From fc892fc5c0a904e7f08d8e5b2e171503c9e0c955 Mon Sep 17 00:00:00 2001
From: tevador <tevador@gmail.com>
Date: Wed, 9 Oct 2019 21:37:14 +0200
Subject: [PATCH] Select AVX2 if both AVX2 and SSSE3 flags are set

---
 src/dataset.hpp         | 17 +++++------------
 src/randomx.cpp         |  8 ++++++--
 src/tests/benchmark.cpp | 14 +++++++++-----
 3 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/src/dataset.hpp b/src/dataset.hpp
index 16a6a84..083a5d7 100644
--- a/src/dataset.hpp
+++ b/src/dataset.hpp
@@ -83,19 +83,12 @@ namespace randomx {
 	void initDataset(randomx_cache* cache, uint8_t* dataset, uint32_t startBlock, uint32_t endBlock);
 
 	inline randomx_argon2_impl* selectArgonImpl(randomx_flags flags) {
-		if ((flags & RANDOMX_FLAG_ARGON2) == 0) {
-			return &randomx_argon2_fill_segment_ref;
+		if (flags & RANDOMX_FLAG_ARGON2_AVX2) {
+			return randomx_argon2_impl_avx2();
 		}
-		randomx_argon2_impl* impl = nullptr;
-		if ((flags & RANDOMX_FLAG_ARGON2) == RANDOMX_FLAG_ARGON2_SSSE3) {
-			impl = randomx_argon2_impl_ssse3();
+		if (flags & RANDOMX_FLAG_ARGON2_SSSE3) {
+			return randomx_argon2_impl_ssse3();
 		}
-		if ((flags & RANDOMX_FLAG_ARGON2) == RANDOMX_FLAG_ARGON2_AVX2) {
-			impl = randomx_argon2_impl_avx2();
-		}
-		if (impl != nullptr) {
-			return impl;
-		}
-		throw std::runtime_error("Unsupported Argon2 implementation");
+		return &randomx_argon2_fill_segment_ref;
 	}
 }
diff --git a/src/randomx.cpp b/src/randomx.cpp
index 10eec4d..451ccca 100644
--- a/src/randomx.cpp
+++ b/src/randomx.cpp
@@ -48,7 +48,7 @@ extern "C" {
 		if (randomx_argon2_impl_avx2() != nullptr && cpu.hasAvx2()) {
 			flags |= RANDOMX_FLAG_ARGON2_AVX2;
 		}
-		else if (randomx_argon2_impl_ssse3() != nullptr && cpu.hasSsse3()) {
+		if (randomx_argon2_impl_ssse3() != nullptr && cpu.hasSsse3()) {
 			flags |= RANDOMX_FLAG_ARGON2_SSSE3;
 		}
 		return flags;
@@ -56,10 +56,14 @@ extern "C" {
 
 	randomx_cache *randomx_alloc_cache(randomx_flags flags) {
 		randomx_cache *cache = nullptr;
+		auto impl = randomx::selectArgonImpl(flags);
+		if (impl == nullptr) {
+			return cache;
+		}
 
 		try {
 			cache = new randomx_cache();
-			cache->argonImpl = randomx::selectArgonImpl(flags);
+			cache->argonImpl = impl;
 			switch (flags & (RANDOMX_FLAG_JIT | RANDOMX_FLAG_LARGE_PAGES)) {
 				case RANDOMX_FLAG_DEFAULT:
 					cache->dealloc = &randomx::deallocCache<randomx::DefaultAllocator>;
diff --git a/src/tests/benchmark.cpp b/src/tests/benchmark.cpp
index f00a3e0..e58166e 100644
--- a/src/tests/benchmark.cpp
+++ b/src/tests/benchmark.cpp
@@ -203,13 +203,15 @@ int main(int argc, char** argv) {
 		flags |= RANDOMX_FLAG_SECURE;
 	}
 
-	if (flags & RANDOMX_FLAG_ARGON2_SSSE3) {
-		std::cout << " - Argon2 implementation: SSSE3" << std::endl;
-	}
-
 	if (flags & RANDOMX_FLAG_ARGON2_AVX2) {
 		std::cout << " - Argon2 implementation: AVX2" << std::endl;
 	}
+	else if (flags & RANDOMX_FLAG_ARGON2_SSSE3) {
+		std::cout << " - Argon2 implementation: SSSE3" << std::endl;
+	}
+	else {
+		std::cout << " - Argon2 implementation: reference" << std::endl;
+	}
 
 	if (flags & RANDOMX_FLAG_FULL_MEM) {
 		std::cout << " - full memory mode (2080 MiB)" << std::endl;
@@ -253,7 +255,9 @@ int main(int argc, char** argv) {
 	std::cout << " ..." << std::endl;
 
 	try {
-		randomx::selectArgonImpl(flags); //just to check if flags are valid
+		if (nullptr == randomx::selectArgonImpl(flags)) {
+			throw std::runtime_error("Unsupported Argon2 implementation");
+		}
 		if ((flags & RANDOMX_FLAG_JIT) && !RANDOMX_HAVE_COMPILER) {
 			throw std::runtime_error("JIT compilation is not supported on this platform. Try without --jit");
 		}