From 7611ea6018b01dd725902c7985bd34aafc9b2cd8 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Thu, 17 Mar 2016 11:08:36 +0100
Subject: [PATCH] Add AVX2 detection

---
 configure.ac                           | 13 +++++++++++++
 src/libsodium/include/sodium/runtime.h |  3 +++
 src/libsodium/sodium/runtime.c         | 15 +++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/configure.ac b/configure.ac
index 1f281da7..38eac7af 100644
--- a/configure.ac
+++ b/configure.ac
@@ -356,6 +356,19 @@ AS_IF([test "x$EMSCRIPTEN" = "x"],[
     [AC_MSG_RESULT(no)])
   CFLAGS="$oldcflags"
 
+  oldcflags="$CFLAGS"
+  AX_CHECK_COMPILE_FLAG([-mavx2], [CFLAGS="$CFLAGS -mavx2"])
+  AC_MSG_CHECKING(for AVX2 instructions set)
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#pragma GCC target("avx2")
+#include <immintrin.h>
+]], [[ __m256i x = _mm256_abs_epi8(_mm256_setzero_si256()); ]])],
+    [AC_MSG_RESULT(yes)
+     AC_DEFINE([HAVE_AVX2INTRIN_H], [1], [AVX2 is available])
+     AX_CHECK_COMPILE_FLAG([-mavx2], [CFLAGS_AVX="-mavx2"])],
+    [AC_MSG_RESULT(no)])
+  CFLAGS="$oldcflags"
+
   oldcflags="$CFLAGS"
   AX_CHECK_COMPILE_FLAG([-maes], [CFLAGS="$CFLAGS -maes"])
   AX_CHECK_COMPILE_FLAG([-mpclmul], [CFLAGS="$CFLAGS -mpclmul"])
diff --git a/src/libsodium/include/sodium/runtime.h b/src/libsodium/include/sodium/runtime.h
index 2c5c0048..76859ea0 100644
--- a/src/libsodium/include/sodium/runtime.h
+++ b/src/libsodium/include/sodium/runtime.h
@@ -26,6 +26,9 @@ int sodium_runtime_has_sse41(void);
 SODIUM_EXPORT
 int sodium_runtime_has_avx(void);
 
+SODIUM_EXPORT
+int sodium_runtime_has_avx2(void);
+
 SODIUM_EXPORT
 int sodium_runtime_has_pclmul(void);
 
diff --git a/src/libsodium/sodium/runtime.c b/src/libsodium/sodium/runtime.c
index e6006715..9a7633c6 100644
--- a/src/libsodium/sodium/runtime.c
+++ b/src/libsodium/sodium/runtime.c
@@ -15,6 +15,7 @@ typedef struct CPUFeatures_ {
     int has_ssse3;
     int has_sse41;
     int has_avx;
+    int has_avx2;
     int has_pclmul;
     int has_aesni;
 } CPUFeatures;
@@ -26,6 +27,7 @@ static CPUFeatures _cpu_features;
 #define CPUIDECX_SSSE3   0x00000200
 #define CPUIDECX_SSE41   0x00080000
 #define CPUIDECX_AVX     0x10000000
+#define CPUIDECX_AVX2    0x00000020
 #define CPUIDECX_PCLMUL  0x00000002
 #define CPUIDECX_AESNI   0x02000000
 #define CPUIDECX_XSAVE   0x04000000
@@ -159,6 +161,14 @@ _sodium_runtime_intel_cpu_features(CPUFeatures * const cpu_features)
     }
 #endif
 
+    cpu_features->has_avx2 = 0;
+#if defined(HAVE_AVX2INTRIN_H) || \
+    (defined(_MSC_VER) && (defined(_M_X64) || defined(_M_AMD64) || defined(_M_IX86)))
+    if (cpu_features->has_avx) {
+        cpu_features->has_avx2 = ((cpu_info[2] & CPUIDECX_AVX2) != 0x0);
+    }
+#endif
+
 #if defined(HAVE_WMMINTRIN_H) || \
     (defined(_MSC_VER) && (defined(_M_X64) || defined(_M_AMD64) || defined(_M_IX86)))
     cpu_features->has_pclmul = ((cpu_info[2] & CPUIDECX_PCLMUL) != 0x0);
@@ -213,6 +223,11 @@ sodium_runtime_has_avx(void) {
     return _cpu_features.has_avx;
 }
 
+int
+sodium_runtime_has_avx2(void) {
+    return _cpu_features.has_avx2;
+}
+
 int
 sodium_runtime_has_pclmul(void) {
     return _cpu_features.has_pclmul;