diff --git a/blas/s_blas1_lib4.c b/blas/s_blas1_lib4.c
new file mode 100644
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--- /dev/null
+++ b/blas/s_blas1_lib4.c
@@ -0,0 +1,123 @@
+/**************************************************************************************************
+*                                                                                                 *
+* This file is part of BLASFEO.                                                                   *
+*                                                                                                 *
+* BLASFEO -- BLAS For Embedded Optimization.                                                      *
+* Copyright (C) 2016-2017 by Gianluca Frison.                                                     *
+* Developed at IMTEK (University of Freiburg) under the supervision of Moritz Diehl.              *
+* All rights reserved.                                                                            *
+*                                                                                                 *
+* HPMPC is free software; you can redistribute it and/or                                          *
+* modify it under the terms of the GNU Lesser General Public                                      *
+* License as published by the Free Software Foundation; either                                    *
+* version 2.1 of the License, or (at your option) any later version.                              *
+*                                                                                                 *
+* HPMPC is distributed in the hope that it will be useful,                                        *
+* but WITHOUT ANY WARRANTY; without even the implied warranty of                                  *
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.                                            *
+* See the GNU Lesser General Public License for more details.                                     *
+*                                                                                                 *
+* You should have received a copy of the GNU Lesser General Public                                *
+* License along with HPMPC; if not, write to the Free Software                                    *
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA                  *
+*                                                                                                 *
+* Author: Gianluca Frison, giaf (at) dtu.dk                                                       *
+*                          gianluca.frison (at) imtek.uni-freiburg.de                             *
+*                                                                                                 *
+**************************************************************************************************/
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "../include/blasfeo_common.h"
+#include "../include/blasfeo_s_kernel.h"
+
+
+
+#if defined(LA_HIGH_PERFORMANCE)
+
+
+
+// z = y + alpha*x, with increments equal to 1
+void saxpy_libstr(int m, float alpha, struct s_strvec *sx, int xi, struct s_strvec *sy, int yi, struct s_strvec *sz, int zi)
+	{
+	float *x = sx->pa + xi;
+	float *y = sy->pa + yi;
+	float *z = sz->pa + zi;
+	int ii;
+	ii = 0;
+	for( ; ii<m-3; ii+=4)
+		{
+		z[ii+0] = y[ii+0] + alpha*x[ii+0];
+		z[ii+1] = y[ii+1] + alpha*x[ii+1];
+		z[ii+2] = y[ii+2] + alpha*x[ii+2];
+		z[ii+3] = y[ii+3] + alpha*x[ii+3];
+		}
+	for( ; ii<m; ii++)
+		{
+		z[ii+0] = y[ii+0] + alpha*x[ii+0];
+		}
+	return;
+	}
+
+
+
+void saxpy_bkp_libstr(int m, float alpha, struct s_strvec *sx, int xi, struct s_strvec *sy, int yi, struct s_strvec *sz, int zi)
+	{
+	float *x = sx->pa + xi;
+	float *y = sy->pa + yi;
+	float *z = sz->pa + zi;
+	int ii;
+	ii = 0;
+	for( ; ii<m-3; ii+=4)
+		{
+		z[ii+0] = y[ii+0];
+		y[ii+0] = y[ii+0] + alpha*x[ii+0];
+		z[ii+1] = y[ii+1];
+		y[ii+1] = y[ii+1] + alpha*x[ii+1];
+		z[ii+2] = y[ii+2];
+		y[ii+2] = y[ii+2] + alpha*x[ii+2];
+		z[ii+3] = y[ii+3];
+		y[ii+3] = y[ii+3] + alpha*x[ii+3];
+		}
+	for( ; ii<m; ii++)
+		{
+		z[ii+0] = y[ii+0];
+		y[ii+0] = y[ii+0] + alpha*x[ii+0];
+		}
+	return;
+	}
+
+
+
+// multiply two vectors and compute dot product
+float svecmuldot_libstr(int m, struct s_strvec *sx, int xi, struct s_strvec *sy, int yi, struct s_strvec *sz, int zi)
+	{
+
+	if(m<=0)
+		return 0.0;
+
+	float *x = sx->pa + xi;
+	float *y = sy->pa + yi;
+	float *z = sz->pa + zi;
+	int ii;
+	float dot = 0.0;
+
+	ii = 0;
+
+	for(; ii<m; ii++)
+		{
+		z[ii+0] = x[ii+0] * y[ii+0];
+		dot += z[ii+0];
+		}
+	return dot;
+	}
+
+
+
+#else
+
+#error : wrong LA choice
+
+#endif
+