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