Merge pull request #1733 from fenrus75/dsymv

Add an AVX512 enabled DSYMV (L) function

kernel/x86_64/dsymv_L.c

@@ -30,8 +30,10 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #if defined(BULLDOZER) || defined(PILEDRIVER) || defined(STEAMROLLER) || defined(EXCAVATOR)
 #include "dsymv_L_microk_bulldozer-2.c"
-#elif defined(HASWELL) || defined(ZEN) || defined (SKYLAKEX)
+#elif defined(HASWELL) || defined(ZEN)
 #include "dsymv_L_microk_haswell-2.c"
+#elif defined (SKYLAKEX)
+#include "dsymv_L_microk_skylakex-2.c"
 #elif defined(SANDYBRIDGE)
 #include "dsymv_L_microk_sandy-2.c"
 #elif defined(NEHALEM)

kernel/x86_64/dsymv_L_microk_skylakex-2.c

@@ -0,0 +1,161 @@
+/***************************************************************************
+Copyright (c) 2014, 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_4x4 1
+
+static void dsymv_kernel_4x4(BLASLONG from, BLASLONG to, FLOAT **a, FLOAT *x, FLOAT *y, FLOAT *temp1, FLOAT *temp2)
+{
+
+
+	__m256d accum_0, accum_1, accum_2, accum_3; 
+	__m256d temp1_0, temp1_1, temp1_2, temp1_3;
+
+	/* the 256 bit wide acculmulator vectors start out as zero */
+	accum_0 = _mm256_setzero_pd();
+	accum_1 = _mm256_setzero_pd();
+	accum_2 = _mm256_setzero_pd();
+	accum_3 = _mm256_setzero_pd();
+
+	temp1_0 = _mm256_broadcastsd_pd(_mm_load_sd(&temp1[0]));
+	temp1_1 = _mm256_broadcastsd_pd(_mm_load_sd(&temp1[1]));
+	temp1_2 = _mm256_broadcastsd_pd(_mm_load_sd(&temp1[2]));
+	temp1_3 = _mm256_broadcastsd_pd(_mm_load_sd(&temp1[3]));
+
+#ifdef __AVX512CD__
+	__m512d accum_05, accum_15, accum_25, accum_35;
+	__m512d temp1_05, temp1_15, temp1_25, temp1_35;
+	BLASLONG to2;
+	int delta;
+
+	/* the 512 bit wide accumulator vectors start out as zero */
+	accum_05 = _mm512_setzero_pd();
+	accum_15 = _mm512_setzero_pd();
+	accum_25 = _mm512_setzero_pd();
+	accum_35 = _mm512_setzero_pd();
+
+	temp1_05 = _mm512_broadcastsd_pd(_mm_load_sd(&temp1[0]));
+	temp1_15 = _mm512_broadcastsd_pd(_mm_load_sd(&temp1[1]));
+	temp1_25 = _mm512_broadcastsd_pd(_mm_load_sd(&temp1[2]));
+	temp1_35 = _mm512_broadcastsd_pd(_mm_load_sd(&temp1[3]));
+
+	delta = (to - from) & ~7;
+	to2 = from + delta;
+
+
+	for (; from < to2; from += 8) {
+		__m512d _x, _y;
+		__m512d a0, a1, a2, a3;
+
+		_y = _mm512_loadu_pd(&y[from]);
+		_x = _mm512_loadu_pd(&x[from]);
+
+		a0 = _mm512_loadu_pd(&a[0][from]);
+		a1 = _mm512_loadu_pd(&a[1][from]);
+		a2 = _mm512_loadu_pd(&a[2][from]);
+		a3 = _mm512_loadu_pd(&a[3][from]);
+
+		_y += temp1_05 * a0 + temp1_15 * a1 + temp1_25 * a2 + temp1_35 * a3;
+
+		accum_05 += _x * a0;
+		accum_15 += _x * a1;
+		accum_25 += _x * a2;
+		accum_35 += _x * a3;
+
+		_mm512_storeu_pd(&y[from], _y);
+
+	};
+
+	/*
+	 * we need to fold our 512 bit wide accumulator vectors into 256 bit wide vectors so that the AVX2 code
+	 * below can continue using the intermediate results in its loop
+	 */
+	accum_0 = _mm256_add_pd(_mm512_extractf64x4_pd(accum_05, 0), _mm512_extractf64x4_pd(accum_05, 1));
+	accum_1 = _mm256_add_pd(_mm512_extractf64x4_pd(accum_15, 0), _mm512_extractf64x4_pd(accum_15, 1));
+	accum_2 = _mm256_add_pd(_mm512_extractf64x4_pd(accum_25, 0), _mm512_extractf64x4_pd(accum_25, 1));
+	accum_3 = _mm256_add_pd(_mm512_extractf64x4_pd(accum_35, 0), _mm512_extractf64x4_pd(accum_35, 1));
+
+#endif
+
+	for (; from != to; from += 4) {
+		__m256d _x, _y;
+		__m256d a0, a1, a2, a3;
+
+		_y = _mm256_loadu_pd(&y[from]);
+		_x = _mm256_loadu_pd(&x[from]);
+
+		/* load 4 rows of matrix data */
+		a0 = _mm256_loadu_pd(&a[0][from]);
+		a1 = _mm256_loadu_pd(&a[1][from]);
+		a2 = _mm256_loadu_pd(&a[2][from]);
+		a3 = _mm256_loadu_pd(&a[3][from]);
+
+		_y += temp1_0 * a0 + temp1_1 * a1 + temp1_2 * a2 + temp1_3 * a3;
+
+		accum_0 += _x * a0;
+		accum_1 += _x * a1;
+		accum_2 += _x * a2;
+		accum_3 += _x * a3;
+
+		_mm256_storeu_pd(&y[from], _y);
+
+	};
+
+	/*
+	 * we now have 4 accumulator vectors. Each vector needs to be summed up element wise and stored in the temp2
+	 * output array. There is no direct instruction for this in 256 bit space, only in 128 space.
+	 */
+
+	__m128d half_accum0, half_accum1, half_accum2, half_accum3;
+
+
+	/* Add upper half to lower half of each of the four 256 bit vectors to get to four 128 bit vectors */
+	half_accum0 = _mm_add_pd(_mm256_extractf128_pd(accum_0, 0), _mm256_extractf128_pd(accum_0, 1));
+	half_accum1 = _mm_add_pd(_mm256_extractf128_pd(accum_1, 0), _mm256_extractf128_pd(accum_1, 1));
+	half_accum2 = _mm_add_pd(_mm256_extractf128_pd(accum_2, 0), _mm256_extractf128_pd(accum_2, 1));
+	half_accum3 = _mm_add_pd(_mm256_extractf128_pd(accum_3, 0), _mm256_extractf128_pd(accum_3, 1));
+
+	/* in 128 bit land there is a hadd operation to do the rest of the element-wise sum in one go */
+	half_accum0 = _mm_hadd_pd(half_accum0, half_accum0);
+	half_accum1 = _mm_hadd_pd(half_accum1, half_accum1);
+	half_accum2 = _mm_hadd_pd(half_accum2, half_accum2);
+	half_accum3 = _mm_hadd_pd(half_accum3, half_accum3);
+
+	/* and store the lowest double value from each of these vectors in the temp2 output */
+	temp2[0] += half_accum0[0];
+	temp2[1] += half_accum1[0];
+	temp2[2] += half_accum2[0];
+	temp2[3] += half_accum3[0];
+} 
+#else
+#include "dsymv_L_microk_haswell-2.c"
+#endif