initial work on SIMD wrappers

Author: kevinushey

.gitignore

@@ -4,3 +4,4 @@
 .DS_Store
 src-i386/
 src-x64/
+.Rprofile

examples/rcpp-simd-transform.cpp

@@ -0,0 +1,51 @@
+// [[Rcpp::depends(RcppParallel)]]
+#include <RcppParallel.h>
+#include <Rcpp.h>
+
+using namespace Rcpp;
+using namespace RcppParallel;
+
+struct add_two_impl {
+   
+   template <typename T>
+   T operator()(T data) const {
+      return data + 2.0;
+   }
+   
+   template <typename T>
+   T operator()(T lhs, T rhs) const {
+      return lhs + rhs;
+   }
+};
+
+// [[Rcpp::export]]
+NumericVector simd_add_two(NumericVector data)
+{
+   return simd::transform(data, add_two_impl());
+}
+
+// [[Rcpp::export]]
+NumericVector simd_add(NumericVector lhs, NumericVector rhs)
+{
+   return simd::transform(lhs, rhs, add_two_impl());
+}
+
+struct plus {
+   template <typename T>
+   T operator()(const T& lhs, const T& rhs) const {
+      return lhs + rhs;
+   }
+};
+
+// [[Rcpp::export]]
+double simd_sum(NumericVector data)
+{
+   return simd::accumulate(data, 0.0, plus());
+}
+
+/*** R
+data <- as.numeric(1:16)
+simd_add_two(data)
+simd_add(data, data)
+simd_sum(data)
+*/

inst/include/RcppParallel.h

@@ -5,6 +5,9 @@
 // TinyThread implementation
 #include "RcppParallel/TinyThread.h"
 
+// SIMD Wrappers
+#include "RcppParallel/SIMD.h"
+
 // Use TBB only where it's known to compile and work correctly
 // (NOTE: Windows TBB is temporarily opt-in for packages for 
 // compatibility with CRAN packages not previously configured

inst/include/RcppParallel/RVector.h

@@ -42,6 +42,7 @@ class RVector {
    inline const_iterator begin() const { return begin_; }
    inline const_iterator end() const { return end_; }
 
+   inline std::size_t size() const { return end_ - begin_; }
    inline std::size_t length() const { return end_ - begin_; }
 
    inline T& operator[](std::size_t i) {

inst/include/RcppParallel/SIMD.h

@@ -0,0 +1,34 @@
+#ifndef RCPP_PARALLEL_SIMD_H
+#define RCPP_PARALLEL_SIMD_H
+
+#include <boost/simd/sdk/simd/algorithm.hpp>
+
+namespace RcppParallel {
+namespace simd {
+
+template <class T, class UnaryFunction>
+T transform(const T& data, UnaryFunction f)
+{
+   T result(data.size());
+   boost::simd::transform(data.begin(), data.end(), result.begin(), f);
+   return result;
+}
+
+template <class T, class BinaryFunction>
+T transform(const T& lhs, const T& rhs, BinaryFunction f)
+{
+   T result(lhs.size());
+   boost::simd::transform(lhs.begin(), lhs.end(), rhs.begin(), result.begin(), f);
+   return result;
+}
+
+template <class T, class U, class F>
+U accumulate(const T& data, U init, F f)
+{
+   return boost::simd::accumulate(data.begin(), data.end(), init, f);
+}
+
+} // namespace simd
+} // namespace RcppParallel
+
+#endif /* RCPP_PARALLEL_SIMD_H */