Require clang 6 for AVX512 support

row.h adds CLANG_HAS_AVX512
function ifdefs in row.h for avx512
source code ifdefed function by function for
avx512 and avx2.

Bug: libyuv:778
Test: LibYUVConvertTest.NV21ToRGB24_Opt
Change-Id: If32b51459685d0d5785c5c1e94c8f668f8e74b55
Reviewed-on: https://chromium-review.googlesource.com/982402
Commit-Queue: Frank Barchard <fbarchard@chromium.org>
Reviewed-by: richard winterton <rrwinterton@gmail.com>

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 1705
+Version: 1706
 License: BSD
 License File: LICENSE
 

include/libyuv/row.h

@@ -55,6 +55,13 @@ extern "C" {
 #endif  // clang >= 3.4
 #endif  // __clang__
 
+// clang >= 6.0.0 required for AVX512.
+#if defined(__clang__) && (defined(__x86_64__) || defined(__i386__))
+#if (__clang_major__ >= 6)
+#define CLANG_HAS_AVX512 1
+#endif  // clang >= 6
+#endif  // __clang__
+
 // Visual C 2012 required for AVX2.
 #if defined(_M_IX86) && !defined(__clang__) && defined(_MSC_VER) && \
     _MSC_VER >= 1700
@@ -277,7 +284,6 @@ extern "C" {
 #define HAS_ARGBTOAR30ROW_AVX2
 #define HAS_ARGBTORAWROW_AVX2
 #define HAS_ARGBTORGB24ROW_AVX2
-#define HAS_ARGBTORGB24ROW_AVX512VBMI
 #define HAS_CONVERT16TO8ROW_AVX2
 #define HAS_CONVERT8TO16ROW_AVX2
 #define HAS_I210TOAR30ROW_AVX2
@@ -289,6 +295,14 @@ extern "C" {
 #define HAS_MULTIPLYROW_16_AVX2
 #endif
 
+// The following are available for AVX512 clang x86 platforms:
+// TODO(fbarchard): Port to GCC and Visual C
+#if !defined(LIBYUV_DISABLE_X86) &&                                       \
+    (defined(__x86_64__) || (defined(__i386__) && !defined(_MSC_VER))) && \
+    (defined(CLANG_HAS_AVX512))
+#define HAS_ARGBTORGB24ROW_AVX512VBMI
+#endif
+
 // The following are available on Neon platforms:
 #if !defined(LIBYUV_DISABLE_NEON) && \
     (defined(__aarch64__) || defined(__ARM_NEON__) || defined(LIBYUV_NEON))

include/libyuv/version.h

@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 1705
+#define LIBYUV_VERSION 1706
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_

source/row_gcc.cc

@@ -505,6 +505,7 @@ void ARGBToRAWRow_SSSE3(const uint8_t* src, uint8_t* dst, int width) {
       : "memory", "cc", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6");
 }
 
+#ifdef HAS_ARGBTORGB24ROW_AVX2
 // vpermd for 12+12 to 24
 static const lvec32 kPermdRGB24_AVX = {0, 1, 2, 4, 5, 6, 3, 7};
 
@@ -551,9 +552,9 @@ void ARGBToRGB24Row_AVX2(const uint8_t* src, uint8_t* dst, int width) {
       : "memory", "cc", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6",
         "xmm7");
 }
+#endif
 
-// TODO(fbarchard): Detect compiler can di avx512 and add ifdefs
-
+#ifdef HAS_ARGBTORGB24ROW_AVX512VBMI
 // Shuffle table for converting ARGBToRGB24
 static const ulvec8 kPermARGBToRGB24_0 = {
     0u,  1u,  2u,  4u,  5u,  6u,  8u,  9u,  10u, 12u, 13u,
@@ -599,7 +600,9 @@ void ARGBToRGB24Row_AVX512VBMI(const uint8_t* src, uint8_t* dst, int width) {
         "m"(kPermARGBToRGB24_2)   // %5
       : "memory", "cc", "xmm0", "xmm1", "xmm2", "xmm3", "xmm5", "xmm6", "xmm7");
 }
+#endif
 
+#ifdef HAS_ARGBTORAWROW_AVX2
 void ARGBToRAWRow_AVX2(const uint8_t* src, uint8_t* dst, int width) {
   asm volatile(
       "vbroadcastf128 %3,%%ymm6                  \n"
@@ -643,6 +646,7 @@ void ARGBToRAWRow_AVX2(const uint8_t* src, uint8_t* dst, int width) {
       : "memory", "cc", "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6",
         "xmm7");
 }
+#endif
 
 void ARGBToRGB565Row_SSE2(const uint8_t* src, uint8_t* dst, int width) {
   asm volatile(