1 files changed, 520 insertions, 0 deletions

diff --git a/src/common/hash.cpp b/src/common/hash.cpp
new file mode 100644
index 000000000..5303f07b5
--- /dev/null
+++ b/src/common/hash.cpp
@@ -0,0 +1,520 @@
+// Copyright 2013 Dolphin Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+
+#include "hash.h"
+#if _M_SSE >= 0x402
+#include "cpu_detect.h"
+#include <nmmintrin.h>
+#endif
+
+static u64 (*ptrHashFunction)(const u8 *src, int len, u32 samples) = &GetMurmurHash3;
+
+// uint32_t
+// WARNING - may read one more byte!
+// Implementation from Wikipedia.
+u32 HashFletcher(const u8* data_u8, size_t length)
+{
+    const u16* data = (const u16*)data_u8; /* Pointer to the data to be summed */
+    size_t len = (length + 1) / 2; /* Length in 16-bit words */
+    u32 sum1 = 0xffff, sum2 = 0xffff;
+
+    while (len)
+    {
+        size_t tlen = len > 360 ? 360 : len;
+        len -= tlen;
+
+        do {
+            sum1 += *data++;
+            sum2 += sum1;
+        }
+        while (--tlen);
+
+        sum1 = (sum1 & 0xffff) + (sum1 >> 16);
+        sum2 = (sum2 & 0xffff) + (sum2 >> 16);
+    }
+
+    // Second reduction step to reduce sums to 16 bits
+    sum1 = (sum1 & 0xffff) + (sum1 >> 16);
+    sum2 = (sum2 & 0xffff) + (sum2 >> 16);
+    return(sum2 << 16 | sum1);
+}
+
+
+// Implementation from Wikipedia
+// Slightly slower than Fletcher above, but slightly more reliable.
+#define MOD_ADLER 65521
+// data: Pointer to the data to be summed; len is in bytes
+u32 HashAdler32(const u8* data, size_t len)
+{
+    u32 a = 1, b = 0;
+
+    while (len)
+    {
+        size_t tlen = len > 5550 ? 5550 : len;
+        len -= tlen;
+
+        do
+        {
+            a += *data++;
+            b += a;
+        }
+        while (--tlen);
+
+        a = (a & 0xffff) + (a >> 16) * (65536 - MOD_ADLER);
+        b = (b & 0xffff) + (b >> 16) * (65536 - MOD_ADLER);
+    }
+
+    // It can be shown that a <= 0x1013a here, so a single subtract will do.
+    if (a >= MOD_ADLER)
+    {
+        a -= MOD_ADLER;
+    }
+
+    // It can be shown that b can reach 0xfff87 here.
+    b = (b & 0xffff) + (b >> 16) * (65536 - MOD_ADLER);
+
+    if (b >= MOD_ADLER)
+    {
+        b -= MOD_ADLER;
+    }
+
+    return((b << 16) | a);
+}
+
+// Stupid hash - but can't go back now :)
+// Don't use for new things. At least it's reasonably fast.
+u32 HashEctor(const u8* ptr, int length)
+{
+    u32 crc = 0;
+
+    for (int i = 0; i < length; i++)
+    {
+        crc ^= ptr[i];
+        crc = (crc << 3) | (crc >> 29);
+    }
+
+    return(crc);
+}
+
+
+#ifdef _M_X64
+
+//-----------------------------------------------------------------------------
+// Block read - if your platform needs to do endian-swapping or can only
+// handle aligned reads, do the conversion here
+
+inline u64 getblock(const u64 * p, int i)
+{
+    return p[i];
+}
+
+//----------
+// Block mix - combine the key bits with the hash bits and scramble everything
+
+inline void bmix64(u64 & h1, u64 & h2, u64 & k1, u64 & k2, u64 & c1, u64 & c2)
+{
+    k1 *= c1; 
+    k1  = _rotl64(k1,23); 
+    k1 *= c2;
+    h1 ^= k1;
+    h1 += h2;
+
+    h2 = _rotl64(h2,41);
+
+    k2 *= c2; 
+    k2  = _rotl64(k2,23);
+    k2 *= c1;
+    h2 ^= k2;
+    h2 += h1;
+
+    h1 = h1*3+0x52dce729;
+    h2 = h2*3+0x38495ab5;
+
+    c1 = c1*5+0x7b7d159c;
+    c2 = c2*5+0x6bce6396;
+}
+
+//----------
+// Finalization mix - avalanches all bits to within 0.05% bias
+
+inline u64 fmix64(u64 k)
+{
+    k ^= k >> 33;
+    k *= 0xff51afd7ed558ccd;
+    k ^= k >> 33;
+    k *= 0xc4ceb9fe1a85ec53;
+    k ^= k >> 33;
+
+    return k;
+}
+
+u64 GetMurmurHash3(const u8 *src, int len, u32 samples)
+{
+    const u8 * data = (const u8*)src;
+    const int nblocks = len / 16;
+    u32 Step = (len / 8);
+    if(samples == 0) samples = max(Step, 1u);
+    Step = Step / samples;
+    if(Step < 1) Step = 1;
+
+    u64 h1 = 0x9368e53c2f6af274;
+    u64 h2 = 0x586dcd208f7cd3fd;
+
+    u64 c1 = 0x87c37b91114253d5;
+    u64 c2 = 0x4cf5ad432745937f;
+
+
+    //----------
+    // body
+
+    const u64 * blocks = (const u64 *)(data);
+
+    for(int i = 0; i < nblocks; i+=Step)
+    {
+        u64 k1 = getblock(blocks,i*2+0);
+        u64 k2 = getblock(blocks,i*2+1);
+
+        bmix64(h1,h2,k1,k2,c1,c2);
+    }
+
+    //----------
+    // tail
+
+    const u8 * tail = (const u8*)(data + nblocks*16);
+
+    u64 k1 = 0;
+    u64 k2 = 0;
+
+    switch(len & 15)
+    {
+    case 15: k2 ^= u64(tail[14]) << 48;
+    case 14: k2 ^= u64(tail[13]) << 40;
+    case 13: k2 ^= u64(tail[12]) << 32;
+    case 12: k2 ^= u64(tail[11]) << 24;
+    case 11: k2 ^= u64(tail[10]) << 16;
+    case 10: k2 ^= u64(tail[ 9]) << 8;
+    case  9: k2 ^= u64(tail[ 8]) << 0;
+
+    case  8: k1 ^= u64(tail[ 7]) << 56;
+    case  7: k1 ^= u64(tail[ 6]) << 48;
+    case  6: k1 ^= u64(tail[ 5]) << 40;
+    case  5: k1 ^= u64(tail[ 4]) << 32;
+    case  4: k1 ^= u64(tail[ 3]) << 24;
+    case  3: k1 ^= u64(tail[ 2]) << 16;
+    case  2: k1 ^= u64(tail[ 1]) << 8;
+    case  1: k1 ^= u64(tail[ 0]) << 0;
+            bmix64(h1,h2,k1,k2,c1,c2);
+    };
+
+    //----------
+    // finalization
+
+    h2 ^= len;
+
+    h1 += h2;
+    h2 += h1;
+
+    h1 = fmix64(h1);
+    h2 = fmix64(h2);
+
+    h1 += h2;
+
+    return h1;
+}
+
+
+// CRC32 hash using the SSE4.2 instruction
+u64 GetCRC32(const u8 *src, int len, u32 samples)
+{
+#if _M_SSE >= 0x402
+    u64 h = len;
+    u32 Step = (len / 8);
+    const u64 *data = (const u64 *)src;
+    const u64 *end = data + Step;
+    if(samples == 0) samples = max(Step, 1u);
+    Step = Step / samples;
+    if(Step < 1) Step = 1;
+    while(data < end)
+    {
+        h = _mm_crc32_u64(h, data[0]);
+        data += Step;
+    }
+
+    const u8 *data2 = (const u8*)end;
+    return _mm_crc32_u64(h, u64(data2[0]));
+#else
+    return 0;
+#endif
+}
+
+
+/* 
+ * NOTE: This hash function is used for custom texture loading/dumping, so
+ * it should not be changed, which would require all custom textures to be
+ * recalculated for their new hash values. If the hashing function is
+ * changed, make sure this one is still used when the legacy parameter is
+ * true.
+ */
+u64 GetHashHiresTexture(const u8 *src, int len, u32 samples)
+{
+    const u64 m = 0xc6a4a7935bd1e995;
+    u64 h = len * m;
+    const int r = 47;
+    u32 Step = (len / 8);
+    const u64 *data = (const u64 *)src;
+    const u64 *end = data + Step;
+    if(samples == 0) samples = max(Step, 1u);
+    Step = Step / samples;
+    if(Step < 1) Step = 1;
+    while(data < end)
+    {
+        u64 k = data[0];
+        data+=Step;
+        k *= m;
+        k ^= k >> r; 
+        k *= m;
+        h ^= k;
+        h *= m;
+    }
+
+    const u8 * data2 = (const u8*)end;
+
+    switch(len & 7)
+    {
+    case 7: h ^= u64(data2[6]) << 48;
+    case 6: h ^= u64(data2[5]) << 40;
+    case 5: h ^= u64(data2[4]) << 32;
+    case 4: h ^= u64(data2[3]) << 24;
+    case 3: h ^= u64(data2[2]) << 16;
+    case 2: h ^= u64(data2[1]) << 8;
+    case 1: h ^= u64(data2[0]);
+            h *= m;
+    };
+ 
+    h ^= h >> r;
+    h *= m;
+    h ^= h >> r;
+
+    return h;
+} 
+#else
+// CRC32 hash using the SSE4.2 instruction
+u64 GetCRC32(const u8 *src, int len, u32 samples)
+{
+#if _M_SSE >= 0x402
+    u32 h = len;
+    u32 Step = (len/4);
+    const u32 *data = (const u32 *)src;
+    const u32 *end = data + Step;
+    if(samples == 0) samples = max(Step, 1u);
+    Step  = Step / samples;
+    if(Step < 1) Step = 1;
+    while(data < end)
+    {
+        h = _mm_crc32_u32(h, data[0]);
+        data += Step;
+    }
+
+    const u8 *data2 = (const u8*)end;
+    return (u64)_mm_crc32_u32(h, u32(data2[0]));
+#else
+    return 0;
+#endif
+}
+
+//-----------------------------------------------------------------------------
+// Block read - if your platform needs to do endian-swapping or can only
+// handle aligned reads, do the conversion here
+
+inline u32 getblock(const u32 * p, int i)
+{
+    return p[i];
+}
+
+//----------
+// Finalization mix - force all bits of a hash block to avalanche
+
+// avalanches all bits to within 0.25% bias
+
+inline u32 fmix32(u32 h)
+{
+    h ^= h >> 16;
+    h *= 0x85ebca6b;
+    h ^= h >> 13;
+    h *= 0xc2b2ae35;
+    h ^= h >> 16;
+
+    return h;
+}
+
+inline void bmix32(u32 & h1, u32 & h2, u32 & k1, u32 & k2, u32 & c1, u32 & c2)
+{
+    k1 *= c1; 
+    k1  = _rotl(k1,11); 
+    k1 *= c2;
+    h1 ^= k1;
+    h1 += h2;
+
+    h2 = _rotl(h2,17);
+
+    k2 *= c2; 
+    k2  = _rotl(k2,11);
+    k2 *= c1;
+    h2 ^= k2;
+    h2 += h1;
+
+    h1 = h1*3+0x52dce729;
+    h2 = h2*3+0x38495ab5;
+
+    c1 = c1*5+0x7b7d159c;
+    c2 = c2*5+0x6bce6396;
+}
+
+//----------
+
+u64 GetMurmurHash3(const u8* src, int len, u32 samples)
+{
+    const u8 * data = (const u8*)src;
+    u32 out[2];
+    const int nblocks = len / 8;
+    u32 Step = (len / 4);
+    if(samples == 0) samples = max(Step, 1u);
+    Step = Step / samples;
+    if(Step < 1) Step = 1;
+
+    u32 h1 = 0x8de1c3ac;
+    u32 h2 = 0xbab98226;
+
+    u32 c1 = 0x95543787;
+    u32 c2 = 0x2ad7eb25;
+
+    //----------
+    // body
+
+    const u32 * blocks = (const u32 *)(data + nblocks*8);
+
+    for(int i = -nblocks; i < 0; i+=Step)
+    {
+        u32 k1 = getblock(blocks,i*2+0);
+        u32 k2 = getblock(blocks,i*2+1);
+
+        bmix32(h1,h2,k1,k2,c1,c2);
+    }
+
+    //----------
+    // tail
+    
+    const u8 * tail = (const u8*)(data + nblocks*8);
+
+    u32 k1 = 0;
+    u32 k2 = 0;
+
+    switch(len & 7)
+    {
+    case 7: k2 ^= tail[6] << 16;
+    case 6: k2 ^= tail[5] << 8;
+    case 5: k2 ^= tail[4] << 0;
+    case 4: k1 ^= tail[3] << 24;
+    case 3: k1 ^= tail[2] << 16;
+    case 2: k1 ^= tail[1] << 8;
+    case 1: k1 ^= tail[0] << 0;
+            bmix32(h1,h2,k1,k2,c1,c2);
+    };
+
+    //----------
+    // finalization
+
+    h2 ^= len;
+
+    h1 += h2;
+    h2 += h1;
+
+    h1 = fmix32(h1);
+    h2 = fmix32(h2);
+
+    h1 += h2;
+    h2 += h1;
+
+    out[0] = h1;
+    out[1] = h2;
+    
+    return *((u64 *)&out);
+}
+
+/*
+ * FIXME: The old 32-bit version of this hash made different hashes than the
+ * 64-bit version. Until someone can make a new version of the 32-bit one that
+ * makes identical hashes, this is just a c/p of the 64-bit one.
+ */
+u64 GetHashHiresTexture(const u8 *src, int len, u32 samples)
+{
+    const u64 m = 0xc6a4a7935bd1e995ULL;
+    u64 h = len * m;
+    const int r = 47;
+    u32 Step = (len / 8);
+    const u64 *data = (const u64 *)src;
+    const u64 *end = data + Step;
+    if(samples == 0) samples = max(Step, 1u);
+    Step = Step / samples;
+    if(Step < 1) Step = 1;
+    while(data < end)
+    {
+        u64 k = data[0];
+        data+=Step;
+        k *= m; 
+        k ^= k >> r; 
+        k *= m;
+        h ^= k;
+        h *= m; 
+    }
+
+    const u8 * data2 = (const u8*)end;
+
+    switch(len & 7)
+    {
+    case 7: h ^= u64(data2[6]) << 48;
+    case 6: h ^= u64(data2[5]) << 40;
+    case 5: h ^= u64(data2[4]) << 32;
+    case 4: h ^= u64(data2[3]) << 24;
+    case 3: h ^= u64(data2[2]) << 16;
+    case 2: h ^= u64(data2[1]) << 8;
+    case 1: h ^= u64(data2[0]);
+            h *= m;
+    };
+ 
+    h ^= h >> r;
+    h *= m;
+    h ^= h >> r;
+
+    return h;
+}
+#endif
+
+u64 GetHash64(const u8 *src, int len, u32 samples)
+{
+    return ptrHashFunction(src, len, samples);
+}
+
+// sets the hash function used for the texture cache
+void SetHash64Function(bool useHiresTextures)
+{
+    if (useHiresTextures)
+    {
+        ptrHashFunction = &GetHashHiresTexture;
+    }
+#if _M_SSE >= 0x402
+    else if (cpu_info.bSSE4_2 && !useHiresTextures) // sse crc32 version
+    {
+        ptrHashFunction = &GetCRC32;
+    }
+#endif
+    else
+    {
+        ptrHashFunction = &GetMurmurHash3;
+    }
+}
+
+
+