From 8572541841898d88d36d2f8f275d8e8ed6a81a72 Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Tue, 22 Jan 2019 03:42:53 -0500
Subject: [PATCH] Use #pragma omp simd for OpenMP 3.0 compilers (GH #787)

---
 salsa.cpp  | 5 +++--
 scrypt.cpp | 5 +++--
 test.cpp   | 3 ++-
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/salsa.cpp b/salsa.cpp
index fb2dc03e..eacdabe7 100644
--- a/salsa.cpp
+++ b/salsa.cpp
@@ -90,11 +90,12 @@ void Salsa20_Core(word32* data, unsigned int rounds)
 		x[15] ^= rotlConstant<18>(x[14]+x[13]);
 	}
 
-#ifdef _MSC_VER
+// OpenMP 3.0 released May 2008.
+#if _OPENMP >= 200805
+	#pragma omp simd
 	for (size_t i = 0; i < 16; ++i)
 		data[i] += x[i];
 #else
-	#pragma omp simd
 	for (size_t i = 0; i < 16; ++i)
 		data[i] += x[i];
 #endif
diff --git a/scrypt.cpp b/scrypt.cpp
index 859d6822..7c1b9e84 100644
--- a/scrypt.cpp
+++ b/scrypt.cpp
@@ -64,11 +64,12 @@ static inline void BlockCopy(byte* dest, byte* src, size_t len)
 
 static inline void BlockXOR(byte* dest, byte* src, size_t len)
 {
-#ifdef _MSC_VER
+// OpenMP 3.0 released May 2008.
+#if _OPENMP >= 200805
+    #pragma omp simd
     for (size_t i = 0; i < len; ++i)
         dest[i] ^= src[i];
 #else
-    #pragma omp simd
     for (size_t i = 0; i < len; ++i)
         dest[i] ^= src[i];
 #endif
diff --git a/test.cpp b/test.cpp
index 6ffd7e6e..8b970a22 100644
--- a/test.cpp
+++ b/test.cpp
@@ -547,7 +547,8 @@ void PrintSeedAndThreads()
 		tc = omp_get_num_threads();
 	}
 
-	std::cout << "Using " << tc << " OMP " << (tc == 1 ? "thread" : "threads") << std::endl;
+	std::cout << "OpenMP version " << (int)_OPENMP << ", ";
+	std::cout << tc << (tc == 1 ? " thread" : "threads") << std::endl;
 #endif
 }