Paradoxical subreg questions

[John Wehle <john at feith dot com>]

I am in need of enlightenment regarding paradoxical subregs.
Specifically:

  1) Can wordnum for a paradoxical subreg ever be non-zero?

  2) What does:

       (set (subreg:DI (reg:SI 76) 0) (reg:DI 77))

     mean and how does it differ from:

       (set (reg:SI 76)) (truncate:SI (reg:DI 77))

  3) The documentation states:

       The reload pass ensures that paradoxical references are
       only made to hard registers.

     I assume that it's valid for paradoxical pseudo registers
     prior to reload.

-- John
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