Fix build.

exp/main.cpp

@@ -19,10 +19,11 @@
  * @date 2014
  * Ethereum client.
  */
+#if ETH_ETHASHCL
 #define __CL_ENABLE_EXCEPTIONS
 #define CL_USE_DEPRECATED_OPENCL_2_0_APIS
 #include "libethash-cl/cl.hpp"
-
+#endif
 #include <functional>
 #include <libdevcore/RangeMask.h>
 #include <libdevcore/Log.h>
@@ -108,6 +109,7 @@ int main()
 #else
 int main()
 {
+#if ETH_ETHASHCL
 	EthashCL ecl;
 	BlockInfo genesis = CanonBlockChain::genesis();
 	genesis.difficulty = 1 << 18;
@@ -118,6 +120,7 @@ int main()
 	cdebug << r.second.mixHash << r.second.nonce;
 	EthashCL::assignResult(r.second, genesis);
 	assert(EthashCPU::verify(genesis));
+#endif
 	return 0;
 }
 #endif

libethcore/BlockInfo.cpp

@@ -75,6 +75,13 @@ h256 const& BlockInfo::hash() const
 	return m_hash;
 }
 
+h256 const& BlockInfo::boundary() const
+{
+	if (!m_boundary)
+		m_boundary = (h256)(u256)((bigint(1) << 256) / difficulty);
+	return m_boundary;
+}
+
 BlockInfo BlockInfo::fromHeader(bytesConstRef _header, Strictness _s, h256 const& _h)
 {
 	BlockInfo ret;

libethcore/BlockInfo.h

@@ -118,7 +118,7 @@ public:
 
 	void clear();
 
-	void noteDirty() const { m_hash = m_seedHash = h256(); }
+	void noteDirty() const { m_hash = m_seedHash = m_boundary = h256(); }
 
 	void populateFromHeader(RLP const& _header, Strictness _s = IgnoreNonce, h256 const& _h = h256());
 	void populate(bytesConstRef _block, Strictness _s = IgnoreNonce, h256 const& _h = h256());
@@ -131,6 +131,7 @@ public:
 	u256 selectGasLimit(BlockInfo const& _parent) const;
 	h256 const& seedHash() const;
 	h256 const& hash() const;
+	h256 const& boundary() const;
 
 	/// sha3 of the header only.
 	h256 headerHash(IncludeNonce _n) const;
@@ -139,6 +140,7 @@ public:
 private:
 	mutable h256 m_seedHash;
 	mutable h256 m_hash;						///< SHA3 hash of the block header! Not serialised.
+	mutable h256 m_boundary;					///< 2^256 / difficulty
 };
 
 inline std::ostream& operator<<(std::ostream& _out, BlockInfo const& _bi)

libethcore/ProofOfWork.cpp

@@ -128,9 +128,9 @@ struct EthashCLHook: public ethash_cl_miner::search_hook
 {
 	void abort()
 	{
-		cdebug << "Attempting to abort";
 		if (m_aborted)
 			return;
+		cdebug << "Attempting to abort";
 		m_abort = true;
 		for (unsigned timeout = 0; timeout < 100 && !m_aborted; ++timeout)
 			std::this_thread::sleep_for(chrono::milliseconds(30));
@@ -198,14 +198,19 @@ std::pair<MineInfo, Ethash::Proof> EthashCL::mine(BlockInfo const& _header, unsi
 		if (m_miner)
 			m_hook->abort();
 		m_miner.reset(new ethash_cl_miner);
-		m_miner->init(Ethasher::params(_header), [&](void* d){ Ethasher::get()->readFull(_header, d); });
+		auto cb = [&](void* d) {
+			Ethasher::get()->readFull(_header, d);
+		};
+		m_miner->init(Ethasher::params(_header), cb);
 	}
 	if (m_lastHeader != _header)
 	{
 		m_hook->abort();
 		static std::random_device s_eng;
 		uint64_t tryNonce = (uint64_t)(u64)(m_last = Nonce::random(s_eng));
-		m_miner->search(_header.headerHash(WithoutNonce).data(), tryNonce, *m_hook);
+		auto hh = _header.headerHash(WithoutNonce);
+		cdebug << "Mining with headerhash" << hh << "from nonce" << m_last << "with boundary" << _header.boundary();
+		m_miner->search(hh.data(), tryNonce, *m_hook);
 	}
 	m_lastHeader = _header;
 
@@ -213,9 +218,14 @@ std::pair<MineInfo, Ethash::Proof> EthashCL::mine(BlockInfo const& _header, unsi
 	auto found = m_hook->fetchFound();
 	if (!found.empty())
 	{
-		Nonce n = (Nonce)(u64)found[0];
-		auto result = Ethasher::eval(_header, n);
-		return std::make_pair(MineInfo(true), EthashCL::Proof{n, result.mixHash});
+		for (auto const& n: found)
+		{
+			auto result = Ethasher::eval(_header, n);
+			cdebug << "Got nonce " << n << "gives result" << result.value;
+			if (result.value < _header.boundary())
+				return std::make_pair(MineInfo(true), EthashCL::Proof{n, result.mixHash});
+		}
+		assert(false);
 	}
 	return std::make_pair(MineInfo(false), EthashCL::Proof());
 }