[Math] Completely remove VecCore dependency

Author: guitargeek

hist/hist/src/TFormula.cxx

@@ -56,7 +56,7 @@ std::string doubleToString(double val)
 // the native SIMD width used in compiled ROOT.
 std::string vectorizedArgType()
 {
-#ifdef ROOT_VECTORIZED_TMATH
+#ifdef R__HAS_VECCORE
    auto n = ROOT::Double_v::size();
    return "std::experimental::resize_simd_t<" + std::to_string(n) + ", ROOT::Double_v>";
 #else

math/mathcore/inc/Math/Types.h

@@ -3,6 +3,8 @@
 
 #include "RConfigure.h"
 
+#include "RtypesCore.h"
+
 #ifdef R__HAS_VECCORE
 
 // We always try to use std::simd as the VecCore backend.
@@ -17,37 +19,30 @@
 
 #define ROOT_VECTORIZED_TMATH
 
-#define VECCORE_ENABLE_STD_SIMD
-#include <VecCore/VecCore>
-#undef VECCORE_ENABLE_STD_SIMD
+#include <experimental/simd>
 
 namespace ROOT {
 
 namespace Internal {
 
-using ScalarBackend = vecCore::backend::Scalar;
-#ifdef ROOT_VECTORIZED_TMATH
-using VectorBackend = vecCore::backend::SIMDNative;
-#else
-using VectorBackend = vecCore::backend::Scalar;
-#endif
+template <typename T>
+using SIMDTag = std::experimental::simd_abi::native<T>;
 
 } // namespace Internal
 
-   using Float_v  = typename Internal::VectorBackend::Float_v;
-   using Double_v = typename Internal::VectorBackend::Double_v;
-   using Int_v    = typename Internal::VectorBackend::Int_v;
-   using Int32_v  = typename Internal::VectorBackend::Int32_v;
-   using UInt_v   = typename Internal::VectorBackend::UInt_v;
-   using UInt32_v = typename Internal::VectorBackend::UInt32_v;
-}
+using Float_v = std::experimental::simd<Float_t, Internal::SIMDTag<Float_t>>;
+using Double_v = std::experimental::simd<Double_t, Internal::SIMDTag<Double_t>>;
+using Int_v = std::experimental::simd<Int_t, Internal::SIMDTag<Int_t>>;
+using Int32_v = std::experimental::simd<Int_t, Internal::SIMDTag<Int_t>>;
+using UInt_v = std::experimental::simd<UInt_t, Internal::SIMDTag<UInt_t>>;
+using UInt32_v = std::experimental::simd<UInt_t, Internal::SIMDTag<UInt_t>>;
+
+} // namespace ROOT
 
 #else // R__HAS_VECCORE
 
 // We do not have explicit vectorisation support enabled. Fall back to regular ROOT types.
 
-#include "RtypesCore.h"
-
 namespace ROOT {
    using Float_v  = Float_t;
    using Double_v = Double_t;

math/mathcore/test/testVectorizedTMath.cxx

@@ -31,10 +31,10 @@ class VectorizedTMathTest : public ::testing::Test {
    VectorizedTMathTest() {}
 
    size_t kVS = ROOT::Double_v::size();
-   Double_t input_array1[N] __attribute__((aligned(VECCORE_SIMD_ALIGN)));
-   Double_t input_array2[N] __attribute__((aligned(VECCORE_SIMD_ALIGN)));
+   Double_t input_array1[N];
+   Double_t input_array2[N];
 
-   Double_t output_array[N] __attribute__((aligned(VECCORE_SIMD_ALIGN)));
+   Double_t output_array[N];
 };
 
 #define TEST_VECTORIZED_TMATH_FUNCTION(tmathfunc, a, b)                                                             \