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IconShow Lessons List
  1. What is SYCL
  2. Enqueueing a Kernel
  3. Managing Data
  4. Handling Errors
  5. Device Discovery
  6. Data Parallelism
  7. Introduction to USM
  8. Using USM
  9. Asynchronous Execution
  10. Data and Dependencies
  11. In Order Queue
  12. Advanced Data Flow
  13. Multiple Devices
  14. Image Convolution
  15. Coalesced Global Memory
  16. Vectors
  17. Local Memory Tiling
  18. Further Optimisations
  19. Matrix Transpose
  20. More SYCL Features
  21. Functors
Lesson
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Solution
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Coalesced Global Memory

In this exercise you will learn how to use vec to explicitly vectorized your kernel function.

1.) Use vectors

Now that global memory access is coalesced another optimization you can do is to use the vec class to present the pixels in the image.

To do this first you want to reinterpret the buffer objects as buffers with the element type float4. You can do this by calling reinterpret on the buffers and specifying the type float4.

Note you will have to provide a new ranges which will be the original ranges divided by 4 to account for the channels which are now represented by the four elements of the vector type.

2.) Refactor the kernel function

Now that you are using vector types, you want to replace the representation of pixels in the kernel function with a float4 and remove any multiplication or offsets to account for the number of channels.

Build and execution hints

For DevCloud via JupiterLab follow these instructions.

For DPC++: instructions.

For AdaptiveCpp: instructions.