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add configuration and compilation instructions; properly indent a function in example01

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Dakota St. Laurent
2015-06-12 19:00:45 -04:00
parent 1ea82c8b76
commit fd6b886c67
2 changed files with 29 additions and 14 deletions
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19
README.md
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@@ -1,5 +1,22 @@
# OpenCL basic examples # OpenCL basic examples
here is my feeble attempt at learning OpenCL, please don't make fun of me too much :hamburger here is my feeble attempt at learning OpenCL, please don't make fun of me too much :hamburger:
## Configuration
This currently runs on OS X, and I'm using local header files instead of global header files because I'm unfamiliar with C++. Deal with it. Run the following in a terminal to set up:
```
git clone git@github.com:SaintDako/OpenCL-examples.git
mkdir CL
curl https://www.khronos.org/registry/cl/api/1.2/cl.hpp -o CL/cl.hpp
```
## Compiling
```
clang++ -std=c++0x -framework OpenCL example01.cpp -o example01.out
```
To ignore the deprecation warnings, add the flag `-Wno-deprecated-declarations`.
## example 00 ## example 00
this example is based off of [this example](simpleopencl.blogspot.ca/2013/06/tutorial-simple-start-with-opencl-and-c.html) (example-ception), but it goes a bit further. In the blogspot example, two 10-element vectors are created and a thread is used for each pair of elements. In this example, 10 threads are spawned but two 100-element vectors are used, and it is shown how to split up a specific number of elements per thread. this example is based off of [this example](simpleopencl.blogspot.ca/2013/06/tutorial-simple-start-with-opencl-and-c.html) (example-ception), but it goes a bit further. In the blogspot example, two 10-element vectors are created and a thread is used for each pair of elements. In this example, 10 threads are spawned but two 100-element vectors are used, and it is shown how to split up a specific number of elements per thread.

6
example01.cpp
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@@ -3,7 +3,7 @@
#include <ctime> #include <ctime>
void compareResults (double CPUtime, double GPUtime, int trial) { void compareResults (double CPUtime, double GPUtime, int trial) {
double time_ratio = (CPUtime / GPUtime); double time_ratio = (CPUtime / GPUtime);
std::cout << "VERSION " << trial << " -----------" << std::endl; std::cout << "VERSION " << trial << " -----------" << std::endl;
std::cout << "CPU time: " << CPUtime << std::endl; std::cout << "CPU time: " << CPUtime << std::endl;
@@ -39,6 +39,7 @@ double timeAddVectorsCPU(int n, int k) {
return duration; return duration;
} }
int main() { int main() {
// get all platforms (drivers), e.g. NVIDIA // get all platforms (drivers), e.g. NVIDIA
std::vector<cl::Platform> all_platforms; std::vector<cl::Platform> all_platforms;
@@ -66,9 +67,6 @@ int main() {
cl::Context context({default_device}); cl::Context context({default_device});
cl::Program::Sources sources; cl::Program::Sources sources;
std::cout << CL_DEVICE_MAX_WORK_ITEM_SIZES << std::endl;
exit(1);
// calculates for each element; C = A + B // calculates for each element; C = A + B
std::string kernel_code= std::string kernel_code=
// is equivalent to the host's "time_add_vectors" function, except the // is equivalent to the host's "time_add_vectors" function, except the