Add a pointer to the first element of the vector

codeplaysoftware · Aug 2, 2023 · 02ea296 · 02ea296
1 parent 57c2913
commit 02ea296
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Showing 2 changed files with 10 additions and 10 deletions.
diff --git a/include/views/view.h b/include/views/view.h
@@ -57,6 +57,10 @@ struct VectorView {
   index_t size_;
   increment_t strd_;  // never size_t, because it could be negative
 
+  // Start of the vector.
+  // If stride is negative, start at the end of the vector and move backward.
+  container_t ptr_;
+
   VectorView(view_container_t data, view_increment_t strd, view_index_t size);
   VectorView(VectorView<view_container_t, view_index_t, view_increment_t> opV,
              view_increment_t strd, view_index_t size);
@@ -97,17 +101,13 @@ struct VectorView {
   template <bool use_as_ptr = false>
   SYCL_BLAS_INLINE typename std::enable_if<!use_as_ptr, value_t &>::type eval(
       index_t i) {
-    return (strd_ == 1)  ? *(data_ + i)
-           : (strd_ > 0) ? *(data_ + i * strd_)
-                         : *(data_ + (size_ * -strd_) + ((i + 1) * strd_));
+    return (strd_ == 1) ? *(ptr_ + i) : *(ptr_ + i * strd_);
   }
 
   template <bool use_as_ptr = false>
   SYCL_BLAS_INLINE typename std::enable_if<!use_as_ptr, value_t>::type eval(
       index_t i) const {
-    return (strd_ == 1)  ? *(data_ + i)
-           : (strd_ > 0) ? *(data_ + i * strd_)
-                         : *(data_ + (size_ * -strd_) + ((i + 1) * strd_));
+    return (strd_ == 1) ? *(ptr_ + i) : *(ptr_ + i * strd_);
   }
 
   SYCL_BLAS_INLINE value_t &eval(cl::sycl::nd_item<1> ndItem) {
@@ -121,13 +121,13 @@ struct VectorView {
   template <bool use_as_ptr = false>
   SYCL_BLAS_INLINE typename std::enable_if<use_as_ptr, value_t &>::type eval(
       index_t indx) {
-    return *(data_ + indx);
+    return *(ptr_ + indx);
   }
 
   template <bool use_as_ptr = false>
   SYCL_BLAS_INLINE typename std::enable_if<use_as_ptr, value_t>::type eval(
       index_t indx) const noexcept {
-    return *(data_ + indx);
+    return *(ptr_ + indx);
   }
 };
 

diff --git a/src/views/view.hpp b/src/views/view.hpp
@@ -45,7 +45,7 @@ SYCL_BLAS_INLINE VectorView<_container_t, _IndexType,
                             _IncrementType>::VectorView(_container_t data,
                                                         _IncrementType strd,
                                                         _IndexType size)
-    : data_(data), size_(size), strd_(strd) {}
+    : data_(data), size_(size), strd_(strd), ptr_(strd > 0 ? data_ : data_ + (size_ - 1) * (-strd_)) {}
 
 /*!
  @brief Creates a view from an existing view.
@@ -55,7 +55,7 @@ SYCL_BLAS_INLINE
 VectorView<_container_t, _IndexType, _IncrementType>::VectorView(
     VectorView<_container_t, _IndexType, _IncrementType> opV,
     _IncrementType strd, _IndexType size)
-    : data_(opV.get_data()), size_(size), strd_(strd) {}
+    : data_(opV.get_data()), size_(size), strd_(strd), ptr_(strd > 0 ? data_ : data_ + (size_ - 1) * (-strd_)) {}
 
 /*!
  * @brief Returns a reference to the container