+/*
+ * This file is part of the GROMACS molecular simulation package.
+ *
+ * Copyright (c) 2014, by the GROMACS development team, led by
+ * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
+ * and including many others, as listed in the AUTHORS file in the
+ * top-level source directory and at http://www.gromacs.org.
+ *
+ * GROMACS 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.
+ *
+ * GROMACS 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 GROMACS; if not, see
+ * http://www.gnu.org/licenses, or write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * If you want to redistribute modifications to GROMACS, please
+ * consider that scientific software is very special. Version
+ * control is crucial - bugs must be traceable. We will be happy to
+ * consider code for inclusion in the official distribution, but
+ * derived work must not be called official GROMACS. Details are found
+ * in the README & COPYING files - if they are missing, get the
+ * official version at http://www.gromacs.org.
+ *
+ * To help us fund GROMACS development, we humbly ask that you cite
+ * the research papers on the package. Check out http://www.gromacs.org.
+ */
+
+#ifndef GMX_SIMD_IMPL_ARM_NEON_H
+#define GMX_SIMD_IMPL_ARM_NEON_H
+
+#include <math.h>
+
+#include <arm_neon.h>
+
+/* ARM 32-bit NEON SIMD instruction wrappers
+ *
+ * Please see documentation in gromacs/simd/simd.h for defines.
+ */
+
+/* Capability definitions for ARM 32-bit NEON */
+#define GMX_SIMD_HAVE_FLOAT
+#undef GMX_SIMD_HAVE_DOUBLE
+#define GMX_SIMD_HAVE_HARDWARE
+#define GMX_SIMD_HAVE_LOADU
+#define GMX_SIMD_HAVE_STOREU
+#define GMX_SIMD_HAVE_LOGICAL
+#define GMX_SIMD_HAVE_FMA
+#undef GMX_SIMD_HAVE_FRACTION
+#define GMX_SIMD_HAVE_FINT32
+#define GMX_SIMD_HAVE_FINT32_EXTRACT
+#define GMX_SIMD_HAVE_FINT32_LOGICAL
+#define GMX_SIMD_HAVE_FINT32_ARITHMETICS
+#undef GMX_SIMD_HAVE_DINT32
+#undef GMX_SIMD_HAVE_DINT32_EXTRACT
+#undef GMX_SIMD_HAVE_DINT32_LOGICAL
+#undef GMX_SIMD_HAVE_DINT32_ARITHMETICS
+#define GMX_SIMD4_HAVE_FLOAT
+#undef GMX_SIMD4_HAVE_DOUBLE
+
+/* Implementation details */
+#define GMX_SIMD_FLOAT_WIDTH 4
+#undef GMX_SIMD_DOUBLE_WIDTH
+#define GMX_SIMD_FINT32_WIDTH 4
+#undef GMX_SIMD_DINT32_WIDTH
+#define GMX_SIMD_RSQRT_BITS 8
+#define GMX_SIMD_RCP_BITS 8
+
+/****************************************************
+ * SINGLE PRECISION SIMD IMPLEMENTATION *
+ ****************************************************/
+#define gmx_simd_float_t float32x4_t
+#define gmx_simd_load_f vld1q_f32
+#define gmx_simd_load1_f vld1q_dup_f32
+#define gmx_simd_set1_f vdupq_n_f32
+#define gmx_simd_store_f vst1q_f32
+#define gmx_simd_loadu_f vld1q_f32
+#define gmx_simd_storeu_f vst1q_f32
+#define gmx_simd_setzero_f() vdupq_n_f32(0.0f)
+#define gmx_simd_add_f vaddq_f32
+#define gmx_simd_sub_f vsubq_f32
+#define gmx_simd_mul_f vmulq_f32
+#ifdef __ARM_FEATURE_FMA
+# define gmx_simd_fmadd_f(a, b, c) vfmaq_f32(c, b, a)
+# define gmx_simd_fmsub_f(a, b, c) vnegq_f32(vfmsq_f32(c, b, a))
+# define gmx_simd_fnmadd_f(a, b, c) vfmaq_f32(c, b, a)
+# define gmx_simd_fnmsub_f(a, b, c) vnegq_f32(vfmaq_f32(c, b, a))
+#else
+# define gmx_simd_fmadd_f(a, b, c) vmlaq_f32(c, b, a)
+# define gmx_simd_fmsub_f(a, b, c) vnegq_f32(vmlsq_f32(c, b, a))
+# define gmx_simd_fnmadd_f(a, b, c) vmlsq_f32(c, b, a)
+# define gmx_simd_fnmsub_f(a, b, c) vnegq_f32(vmlaq_f32(c, b, a))
+#endif
+#define gmx_simd_and_f(a, b) vreinterpretq_f32_s32(vandq_s32(vreinterpretq_s32_f32(a), vreinterpretq_s32_f32(b)))
+#define gmx_simd_andnot_f(a, b) vreinterpretq_f32_s32(vbicq_s32(vreinterpretq_s32_f32(b), vreinterpretq_s32_f32(a)))
+#define gmx_simd_or_f(a, b) vreinterpretq_f32_s32(vorrq_s32(vreinterpretq_s32_f32(a), vreinterpretq_s32_f32(b)))
+#define gmx_simd_xor_f(a, b) vreinterpretq_f32_s32(veorq_s32(vreinterpretq_s32_f32(a), vreinterpretq_s32_f32(b)))
+#define gmx_simd_rsqrt_f vrsqrteq_f32
+#define gmx_simd_rsqrt_iter_f(lu, x) vmulq_f32(lu, vrsqrtsq_f32(vmulq_f32(lu, lu), x))
+#define gmx_simd_rcp_f vrecpeq_f32
+#define gmx_simd_rcp_iter_f(lu, x) vmulq_f32(lu, vrecpsq_f32(lu, x))
+#define gmx_simd_fabs_f(x) vabsq_f32(x)
+#define gmx_simd_fneg_f(x) vnegq_f32(x)
+#define gmx_simd_max_f vmaxq_f32
+#define gmx_simd_min_f vminq_f32
+#define gmx_simd_round_f(x) gmx_simd_cvt_i2f(gmx_simd_cvt_f2i(x))
+#define gmx_simd_trunc_f(x) gmx_simd_cvt_i2f(gmx_simd_cvtt_f2i(x))
+#define gmx_simd_fraction_f(x) vsubq_f32(x, gmx_simd_trunc_f(x))
+#define gmx_simd_get_exponent_f gmx_simd_get_exponent_f_arm_neon
+#define gmx_simd_get_mantissa_f gmx_simd_get_mantissa_f_arm_neon
+#define gmx_simd_set_exponent_f gmx_simd_set_exponent_f_arm_neon
+/* integer datatype corresponding to float: gmx_simd_fint32_t */
+#define gmx_simd_fint32_t int32x4_t
+#define gmx_simd_load_fi(m) vld1q_s32(m)
+#define gmx_simd_set1_fi vdupq_n_s32
+#define gmx_simd_store_fi(m, x) vst1q_s32(m, x)
+#define gmx_simd_loadu_fi(m) vld1q_s32(m)
+#define gmx_simd_storeu_fi(m, x) vst1q_s32(m, x)
+#define gmx_simd_setzero_fi() vdupq_n_s32(0)
+#define gmx_simd_cvtt_f2i vcvtq_s32_f32
+#define gmx_simd_cvt_f2i(x) vcvtq_s32_f32(gmx_simd_add_f(gmx_simd_or_f(gmx_simd_and_f(vdupq_n_f32(-0.0f), x), vdupq_n_f32(0.5f)), x))
+#define gmx_simd_cvt_i2f vcvtq_f32_s32
+#define gmx_simd_extract_fi(x, i) vgetq_lane_s32(x, i)
+/* Integer logical ops on gmx_simd_fint32_t */
+#define gmx_simd_slli_fi vshlq_n_s32
+#define gmx_simd_srli_fi vshrq_n_s32
+#define gmx_simd_and_fi vandq_s32
+#define gmx_simd_andnot_fi(a, b) vbicq_s32(b, a)
+#define gmx_simd_or_fi vorrq_s32
+#define gmx_simd_xor_fi veorq_s32
+/* Integer arithmetic ops on gmx_simd_fint32_t */
+#define gmx_simd_add_fi vaddq_s32
+#define gmx_simd_sub_fi vsubq_s32
+#define gmx_simd_mul_fi vmulq_s32
+/* Boolean & comparison operations on gmx_simd_float_t */
+#define gmx_simd_fbool_t uint32x4_t
+#define gmx_simd_cmpeq_f vceqq_f32
+#define gmx_simd_cmplt_f vcltq_f32
+#define gmx_simd_cmple_f vcleq_f32
+#define gmx_simd_and_fb vandq_u32
+#define gmx_simd_or_fb vorrq_u32
+#define gmx_simd_anytrue_fb gmx_simd_anytrue_fb_arm_neon
+#define gmx_simd_blendzero_f(a, sel) vreinterpretq_f32_u32(vandq_u32(vreinterpretq_u32_f32(a), sel))
+#define gmx_simd_blendnotzero_f(a, sel) vreinterpretq_f32_u32(vbicq_u32(vreinterpretq_u32_f32(a), sel))
+#define gmx_simd_blendv_f(a, b, sel) vbslq_f32(sel, b, a)
+#define gmx_simd_reduce_f(a) gmx_simd_reduce_f_arm_neon(a)
+/* Boolean & comparison operations on gmx_simd_fint32_t */
+#define gmx_simd_fibool_t uint32x4_t
+#define gmx_simd_cmpeq_fi vceqq_s32
+#define gmx_simd_cmplt_fi vcltq_s32
+#define gmx_simd_and_fib vandq_u32
+#define gmx_simd_or_fib vorrq_u32
+#define gmx_simd_anytrue_fib gmx_simd_anytrue_fb
+#define gmx_simd_blendzero_fi(a, sel) vandq_s32(a, vreinterpretq_s32_u32(sel))
+#define gmx_simd_blendnotzero_fi(a, sel) vbicq_s32(a, vreinterpretq_s32_u32(sel))
+#define gmx_simd_blendv_fi(a, b, sel) vbslq_s32(sel, b, a)
+/* Conversions between different booleans */
+#define gmx_simd_cvt_fb2fib(x) (x)
+#define gmx_simd_cvt_fib2fb(x) (x)
+
+/****************************************************
+ * NO DOUBLE PRECISION SIMD AVAILABLE *
+ ****************************************************/
+
+
+/****************************************************
+ * SINGLE PRECISION IMPLEMENTATION HELPER FUNCTIONS *
+ ****************************************************/
+static gmx_inline gmx_simd_float_t
+gmx_simd_get_exponent_f_arm_neon(gmx_simd_float_t x)
+{
+ const float32x4_t expmask = vreinterpretq_f32_s32( vdupq_n_s32(0x7F800000) );
+ int32x4_t iexp;
+
+ iexp = vreinterpretq_s32_f32(gmx_simd_and_f(x, expmask));
+ iexp = vsubq_s32(vshrq_n_s32(iexp, 23), vdupq_n_s32(127));
+ return vcvtq_f32_s32(iexp);
+}
+
+
+static gmx_inline gmx_simd_float_t
+gmx_simd_get_mantissa_f_arm_neon(gmx_simd_float_t x)
+{
+ const float32x4_t mantmask = vreinterpretq_f32_s32( vdupq_n_s32(0x007FFFFF) );
+ const float32x4_t one = vdupq_n_f32(1.0f);
+
+ /* Get mantissa */
+ x = gmx_simd_and_f(mantmask, x);
+ /* Reset zero (but correctly biased) exponent */
+ return gmx_simd_or_f(x, one);
+}
+
+
+static gmx_inline gmx_simd_float_t
+gmx_simd_set_exponent_f_arm_neon(gmx_simd_float_t x)
+{
+ int32x4_t iexp = gmx_simd_cvt_f2i(x);
+
+ iexp = vshlq_n_s32(vaddq_s32(iexp, vdupq_n_s32(127)), 23);
+ return vreinterpretq_f32_s32(iexp);
+}
+
+static gmx_inline float
+gmx_simd_reduce_f_arm_neon(gmx_simd_float_t a)
+{
+ float32x4_t b = vextq_f32(a, a, 2);
+
+ a = vaddq_f32(a, b);
+ b = vextq_f32(a, a, 1);
+ a = vaddq_f32(a, b);
+ return vgetq_lane_f32(a, 0);
+}
+
+static gmx_inline int
+gmx_simd_anytrue_fb_arm_neon(gmx_simd_fbool_t a)
+{
+ uint32x4_t b = vextq_u32(a, a, 2);
+
+ a = gmx_simd_or_fb(a, b);
+ b = vextq_u32(a, a, 1);
+ a = gmx_simd_or_fb(a, b);
+ return (vgetq_lane_u32(a, 0) != 0);
+}
+
+
+/* ARM 32-bit Neon is already 4-wide in single, so just reuse float type for SIMD4 */
+#define gmx_simd4_float_t gmx_simd_float_t
+#define gmx_simd4_load_f gmx_simd_load_f
+#define gmx_simd4_load1_f gmx_simd_load1_f
+#define gmx_simd4_set1_f gmx_simd_set1_f
+#define gmx_simd4_store_f gmx_simd_store_f
+#define gmx_simd4_loadu_f gmx_simd_loadu_f
+#define gmx_simd4_storeu_f gmx_simd_storeu_f
+#define gmx_simd4_setzero_f gmx_simd_setzero_f
+#define gmx_simd4_add_f gmx_simd_add_f
+#define gmx_simd4_sub_f gmx_simd_sub_f
+#define gmx_simd4_mul_f gmx_simd_mul_f
+#define gmx_simd4_fmadd_f gmx_simd_fmadd_f
+#define gmx_simd4_fmsub_f gmx_simd_fmsub_f
+#define gmx_simd4_fnmadd_f gmx_simd_fnmadd_f
+#define gmx_simd4_fnmsub_f gmx_simd_fnmsub_f
+#define gmx_simd4_and_f gmx_simd_and_f
+#define gmx_simd4_andnot_f gmx_simd_andnot_f
+#define gmx_simd4_or_f gmx_simd_or_f
+#define gmx_simd4_xor_f gmx_simd_xor_f
+#define gmx_simd4_rsqrt_f gmx_simd_rsqrt_f
+#define gmx_simd4_fabs_f gmx_simd_fabs_f
+#define gmx_simd4_fneg_f gmx_simd_fneg_f
+#define gmx_simd4_max_f gmx_simd_max_f
+#define gmx_simd4_min_f gmx_simd_min_f
+#define gmx_simd4_round_f gmx_simd_round_f
+#define gmx_simd4_trunc_f gmx_simd_trunc_f
+#define gmx_simd4_dotproduct3_f gmx_simd4_dotproduct3_f_arm_neon
+#define gmx_simd4_fbool_t gmx_simd_fbool_t
+#define gmx_simd4_cmpeq_f gmx_simd_cmpeq_f
+#define gmx_simd4_cmplt_f gmx_simd_cmplt_f
+#define gmx_simd4_cmple_f gmx_simd_cmple_f
+#define gmx_simd4_and_fb gmx_simd_and_fb
+#define gmx_simd4_or_fb gmx_simd_or_fb
+#define gmx_simd4_anytrue_fb gmx_simd_anytrue_fb
+#define gmx_simd4_blendzero_f gmx_simd_blendzero_f
+#define gmx_simd4_blendnotzero_f gmx_simd_blendnotzero_f
+#define gmx_simd4_blendv_f gmx_simd_blendv_f
+#define gmx_simd4_reduce_f gmx_simd_reduce_f
+
+/* SIMD4 Dotproduct helper function */
+static gmx_inline float
+gmx_simd4_dotproduct3_f_arm_neon(gmx_simd_float_t a, gmx_simd_float_t b)
+{
+ gmx_simd_float_t c;
+ c = gmx_simd_mul_f(a, b);
+ /* set 4th element to 0, then add all of them */
+ c = vsetq_lane_f32(0.0f, c, 3);
+ return gmx_simd_reduce_f_arm_neon(c);
+}
+
+#endif /* GMX_SIMD_IMPL_ARM_NEON_H */