, OP_NEG(c)))
 
-template<int r>
-__forceinline const MD5Vector StepOuter(const MD5Vector a, const MD5Vector b, const MD5Vector x) { return OP_ADD(b, OP_ROT<r>(x)); }
+#define StepOuter(r, a, b, x) \
+    a = x; \
+    a = OP_ADD(b, OP_ROT(a, r));
 
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step1(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d, const MD5Vector w) {
-    return StepOuter<r>(a, b, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))));
-}
-
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step1(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d) {
-    return StepOuter<r>(a, b, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), a)));
-}
-
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step2(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d, const MD5Vector w) {
-    return StepOuter<r>(a, c, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))));
-}
-
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step2(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d) {
-    return StepOuter<r>(a, c, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), a)));
-}
-
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step3(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d, const MD5Vector w) {
-    return StepOuter<r>(a, b, OP_ADD(Xor(b, c, d), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))));
-}
+#define Step1(r, a, b, c, d, k, w) StepOuter(r, a, b, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))))
+#define Step1E(r, a, b, c, d, k)   StepOuter(r, a, b, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), a)))
 
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step3(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d) {
-    return StepOuter<r>(a, b, OP_ADD(Xor(b, c, d), OP_ADD(CREATE_VECTOR(k), a)));
-}
+#define Step2(r, a, b, c, d, k, w) StepOuter(r, a, c, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))))
+#define Step2E(r, a, b, c, d, k)   StepOuter(r, a, c, OP_ADD(Blend(d, c, b), OP_ADD(CREATE_VECTOR(k), a)))
 
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step4(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d, const MD5Vector w) {
-    return StepOuter<r>(a, b, OP_ADD(I(c, b, d), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))));
-}
+#define Step3(r, a, b, c, d, k, w) StepOuter(r, a, b, OP_ADD(Xor(b, c, d), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))))
+#define Step3E(r, a, b, c, d, k)   StepOuter(r, a, b, OP_ADD(Xor(b, c, d), OP_ADD(CREATE_VECTOR(k), a)))
 
-template<int r, unsigned __int32 k>
-__forceinline const MD5Vector Step4(const MD5Vector a, const MD5Vector b, const MD5Vector c, const MD5Vector d) {
-    return StepOuter<r>(a, b, OP_ADD(I(c, b, d), OP_ADD(CREATE_VECTOR(k), a)));
-}
+#define Step4(r, a, b, c, d, k, w) StepOuter(r, a, b, OP_ADD(I(c, b, d), OP_ADD(CREATE_VECTOR(k), OP_ADD(a, w))))
+#define Step4E(r, a, b, c, d, k)   StepOuter(r, a, b, OP_ADD(I(c, b, d), OP_ADD(CREATE_VECTOR(k), a)))
 
-void md5(unsigned __int32 * input, unsigned __int32 * expected)
+void md5(unsigned __int32 * input, unsigned __int32 * output)
 {
-    MD5Vector a = CREATE_VECTOR(0x67452301);
-    MD5Vector b = CREATE_VECTOR(0xefcdab89);
-    MD5Vector c = CREATE_VECTOR(0x98badcfe);
-    MD5Vector d = CREATE_VECTOR(0x10325476);
+    MD5Vector a = CREATE_VECTOR(Parameters.Init[0]);
+    MD5Vector b = CREATE_VECTOR(Parameters.Init[1]);
+    MD5Vector c = CREATE_VECTOR(Parameters.Init[2]);
+    MD5Vector d = CREATE_VECTOR(Parameters.Init[3]);
 
     MD5Vector inputVector0 = CREATE_VECTOR_FROM_INPUT(input, 0);
     MD5Vector inputVector1 = CREATE_VECTOR_FROM_INPUT(input, 1);
@@ -164,73 +195,73 @@ void md5(unsigned __int32 * input, unsigned __int32 * expected)
     MD5Vector inputVector6 = CREATE_VECTOR_FROM_INPUT(input, 6);
     MD5Vector inputVector7 = CREATE_VECTOR_FROM_INPUT(input, 7);
 
-    a = Step1< 7, 0xd76aa478>(a, b, c, d, inputVector0);
-    d = Step1<12, 0xe8c7b756>(d, a, b, c, inputVector1);
-    c = Step1<17, 0x242070db>(c, d, a, b, inputVector2);
-    b = Step1<22, 0xc1bdceee>(b, c, d, a, inputVector3);
-    a = Step1< 7, 0xf57c0faf>(a, b, c, d, inputVector4);
-    d = Step1<12, 0x4787c62a>(d, a, b, c, inputVector5);
-    c = Step1<17, 0xa8304613>(c, d, a, b, inputVector6);
-    b = Step1<22, 0xfd469501>(b, c, d, a);
-    a = Step1< 7, 0x698098d8>(a, b, c, d);
-    d = Step1<12, 0x8b44f7af>(d, a, b, c);
-    c = Step1<17, 0xffff5bb1>(c, d, a, b);
-    b = Step1<22, 0x895cd7be>(b, c, d, a);
-    a = Step1< 7, 0x6b901122>(a, b, c, d);
-    d = Step1<12, 0xfd987193>(d, a, b, c);
-    c = Step1<17, 0xa679438e>(c, d, a, b, inputVector7);
-    b = Step1<22, 0x49b40821>(b, c, d, a);
-
-    a = Step2< 5, 0xf61e2562>(a, d, b, c, inputVector1);
-    d = Step2< 9, 0xc040b340>(d, c, a, b, inputVector6);
-    c = Step2<14, 0x265e5a51>(c, b, d, a);
-    b = Step2<20, 0xe9b6c7aa>(b, a, c, d, inputVector0);
-    a = Step2< 5, 0xd62f105d>(a, d, b, c, inputVector5);
-    d = Step2< 9, 0x02441453>(d, c, a, b);
-    c = Step2<14, 0xd8a1e681>(c, b, d, a);
-    b = Step2<20, 0xe7d3fbc8>(b, a, c, d, inputVector4);
-    a = Step2< 5, 0x21e1cde6>(a, d, b, c);
-    d = Step2< 9, 0xc33707d6>(d, c, a, b, inputVector7);
-    c = Step2<14, 0xf4d50d87>(c, b, d, a, inputVector3);
-    b = Step2<20, 0x455a14ed>(b, a, c, d);
-    a = Step2< 5, 0xa9e3e905>(a, d, b, c);
-    d = Step2< 9, 0xfcefa3f8>(d, c, a, b, inputVector2);
-    c = Step2<14, 0x676f02d9>(c, b, d, a);
-    b = Step2<20, 0x8d2a4c8a>(b, a, c, d);
-
-    a = Step3< 4, 0xfffa3942>(a, b, c, d, inputVector5);
-    d = Step3<11, 0x8771f681>(d, a, b, c);
-    c = Step3<16, 0x6d9d6122>(c, d, a, b);
-    b = Step3<23, 0xfde5380c>(b, c, d, a, inputVector7);
-    a = Step3< 4, 0xa4beea44>(a, b, c, d, inputVector1);
-    d = Step3<11, 0x4bdecfa9>(d, a, b, c, inputVector4);
-    c = Step3<16, 0xf6bb4b60>(c, d, a, b);
-    b = Step3<23, 0xbebfbc70>(b, c, d, a);
-    a = Step3< 4, 0x289b7ec6>(a, b, c, d);
-    d = Step3<11, 0xeaa127fa>(d, a, b, c, inputVector0);
-    c = Step3<16, 0xd4ef3085>(c, d, a, b, inputVector3);
-    b = Step3<23, 0x04881d05>(b, c, d, a, inputVector6);
-    a = Step3< 4, 0xd9d4d039>(a, b, c, d);
-    d = Step3<11, 0xe6db99e5>(d, a, b, c);
-    c = Step3<16, 0x1fa27cf8>(c, d, a, b);
-    b = Step3<23, 0xc4ac5665>(b, c, d, a, inputVector2);
-
-    a = Step4< 6, 0xf4292244>(a, b, c, d, inputVector0);
-    d = Step4<10, 0x432aff97>(d, a, b, c);
-    c = Step4<15, 0xab9423a7>(c, d, a, b, inputVector7);
-    b = Step4<21, 0xfc93a039>(b, c, d, a, inputVector5);
-    a = Step4< 6, 0x655b59c3>(a, b, c, d);
-    d = Step4<10, 0x8f0ccc92>(d, a, b, c, inputVector3);
-    c = Step4<15, 0xffeff47d>(c, d, a, b);
-    b = Step4<21, 0x85845dd1>(b, c, d, a, inputVector1);
-    a = Step4< 6, 0x6fa87e4f>(a, b, c, d);
-    d = Step4<10, 0xfe2ce6e0>(d, a, b, c);
-    c = Step4<15, 0xa3014314>(c, d, a, b, inputVector6);
-    b = Step4<21, 0x4e0811a1>(b, c, d, a);
-    a = Step4< 6, 0xf7537e82>(a, b, c, d, inputVector4);
-
-    a = OP_ADD(CREATE_VECTOR(0x67452301), a);
-
-    WRITE_TO_OUTPUT(a, ((__int32*)input), ((__m256i*)expected));
+    a = Step1 ( 7, a, b, c, d, Parameters.K[ 0], inputVector0);
+    d = Step1 (12, d, a, b, c, Parameters.K[ 1], inputVector1);
+    c = Step1 (17, c, d, a, b, Parameters.K[ 2], inputVector2);
+    b = Step1 (22, b, c, d, a, Parameters.K[ 3], inputVector3);
+    a = Step1 ( 7, a, b, c, d, Parameters.K[ 4], inputVector4);
+    d = Step1 (12, d, a, b, c, Parameters.K[ 5], inputVector5);
+    c = Step1 (17, c, d, a, b, Parameters.K[ 6], inputVector6);
+    b = Step1E(22, b, c, d, a, Parameters.K[ 7]);
+    a = Step1E( 7, a, b, c, d, Parameters.K[ 8]);
+    d = Step1E(12, d, a, b, c, Parameters.K[ 9]);
+    c = Step1E(17, c, d, a, b, Parameters.K[10]);
+    b = Step1E(22, b, c, d, a, Parameters.K[11]);
+    a = Step1E( 7, a, b, c, d, Parameters.K[12]);
+    d = Step1E(12, d, a, b, c, Parameters.K[13]);
+    c = Step1 (17, c, d, a, b, Parameters.K[14], inputVector7);
+    b = Step1E(22, b, c, d, a, Parameters.K[15]);
+
+    a = Step2 ( 5, a, d, b, c, Parameters.K[16], inputVector1);
+    d = Step2 ( 9, d, c, a, b, Parameters.K[17], inputVector6);
+    c = Step2E(14, c, b, d, a, Parameters.K[18]);
+    b = Step2 (20, b, a, c, d, Parameters.K[19], inputVector0);
+    a = Step2 ( 5, a, d, b, c, Parameters.K[20], inputVector5);
+    d = Step2E( 9, d, c, a, b, Parameters.K[21]);
+    c = Step2E(14, c, b, d, a, Parameters.K[22]);
+    b = Step2 (20, b, a, c, d, Parameters.K[23], inputVector4);
+    a = Step2E( 5, a, d, b, c, Parameters.K[24]);
+    d = Step2 ( 9, d, c, a, b, Parameters.K[25], inputVector7);
+    c = Step2 (14, c, b, d, a, Parameters.K[26], inputVector3);
+    b = Step2E(20, b, a, c, d, Parameters.K[27]);
+    a = Step2E( 5, a, d, b, c, Parameters.K[28]);
+    d = Step2 ( 9, d, c, a, b, Parameters.K[29], inputVector2);
+    c = Step2E(14, c, b, d, a, Parameters.K[30]);
+    b = Step2E(20, b, a, c, d, Parameters.K[31]);
+
+    a = Step3 ( 4, a, b, c, d, Parameters.K[32], inputVector5);
+    d = Step3E(11, d, a, b, c, Parameters.K[33]);
+    c = Step3E(16, c, d, a, b, Parameters.K[34]);
+    b = Step3 (23, b, c, d, a, Parameters.K[35], inputVector7);
+    a = Step3 ( 4, a, b, c, d, Parameters.K[36], inputVector1);
+    d = Step3 (11, d, a, b, c, Parameters.K[37], inputVector4);
+    c = Step3E(16, c, d, a, b, Parameters.K[38]);
+    b = Step3E(23, b, c, d, a, Parameters.K[39]);
+    a = Step3E( 4, a, b, c, d, Parameters.K[40]);
+    d = Step3 (11, d, a, b, c, Parameters.K[41], inputVector0);
+    c = Step3 (16, c, d, a, b, Parameters.K[42], inputVector3);
+    b = Step3 (23, b, c, d, a, Parameters.K[43], inputVector6);
+    a = Step3E( 4, a, b, c, d, Parameters.K[44]);
+    d = Step3E(11, d, a, b, c, Parameters.K[45]);
+    c = Step3E(16, c, d, a, b, Parameters.K[46]);
+    b = Step3 (23, b, c, d, a, Parameters.K[47], inputVector2);
+
+    a = Step4 ( 6, a, b, c, d, Parameters.K[48], inputVector0);
+    d = Step4E(10, d, a, b, c, Parameters.K[49]);
+    c = Step4 (15, c, d, a, b, Parameters.K[50], inputVector7);
+    b = Step4 (21, b, c, d, a, Parameters.K[51], inputVector5);
+    a = Step4E( 6, a, b, c, d, Parameters.K[52]);
+    d = Step4 (10, d, a, b, c, Parameters.K[53], inputVector3);
+    c = Step4E(15, c, d, a, b, Parameters.K[54]);
+    b = Step4 (21, b, c, d, a, Parameters.K[55], inputVector1);
+    a = Step4E( 6, a, b, c, d, Parameters.K[56]);
+    d = Step4E(10, d, a, b, c, Parameters.K[57]);
+    c = Step4 (15, c, d, a, b, Parameters.K[58], inputVector6);
+    b = Step4E(21, b, c, d, a, Parameters.K[59]);
+    a = Step4 ( 6, a, b, c, d, Parameters.K[60], inputVector4);
+
+    a = OP_ADD(CREATE_VECTOR(Parameters.Init[0]), a);
+
+    WRITE_TO_OUTPUT(a, output);
 }
 #pragma managed

dotnet/WhiteRabbit.UnmanagedBridge/md5.h

@@ -1,3 +1,3 @@
 #pragma once
 
-void md5(unsigned int* input, unsigned __int32 * expected);
+void md5(unsigned int* input, unsigned int* output);

dotnet/WhiteRabbit.UnmanagedBridge/phraseset.cpp

@@ -1,86 +0,0 @@
-#include "stdafx.h"
-#include "phraseset.h"
-#include "constants.h"
-
-#include "intrin.h"
-
-#pragma unmanaged
-
-template<int numberOfWords>
-class Processor
-{
-public:
-    template<int wordNumber>
-    static __forceinline const __m256i ProcessWord(const __m256i phrase, const unsigned __int64 cumulativeWordOffset, const unsigned __int64 permutation, unsigned __int64* allWordsPointer, __int32* wordIndexes)
-    {
-        auto currentWord = allWordsPointer + wordIndexes[_bextr_u64(permutation, 4 * wordNumber, 4)] * 128;
-
-        return ProcessWord<wordNumber + 1>(
-            _mm256_xor_si256(phrase, *(__m256i*)(currentWord + cumulativeWordOffset)),
-            cumulativeWordOffset + currentWord[127],
-            permutation,
-            allWordsPointer,
-            wordIndexes);
-    }
-
-    template<>
-    static __forceinline const __m256i ProcessWord<numberOfWords>(const __m256i phrase, const unsigned __int64 cumulativeWordOffset, const unsigned __int64 permutation, unsigned __int64* allWordsPointer, __int32* wordIndexes)
-    {
-        return phrase;
-    }
-
-    template<int phraseNumber>
-    static __forceinline void ProcessWordsForPhrase(__m256i* avx2initialBuffer, __m256i* avx2buffer, unsigned __int64* allWordsPointer, __int32* wordIndexes, unsigned __int64* permutationsPointer)
-    {
-        avx2buffer[phraseNumber] = ProcessWord<0>(*avx2initialBuffer, 0, permutationsPointer[phraseNumber], allWordsPointer, wordIndexes);
-        ProcessWordsForPhrase<phraseNumber + 1>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-    }
-
-    template<>
-    static __forceinline void ProcessWordsForPhrase<PHRASES_PER_SET>(__m256i* avx2initialBuffer, __m256i* avx2buffer, unsigned __int64* allWordsPointer, __int32* wordIndexes, unsigned __int64* permutationsPointer)
-    {
-        return;
-    }
-};
-
-void fillPhraseSet(unsigned __int64* initialBufferPointer, unsigned __int64* bufferPointer, unsigned __int64* allWordsPointer, __int32* wordIndexes, unsigned __int64* permutationsPointer, int numberOfWords)
-{
-    auto avx2initialBuffer = (__m256i*)initialBufferPointer;
-    auto avx2buffer = (__m256i*)bufferPointer;
-
-    switch (numberOfWords)
-    {
-    case 1:
-        Processor<1>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 2:
-        Processor<2>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 3:
-        Processor<3>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 4:
-        Processor<4>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 5:
-        Processor<5>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 6:
-        Processor<6>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 7:
-        Processor<7>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 8:
-        Processor<8>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 9:
-        Processor<9>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    case 10:
-        Processor<10>::ProcessWordsForPhrase<0>(avx2initialBuffer, avx2buffer, allWordsPointer, wordIndexes, permutationsPointer);
-        break;
-    }
-}
-
-#pragma managed

dotnet/WhiteRabbit.UnmanagedBridge/phraseset.h

@@ -1,3 +0,0 @@
-#pragma once
-
-void fillPhraseSet(unsigned __int64* initialBufferPointer, unsigned __int64* bufferPointer, unsigned __int64* allWordsPointer, __int32* wordIndexes, unsigned __int64* permutationsPointer, int numberOfWords);

dotnet/WhiteRabbit/App.config

@@ -1,7 +1,7 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8" ?>
 <configuration>
   <startup> 
-    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7"/>
+    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6" />
   </startup>
   <appSettings>
     <add key="SourcePhrase" value="poultry outwits ants" />

dotnet/WhiteRabbit/Constants.cs

@@ -2,10 +2,6 @@
 {
     internal class Constants
     {
-        public const int PhrasesPerSet = WhiteRabbitUnmanagedBridge.MD5Unmanaged.PhrasesPerSet;
-
-        public const int MaxNumberOfWords = 8;
-
-        public const int NumberOfThreads = 4;
+        public const int PhrasesPerSet = 8;
     }
 }

dotnet/WhiteRabbit/Flattener.cs

@@ -1,6 +1,5 @@
 namespace WhiteRabbit
 {
-    using System;
     using System.Collections.Generic;
     using System.Collections.Immutable;
     using System.Linq;
@@ -10,11 +9,28 @@
     /// </summary>
     internal static class Flattener
     {
+        // Slow universal implementation
+        private static IEnumerable<ImmutableStack<T>> FlattenAny<T>(ImmutableStack<T[]> phrase)
+        {
+            if (phrase.IsEmpty)
+            {
+                return new[] { ImmutableStack.Create<T>() };
+            }
+
+            T[] wordVariants;
+            var newStack = phrase.Pop(out wordVariants);
+            return FlattenAny(newStack).SelectMany(remainder => wordVariants.Select(word => remainder.Push(word)));
+        }
+
+        // Fast hard-coded implementation for 3 words
         private static IEnumerable<T[]> Flatten3<T>(T[][] phrase)
         {
             foreach (var item0 in phrase[0])
+            {
                 foreach (var item1 in phrase[1])
+                {
                     foreach (var item2 in phrase[2])
+                    {
                         yield return new T[]
                         {
                             item0,
@@ -22,13 +38,21 @@
                             item2,
                         };
                     }
+                }
+            }
+        }
 
+        // Fast hard-coded implementation for 4 words
         private static IEnumerable<T[]> Flatten4<T>(T[][] phrase)
         {
             foreach (var item0 in phrase[0])
+            {
                 foreach (var item1 in phrase[1])
+                {
                     foreach (var item2 in phrase[2])
+                    {
                         foreach (var item3 in phrase[3])
+                        {
                             yield return new T[]
                             {
                                 item0,
@@ -37,14 +61,24 @@
                                 item3,
                             };
                         }
+                    }
+                }
+            }
+        }
 
+        // Fast hard-coded implementation for 5 words
         private static IEnumerable<T[]> Flatten5<T>(T[][] phrase)
         {
             foreach (var item0 in phrase[0])
+            {
                 foreach (var item1 in phrase[1])
+                {
                     foreach (var item2 in phrase[2])
+                    {
                         foreach (var item3 in phrase[3])
+                        {
                             foreach (var item4 in phrase[4])
+                            {
                                 yield return new T[]
                                 {
                                     item0,
@@ -54,15 +88,27 @@
                                     item4,
                                 };
                             }
+                        }
+                    }
+                }
+            }
+        }
 
+        // Fast hard-coded implementation for 6 words
         private static IEnumerable<T[]> Flatten6<T>(T[][] phrase)
         {
             foreach (var item0 in phrase[0])
+            {
                 foreach (var item1 in phrase[1])
+                {
                     foreach (var item2 in phrase[2])
+                    {
                         foreach (var item3 in phrase[3])
+                        {
                             foreach (var item4 in phrase[4])
+                            {
                                 foreach (var item5 in phrase[5])
+                                {
                                     yield return new T[]
                                     {
                                         item0,
@@ -73,88 +119,30 @@
                                         item5,
                                     };
                                 }
+                            }
+                        }
+                    }
+                }
+            }
+        }
 
+        // Fast hard-coded implementation for 7 words
         private static IEnumerable<T[]> Flatten7<T>(T[][] phrase)
         {
             foreach (var item0 in phrase[0])
-            foreach (var item1 in phrase[1])
-            foreach (var item2 in phrase[2])
-            foreach (var item3 in phrase[3])
-            foreach (var item4 in phrase[4])
-            foreach (var item5 in phrase[5])
-            foreach (var item6 in phrase[6])
-                yield return new T[]
-                {
-                    item0,
-                    item1,
-                    item2,
-                    item3,
-                    item4,
-                    item5,
-                    item6,
-                };
-        }
-
-        private static IEnumerable<T[]> Flatten8<T>(T[][] phrase)
             {
-            foreach (var item0 in phrase[0])
                 foreach (var item1 in phrase[1])
-            foreach (var item2 in phrase[2])
-            foreach (var item3 in phrase[3])
-            foreach (var item4 in phrase[4])
-            foreach (var item5 in phrase[5])
-            foreach (var item6 in phrase[6])
-            foreach (var item7 in phrase[7])
-                yield return new T[]
-                {
-                    item0,
-                    item1,
-                    item2,
-                    item3,
-                    item4,
-                    item5,
-                    item6,
-                    item7,
-                };
-        }
-
-        private static IEnumerable<T[]> Flatten9<T>(T[][] phrase)
                 {
-            foreach (var item0 in phrase[0])
-            foreach (var item1 in phrase[1])
                     foreach (var item2 in phrase[2])
-            foreach (var item3 in phrase[3])
-            foreach (var item4 in phrase[4])
-            foreach (var item5 in phrase[5])
-            foreach (var item6 in phrase[6])
-            foreach (var item7 in phrase[7])
-            foreach (var item8 in phrase[8])
-                yield return new T[]
-                {
-                    item0,
-                    item1,
-                    item2,
-                    item3,
-                    item4,
-                    item5,
-                    item6,
-                    item7,
-                    item8,
-                };
-        }
-
-        private static IEnumerable<T[]> Flatten10<T>(T[][] phrase)
                     {
-            foreach (var item0 in phrase[0])
-            foreach (var item1 in phrase[1])
-            foreach (var item2 in phrase[2])
                         foreach (var item3 in phrase[3])
+                        {
                             foreach (var item4 in phrase[4])
+                            {
                                 foreach (var item5 in phrase[5])
+                                {
                                     foreach (var item6 in phrase[6])
-            foreach (var item7 in phrase[7])
-            foreach (var item8 in phrase[8])
-            foreach (var item9 in phrase[9])
+                                    {
                                         yield return new T[]
                                         {
                                             item0,
@@ -164,11 +152,15 @@
                                             item4,
                                             item5,
                                             item6,
-                    item7,
-                    item8,
-                    item9,
                                         };
                                     }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
 
         public static IEnumerable<T[]> Flatten<T>(T[][] wordVariants)
         {
@@ -184,14 +176,8 @@
                     return Flatten6(wordVariants);
                 case 7:
                     return Flatten7(wordVariants);
-                case 8:
-                    return Flatten8(wordVariants);
-                case 9:
-                    return Flatten9(wordVariants);
-                case 10:
-                    return Flatten10(wordVariants);
                 default:
-                    throw new ArgumentOutOfRangeException(nameof(wordVariants));
+                    return FlattenAny(ImmutableStack.Create(wordVariants)).Select(words => words.ToArray());
             }
         }
     }

dotnet/WhiteRabbit/MD5Digest.cs

@@ -0,0 +1,21 @@
+namespace WhiteRabbit
+{
+    using System.Runtime.CompilerServices;
+    using WhiteRabbitUnmanagedBridge;
+
+    internal static class MD5Digest
+    {
+        // It only returns first component of MD5 hash
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static unsafe uint[] Compute(PhraseSet input)
+        {
+            var result = new uint[Constants.PhrasesPerSet];
+            fixed (uint* resultPointer = result)
+            {
+                MD5Unmanaged.ComputeMD5(input.Buffer, resultPointer);
+            }
+
+            return result;
+        }
+    }
+}

dotnet/WhiteRabbit/PhraseSet.cs

@@ -1,107 +1,53 @@
 namespace WhiteRabbit
 {
-    using System;
-    using System.Diagnostics;
-    using System.Linq;
-    using System.Numerics;
-    using System.Runtime.CompilerServices;
-    using WhiteRabbitUnmanagedBridge;
-
     // Anagram representation optimized for MD5
-    internal struct PhraseSet
+    internal unsafe struct PhraseSet
     {
-        private uint[] Buffer;
+        public fixed uint Buffer[8 * Constants.PhrasesPerSet];
 
-        public void Init()
-        {
-            this.Buffer = new uint[8 * Constants.PhrasesPerSet];
-        }
-
-        public unsafe void FillLength(int numberOfCharacters, int numberOfWords)
+        public PhraseSet(byte[][] words, int[][] permutations, int offset, int numberOfCharacters)
         {
             fixed (uint* bufferPointer = this.Buffer)
             {
-                var length = (uint)(numberOfCharacters + numberOfWords - 1);
-                var lengthInBits = (uint)(length << 3);
+                var length = numberOfCharacters + words.Length - 1;
+
                 for (var i = 0; i < Constants.PhrasesPerSet; i++)
                 {
-                    bufferPointer[7 + i * 8] = lengthInBits;
-                    ((byte*)bufferPointer)[length + i * 32] = 128 ^ ' ';
-                }
-            }
-        }
+                    var permutation = permutations[offset + i];
+                    var startPointer = bufferPointer + i * 8;
+                    byte[] currentWord;
+                    var j = 0;
+                    var wordIndex = 0;
+                    var currentPointer = (byte*)startPointer;
+                    byte* lastPointer = currentPointer + length;
 
-        public unsafe void ProcessPermutations(PhraseSet initialPhraseSet, Word[] allWords, int[] wordIndexes, ulong[] permutations, uint[] expectedHashesVector, Action<byte[], uint> action)
-        {
-            fixed (uint* bufferPointer = this.Buffer, initialBufferPointer = initialPhraseSet.Buffer)
+                    for (; currentPointer < lastPointer; currentPointer++)
                     {
-                fixed (ulong* permutationsPointer = permutations)
-                {
-                    fixed (int* wordIndexesPointer = wordIndexes)
-                    {
-                        fixed (Word* allWordsPointer = allWords)
-                        {
-                            fixed (uint* expectedHashesPointer = expectedHashesVector)
-                            {
-                                for (var i = 0; i < permutations.Length; i += Constants.PhrasesPerSet)
-                                {
-                                    MD5Unmanaged.FillPhraseSet(
-                                        (ulong*)initialBufferPointer,
-                                        (ulong*)bufferPointer,
-                                        (ulong*)allWordsPointer,
-                                        wordIndexesPointer,
-                                        permutationsPointer + i,
-                                        wordIndexes.Length);
+                        currentWord = words[permutation[wordIndex]];
+                        *currentPointer = currentWord[j];
 
-                                    MD5Unmanaged.ComputeMD5(bufferPointer, expectedHashesPointer);
+                        j++;
 
-                                    if (bufferPointer[Constants.PhrasesPerSet / 2] != 0xFFFFFFFF)
-                                    {
-                                        for (var j = 0; j < Constants.PhrasesPerSet; j++)
-                                        {
-                                            // 16 matches are packed in 8 32-bit numbers: [0,1], [8,9], [2,3], [10,11], [4, 5], [12, 13], [6, 7], [14, 15]
-                                            var position = ((j / 2) % 4) * 2 + (j / 8);
-                                            var match = (bufferPointer[position] >> (4 * (j % 2))) & 0xF0F0F0F;
-                                            if (match != 0)
-                                            {
-                                                var bufferInfo = ((ulong)bufferPointer[Constants.PhrasesPerSet] << 32) | bufferPointer[j];
-                                                MD5Unmanaged.FillPhraseSet(
-                                                    (ulong*)initialBufferPointer,
-                                                    (ulong*)bufferPointer,
-                                                    (ulong*)allWordsPointer,
-                                                    wordIndexesPointer,
-                                                    permutationsPointer + i,
-                                                    wordIndexes.Length);
-                                                action(this.GetBytes(j), match);
-                                                break;
-                                            }
-                                        }
-                                    }
-                                }
-                            }
-                        }
+                        // 0xffffffff if greater than or equal, 0 if less than
+                        var comparisonResult = unchecked((int)((((uint)j - (uint)currentWord.Length) >> 31) - 1));
+                        j = (comparisonResult & 0) | (~comparisonResult & j);
+                        wordIndex = (comparisonResult & (wordIndex + 1)) | (~comparisonResult & wordIndex);
                     }
+                    *currentPointer = 128;
+
+                    startPointer[7] = (uint)(length << 3);
                 }
             }
         }
 
-        public unsafe byte[] GetBytes(int number)
+        public byte[] GetBytes(int number)
         {
-            Debug.Assert(number < Constants.PhrasesPerSet);
+            System.Diagnostics.Debug.Assert(number < Constants.PhrasesPerSet);
 
             fixed(uint* bufferPointer = this.Buffer)
             {
                 var phrasePointer = bufferPointer + 8 * number;
-                var length = 0;
-                for (var i = 27; i >= 0; i--)
-                {
-                    if (((byte*)phrasePointer)[i] == 128)
-                    {
-                        length = i;
-                        break;
-                    }
-                }
-
+                var length = phrasePointer[7] >> 3;
                 var result = new byte[length];
                 for (var i = 0; i < length; i++)
                 {
@@ -111,16 +57,5 @@
                 return result;
             }
         }
-
-        public unsafe string DebugBytes(int number)
-        {
-            Debug.Assert(number < Constants.PhrasesPerSet);
-
-            fixed (uint* bufferPointer = this.Buffer)
-            {
-                var bytes = (byte*)bufferPointer;
-                return string.Concat(Enumerable.Range(32 * number, 32).Select(i => bytes[i].ToString("X2")));
-            }
-        }
     }
 }

dotnet/WhiteRabbit/PrecomputedPermutationsGenerator.cs

@@ -1,137 +1,29 @@
 namespace WhiteRabbit
 {
-    using System;
     using System.Collections.Generic;
     using System.Linq;
 
     internal static class PrecomputedPermutationsGenerator
     {
-        static PrecomputedPermutationsGenerator()
-        {
-            Permutations = new ulong[Constants.MaxNumberOfWords + 1][][];
-            PermutationsNumbers = new long[Constants.MaxNumberOfWords + 1][];
-            for (var i = 0; i <= Constants.MaxNumberOfWords; i++)
-            {
-                var permutationsInfo = GeneratePermutations(i);
-                Permutations[i] = permutationsInfo.Item1;
-                PermutationsNumbers[i] = permutationsInfo.Item2;
-            }
-        }
+        private static int[][][] Permutations { get; } = Enumerable.Range(0, 8).Select(GeneratePermutations).ToArray();
 
-        private static ulong[][][] Permutations { get; }
+        private static long[] PermutationsNumbers { get; } = GeneratePermutationsNumbers().Take(19).ToArray();
 
-        private static long[][] PermutationsNumbers { get; }
+        public static int[][] HamiltonianPermutations(int n) => Permutations[n];
 
-        public static ulong[] HamiltonianPermutations(int n, uint filter) => Permutations[n][filter];
+        public static long GetPermutationsNumber(int n) => PermutationsNumbers[n];
 
-        public static long GetPermutationsNumber(int n, uint filter) => PermutationsNumbers[n][filter];
-
-        private static Tuple<ulong[][], long[]> GeneratePermutations(int n)
-        {
-            if (n == 0)
-            {
-                return Tuple.Create(new ulong[0][], new long[0]);
-            }
-
-            var allPermutations = PermutationsGenerator.HamiltonianPermutations(n)
-                .Select(FormatPermutation)
-                .ToArray();
-
-            var statesCount = (uint)1 << (n - 1);
-            var resultUnpadded = new PermutationInfo[statesCount][];
-
-            resultUnpadded[0] = allPermutations;
-            for (uint i = 1; i < statesCount; i++)
-            {
-                var mask = i;
-                mask |= mask >> 1;
-                mask |= mask >> 2;
-                mask |= mask >> 4;
-                mask |= mask >> 8;
-                mask |= mask >> 16;
-                mask = mask >> 1;
-                var existing = i & mask;
-                var seniorBit = i ^ existing;
-                var position = 0;
-                while (seniorBit != 0)
+        private static int[][] GeneratePermutations(int n)
         {
-                    seniorBit = seniorBit >> 1;
-                    position++;
-                }
-
-                resultUnpadded[i] = resultUnpadded[existing]
-                    .Where(info => ((info.PermutationInverse >> (4 * (position - 1))) % 16 < (info.PermutationInverse >> (4 * position)) % 16))
+            var result = PermutationsGenerator.HamiltonianPermutations(n)
+                .Select(permutation => permutation.PermutationData)
                 .ToArray();
-            }
-
-            var result = new ulong[statesCount][];
-            var numbers = new long[statesCount];
-            for (uint i = 0; i < statesCount; i++)
+            if (result.Length % Constants.PhrasesPerSet == 0)
             {
-                result[i] = PadToWholeChunks(resultUnpadded[i], Constants.PhrasesPerSet);
-                numbers[i] = resultUnpadded[i].LongLength;
-            }
-
-            return Tuple.Create(result, numbers);
-        }
-
-        public static bool IsOrderPreserved(ulong permutation, uint position)
-        {
-            var currentPermutation = permutation;
-
-            while (currentPermutation != 0)
-            {
-                if ((currentPermutation & 15) == position)
-                {
-                    return true;
-                }
-
-                if ((currentPermutation & 15) == (position + 1))
-                {
-                    return false;
-                }
-
-                currentPermutation = currentPermutation >> 4;
-            }
-
-            throw new ApplicationException("Malformed permutation " + permutation + " for position " + position);
-        }
-
-        private static ulong[] PadToWholeChunks(PermutationInfo[] original, int chunkSize)
-        {
-            ulong[] result;
-            if (original.Length % chunkSize == 0)
-            {
-                result = new ulong[original.Length];
-            }
-            else
-            {
-                result = new ulong[original.Length + chunkSize - (original.Length % chunkSize)];
-            }
-
-            for (var i = 0; i < original.Length; i++)
-            {
-                result[i] = original[i].Permutation;
-            }
-
                 return result;
             }
 
-        private static PermutationInfo FormatPermutation(PermutationsGenerator.Permutation permutation)
-        {
-            System.Diagnostics.Debug.Assert(permutation.PermutationData.Length <= 16);
-
-            ulong result = 0;
-            ulong resultInverse = 0;
-            for (var i = 0; i < permutation.PermutationData.Length; i++)
-            {
-                var source = i;
-                var target = permutation.PermutationData[i];
-                result |= (ulong)(target) << (4 * source);
-                resultInverse |= (ulong)(source) << (4 * target);
-            }
-
-            return new PermutationInfo { Permutation = result, PermutationInverse = resultInverse };
+            return result.Concat(Enumerable.Repeat(result[0], Constants.PhrasesPerSet - (result.Length % Constants.PhrasesPerSet))).ToArray();
         }
 
         private static IEnumerable<long> GeneratePermutationsNumbers()
@@ -147,11 +39,5 @@
                 i++;
             }
         }
-
-        private struct PermutationInfo
-        {
-            public ulong Permutation;
-            public ulong PermutationInverse;
-        }
     }
 }

dotnet/WhiteRabbit/Program.cs

@@ -1,10 +1,10 @@
 namespace WhiteRabbit
 {
     using System;
+    using System.Collections.Concurrent;
     using System.Collections.Generic;
     using System.Configuration;
     using System.Diagnostics;
-    using System.IO;
     using System.Linq;
     using System.Numerics;
     using System.Security.Cryptography;
@@ -24,18 +24,13 @@
             stopwatch.Start();
 
             var sourcePhrase = ConfigurationManager.AppSettings["SourcePhrase"];
+            var sourceChars = ToOrderedChars(sourcePhrase);
 
             var maxWordsInPhrase = int.Parse(ConfigurationManager.AppSettings["MaxWordsInPhrase"]);
 
-            if (sourcePhrase.Where(ch => ch != ' ').Count() + maxWordsInPhrase > 28)
+            if (sourceChars.Length + maxWordsInPhrase > 27)
             {
-                Console.WriteLine("Only anagrams of up to 27 characters (including whitespace) are allowed");
-                return;
-            }
-
-            if (maxWordsInPhrase > Constants.MaxNumberOfWords)
-            {
-                Console.WriteLine($"Only anagrams of up to {Constants.MaxNumberOfWords} words are allowed");
+                Console.WriteLine("Only anagrams of up to 27 characters are allowed");
                 return;
             }
 
@@ -50,16 +45,12 @@
                 Console.WriteLine("Only 64-bit systems are supported due to MD5Digest optimizations");
             }
 
-            var expectedHashesFirstComponentsArray = new uint[8];
-            {
-                int i = 0;
-                foreach (var expectedHash in ConfigurationManager.AppSettings["ExpectedHashes"].Split(','))
-                {
-                    expectedHashesFirstComponentsArray[i] = HexadecimalStringToUnsignedIntArray(expectedHash)[0];
-                    expectedHashesFirstComponentsArray[i + 1] = HexadecimalStringToUnsignedIntArray(expectedHash)[0];
-                    i += 2;
-                }
-            }
+            var expectedHashesAsVectors = ConfigurationManager.AppSettings["ExpectedHashes"]
+                .Split(',')
+                .Select(hash => new Vector<uint>(HexadecimalStringToUnsignedIntArray(hash)))
+                .ToArray();
+
+            var expectedHashesFirstComponents = expectedHashesAsVectors.Select(vector => vector[0]).ToArray();
 
             var processor = new StringsProcessor(
                 Encoding.ASCII.GetBytes(sourcePhrase),
@@ -75,14 +66,27 @@
 
             stopwatch.Restart();
 
-            processor.CheckPhrases(expectedHashesFirstComponentsArray, (phraseBytes, hashFirstComponent) =>
+            processor.GeneratePhrases()
+                .ForAll(phraseSet =>
+                {
+                    var hashesFirstComponents = MD5Digest.Compute(phraseSet);
+                    for (var i = 0; i < Constants.PhrasesPerSet; i++)
                     {
-                var phrase = Encoding.ASCII.GetString(phraseBytes);
-                var hash = ComputeFullMD5(phraseBytes);
-                Console.WriteLine($"Found phrase for {hash} ({hashFirstComponent:x8}): {phrase}; time from start is {stopwatch.Elapsed}");
+                        Debug.Assert(
+                            sourceChars == ToOrderedChars(ToString(phraseSet, i)),
+                            $"StringsProcessor produced incorrect anagram: {ToString(phraseSet, i)}");
+
+                        if (Array.IndexOf(expectedHashesFirstComponents, hashesFirstComponents[i]) >= 0)
+                        {
+                            var phrase = ToString(phraseSet, i);
+                            var hash = ComputeFullMD5(phrase);
+                            Console.WriteLine($"Found phrase for {hash}: {phrase}; time from start is {stopwatch.Elapsed}");
+                        }
+                    }
                 });
 
             Console.WriteLine($"Done; time from start: {stopwatch.Elapsed}");
+
         }
 
         // Code taken from http://stackoverflow.com/a/321404/831314
@@ -96,8 +100,9 @@
         }
 
         // We can afford to spend some time here; this code will only run for matched phrases (and for one in several billion non-matched)
-        private static string ComputeFullMD5(byte[] phraseBytes)
+        private static string ComputeFullMD5(string phrase)
         {
+            var phraseBytes = Encoding.ASCII.GetBytes(phrase);
             using (var hashAlgorithm = new MD5CryptoServiceProvider())
             {
                 var resultBytes = hashAlgorithm.ComputeHash(phraseBytes);
@@ -110,6 +115,11 @@
             return hex.Substring(6, 2) + hex.Substring(4, 2) + hex.Substring(2, 2) + hex.Substring(0, 2);
         }
 
+        private static string ToString(PhraseSet phrase, int offset)
+        {
+            return Encoding.ASCII.GetString(phrase.GetBytes(offset));
+        }
+
         private static IEnumerable<byte[]> ReadInput()
         {
             string line;
@@ -118,5 +128,20 @@
                 yield return Encoding.ASCII.GetBytes(line);
             }
         }
+
+        private static string ToOrderedChars(string source)
+        {
+            return new string(source.Where(ch => ch != ' ').OrderBy(ch => ch).ToArray());
+        }
+
+#if SINGLE_THREADED
+        private static void ForAll<T>(this IEnumerable<T> source, Action<T> action)
+        {
+            foreach (var entry in source)
+            {
+                action(entry);
+            }
+        }
+#endif
     }
 }

dotnet/WhiteRabbit/StringsProcessor.cs

@@ -3,8 +3,6 @@
     using System;
     using System.Collections.Generic;
     using System.Linq;
-    using System.Numerics;
-    using System.Threading.Tasks;
 
     internal sealed class StringsProcessor
     {
@@ -13,7 +11,7 @@
         // Ensure that permutations are precomputed prior to main run, so that processing times will be correct
         static StringsProcessor()
         {
-            PrecomputedPermutationsGenerator.HamiltonianPermutations(1, 0);
+            PrecomputedPermutationsGenerator.HamiltonianPermutations(0);
         }
 
         public StringsProcessor(byte[] sourceString, int maxWordsCount, IEnumerable<byte[]> words)
@@ -22,26 +20,18 @@
             this.NumberOfCharacters = filteredSource.Length;
             this.VectorsConverter = new VectorsConverter(filteredSource);
 
-            var allWordsAndVectors = words
+            // Dictionary of vectors to array of words represented by this vector
+            var vectorsToWords = words
                 .Where(word => word != null && word.Length > 0)
-                .Select(word => new { word, vector = this.VectorsConverter.GetVector(word) })
+                .Select(word => new { word = word.Concat(new byte[] { SPACE }).ToArray(), vector = this.VectorsConverter.GetVector(word) })
                 .Where(tuple => tuple.vector != null)
-                .Select(tuple => tuple.word)
-                .Distinct(new ByteArrayEqualityComparer())
-                .Select(word => word)
-                .ToArray();
-
-            // Dictionary of vectors to array of words represented by this vector
-            var vectorsToWords = allWordsAndVectors
-                .Select((word, index) => new { word, index, vector = this.VectorsConverter.GetVector(word).Value })
+                .Select(tuple => new { tuple.word, vector = tuple.vector.Value })
                 .GroupBy(tuple => tuple.vector)
-                .Select(group => new { vector = group.Key, words = group.Select(tuple => tuple.index).ToArray() })
+                .Select(group => new { vector = group.Key, words = group.Select(tuple => tuple.word).Distinct(new ByteArrayEqualityComparer()).ToArray() })
                 .ToList();
 
             this.WordsDictionary = vectorsToWords.Select(tuple => tuple.words).ToArray();
 
-            this.AllWords = allWordsAndVectors.Select(word => new Word(word)).ToArray();
-
             this.VectorsProcessor = new VectorsProcessor(
                 this.VectorsConverter.GetVector(filteredSource).Value,
                 maxWordsCount,
@@ -50,56 +40,42 @@
 
         private VectorsConverter VectorsConverter { get; }
 
-        private Word[] AllWords { get; }
-
         /// <summary>
-        /// WordsDictionary[vectorIndex] = [word1index, word2index, ...]
+        /// WordsDictionary[vectorIndex] = [word1, word2, ...]
         /// </summary>
-        private int[][] WordsDictionary { get; }
+        private byte[][][] WordsDictionary { get; }
 
         private VectorsProcessor VectorsProcessor { get; }
 
         private int NumberOfCharacters { get; }
 
-        public void CheckPhrases(uint[] expectedHashesVector, Action<byte[], uint> action)
+#if SINGLE_THREADED
+        public IEnumerable<PhraseSet> GeneratePhrases()
+#else
+        public ParallelQuery<PhraseSet> GeneratePhrases()
+#endif
         {
             // task of finding anagrams could be reduced to the task of finding sequences of dictionary vectors with the target sum
             var sums = this.VectorsProcessor.GenerateSequences();
 
             // converting sequences of vectors to the sequences of words...
-            Parallel.ForEach(sums, new ParallelOptions { MaxDegreeOfParallelism = Constants.NumberOfThreads }, sum => ProcessSum(sum, expectedHashesVector, action));
+            return sums
+                .Select(this.ConvertVectorsToWords)
+                .SelectMany(Flattener.Flatten)
+                .SelectMany(this.ConvertWordsToPhrases);
         }
 
         public long GetPhrasesCount()
         {
-            var sums = this.VectorsProcessor.GenerateSequences();
-            return (from sum in sums
-                    let filter = ComputeFilter(sum)
-                    let wordsVariantsNumber = this.ConvertVectorsToWordsNumber(sum)
-                    let permutationsNumber = PrecomputedPermutationsGenerator.GetPermutationsNumber(sum.Length, filter)
-                    let total = wordsVariantsNumber * permutationsNumber
-                    select total)
-                    .Sum();
-        }
-
-        private static uint ComputeFilter(int[] vectors)
-        {
-            uint result = 0;
-            for (var i = 1; i < vectors.Length; i++)
-            {
-                if (vectors[i] == vectors[i - 1])
-                {
-                    result |= (uint)1 << (i - 1);
-                }
-            }
-
-            return result;
+            return this.VectorsProcessor.GenerateSequences()
+                .Select(this.ConvertVectorsToWordsNumber)
+                .Sum(tuple => tuple.Item2 * PrecomputedPermutationsGenerator.GetPermutationsNumber(tuple.Item1));
         }
 
-        private int[][] ConvertVectorsToWordIndexes(int[] vectors)
+        private byte[][][] ConvertVectorsToWords(int[] vectors)
         {
             var length = vectors.Length;
-            var words = new int[length][];
+            var words = new byte[length][][];
             for (var i = 0; i < length; i++)
             {
                 words[i] = this.WordsDictionary[vectors[i]];
@@ -108,7 +84,7 @@
             return words;
         }
 
-        private long ConvertVectorsToWordsNumber(int[] vectors)
+        private Tuple<int, long> ConvertVectorsToWordsNumber(int[] vectors)
         {
             long result = 1;
             for (var i = 0; i < vectors.Length; i++)
@@ -116,27 +92,16 @@
                 result *= this.WordsDictionary[vectors[i]].Length;
             }
 
-            return result;
+            return Tuple.Create(vectors.Length, result);
         }
 
-        private void ProcessSum(int[] sum, uint[] expectedHashesVector, Action<byte[], uint> action)
+        private IEnumerable<PhraseSet> ConvertWordsToPhrases(byte[][] words)
         {
-            var initialPhraseSet = new PhraseSet();
-            initialPhraseSet.Init();
-            initialPhraseSet.FillLength(this.NumberOfCharacters, sum.Length);
-            var phraseSet = new PhraseSet();
-            phraseSet.Init();
-            var permutationsFilter = ComputeFilter(sum);
-            var wordsVariants = this.ConvertVectorsToWordIndexes(sum);
-            foreach (var wordsArray in Flattener.Flatten(wordsVariants))
+            var permutations = PrecomputedPermutationsGenerator.HamiltonianPermutations(words.Length);
+            var permutationsLength = permutations.Length;
+            for (var i = 0; i < permutationsLength; i += Constants.PhrasesPerSet)
             {
-                phraseSet.ProcessPermutations(
-                    initialPhraseSet,
-                    this.AllWords,
-                    wordsArray,
-                    PrecomputedPermutationsGenerator.HamiltonianPermutations(wordsArray.Length, permutationsFilter),
-                    expectedHashesVector,
-                    action);
+                yield return new PhraseSet(words, permutations, i, this.NumberOfCharacters);
             }
         }
     }

dotnet/WhiteRabbit/VectorsProcessor.cs

@@ -48,9 +48,16 @@
         private ImmutableArray<int> NormsIndex { get; }
 
         // Produces all sets of vectors with the target sum
+#if SINGLE_THREADED
         public IEnumerable<int[]> GenerateSequences()
+#else
+        public ParallelQuery<int[]> GenerateSequences()
+#endif
         {
             return this.GenerateUnorderedSequences(this.Target, GetVectorNorm(this.Target, this.Target), this.MaxVectorsCount, 0)
+#if !SINGLE_THREADED
+                .AsParallel()
+#endif
                 .Select(Enumerable.ToArray);
         }
 

dotnet/WhiteRabbit/WhiteRabbit.csproj

@@ -9,11 +9,10 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>WhiteRabbit</RootNamespace>
     <AssemblyName>WhiteRabbit</AssemblyName>
-    <TargetFrameworkVersion>v4.7</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>x64</PlatformTarget>
@@ -61,6 +60,7 @@
     <Compile Include="ByteArrayEqualityComparer.cs" />
     <Compile Include="Constants.cs" />
     <Compile Include="Flattener.cs" />
+    <Compile Include="MD5Digest.cs" />
     <Compile Include="PhraseSet.cs" />
     <Compile Include="PrecomputedPermutationsGenerator.cs" />
     <Compile Include="PermutationsGenerator.cs" />
@@ -69,7 +69,6 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="VectorsProcessor.cs" />
     <Compile Include="VectorsConverter.cs" />
-    <Compile Include="Word.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />

dotnet/WhiteRabbit/Word.cs

@@ -1,53 +0,0 @@
-namespace WhiteRabbit
-{
-    internal unsafe struct Word
-    {
-        public fixed long Buffers[128];
-
-        public unsafe Word(byte[] word)
-        {
-            var tmpWord = new byte[word.Length + 1];
-            tmpWord[word.Length] = (byte)' ';
-            for (var i = 0; i < word.Length; i++)
-            {
-                tmpWord[i] = word[i];
-            }
-
-            fixed (long* buffersPointer = this.Buffers)
-            {
-                for (var i = 0; i < 32; i++)
-                {
-                    var bytePointer = (byte*)(buffersPointer + 4 * i);
-                    var endPointer = bytePointer + 32;
-                    var currentPointer = bytePointer + i;
-                    for (var j = 0; j < tmpWord.Length && currentPointer < endPointer; j++, currentPointer++)
-                    {
-                        *currentPointer = tmpWord[j];
-                    }
-                }
-
-                buffersPointer[127] = tmpWord.Length * 4;
-            }
-        }
-
-        public unsafe byte[] Original
-        {
-            get
-            {
-                fixed (long* buffersPointer = this.Buffers)
-                {
-                    var length = buffersPointer[127] / 4;
-                    var result = new byte[length];
-                    for (var i = 0; i < length; i++)
-                    {
-                        result[i] = ((byte*)buffersPointer)[i];
-                    }
-
-                    return result;
-                }
-            }
-        }
-
-        private static Word Empty { get; } = new Word();
-    }
-}