more flexible vector lengths

pocketfft_hdronly.h

@@ -95,15 +95,21 @@ constexpr bool FORWARD  = true,
 #endif
 #endif
 
+template<typename T> struct VLEN { static constexpr size_t val=1; };
+
 #ifndef POCKETFFT_NO_VECTORS
 #if (defined(__AVX512F__))
-constexpr int VBYTELEN=64;
+template<> struct VLEN<float> { static constexpr size_t val=16; };
+template<> struct VLEN<double> { static constexpr size_t val=8; };
 #elif (defined(__AVX__))
-constexpr int VBYTELEN=32;
+template<> struct VLEN<float> { static constexpr size_t val=8; };
+template<> struct VLEN<double> { static constexpr size_t val=4; };
 #elif (defined(__SSE2__))
-constexpr int VBYTELEN=16;
+template<> struct VLEN<float> { static constexpr size_t val=4; };
+template<> struct VLEN<double> { static constexpr size_t val=2; };
 #elif (defined(__VSX__))
-constexpr int VBYTELEN=16;
+template<> struct VLEN<float> { static constexpr size_t val=4; };
+template<> struct VLEN<double> { static constexpr size_t val=2; };
 #else
 #define POCKETFFT_NO_VECTORS
 #endif
@@ -2314,31 +2320,25 @@ template<size_t N, typename Ti, typename To> class multi_iter
 
 #ifndef POCKETFFT_NO_VECTORS
 template<typename T> struct VTYPE {};
-template<> struct VTYPE<long double>
+template<> struct VTYPE<float>
   {
-  using type = long double __attribute__ ((vector_size (sizeof(long double))));
-  static constexpr size_t vlen=1;
+  using type = float __attribute__ ((vector_size (VLEN<float>::val*sizeof(float))));
   };
 template<> struct VTYPE<double>
   {
-  using type = double __attribute__ ((vector_size (VBYTELEN)));
-  static constexpr size_t vlen=VBYTELEN/sizeof(double);
+  using type = double __attribute__ ((vector_size (VLEN<double>::val*sizeof(double))));
   };
-template<> struct VTYPE<float>
+template<> struct VTYPE<long double>
   {
-  using type = float __attribute__ ((vector_size (VBYTELEN)));
-  static constexpr size_t vlen=VBYTELEN/sizeof(float);
+  using type = long double __attribute__ ((vector_size (VLEN<long double>::val*sizeof(long double))));
   };
-#else
-template<typename T> struct VTYPE
-  { static constexpr size_t vlen=1; };
 #endif
 
 template<typename T> arr<char> alloc_tmp(const shape_t &shape,
   size_t axsize, size_t elemsize)
   {
   auto othersize = util::prod(shape)/axsize;
-  auto tmpsize = axsize*((othersize>=VTYPE<T>::vlen) ? VTYPE<T>::vlen : 1);
+  auto tmpsize = axsize*((othersize>=VLEN<T>::val) ? VLEN<T>::val : 1);
   return arr<char>(tmpsize*elemsize);
   }
 template<typename T> arr<char> alloc_tmp(const shape_t &shape,
@@ -2350,7 +2350,7 @@ template<typename T> arr<char> alloc_tmp(const shape_t &shape,
     {
     auto axsize = shape[axes[i]];
     auto othersize = fullsize/axsize;
-    auto sz = axsize*((othersize>=VTYPE<T>::vlen) ? VTYPE<T>::vlen : 1);
+    auto sz = axsize*((othersize>=VLEN<T>::val) ? VLEN<T>::val : 1);
     if (sz>tmpsize) tmpsize=sz;
     }
   return arr<char>(tmpsize*elemsize);
@@ -2370,7 +2370,7 @@ template<typename T> NOINLINE void general_c(
 
   for (size_t iax=0; iax<axes.size(); ++iax)
     {
-    constexpr auto vlen = VTYPE<T>::vlen;
+    constexpr auto vlen = VLEN<T>::val;
     size_t len=in.shape(axes[iax]);
     if ((!plan) || (len!=plan->length()))
       plan.reset(new pocketfft_c<T>(len));
@@ -2433,7 +2433,7 @@ template<typename T> NOINLINE void general_hartley(
 
   for (size_t iax=0; iax<axes.size(); ++iax)
     {
-    constexpr auto vlen = VTYPE<T>::vlen;
+    constexpr auto vlen = VLEN<T>::val;
     size_t len=in.shape(axes[iax]);
     if ((!plan) || (len!=plan->length()))
       plan.reset(new pocketfft_r<T>(len));
@@ -2494,7 +2494,7 @@ template<typename T> NOINLINE void general_r2c(
   size_t POCKETFFT_NTHREADS)
   {
   pocketfft_r<T> plan(in.shape(axis));
-  constexpr auto vlen = VTYPE<T>::vlen;
+  constexpr auto vlen = VLEN<T>::val;
   size_t len=in.shape(axis);
 #ifdef POCKETFFT_OPENMP
 #pragma omp parallel num_threads(util::thread_count(nthreads, in.shape(), axis))
@@ -2545,7 +2545,7 @@ template<typename T> NOINLINE void general_c2r(
   size_t POCKETFFT_NTHREADS)
   {
   pocketfft_r<T> plan(out.shape(axis));
-  constexpr auto vlen = VTYPE<T>::vlen;
+  constexpr auto vlen = VLEN<T>::val;
   size_t len=out.shape(axis);
 #ifdef POCKETFFT_OPENMP
 #pragma omp parallel num_threads(util::thread_count(nthreads, in.shape(), axis))
@@ -2600,7 +2600,7 @@ template<typename T> NOINLINE void general_r(
   const ndarr<T> &in, ndarr<T> &out, size_t axis, bool forward, T fct,
   size_t POCKETFFT_NTHREADS)
   {
-  constexpr auto vlen = VTYPE<T>::vlen;
+  constexpr auto vlen = VLEN<T>::val;
   size_t len=in.shape(axis);
   pocketfft_r<T> plan(len);
 #ifdef POCKETFFT_OPENMP