Quote from: catfish on June 30, 2011, 11:59:19 PM

OK, this would be better in the mining hardware forum, but I'm very new to this so only allowed to post here.

Back before GPUs had APIs to run SIMD effectively for embarrassingly-parallel algorithms, supercomputers used 'vector processors' and Apple (along with the PowerPC consortium) had their own little version of this - Altivec.

On the G4 and G5 series of PowerPC CPUs, used before Apple caved in and switched to Intel CPUs, each chip had a special vector processing unit called Altivec. The key difference between this and the MMX/SSE instructions that Intel then developed was one instruction called 'vector permute'. I won't go into the details of processor architecture but for certain algorithms - especially those amenable to parallelisation - the Altivec units in the PowerPC chips could run a lot faster than Intel's otherwise *massively* superior CPUs.

Apple wasn't willing to pay for proper R&D, so the G5 never became competitive as a *general purpose* CPU, and Apple then got into bed with Intel, who most certainly *did* pay for R&D.

However, again, before the GPU revolution, similar distributed-computing efforts, when optimised for Altivec, made Apple look rather good. The Seti@Home project had a leaderboard for 'recent average credit' - which effectively meant 'who has the fastest box right now' - and I managed to get to number 1 in the WORLD for a while with my 'last of the PowerMacs' - the liquid-cooled Quad G5 monster Mac. It was insane.

So... would any of these old PowerMacs be reasonably useful for bitcoin mining? My gut feeling says no, since my Quad G5 (still sitting here...) had a special cable because it needed a 2 kW power supply or something similarly idiotic. If power was free, and you need to heat your house, it may make sense... Wink

Hello catfish,

I´m still using a PowerBook G4 laptop from Apple and are also interested how well the Altivec unit will perform. Currently I´m translating the 4way SSE code into Altivec code. My very first version is already working with jgarzik´s cpuminer:

My sha256_altivec_4way.c file:

Code:

// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2011 Gilles Risch
// Distributed under the MIT/X11 software license, see the accompanying
// file license.txt or http://www.opensource.org/licenses/mit-license.php.

// 4-way 128-bit Altivec SHA-256,
// based on tcatm's 4-way 128-bit SSE2 SHA-256
//

#include "cpuminer-config.h"
#include "miner.h"

#ifdef WANT_ALTIVEC_4WAY

#include
#include

//#include
#include
#include

#define NPAR 32

static void DoubleBlockSHA256(const void* pin, void* pout, const void* pinit, unsigned int hash[8][NPAR], const void* init2);

static const unsigned int sha256_consts[] = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, /* 0 */
0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, /* 8 */
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, /* 16 */
0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, /* 24 */
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, /* 32 */
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, /* 40 */
0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, /* 48 */
0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, /* 56 */
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};

static inline vector unsigned int Ch(const vector unsigned int b, const vector unsigned int c, const vector unsigned int d) {
return vec_sel(d,c,b);
}

static inline vector unsigned int Maj(const vector unsigned int b, const vector unsigned int c, const vector unsigned int d) {
return vec_sel(b,c, vec_xor(b,d));
}

/* RotateRight(x, n) := RotateLeft(x, 32-n) */
/* SHA256 Functions */
#define BIGSIGMA0_256(x) (vec_xor(vec_xor(vec_rl((x), (vector unsigned int)(32-2)),vec_rl((x), (vector unsigned int)(32-13))),vec_rl((x), (vector unsigned int)(32-22))))
#define BIGSIGMA1_256(x) (vec_xor(vec_xor(vec_rl((x), (vector unsigned int)(32-6)),vec_rl((x), (vector unsigned int)(32-11))),vec_rl((x), (vector unsigned int)(32-25))))

#define SIGMA0_256(x) (vec_xor(vec_xor(vec_rl((x), (vector unsigned int)(32- 7)),vec_rl((x), (vector unsigned int)(32-18))), vec_sr((x), (vector unsigned int)(3 ))))
#define SIGMA1_256(x) (vec_xor(vec_xor(vec_rl((x), (vector unsigned int)(32-17)),vec_rl((x), (vector unsigned int)(32-19))), vec_sr((x), (vector unsigned int)(10))))

#define add4(x0, x1, x2, x3) vec_add(vec_add(x0, x1),vec_add( x2,x3))
#define add5(x0, x1, x2, x3, x4) vec_add(add4(x0, x1, x2, x3), x4)

#define SHA256ROUND(a, b, c, d, e, f, g, h, i, w) \
T1 = add5(h, BIGSIGMA1_256(e), Ch(e, f, g), (vector unsigned int)(sha256_consts[i],sha256_consts[i],sha256_consts[i],sha256_consts[i]), w); \
d = vec_add(d, T1); \
h = vec_add(T1, vec_add(BIGSIGMA0_256(a), Maj(a, b, c)));

static const unsigned int pSHA256InitState[8] =
{0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};

unsigned int scanhash_altivec_4way(int thr_id, const unsigned char *pmidstate,
unsigned char *pdata,
unsigned char *phash1, unsigned char *phash,
const unsigned char *ptarget,
uint32_t max_nonce, unsigned long *nHashesDone)
{
unsigned int *nNonce_p = (unsigned int*)(pdata + 12);
unsigned int nonce = 0;

work_restart[thr_id].restart = 0;

for (;;)
{
unsigned int thash[9][NPAR] __attribute__((aligned(128)));
int j, ic;

*nNonce_p = nonce;

DoubleBlockSHA256(pdata, phash1, pmidstate, thash, pSHA256InitState);

for (j = 0; j < NPAR; j++)
{
if (unlikely(thash[7][j] == 0))
{
int i;

for (i = 0; i < 32/4; i++)
((unsigned int*)phash)[i] = thash[i][j];

if (fulltest(phash, ptarget)) {
*nHashesDone = nonce;
*nNonce_p = nonce + j;
return nonce + j;
}
}
}

if ((nonce >= max_nonce) || work_restart[thr_id].restart)
{
*nHashesDone = nonce;
return -1;
}

nonce += NPAR;
}
}

static void DoubleBlockSHA256(const void* pin, void* pad, const void *pre, unsigned int thash[9][NPAR], const void *init)
{
unsigned int* In = (unsigned int*)pin;
unsigned int* Pad = (unsigned int*)pad;
unsigned int* hPre = (unsigned int*)pre;
unsigned int* hInit = (unsigned int*)init;
unsigned int /* i, j, */ k;

/* vectors used in calculation */
vector unsigned int w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;
vector unsigned int T1;
vector unsigned int a, b, c, d, e, f, g, h;
vector unsigned int nonce, preNonce;

/* nonce offset for vector */
vector unsigned int offset = (vector unsigned int)(0, 1, 2, 3);

preNonce = vec_add((vector unsigned int)(In[3],In[3],In[3],In[3]), offset);

for(k = 0; k {
w0 = (vector unsigned int)(In[0],In[0],In[0],In[0]);
w1 = (vector unsigned int)(In[1],In[1],In[1],In[1]);
w2 = (vector unsigned int)(In[2],In[2],In[2],In[2]);
//w3 = (vector unsigned int)(In[3],In[3],In[3],In[3]); nonce will be later hacked into the hash
w4 = (vector unsigned int)(In[4],In[4],In[4],In[4]);
w5 = (vector unsigned int)(In[5],In[5],In[5],In[5]);
w6 = (vector unsigned int)(In[6],In[6],In[6],In[6]);
w7 = (vector unsigned int)(In[7],In[7],In[7],In[7]);
w8 = (vector unsigned int)(In[8],In[8],In[8],In[8]);
w9 = (vector unsigned int)(In[9],In[9],In[9],In[9]);
w10 = (vector unsigned int)(In[10],In[10],In[10],In[10]);
w11 = (vector unsigned int)(In[11],In[11],In[11],In[11]);
w12 = (vector unsigned int)(In[12],In[12],In[12],In[12]);
w13 = (vector unsigned int)(In[13],In[13],In[13],In[13]);
w14 = (vector unsigned int)(In[14],In[14],In[14],In[14]);
w15 = (vector unsigned int)(In[15],In[15],In[15],In[15]);

/* hack nonce into lowest byte of w3 */
nonce = vec_add(preNonce, (vector unsigned int)(k,k,k,k));

w3 = nonce;
//printf ("W3: %08vlx\n", w3);

a = (vector unsigned int)(hPre[0],hPre[0],hPre[0],hPre[0]);
b = (vector unsigned int)(hPre[1],hPre[1],hPre[1],hPre[1]);
c = (vector unsigned int)(hPre[2],hPre[2],hPre[2],hPre[2]);
d = (vector unsigned int)(hPre[3],hPre[3],hPre[3],hPre[3]);
e = (vector unsigned int)(hPre[4],hPre[4],hPre[4],hPre[4]);
f = (vector unsigned int)(hPre[5],hPre[5],hPre[5],hPre[5]);
g = (vector unsigned int)(hPre[6],hPre[6],hPre[6],hPre[6]);
h = (vector unsigned int)(hPre[7],hPre[7],hPre[7],hPre[7]);

SHA256ROUND(a, b, c, d, e, f, g, h, 0, w0);
SHA256ROUND(h, a, b, c, d, e, f, g, 1, w1);
SHA256ROUND(g, h, a, b, c, d, e, f, 2, w2);
SHA256ROUND(f, g, h, a, b, c, d, e, 3, w3);
SHA256ROUND(e, f, g, h, a, b, c, d, 4, w4);
SHA256ROUND(d, e, f, g, h, a, b, c, 5, w5);
SHA256ROUND(c, d, e, f, g, h, a, b, 6, w6);
SHA256ROUND(b, c, d, e, f, g, h, a, 7, w7);
SHA256ROUND(a, b, c, d, e, f, g, h, 8, w8);
SHA256ROUND(h, a, b, c, d, e, f, g, 9, w9);
SHA256ROUND(g, h, a, b, c, d, e, f, 10, w10);
SHA256ROUND(f, g, h, a, b, c, d, e, 11, w11);
SHA256ROUND(e, f, g, h, a, b, c, d, 12, w12);
SHA256ROUND(d, e, f, g, h, a, b, c, 13, w13);
SHA256ROUND(c, d, e, f, g, h, a, b, 14, w14);
SHA256ROUND(b, c, d, e, f, g, h, a, 15, w15);

w0 = add4(SIGMA1_256(w14), w9, SIGMA0_256(w1), w0);
SHA256ROUND(a, b, c, d, e, f, g, h, 16, w0);
w1 = add4(SIGMA1_256(w15), w10, SIGMA0_256(w2), w1);
SHA256ROUND(h, a, b, c, d, e, f, g, 17, w1);
w2 = add4(SIGMA1_256(w0), w11, SIGMA0_256(w3), w2);
SHA256ROUND(g, h, a, b, c, d, e, f, 18, w2);
w3 = add4(SIGMA1_256(w1), w12, SIGMA0_256(w4), w3);
SHA256ROUND(f, g, h, a, b, c, d, e, 19, w3);
w4 = add4(SIGMA1_256(w2), w13, SIGMA0_256(w5), w4);
SHA256ROUND(e, f, g, h, a, b, c, d, 20, w4);
w5 = add4(SIGMA1_256(w3), w14, SIGMA0_256(w6), w5);
SHA256ROUND(d, e, f, g, h, a, b, c, 21, w5);
w6 = add4(SIGMA1_256(w4), w15, SIGMA0_256(w7), w6);
SHA256ROUND(c, d, e, f, g, h, a, b, 22, w6);
w7 = add4(SIGMA1_256(w5), w0, SIGMA0_256(w8), w7);
SHA256ROUND(b, c, d, e, f, g, h, a, 23, w7);
w8 = add4(SIGMA1_256(w6), w1, SIGMA0_256(w9), w8);
SHA256ROUND(a, b, c, d, e, f, g, h, 24, w8);
w9 = add4(SIGMA1_256(w7), w2, SIGMA0_256(w10), w9);
SHA256ROUND(h, a, b, c, d, e, f, g, 25, w9);
w10 = add4(SIGMA1_256(w8), w3, SIGMA0_256(w11), w10);
SHA256ROUND(g, h, a, b, c, d, e, f, 26, w10);
w11 = add4(SIGMA1_256(w9), w4, SIGMA0_256(w12), w11);
SHA256ROUND(f, g, h, a, b, c, d, e, 27, w11);
w12 = add4(SIGMA1_256(w10), w5, SIGMA0_256(w13), w12);
SHA256ROUND(e, f, g, h, a, b, c, d, 28, w12);
w13 = add4(SIGMA1_256(w11), w6, SIGMA0_256(w14), w13);
SHA256ROUND(d, e, f, g, h, a, b, c, 29, w13);
w14 = add4(SIGMA1_256(w12), w7, SIGMA0_256(w15), w14);
SHA256ROUND(c, d, e, f, g, h, a, b, 30, w14);
w15 = add4(SIGMA1_256(w13), w8, SIGMA0_256(w0), w15);
SHA256ROUND(b, c, d, e, f, g, h, a, 31, w15);

w0 = add4(SIGMA1_256(w14), w9, SIGMA0_256(w1), w0);
SHA256ROUND(a, b, c, d, e, f, g, h, 32, w0);
w1 = add4(SIGMA1_256(w15), w10, SIGMA0_256(w2), w1);
SHA256ROUND(h, a, b, c, d, e, f, g, 33, w1);
w2 = add4(SIGMA1_256(w0), w11, SIGMA0_256(w3), w2);
SHA256ROUND(g, h, a, b, c, d, e, f, 34, w2);
w3 = add4(SIGMA1_256(w1), w12, SIGMA0_256(w4), w3);
SHA256ROUND(f, g, h, a, b, c, d, e, 35, w3);
w4 = add4(SIGMA1_256(w2), w13, SIGMA0_256(w5), w4);
SHA256ROUND(e, f, g, h, a, b, c, d, 36, w4);
w5 = add4(SIGMA1_256(w3), w14, SIGMA0_256(w6), w5);
SHA256ROUND(d, e, f, g, h, a, b, c, 37, w5);
w6 = add4(SIGMA1_256(w4), w15, SIGMA0_256(w7), w6);
SHA256ROUND(c, d, e, f, g, h, a, b, 38, w6);
w7 = add4(SIGMA1_256(w5), w0, SIGMA0_256(w8), w7);
SHA256ROUND(b, c, d, e, f, g, h, a, 39, w7);
w8 = add4(SIGMA1_256(w6), w1, SIGMA0_256(w9), w8);
SHA256ROUND(a, b, c, d, e, f, g, h, 40, w8);
w9 = add4(SIGMA1_256(w7), w2, SIGMA0_256(w10), w9);
SHA256ROUND(h, a, b, c, d, e, f, g, 41, w9);
w10 = add4(SIGMA1_256(w8), w3, SIGMA0_256(w11), w10);
SHA256ROUND(g, h, a, b, c, d, e, f, 42, w10);
w11 = add4(SIGMA1_256(w9), w4, SIGMA0_256(w12), w11);
SHA256ROUND(f, g, h, a, b, c, d, e, 43, w11);
w12 = add4(SIGMA1_256(w10), w5, SIGMA0_256(w13), w12);
SHA256ROUND(e, f, g, h, a, b, c, d, 44, w12);
w13 = add4(SIGMA1_256(w11), w6, SIGMA0_256(w14), w13);
SHA256ROUND(d, e, f, g, h, a, b, c, 45, w13);
w14 = add4(SIGMA1_256(w12), w7, SIGMA0_256(w15), w14);
SHA256ROUND(c, d, e, f, g, h, a, b, 46, w14);
w15 = add4(SIGMA1_256(w13), w8, SIGMA0_256(w0), w15);
SHA256ROUND(b, c, d, e, f, g, h, a, 47, w15);

w0 = add4(SIGMA1_256(w14), w9, SIGMA0_256(w1), w0);
SHA256ROUND(a, b, c, d, e, f, g, h, 48, w0);
w1 = add4(SIGMA1_256(w15), w10, SIGMA0_256(w2), w1);
SHA256ROUND(h, a, b, c, d, e, f, g, 49, w1);
w2 = add4(SIGMA1_256(w0), w11, SIGMA0_256(w3), w2);
SHA256ROUND(g, h, a, b, c, d, e, f, 50, w2);
w3 = add4(SIGMA1_256(w1), w12, SIGMA0_256(w4), w3);
SHA256ROUND(f, g, h, a, b, c, d, e, 51, w3);
w4 = add4(SIGMA1_256(w2), w13, SIGMA0_256(w5), w4);
SHA256ROUND(e, f, g, h, a, b, c, d, 52, w4);
w5 = add4(SIGMA1_256(w3), w14, SIGMA0_256(w6), w5);
SHA256ROUND(d, e, f, g, h, a, b, c, 53, w5);
w6 = add4(SIGMA1_256(w4), w15, SIGMA0_256(w7), w6);
SHA256ROUND(c, d, e, f, g, h, a, b, 54, w6);
w7 = add4(SIGMA1_256(w5), w0, SIGMA0_256(w8), w7);
SHA256ROUND(b, c, d, e, f, g, h, a, 55, w7);
w8 = add4(SIGMA1_256(w6), w1, SIGMA0_256(w9), w8);
SHA256ROUND(a, b, c, d, e, f, g, h, 56, w8);
w9 = add4(SIGMA1_256(w7), w2, SIGMA0_256(w10), w9);
SHA256ROUND(h, a, b, c, d, e, f, g, 57, w9);
w10 = add4(SIGMA1_256(w8), w3, SIGMA0_256(w11), w10);
SHA256ROUND(g, h, a, b, c, d, e, f, 58, w10);
w11 = add4(SIGMA1_256(w9), w4, SIGMA0_256(w12), w11);
SHA256ROUND(f, g, h, a, b, c, d, e, 59, w11);
w12 = add4(SIGMA1_256(w10), w5, SIGMA0_256(w13), w12);
SHA256ROUND(e, f, g, h, a, b, c, d, 60, w12);
w13 = add4(SIGMA1_256(w11), w6, SIGMA0_256(w14), w13);
SHA256ROUND(d, e, f, g, h, a, b, c, 61, w13);
w14 = add4(SIGMA1_256(w12), w7, SIGMA0_256(w15), w14);
SHA256ROUND(c, d, e, f, g, h, a, b, 62, w14);
w15 = add4(SIGMA1_256(w13), w8, SIGMA0_256(w0), w15);
SHA256ROUND(b, c, d, e, f, g, h, a, 63, w15);

#define store_load(x, i, dest) \
T1 = (vector unsigned int)((hPre)[i],(hPre)[i],(hPre)[i],(hPre)[i]); \
dest = vec_add(T1, x);

store_load(a, 0, w0);
store_load(b, 1, w1);
store_load(c, 2, w2);
store_load(d, 3, w3);
store_load(e, 4, w4);
store_load(f, 5, w5);
store_load(g, 6, w6);
store_load(h, 7, w7);

/* end of first SHA256 round */

w8 = (vector unsigned int)(Pad[8],Pad[8],Pad[8],Pad[8]);
w9 = (vector unsigned int)(Pad[9],Pad[9],Pad[9],Pad[9]);
w10 = (vector unsigned int)(Pad[10],Pad[10],Pad[10],Pad[10]);
w11 = (vector unsigned int)(Pad[11],Pad[11],Pad[11],Pad[11]);
w12 = (vector unsigned int)(Pad[12],Pad[12],Pad[12],Pad[12]);
w13 = (vector unsigned int)(Pad[13],Pad[13],Pad[13],Pad[13]);
w14 = (vector unsigned int)(Pad[14],Pad[14],Pad[14],Pad[14]);
w15 = (vector unsigned int)(Pad[15],Pad[15],Pad[15],Pad[15]);

a = (vector unsigned int)(hInit[0],hInit[0],hInit[0],hInit[0]);
b = (vector unsigned int)(hInit[1],hInit[1],hInit[1],hInit[1]);
c = (vector unsigned int)(hInit[2],hInit[2],hInit[2],hInit[2]);
d = (vector unsigned int)(hInit[3],hInit[3],hInit[3],hInit[3]);
e = (vector unsigned int)(hInit[4],hInit[4],hInit[4],hInit[4]);
f = (vector unsigned int)(hInit[5],hInit[5],hInit[5],hInit[5]);
g = (vector unsigned int)(hInit[6],hInit[6],hInit[6],hInit[6]);
h = (vector unsigned int)(hInit[7],hInit[7],hInit[7],hInit[7]);

SHA256ROUND(a, b, c, d, e, f, g, h, 0, w0);
SHA256ROUND(h, a, b, c, d, e, f, g, 1, w1);
SHA256ROUND(g, h, a, b, c, d, e, f, 2, w2);
SHA256ROUND(f, g, h, a, b, c, d, e, 3, w3);
SHA256ROUND(e, f, g, h, a, b, c, d, 4, w4);
SHA256ROUND(d, e, f, g, h, a, b, c, 5, w5);
SHA256ROUND(c, d, e, f, g, h, a, b, 6, w6);
SHA256ROUND(b, c, d, e, f, g, h, a, 7, w7);
SHA256ROUND(a, b, c, d, e, f, g, h, 8, w8);
SHA256ROUND(h, a, b, c, d, e, f, g, 9, w9);
SHA256ROUND(g, h, a, b, c, d, e, f, 10, w10);
SHA256ROUND(f, g, h, a, b, c, d, e, 11, w11);
SHA256ROUND(e, f, g, h, a, b, c, d, 12, w12);
SHA256ROUND(d, e, f, g, h, a, b, c, 13, w13);
SHA256ROUND(c, d, e, f, g, h, a, b, 14, w14);
SHA256ROUND(b, c, d, e, f, g, h, a, 15, w15);

w0 = add4(SIGMA1_256(w14), w9, SIGMA0_256(w1), w0);
SHA256ROUND(a, b, c, d, e, f, g, h, 16, w0);
w1 = add4(SIGMA1_256(w15), w10, SIGMA0_256(w2), w1);
SHA256ROUND(h, a, b, c, d, e, f, g, 17, w1);
w2 = add4(SIGMA1_256(w0), w11, SIGMA0_256(w3), w2);
SHA256ROUND(g, h, a, b, c, d, e, f, 18, w2);
w3 = add4(SIGMA1_256(w1), w12, SIGMA0_256(w4), w3);
SHA256ROUND(f, g, h, a, b, c, d, e, 19, w3);
w4 = add4(SIGMA1_256(w2), w13, SIGMA0_256(w5), w4);
SHA256ROUND(e, f, g, h, a, b, c, d, 20, w4);
w5 = add4(SIGMA1_256(w3), w14, SIGMA0_256(w6), w5);
SHA256ROUND(d, e, f, g, h, a, b, c, 21, w5);
w6 = add4(SIGMA1_256(w4), w15, SIGMA0_256(w7), w6);
SHA256ROUND(c, d, e, f, g, h, a, b, 22, w6);
w7 = add4(SIGMA1_256(w5), w0, SIGMA0_256(w8), w7);
SHA256ROUND(b, c, d, e, f, g, h, a, 23, w7);
w8 = add4(SIGMA1_256(w6), w1, SIGMA0_256(w9), w8);
SHA256ROUND(a, b, c, d, e, f, g, h, 24, w8);
w9 = add4(SIGMA1_256(w7), w2, SIGMA0_256(w10), w9);
SHA256ROUND(h, a, b, c, d, e, f, g, 25, w9);
w10 = add4(SIGMA1_256(w8), w3, SIGMA0_256(w11), w10);
SHA256ROUND(g, h, a, b, c, d, e, f, 26, w10);
w11 = add4(SIGMA1_256(w9), w4, SIGMA0_256(w12), w11);
SHA256ROUND(f, g, h, a, b, c, d, e, 27, w11);
w12 = add4(SIGMA1_256(w10), w5, SIGMA0_256(w13), w12);
SHA256ROUND(e, f, g, h, a, b, c, d, 28, w12);
w13 = add4(SIGMA1_256(w11), w6, SIGMA0_256(w14), w13);
SHA256ROUND(d, e, f, g, h, a, b, c, 29, w13);
w14 = add4(SIGMA1_256(w12), w7, SIGMA0_256(w15), w14);
SHA256ROUND(c, d, e, f, g, h, a, b, 30, w14);
w15 = add4(SIGMA1_256(w13), w8, SIGMA0_256(w0), w15);
SHA256ROUND(b, c, d, e, f, g, h, a, 31, w15);

w0 = add4(SIGMA1_256(w14), w9, SIGMA0_256(w1), w0);
SHA256ROUND(a, b, c, d, e, f, g, h, 32, w0);
w1 = add4(SIGMA1_256(w15), w10, SIGMA0_256(w2), w1);
SHA256ROUND(h, a, b, c, d, e, f, g, 33, w1);
w2 = add4(SIGMA1_256(w0), w11, SIGMA0_256(w3), w2);
SHA256ROUND(g, h, a, b, c, d, e, f, 34, w2);
w3 = add4(SIGMA1_256(w1), w12, SIGMA0_256(w4), w3);
SHA256ROUND(f, g, h, a, b, c, d, e, 35, w3);
w4 = add4(SIGMA1_256(w2), w13, SIGMA0_256(w5), w4);
SHA256ROUND(e, f, g, h, a, b, c, d, 36, w4);
w5 = add4(SIGMA1_256(w3), w14, SIGMA0_256(w6), w5);
SHA256ROUND(d, e, f, g, h, a, b, c, 37, w5);
w6 = add4(SIGMA1_256(w4), w15, SIGMA0_256(w7), w6);
SHA256ROUND(c, d, e, f, g, h, a, b, 38, w6);
w7 = add4(SIGMA1_256(w5), w0, SIGMA0_256(w8), w7);
SHA256ROUND(b, c, d, e, f, g, h, a, 39, w7);
w8 = add4(SIGMA1_256(w6), w1, SIGMA0_256(w9), w8);
SHA256ROUND(a, b, c, d, e, f, g, h, 40, w8);
w9 = add4(SIGMA1_256(w7), w2, SIGMA0_256(w10), w9);
SHA256ROUND(h, a, b, c, d, e, f, g, 41, w9);
w10 = add4(SIGMA1_256(w8), w3, SIGMA0_256(w11), w10);
SHA256ROUND(g, h, a, b, c, d, e, f, 42, w10);
w11 = add4(SIGMA1_256(w9), w4, SIGMA0_256(w12), w11);
SHA256ROUND(f, g, h, a, b, c, d, e, 43, w11);
w12 = add4(SIGMA1_256(w10), w5, SIGMA0_256(w13), w12);
SHA256ROUND(e, f, g, h, a, b, c, d, 44, w12);
w13 = add4(SIGMA1_256(w11), w6, SIGMA0_256(w14), w13);
SHA256ROUND(d, e, f, g, h, a, b, c, 45, w13);
w14 = add4(SIGMA1_256(w12), w7, SIGMA0_256(w15), w14);
SHA256ROUND(c, d, e, f, g, h, a, b, 46, w14);
w15 = add4(SIGMA1_256(w13), w8, SIGMA0_256(w0), w15);
SHA256ROUND(b, c, d, e, f, g, h, a, 47, w15);

w0 = add4(SIGMA1_256(w14), w9, SIGMA0_256(w1), w0);
SHA256ROUND(a, b, c, d, e, f, g, h, 48, w0);
w1 = add4(SIGMA1_256(w15), w10, SIGMA0_256(w2), w1);
SHA256ROUND(h, a, b, c, d, e, f, g, 49, w1);
w2 = add4(SIGMA1_256(w0), w11, SIGMA0_256(w3), w2);
SHA256ROUND(g, h, a, b, c, d, e, f, 50, w2);
w3 = add4(SIGMA1_256(w1), w12, SIGMA0_256(w4), w3);
SHA256ROUND(f, g, h, a, b, c, d, e, 51, w3);
w4 = add4(SIGMA1_256(w2), w13, SIGMA0_256(w5), w4);
SHA256ROUND(e, f, g, h, a, b, c, d, 52, w4);
w5 = add4(SIGMA1_256(w3), w14, SIGMA0_256(w6), w5);
SHA256ROUND(d, e, f, g, h, a, b, c, 53, w5);
w6 = add4(SIGMA1_256(w4), w15, SIGMA0_256(w7), w6);
SHA256ROUND(c, d, e, f, g, h, a, b, 54, w6);
w7 = add4(SIGMA1_256(w5), w0, SIGMA0_256(w8), w7);
SHA256ROUND(b, c, d, e, f, g, h, a, 55, w7);
w8 = add4(SIGMA1_256(w6), w1, SIGMA0_256(w9), w8);
SHA256ROUND(a, b, c, d, e, f, g, h, 56, w8);
w9 = add4(SIGMA1_256(w7), w2, SIGMA0_256(w10), w9);
SHA256ROUND(h, a, b, c, d, e, f, g, 57, w9);
w10 = add4(SIGMA1_256(w8), w3, SIGMA0_256(w11), w10);
SHA256ROUND(g, h, a, b, c, d, e, f, 58, w10);
w11 = add4(SIGMA1_256(w9), w4, SIGMA0_256(w12), w11);
SHA256ROUND(f, g, h, a, b, c, d, e, 59, w11);
w12 = add4(SIGMA1_256(w10), w5, SIGMA0_256(w13), w12);
SHA256ROUND(e, f, g, h, a, b, c, d, 60, w12);

/* Skip last 3-rounds; not necessary for H==0 */
/*#if 0
w13 = add4(SIGMA1_256(w11), w6, SIGMA0_256(w14), w13);
SHA256ROUND(d, e, f, g, h, a, b, c, 61, w13);
w14 = add4(SIGMA1_256(w12), w7, SIGMA0_256(w15), w14);
SHA256ROUND(c, d, e, f, g, h, a, b, 62, w14);
w15 = add4(SIGMA1_256(w13), w8, SIGMA0_256(w0), w15);
SHA256ROUND(b, c, d, e, f, g, h, a, 63, w15);
#endif*/

/* store resulsts directly in thash */
#define store_2(x,i) \
w0 = (vector unsigned int)(hInit[i],hInit[i],hInit[i],hInit[i]); \
vec_st(vec_add(w0, x), 0 ,&thash[i][k]);

store_2(a, 0);
store_2(b, 1);
store_2(c, 2);
store_2(d, 3);
store_2(e, 4);
store_2(f, 5);
store_2(g, 6);
store_2(h, 7);

vec_st(nonce, 0 ,&thash[8][k]);
/* writing the results into the array is time intensive */
/* -> try if it´s faster to compare the results with the target inside this function */
}

}

#endif /* WANT_ALTIVEC_4WAY */

I´ll send the file to the author of the cpuminer. Beside of this file one must also change two functions inside the cpu-miner.c file because the code is for little-endian machines and the PowerPc is big-endian:

Code:

static bool work_decode(const json_t *val, struct work *work) {
if (unlikely(!jobj_binary(val, "midstate",
work->midstate, sizeof (work->midstate)))) {
applog(LOG_ERR, "JSON inval midstate");
goto err_out;
}

if (unlikely(!jobj_binary(val, "data", work->data, sizeof (work->data)))) {
applog(LOG_ERR, "JSON inval data");
goto err_out;
}

if (unlikely(!jobj_binary(val, "hash1", work->hash1, sizeof (work->hash1)))) {
applog(LOG_ERR, "JSON inval hash1");
goto err_out;
}

if (unlikely(!jobj_binary(val, "target", work->target, sizeof (work->target)))) {
applog(LOG_ERR, "JSON inval target");
goto err_out;
}

memset(work->hash, 0, sizeof (work->hash));

#ifdef __BIG_ENDIAN__
int swapcounter = 0;
for (swapcounter = 0; swapcounter < 32; swapcounter++)
(((uint32_t*) (work->data))[swapcounter]) = swab32(((uint32_t*) (work->data))[swapcounter]);
for (swapcounter = 0; swapcounter < 16; swapcounter++)
(((uint32_t*) (work->hash1))[swapcounter]) = swab32(((uint32_t*) (work->hash1))[swapcounter]);
for (swapcounter = 0; swapcounter < 8; swapcounter++)
(((uint32_t*) (work->midstate))[swapcounter]) = swab32(((uint32_t*) (work->midstate))[swapcounter]);
for (swapcounter = 0; swapcounter < 8; swapcounter++)
(((uint32_t*) (work->target))[swapcounter]) = swab32(((uint32_t*) (work->target))[swapcounter]);
#endif

return true;

err_out:
return false;
}

static bool submit_upstream_work(CURL *curl, const struct work *work) {
char *hexstr = NULL;
json_t *val, *res;
char s[345];
bool rc = false;

#ifdef __BIG_ENDIAN__
int swapcounter;
for (swapcounter = 0; swapcounter < 32; swapcounter++)
(((uint32_t*) (work->data))[swapcounter]) = swab32(((uint32_t*) (work->data))[swapcounter]);
#endif

/* build hex string */
hexstr = bin2hex(work->data, sizeof (work->data));
if (unlikely(!hexstr)) {
applog(LOG_ERR, "submit_upstream_work OOM");
goto out;
}

/* build JSON-RPC request */
sprintf(s,
"{\"method\": \"getwork\", \"params\": [ \"%s\" ], \"id\":1}\r\n",
hexstr);

if (opt_debug)
applog(LOG_DEBUG, "DBG: sending RPC call: %s", s);

/* issue JSON-RPC request */
val = json_rpc_call(curl, rpc_url, rpc_userpass, s, false, false);
if (unlikely(!val)) {
applog(LOG_ERR, "submit_upstream_work json_rpc_call failed");
goto out;
}

res = json_object_get(val, "result");

applog(LOG_INFO, "PROOF OF WORK RESULT: %s",
json_is_true(res) ? "true (yay!!!)" : "false (booooo)");

json_decref(val);

rc = true;

out:
free(hexstr);
return rc;
}

These changes could also be useful if you like to use the cpuminer on an ARM cpu.

Regards,
Gilles