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