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Re-enable deftransform for random integers

Describe the bug

We have a deftransform for word-sized random integers. This was used for the MT19937 generator. I think we forgot about this when we implemented the xoroshiro generator.

We can see this if we place this code in a file and compile it to produce a trace file:

(defun zot ()
  (random 100000))

To Reproduce

Steps to reproduce the behavior:

  1. Compile the above code with :trace-file t
  2. Look at the trace file. You can see a call to truncate.

Expected behavior

We should be doing a multiply instead of a truncate. Note also that this is a bug in that random uses a multiplication. We need to be consistent between the two code paths. I guess in practice, this is not so easy to see, but we could probably create a simple test for this.

Desktop (please complete the following information):

  • OS: All
  • Version: Any version after xoroshiro was implemented.