// Copyright 2013 Dolphin Emulator Project / 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include "common/common_funcs.h" // For rotl
#include "common/hash.h"
#include "common/platform.h"
#if _M_SSE >= 0x402
#include "common/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);
}
#if EMU_ARCH_BITS == 64
//-----------------------------------------------------------------------------
// 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 = std::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 = std::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 = std::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 = std::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 = std::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 = std::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;
}
}
