Merge remote-tracking branch 'monero-project/master' into blockchain

3 files changed, 62 insertions, 4 deletions

diff --git a/README.md b/README.md
index 2fb87ef5e..295d05881 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,22 @@ As with many development projects, the repository on Github is considered to be
 
 Anyone is able to contribute to Monero. If you have a fix or code change, feel free to submit is as a pull request directly to the "development" branch. In cases where the change is relatively small or does not affect other parts of the codebase it may be merged in immediately by any one of the collaborators. On the other hand, if the change is particularly large or complex, it is expected that it will be discussed at length either well in advance of the pull request being submitted, or even directly on the pull request.
 
+## Supporting the Project
+
+Monero development can be supported directly through donations.
+
+Both Monero and Bitcoin donations can be made to donate.monero.cc if using a client that supports the [OpenAlias](https://openalias.org) standard
+
+The Monero donation address is: 46BeWrHpwXmHDpDEUmZBWZfoQpdc6HaERCNmx1pEYL2rAcuwufPN9rXHHtyUA4QVy66qeFQkn6sfK8aHYjA3jk3o1Bv16em (viewkey: e422831985c9205238ef84daf6805526c14d96fd7b059fe68c7ab98e495e5703)
+
+The Bitcoin donation address is: 1FhnVJi2V1k4MqXm2nHoEbY5LV7FPai7bb
+
+Core development funding and/or some supporting services are also graciously provided by sponsors:
+
+[![MyMonero](http://i.imgur.com/xdp7mNG.png?)](https://mymonero.com) [![Dome9](http://i.imgur.com/THVVafx.png)](http://dome9.com)
+
+There are also several mining pools that kindly donate a portion of their fees, [a list of them can be found on our Bitcointalk post](https://bitcointalk.org/index.php?topic=583449.0).
+
 ## License
 
 Copyright (c) 2014-2015, The Monero Project
diff --git a/src/crypto/slow-hash.c b/src/crypto/slow-hash.c
index fda854ea5..6b410b01a 100644
--- a/src/crypto/slow-hash.c
+++ b/src/crypto/slow-hash.c
@@ -627,6 +627,18 @@ void cn_slow_hash(const void *data, size_t length, char *hash)
 #else
 // Portable implementation as a fallback
 
+void slow_hash_allocate_state(void)
+{
+  // Do nothing, this is just to maintain compatibility with the upgraded slow-hash.c
+  return;
+}
+
+void slow_hash_free_state(void)
+{
+  // As above
+  return;
+}
+
 static void (*const extra_hashes[4])(const void *, size_t, char *) = {
   hash_extra_blake, hash_extra_groestl, hash_extra_jh, hash_extra_skein
 };
diff --git a/src/cryptonote_core/difficulty.cpp b/src/cryptonote_core/difficulty.cpp
index 106520440..6486d8124 100644
--- a/src/cryptonote_core/difficulty.cpp
+++ b/src/cryptonote_core/difficulty.cpp
@@ -56,10 +56,40 @@ namespace cryptonote {
 #else
 
   static inline void mul(uint64_t a, uint64_t b, uint64_t &low, uint64_t &high) {
-    typedef unsigned __int128 uint128_t;
-    uint128_t res = (uint128_t) a * (uint128_t) b;
-    low = (uint64_t) res;
-    high = (uint64_t) (res >> 64);
+	// __int128 isn't part of the standard, so the previous function wasn't portable. mul128() in Windows is fine,
+	// but this portable function should be used elsewhere. Credit for this function goes to latexi95.
+
+	uint64_t aLow = a & 0xFFFFFFFF;
+	uint64_t aHigh = a >> 32;
+	uint64_t bLow = b & 0xFFFFFFFF;
+	uint64_t bHigh = b >> 32;
+ 
+	uint64_t res = aLow * bLow;
+	uint64_t lowRes1 = res & 0xFFFFFFFF;
+	uint64_t carry = res >> 32;
+ 
+	res = aHigh * bLow + carry;
+	uint64_t highResHigh1 = res >> 32;
+	uint64_t highResLow1 = res & 0xFFFFFFFF;
+ 
+	res = aLow * bHigh;
+	uint64_t lowRes2 = res & 0xFFFFFFFF;
+	carry = res >> 32;
+ 
+	res = aHigh * bHigh + carry;
+	uint64_t highResHigh2 = res >> 32;
+	uint64_t highResLow2 = res & 0xFFFFFFFF;
+ 
+	//Addition
+ 
+	uint64_t r = highResLow1 + lowRes2;
+	carry = r >> 32;
+	low = (r << 32) | lowRes1;
+	r = highResHigh1 + highResLow2 + carry;
+	uint64_t d3 = r & 0xFFFFFFFF;
+	carry = r >> 32;
+	r = highResHigh2 + carry;
+	high = d3 | (r << 32);
   }
 
 #endif