Add an AVX512 enabled DSCAL function

written in C intrinsics for best readability.
(the same C code works for Haswell as well)

For logistical reasons the code falls back to the existing
haswell AVX2 implementation if the GCC or LLVM compiler is not new enough

diff --git a/kernel/x86_64/dscal.c b/kernel/x86_64/dscal.c
index 2c7b3b1..ef9a0a6 100644 (file)
--- a/kernel/x86_64/dscal.c
+++ b/kernel/x86_64/dscal.c
@@ -31,8 +31,10 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "dscal_microk_bulldozer-2.c"
 #elif defined(SANDYBRIDGE)
 #include "dscal_microk_sandy-2.c"
-#elif defined(HASWELL) || defined(ZEN) || defined (SKYLAKEX)
+#elif defined(HASWELL) || defined(ZEN)
 #include "dscal_microk_haswell-2.c"
+#elif  defined (SKYLAKEX)
+#include "dscal_microk_skylakex-2.c"
 #endif
 
 

diff --git a/kernel/x86_64/dscal_microk_skylakex-2.c b/kernel/x86_64/dscal_microk_skylakex-2.c
new file mode 100644 (file)
index 0000000..e059827
--- /dev/null
+++ b/kernel/x86_64/dscal_microk_skylakex-2.c
@@ -0,0 +1,77 @@
+/***************************************************************************
+Copyright (c) 2014-2015, The OpenBLAS Project
+All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+1. Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in
+the documentation and/or other materials provided with the
+distribution.
+3. Neither the name of the OpenBLAS project nor the names of
+its contributors may be used to endorse or promote products
+derived from this software without specific prior written permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*****************************************************************************/
+
+/* need a new enough GCC for avx512 support */
+#if (( defined(__GNUC__)  && __GNUC__   > 6 && defined(__AVX2__)) || (defined(__clang__) && __clang_major__ >= 6))
+
+#include <immintrin.h>
+
+#define HAVE_KERNEL_8 1
+
+static void dscal_kernel_8( BLASLONG n, FLOAT *alpha, FLOAT *x)
+{
+       int i = 0;
+
+#ifdef __AVX512CD__
+       __m512d __alpha5 = _mm512_broadcastsd_pd(_mm_load_sd(alpha));
+       for (; i < n; i += 8) {
+                _mm512_storeu_pd(&x[i +  0], __alpha5 * _mm512_loadu_pd(&x[i +  0]));
+       }
+#else
+       __m256d __alpha = _mm256_broadcastsd_pd(_mm_load_sd(alpha));
+       for (; i < n; i += 8) {
+                _mm256_storeu_pd(&x[i +  0], __alpha * _mm256_loadu_pd(&x[i +  0]));
+                _mm256_storeu_pd(&x[i +  4], __alpha * _mm256_loadu_pd(&x[i +  4]));
+       }
+#endif
+} 
+
+
+static void dscal_kernel_8_zero( BLASLONG n, FLOAT *alpha, FLOAT *x)
+{
+       int i = 0;
+
+       /* question to self: Why is this not just memset() */
+
+#ifdef __AVX512CD__
+       __m512d zero = _mm512_setzero_pd();
+       for (; i < n; i += 8) {
+                _mm512_storeu_pd(&x[i], zero);
+       }
+#else
+       __m256d zero = _mm256_setzero_pd();
+       for (; i < n; i += 8) {
+                _mm256_storeu_pd(&x[i +  0], zero);
+                _mm256_storeu_pd(&x[i +  4], zero);
+       }
+#endif
+
+} 
+
+#else
+#include "dscal_microk_haswell-2.c"
+#endif