From d58490911a1c3245176a44a32ae7774a2a3402f0 Mon Sep 17 00:00:00 2001
From: Tanguy Pruvot <tanguy.pruvot@gmail.com>
Date: Sun, 28 Feb 2016 18:03:12 +0100
Subject: [PATCH] decred: remove some useless double flip

---
 Algo256/decred.cu  |  2 +-
 Algo256/vanilla.cu |  2 +-
 ccminer.cpp        | 35 +++++++++++++++--------------------
 3 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/Algo256/decred.cu b/Algo256/decred.cu
index 5ba4550..770cc38 100644
--- a/Algo256/decred.cu
+++ b/Algo256/decred.cu
@@ -36,7 +36,7 @@ extern "C" void decred_hash(void *output, const void *input)
 
 __constant__ uint32_t _ALIGN(4) d_data[24];
 
-/* 8 adapters max */
+/* 16 adapters max */
 static uint32_t *d_resNonce[MAX_GPUS];
 static uint32_t *h_resNonce[MAX_GPUS];
 
diff --git a/Algo256/vanilla.cu b/Algo256/vanilla.cu
index d35ade4..c1dc40f 100644
--- a/Algo256/vanilla.cu
+++ b/Algo256/vanilla.cu
@@ -32,7 +32,7 @@ extern "C" {
 
 __constant__ uint32_t d_data[16];
 
-/* 8 adapters max */
+/* 16 gpu threads max */
 static uint32_t *d_resNonce[MAX_GPUS];
 static uint32_t *h_resNonce[MAX_GPUS];
 
diff --git a/ccminer.cpp b/ccminer.cpp
index 48aef1f..2b7fd9c 100644
--- a/ccminer.cpp
+++ b/ccminer.cpp
@@ -1324,9 +1324,8 @@ err_out:
 
 static bool stratum_gen_work(struct stratum_ctx *sctx, struct work *work)
 {
-	uint32_t extraheader[32] = { 0 };
 	uchar merkle_root[64] = { 0 };
-	int i, headersize = 0;
+	int i;
 
 	if (!sctx->job.job_id) {
 		// applog(LOG_WARNING, "stratum_gen_work: job not yet retrieved");
@@ -1349,10 +1348,7 @@ static bool stratum_gen_work(struct stratum_ctx *sctx, struct work *work)
 	/* Generate merkle root */
 	switch (opt_algo) {
 		case ALGO_DECRED:
-			// getwork over stratum, getwork merkle + header passed in coinb1
-			memcpy(merkle_root, sctx->job.coinbase, 32);
-			headersize = min((int)sctx->job.coinbase_size - 32, sizeof(extraheader));
-			memcpy(extraheader, &sctx->job.coinbase[32], headersize);
+			// getwork over stratum, no merkle to generate
 			break;
 		case ALGO_HEAVY:
 		case ALGO_MJOLLNIR:
@@ -1374,7 +1370,7 @@ static bool stratum_gen_work(struct stratum_ctx *sctx, struct work *work)
 		memcpy(merkle_root + 32, sctx->job.merkle[i], 32);
 		if (opt_algo == ALGO_HEAVY || opt_algo == ALGO_MJOLLNIR)
 			heavycoin_hash(merkle_root, merkle_root, 64);
-		else if (!headersize)
+		else
 			sha256d(merkle_root, merkle_root, 64);
 	}
 	
@@ -1386,26 +1382,25 @@ static bool stratum_gen_work(struct stratum_ctx *sctx, struct work *work)
 	work->data[0] = le32dec(sctx->job.version);
 	for (i = 0; i < 8; i++)
 		work->data[1 + i] = le32dec((uint32_t *)sctx->job.prevhash + i);
-	for (i = 0; i < 8; i++)
-		work->data[9 + i] = be32dec((uint32_t *)merkle_root + i);
 
 	if (opt_algo == ALGO_DECRED) {
-		for (i = 0; i < 8; i++) // prevhash
+		for (i = 0; i < 8; i++) // reversed prevhash
 			work->data[1 + i] = swab32(work->data[1 + i]);
-		for (i = 0; i < 8; i++) // merkle
-			work->data[9 + i] = swab32(work->data[9 + i]);
-		for (i = 0; i < headersize/4; i++) // header
-			work->data[17 + i] = extraheader[i];
+		// decred header (coinb1) [merkle...nonce]
+		memcpy(&work->data[9], sctx->job.coinbase, 112);
 		// extradata
-		uint32_t* extradata = (uint32_t*) sctx->xnonce1;
-		for (i = 0; i < sctx->xnonce1_size/4; i++)
-			work->data[36 + i] = extradata[i];
-		for (i = 36 + sctx->xnonce1_size/4; i < 45; i++)
-			work->data[i] = 0;
-		work->data[37] = (rand()*4) << 8;
+		if (sctx->xnonce1_size > sizeof(work->data)-(36*4)) {
+			// should never happen...
+			applog(LOG_ERR, "extranonce size overflow!");
+			sctx->xnonce1_size = sizeof(work->data)-(36*4);
+		}
+		memcpy(&work->data[36], sctx->xnonce1, sctx->xnonce1_size);
+		work->data[37] = (rand()*4) << 8; // random work data
 		sctx->job.height = work->data[32];
 		//applog_hex(work->data, 180);
 	} else {
+		for (i = 0; i < 8; i++)
+			work->data[9 + i] = be32dec((uint32_t *)merkle_root + i);
 		work->data[17] = le32dec(sctx->job.ntime);
 		work->data[18] = le32dec(sctx->job.nbits);
 		work->data[20] = 0x80000000;