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39 #include "gromacs/simd/simd.h"
40 #include "gromacs/simd/vector_operations.h"
55 /*! \addtogroup module_simd */
58 # if GMX_SIMD_HAVE_REAL
60 /*! \internal \brief Test fixture for vector operations tests (identical to the generic \ref SimdTest) */
61 typedef SimdTest SimdVectorOperationsTest;
63 TEST_F(SimdVectorOperationsTest, iprod)
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(
72 c0 * c3 + c3 * c4 + c6 * c7, c1 * c0 + c4 * c6 + c7 * c2, c2 * c4 + c5 * c8 + c8 * c3);
75 GMX_EXPECT_SIMD_REAL_NEAR(iprodRef, iprod(aX, aY, aZ, bX, bY, bZ));
78 TEST_F(SimdVectorOperationsTest, norm2)
80 SimdReal simdX = rSimd_c0c1c2;
81 SimdReal simdY = rSimd_c3c4c5;
82 SimdReal simdZ = rSimd_c6c7c8;
83 SimdReal norm2Ref = setSimdRealFrom3R(
84 c0 * c0 + c3 * c3 + c6 * c6, c1 * c1 + c4 * c4 + c7 * c7, c2 * c2 + c5 * c5 + c8 * c8);
87 GMX_EXPECT_SIMD_REAL_NEAR(norm2Ref, norm2(simdX, simdY, simdZ));
90 TEST_F(SimdVectorOperationsTest, cprod)
92 SimdReal aX = rSimd_c0c1c2;
93 SimdReal aY = rSimd_c3c4c5;
94 SimdReal aZ = rSimd_c6c7c8;
95 SimdReal bX = rSimd_c3c0c4;
96 SimdReal bY = rSimd_c4c6c8;
97 SimdReal bZ = rSimd_c7c2c3;
98 // The SIMD version might use FMA. If we don't force FMA for the reference value, the compiler is free to use FMA
99 // for either product. If the compiler uses FMA for one product and the SIMD version uses FMA for the other, the
100 // rounding error of each product adds up and the total possible ulp-error is 12.
101 SimdReal refcX = setSimdRealFrom3R(
102 std::fma(-c6, c4, c3 * c7), std::fma(-c7, c6, c4 * c2), std::fma(-c8, c8, c5 * c3));
103 SimdReal refcY = setSimdRealFrom3R(
104 std::fma(-c0, c7, c6 * c3), std::fma(-c1, c2, c7 * c0), std::fma(-c2, c3, c8 * c4));
105 SimdReal refcZ = setSimdRealFrom3R(
106 std::fma(-c3, c3, c0 * c4), std::fma(-c4, c0, c1 * c6), std::fma(-c5, c4, c2 * c8));
109 // The test assumes that cprod uses FMA on architectures which have FMA so that the compiler
110 // can't choose which product is computed with FMA.
111 cprod(aX, aY, aZ, bX, bY, bZ, &cX, &cY, &cZ);
113 // The test values cannot be computed without FMA for the case that SIMD has no FMA. Even if no
114 // explicit FMA were used, the compiler could choose to use FMA. This causes up to 6upl error
115 // because of the product is up to 6 times larger than the final result after the difference.
116 setUlpTol(GMX_SIMD_HAVE_FMA ? ulpTol_ : 6);
118 GMX_EXPECT_SIMD_REAL_NEAR(refcX, cX);
119 GMX_EXPECT_SIMD_REAL_NEAR(refcY, cY);
120 GMX_EXPECT_SIMD_REAL_NEAR(refcZ, cZ);
123 # endif // GMX_SIMD_HAVE_REAL