[Qemu-devel] [PATCH 1/2] cutils: add the AVX2 optimization

[Liang Li <liang.z.li@intel.com>]

For platform that supports AVX2 instructions, use the AVX2 instructions
instead of SSE2 instructions in buffer_find_nonzero_offset() can help to
improve the performance about 30%. Zero page check during live migration
can be faster with this optimization.

Signed-off-by: Liang Li <liang.z.li@intel.com>
---
 include/qemu-common.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/qemu-common.h b/include/qemu-common.h
index bbaffd1..629fcac 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -468,6 +468,13 @@ void qemu_hexdump(const char *buf, FILE *fp, const char *prefix, size_t size);
 /* altivec.h may redefine the bool macro as vector type.
  * Reset it to POSIX semantics. */
 #define bool _Bool
+#elif defined __AVX2__
+#include <immintrin.h>
+#define VECTYPE        __m256i
+#define SPLAT(p)       _mm256_set1_epi8(*(p))
+#define ALL_EQ(v1, v2) \
+    (_mm256_movemask_epi8(_mm256_cmpeq_epi8(v1, v2)) == 0xFFFFFFFF)
+#define VEC_OR(v1, v2) (_mm256_or_si256(v1, v2))
 #elif defined __SSE2__
 #include <emmintrin.h>
 #define VECTYPE        __m128i
-- 
1.9.1