mn416
commented
7 years ago Hi @yoterel, many thanks for the report.
After repeated runs of this example I was able to reproduce the non-deterministic behaviour you describe. I believe the problem arises because the Rot3D examples did not obey the following rule: for every call of gather() there should be a call of receive(). Breaking this rule could leave the QPUs in an inconsistent state. I've committed a fix. Let me know if you still encounter the problem.
Hi, when running the example 3d rotation and tweeking the source to post vertex x[0] y[0] before and after transformation, i receieve different values each time i run the program (vector 2 is being used).
tested on raspberry pi 3.
the function i am writing about: void rot3D(Int n, Float cosTheta, Float sinTheta, Ptr x, Ptr y)
{
// Function index() returns vector <0 1 2 ... 14 15>
Ptr p = x + index();
Ptr q = y + index();
// Pre-fetch first two vectors
gather(p); gather(q);
Float xOld, yOld; //initialiased to nothing at first For (Int i = 0, i < n, i = i+16) // Pre-fetch two vectors for the next iteration gather(p+16); gather(q+16); // Receive vectors for this iteration receive(xOld); receive(yOld); // Store results store(xOld cosTheta - yOld sinTheta, p); store(yOld cosTheta + xOld sinTheta, q); p = p+16; q = q+16; End }