src/gromacs/simd/tests/simd_floatingpoint.cpp

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 2014, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   6  * and including many others, as listed in the AUTHORS file in the
   7  * top-level source directory and at http://www.gromacs.org.
   8  *
   9  * GROMACS is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 2.1
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  13  *
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  35 #include "gmxpre.h"
  36
  37 #include "config.h"
  38
  39 #include <math.h>
  40 #include "gromacs/math/utilities.h"
  41
  42 #include "simd.h"
  43
  44 namespace gmx
  45 {
  46 namespace test
  47 {
  48 namespace
  49 {
  50
  51 /*! \cond internal */
  52 /*! \addtogroup module_simd */
  53 /*! \{ */
  54
  55 #ifdef GMX_SIMD_HAVE_REAL
  56
  57 /*! \brief Test fixture for floating-point tests (identical to the generic \ref SimdTest) */
  58 typedef SimdTest SimdFloatingpointTest;
  59
  60 TEST_F(SimdFloatingpointTest, gmxSimdSetZeroR)
  61 {
  62     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(0.0), gmx_simd_setzero_r());
  63 }
  64
  65 TEST_F(SimdFloatingpointTest, gmxSimdSet1R)
  66 {
  67     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(1.0), gmx_simd_set1_r(1.0));
  68 }
  69
  70 TEST_F(SimdFloatingpointTest, gmxSimdLoad1R)
  71 {
  72     real r = 2.0;
  73     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(r), gmx_simd_load1_r(&r));
  74 }
  75
  76 TEST_F(SimdFloatingpointTest, gmxSimdAddR)
  77 {
  78     GMX_EXPECT_SIMD_REAL_EQ(rSimd_5_7_9,
  79                             gmx_simd_add_r(rSimd_1_2_3, rSimd_4_5_6)); // 1+4=5, 2+5=7, 3+6=9
  80 }
  81
  82 TEST_F(SimdFloatingpointTest, gmxSimdSubR)
  83 {
  84     GMX_EXPECT_SIMD_REAL_EQ(rSimd_4_5_6,
  85                             gmx_simd_sub_r(rSimd_5_7_9, rSimd_1_2_3)); // 5-1=4, 7-2=5, 9-3=6
  86 }
  87
  88 TEST_F(SimdFloatingpointTest, gmxSimdMulR)
  89 {
  90     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(4, 10, 18),
  91                             gmx_simd_mul_r(rSimd_1_2_3, rSimd_4_5_6));
  92 }
  93
  94 TEST_F(SimdFloatingpointTest, gmxSimdFmaddR)
  95 {
  96     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(11, 18, 27),
  97                             gmx_simd_fmadd_r(rSimd_1_2_3, rSimd_4_5_6, rSimd_7_8_9)); // 1*4+7, etc.
  98 }
  99
 100 TEST_F(SimdFloatingpointTest, gmxSimdFmsubR)
 101 {
 102     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(-3, 2, 9),
 103                             gmx_simd_fmsub_r(rSimd_1_2_3, rSimd_4_5_6, rSimd_7_8_9)); // 1*4-7, etc.
 104 }
 105
 106 TEST_F(SimdFloatingpointTest, gmxSimdFnmaddR)
 107 {
 108     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(3, -2, -9),
 109                             gmx_simd_fnmadd_r(rSimd_1_2_3, rSimd_4_5_6, rSimd_7_8_9)); // -1*4+7, etc.
 110 }
 111
 112 TEST_F(SimdFloatingpointTest, gmxSimdFnmsubR)
 113 {
 114     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(-11, -18, -27),
 115                             gmx_simd_fnmsub_r(rSimd_1_2_3, rSimd_4_5_6, rSimd_7_8_9)); // -1*4-7, etc.
 116 }
 117
 118 TEST_F(SimdFloatingpointTest, gmxSimdFabsR)
 119 {
 120     GMX_EXPECT_SIMD_REAL_EQ(rSimd_1_2_3, gmx_simd_fabs_r(rSimd_1_2_3));    // fabs(x)=x
 121     GMX_EXPECT_SIMD_REAL_EQ(rSimd_1_2_3, gmx_simd_fabs_r(rSimd_m1_m2_m3)); // fabs(-x)=x
 122 }
 123
 124 TEST_F(SimdFloatingpointTest, gmxSimdFnegR)
 125 {
 126     GMX_EXPECT_SIMD_REAL_EQ(rSimd_m1_m2_m3, gmx_simd_fneg_r(rSimd_1_2_3));    // fneg(x)=-x
 127     GMX_EXPECT_SIMD_REAL_EQ(rSimd_1_2_3,    gmx_simd_fneg_r(rSimd_m1_m2_m3)); // fneg(-x)=x
 128 }
 129
 130 #ifdef GMX_SIMD_HAVE_LOGICAL
 131 /* 1.3333282470703125 has mantissa 0101010101010101 (followed by zeros)
 132  * 1.79998779296875   has mantissa 1100110011001100 (followed by zeros)
 133  * 1.26666259765625   has mantissa 0100010001000100 (followed by zeros)
 134  * 1.8666534423828125 has mantissa 1101110111011101 (followed by zeros)
 135  *
 136  * Since all of them have the same exponent (2^0), the exponent will
 137  * not change with AND or OR operations.
 138  */
 139 TEST_F(SimdFloatingpointTest, gmxSimdAndR)
 140 {
 141     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(1.26666259765625),
 142                             gmx_simd_and_r(gmx_simd_set1_r(1.3333282470703125),
 143                                            gmx_simd_set1_r(1.79998779296875)));
 144 }
 145
 146 TEST_F(SimdFloatingpointTest, gmxSimdOrR)
 147 {
 148     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(1.8666534423828125),
 149                             gmx_simd_or_r(gmx_simd_set1_r(1.3333282470703125),
 150                                           gmx_simd_set1_r(1.79998779296875)));
 151 }
 152
 153 TEST_F(SimdFloatingpointTest, gmxSimdXorR)
 154 {
 155     /* Test xor by taking xor with a number and its negative. This should result
 156      * in only the sign bit being set. We then use this bit change the sign of
 157      * different numbers.
 158      */
 159     gmx_simd_real_t signbit = gmx_simd_xor_r(gmx_simd_set1_r(1.5), gmx_simd_set1_r(-1.5));
 160     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(-1, 2, -3), gmx_simd_xor_r(signbit, setSimdRealFrom3R(1, -2, 3)));
 161 }
 162
 163 TEST_F(SimdFloatingpointTest, gmxSimdAndnotR)
 164 {
 165     /* Use xor (which we already tested, so fix that first if both tests fail)
 166      * to extract the sign bit, and then use andnot to take absolute values.
 167      */
 168     gmx_simd_real_t signbit = gmx_simd_xor_r(gmx_simd_set1_r(1.5), gmx_simd_set1_r(-1.5));
 169     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1, 2, 3), gmx_simd_andnot_r(signbit, setSimdRealFrom3R(-1, 2, -3)));
 170 }
 171
 172 #endif
 173
 174 TEST_F(SimdFloatingpointTest, gmxSimdMaxR)
 175 {
 176     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(3, 2, 4), gmx_simd_max_r(rSimd_1_2_3, rSimd_3_1_4));
 177     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(3, 2, 4), gmx_simd_max_r(rSimd_3_1_4, rSimd_1_2_3));
 178     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(-1, -1, -3), gmx_simd_max_r(rSimd_m1_m2_m3, rSimd_m3_m1_m4));
 179     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(-1, -1, -3), gmx_simd_max_r(rSimd_m3_m1_m4, rSimd_m1_m2_m3));
 180 }
 181
 182 TEST_F(SimdFloatingpointTest, gmxSimdMinR)
 183 {
 184     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1, 1, 3), gmx_simd_min_r(rSimd_1_2_3, rSimd_3_1_4));
 185     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1, 1, 3), gmx_simd_min_r(rSimd_3_1_4, rSimd_1_2_3));
 186     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(-3, -2, -4), gmx_simd_min_r(rSimd_m1_m2_m3, rSimd_m3_m1_m4));
 187     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(-3, -2, -4), gmx_simd_min_r(rSimd_m3_m1_m4, rSimd_m1_m2_m3));
 188 }
 189
 190 TEST_F(SimdFloatingpointTest, gmxSimdRoundR)
 191 {
 192     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(2), gmx_simd_round_r(gmx_simd_set1_r(2.25)));
 193     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(4), gmx_simd_round_r(gmx_simd_set1_r(3.75)));
 194     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(-2), gmx_simd_round_r(gmx_simd_set1_r(-2.25)));
 195     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(-4), gmx_simd_round_r(gmx_simd_set1_r(-3.75)));
 196 }
 197
 198 TEST_F(SimdFloatingpointTest, gmxSimdTruncR)
 199 {
 200     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(2), gmx_simd_trunc_r(rSimd_2p25));
 201     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(3), gmx_simd_trunc_r(rSimd_3p75));
 202     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(-2), gmx_simd_trunc_r(rSimd_m2p25));
 203     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(-3), gmx_simd_trunc_r(rSimd_m3p75));
 204 }
 205
 206 TEST_F(SimdFloatingpointTest, gmxSimdFractionR)
 207 {
 208     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(0.25), gmx_simd_fraction_r(rSimd_2p25));   // fract(2.25)=0.25
 209     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(0.75), gmx_simd_fraction_r(rSimd_3p75));   // fract(3.75)=0.75
 210     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(-0.25), gmx_simd_fraction_r(rSimd_m2p25)); // fract(-2.25)=-0.25
 211     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom1R(-0.75), gmx_simd_fraction_r(rSimd_m3p75)); // fract(-3.75)=-0.75
 212 }
 213
 214 // We explicitly test the exponent/mantissa routines with double precision data,
 215 // since these usually rely on direct manipulation and shift of the SIMD registers,
 216 // where it is easy to make mistakes with single vs double precision.
 217
 218 TEST_F(SimdFloatingpointTest, gmxSimdGetExponentR)
 219 {
 220     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(60.0, -41.0, 54.0), gmx_simd_get_exponent_r(rSimd_Exp));
 221 #if (defined GMX_SIMD_HAVE_DOUBLE) && (defined GMX_DOUBLE)
 222     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(587.0, -462.0, 672.0), gmx_simd_get_exponent_r(rSimd_ExpDouble));
 223 #endif
 224 }
 225
 226 TEST_F(SimdFloatingpointTest, gmxSimdGetMantissaR)
 227 {
 228     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1.219097320577810839026256,
 229                                               1.166738027848349235071623,
 230                                               1.168904015004464724825084), gmx_simd_get_mantissa_r(rSimd_Exp));
 231 #if (defined GMX_SIMD_HAVE_DOUBLE) && (defined GMX_DOUBLE)
 232     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1.241261238952345623563251,
 233                                               1.047294723759123852359232,
 234                                               1.856066204750275957395734), gmx_simd_get_mantissa_r(rSimd_ExpDouble));
 235 #endif
 236 }
 237
 238 TEST_F(SimdFloatingpointTest, gmxSimdSetExponentR)
 239 {
 240     gmx_simd_real_t x0 = setSimdRealFrom3R(0.5, 11.5, 99.5);
 241     gmx_simd_real_t x1 = setSimdRealFrom3R(-0.5, -11.5, -99.5);
 242
 243     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(pow(2.0, 60.0), pow(2.0, -41.0), pow(2.0, 54.0)),
 244                             gmx_simd_set_exponent_r(setSimdRealFrom3R(60.0, -41.0, 54.0)));
 245 #if (defined GMX_SIMD_HAVE_DOUBLE) && (defined GMX_DOUBLE)
 246     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(pow(2.0, 587.0), pow(2.0, -462.0), pow(2.0, 672.0)),
 247                             gmx_simd_set_exponent_r(setSimdRealFrom3R(587.0, -462.0, 672.0)));
 248 #endif
 249     /* Rounding mode in gmx_simd_set_exponent_r() must be consistent with gmx_simd_round_r() */
 250     GMX_EXPECT_SIMD_REAL_EQ(gmx_simd_set_exponent_r(gmx_simd_round_r(x0)), gmx_simd_set_exponent_r(x0));
 251     GMX_EXPECT_SIMD_REAL_EQ(gmx_simd_set_exponent_r(gmx_simd_round_r(x1)), gmx_simd_set_exponent_r(x1));
 252 }
 253
 254 /*
 255  * We do extensive 1/sqrt(x) and 1/x accuracy testing in the math module, so
 256  * we just make sure the lookup instructions appear to work here
 257  */
 258
 259 TEST_F(SimdFloatingpointTest, gmxSimdRsqrtR)
 260 {
 261     gmx_simd_real_t x      = setSimdRealFrom3R(4.0, M_PI, 1234567890.0);
 262     gmx_simd_real_t ref    = setSimdRealFrom3R(0.5, 1.0/sqrt(M_PI), 1.0/sqrt(1234567890.0));
 263
 264     /* Set the allowed ulp error as 2 to the power of the number of bits in
 265      * the mantissa that do not have to be correct after the table lookup.
 266      */
 267     setUlpTol(1LL << (std::numeric_limits<real>::digits-GMX_SIMD_RSQRT_BITS));
 268
 269     GMX_EXPECT_SIMD_REAL_NEAR(ref, gmx_simd_rsqrt_r(x));
 270 }
 271
 272 TEST_F(SimdFloatingpointTest, gmxSimdRcpR)
 273 {
 274     gmx_simd_real_t x      = setSimdRealFrom3R(4.0, M_PI, 1234567890.0);
 275     gmx_simd_real_t ref    = setSimdRealFrom3R(0.25, 1.0/M_PI, 1.0/1234567890.0);
 276
 277     /* Set the allowed ulp error as 2 to the power of the number of bits in
 278      * the mantissa that do not have to be correct after the table lookup.
 279      */
 280     setUlpTol(1LL << (std::numeric_limits<real>::digits-GMX_SIMD_RCP_BITS));
 281
 282     GMX_EXPECT_SIMD_REAL_NEAR(ref, gmx_simd_rcp_r(x));
 283 }
 284
 285 TEST_F(SimdFloatingpointTest, gmxSimdBoolCmpEqAndBlendZeroR)
 286 {
 287     gmx_simd_bool_t eq   = gmx_simd_cmpeq_r(rSimd_5_7_9, rSimd_7_8_9);
 288     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(0, 0, 3), gmx_simd_blendzero_r(rSimd_1_2_3, eq));
 289 }
 290
 291 TEST_F(SimdFloatingpointTest, gmxSimdBlendNotZeroR)
 292 {
 293     gmx_simd_bool_t eq   = gmx_simd_cmpeq_r(rSimd_5_7_9, rSimd_7_8_9);
 294     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1, 2, 0), gmx_simd_blendnotzero_r(rSimd_1_2_3, eq));
 295 }
 296
 297 TEST_F(SimdFloatingpointTest, gmxSimdBoolCmpLER)
 298 {
 299     gmx_simd_bool_t le   = gmx_simd_cmple_r(rSimd_5_7_9, rSimd_7_8_9);
 300     GMX_EXPECT_SIMD_REAL_EQ(rSimd_1_2_3, gmx_simd_blendzero_r(rSimd_1_2_3, le));
 301 }
 302
 303 TEST_F(SimdFloatingpointTest, gmxSimdBoolCmpLTR)
 304 {
 305     gmx_simd_bool_t lt   = gmx_simd_cmplt_r(rSimd_5_7_9, rSimd_7_8_9);
 306     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1, 2, 0), gmx_simd_blendzero_r(rSimd_1_2_3, lt));
 307 }
 308
 309 TEST_F(SimdFloatingpointTest, gmxSimdBoolAndB)
 310 {
 311     gmx_simd_bool_t eq   = gmx_simd_cmpeq_r(rSimd_5_7_9, rSimd_7_8_9);
 312     gmx_simd_bool_t le   = gmx_simd_cmple_r(rSimd_5_7_9, rSimd_7_8_9);
 313     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(0, 0, 3), gmx_simd_blendzero_r(rSimd_1_2_3, gmx_simd_and_b(eq, le)));
 314 }
 315
 316 TEST_F(SimdFloatingpointTest, gmxSimdBoolOrB)
 317 {
 318     gmx_simd_bool_t eq   = gmx_simd_cmpeq_r(rSimd_5_7_9, rSimd_7_8_9);
 319     gmx_simd_bool_t lt   = gmx_simd_cmplt_r(rSimd_5_7_9, rSimd_7_8_9);
 320     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(1, 2, 3), gmx_simd_blendzero_r(rSimd_1_2_3, gmx_simd_or_b(eq, lt)));
 321 }
 322
 323 TEST_F(SimdFloatingpointTest, gmxSimdAnytrueB)
 324 {
 325     gmx_simd_bool_t eq;
 326
 327     /* this test is a bit tricky since we don't know the simd width.
 328      * We cannot check for truth values for "any" element beyond the first,
 329      * since that part of the data will not be used if simd width is 1.
 330      */
 331     eq = gmx_simd_cmpeq_r(rSimd_5_7_9, setSimdRealFrom3R(5, 0, 0));
 332     EXPECT_NE(0, gmx_simd_anytrue_b(eq));
 333
 334     eq = gmx_simd_cmpeq_r(rSimd_1_2_3, rSimd_4_5_6);
 335     EXPECT_EQ(0, gmx_simd_anytrue_b(eq));
 336 }
 337
 338 TEST_F(SimdFloatingpointTest, gmxSimdBlendvR)
 339 {
 340     gmx_simd_bool_t lt   = gmx_simd_cmplt_r(rSimd_5_7_9, rSimd_7_8_9);
 341     GMX_EXPECT_SIMD_REAL_EQ(setSimdRealFrom3R(4, 5, 3), gmx_simd_blendv_r(rSimd_1_2_3, rSimd_4_5_6, lt));
 342 }
 343
 344 TEST_F(SimdFloatingpointTest, gmxSimdReduceR)
 345 {
 346     // The horizontal sum of the SIMD variable depends on the width, so
 347     // simply store it an extra time and calculate what the sum should be
 348     std::vector<real> v   = simdReal2Vector(rSimd_4_5_6);
 349     real              sum = 0.0;
 350
 351     for (int i = 0; i < GMX_SIMD_REAL_WIDTH; i++)
 352     {
 353         sum += v[i];
 354     }
 355
 356     EXPECT_EQ(sum, gmx_simd_reduce_r(rSimd_4_5_6));
 357 }
 358
 359 #endif      // GMX_SIMD_HAVE_REAL
 360
 361 /*! \} */
 362 /*! \endcond */
 363
 364 }      // namespace
 365 }      // namespace
 366 }      // namespace