src/gromacs/simd/tests/simd_vector_operations.cpp

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  35 #include "gmxpre.h"
  36
  37 #include <cmath>
  38
  39 #include "gromacs/simd/simd.h"
  40 #include "gromacs/simd/vector_operations.h"
  41
  42 #include "data.h"
  43 #include "simd.h"
  44
  45 #if GMX_SIMD
  46
  47 namespace gmx
  48 {
  49 namespace test
  50 {
  51 namespace
  52 {
  53
  54 /*! \cond internal */
  55 /*! \addtogroup module_simd */
  56 /*! \{ */
  57
  58 #if GMX_SIMD_HAVE_REAL
  59
  60 /*! \internal \brief Test fixture for vector operations tests (identical to the generic \ref SimdTest) */
  61 typedef SimdTest SimdVectorOperationsTest;
  62
  63 TEST_F(SimdVectorOperationsTest, iprod)
  64 {
  65     SimdReal aX       = rSimd_c0c1c2;
  66     SimdReal aY       = rSimd_c3c4c5;
  67     SimdReal aZ       = rSimd_c6c7c8;
  68     SimdReal bX       = rSimd_c3c0c4;
  69     SimdReal bY       = rSimd_c4c6c8;
  70     SimdReal bZ       = rSimd_c7c2c3;
  71     SimdReal iprodRef = setSimdRealFrom3R(c0*c3 + c3*c4 + c6*c7,
  72                                           c1*c0 + c4*c6 + c7*c2,
  73                                           c2*c4 + c5*c8 + c8*c3);
  74
  75     setUlpTol(2);
  76     GMX_EXPECT_SIMD_REAL_NEAR(iprodRef, iprod(aX, aY, aZ, bX, bY, bZ));
  77 }
  78
  79 TEST_F(SimdVectorOperationsTest, norm2)
  80 {
  81     SimdReal simdX    = rSimd_c0c1c2;
  82     SimdReal simdY    = rSimd_c3c4c5;
  83     SimdReal simdZ    = rSimd_c6c7c8;
  84     SimdReal norm2Ref = setSimdRealFrom3R(c0*c0 + c3*c3 + c6*c6,
  85                                           c1*c1 + c4*c4 + c7*c7,
  86                                           c2*c2 + c5*c5 + c8*c8);
  87
  88     setUlpTol(2);
  89     GMX_EXPECT_SIMD_REAL_NEAR(norm2Ref, norm2(simdX, simdY, simdZ));
  90 }
  91
  92 TEST_F(SimdVectorOperationsTest, cprod)
  93 {
  94     SimdReal aX    = rSimd_c0c1c2;
  95     SimdReal aY    = rSimd_c3c4c5;
  96     SimdReal aZ    = rSimd_c6c7c8;
  97     SimdReal bX    = rSimd_c3c0c4;
  98     SimdReal bY    = rSimd_c4c6c8;
  99     SimdReal bZ    = rSimd_c7c2c3;
 100     //The SIMD version might use FMA. If we don't force FMA for the reference value, the compiler is free to use FMA
 101     //for either product. If the compiler uses FMA for one product and the SIMD version uses FMA for the other, the
 102     //rounding error of each product adds up and the total possible ulp-error is 12.
 103     SimdReal refcX = setSimdRealFrom3R( std::fma(-c6, c4, c3*c7), std::fma(-c7, c6, c4*c2), std::fma(-c8, c8, c5*c3));
 104     SimdReal refcY = setSimdRealFrom3R( std::fma(-c0, c7, c6*c3), std::fma(-c1, c2, c7*c0), std::fma(-c2, c3, c8*c4));
 105     SimdReal refcZ = setSimdRealFrom3R( std::fma(-c3, c3, c0*c4), std::fma(-c4, c0, c1*c6), std::fma(-c5, c4, c2*c8));
 106     SimdReal cX, cY, cZ;
 107
 108     //The test assumes that cprod uses FMA on architectures which have FMA so that the compiler can't choose which
 109     //product is computed with FMA.
 110     cprod(aX, aY, aZ, bX, bY, bZ, &cX, &cY, &cZ);
 111
 112     //The test values cannot be computed without FMA for the case that SIMD has no FMA. Even if no explicit FMA were
 113     //used, the compiler could choose to use FMA. This causes up to 6upl error because of the product is up to 6 times
 114     //larger than the final result after the difference.
 115     setUlpTol(GMX_SIMD_HAVE_FMA ? ulpTol_ : 6);
 116
 117     GMX_EXPECT_SIMD_REAL_NEAR(refcX, cX);
 118     GMX_EXPECT_SIMD_REAL_NEAR(refcY, cY);
 119     GMX_EXPECT_SIMD_REAL_NEAR(refcZ, cZ);
 120 }
 121
 122 #endif      // GMX_SIMD_HAVE_REAL
 123
 124 /*! \} */
 125 /*! \endcond */
 126
 127 }      // namespace
 128 }      // namespace test
 129 }      // namespace gmx
 130
 131 #endif // GMX_SIMD