>> 0x7f786048 <strtod+2498>:       movd r8,r0

> So the next question would be should the vax be signaling an illegal
> instruction for this, signaling some other condition, or dealing with
> the "reserved operand"?.

If r8 contains 0x00008000, then yes, that movd should take a reserved
operand fault (regardless of r9 - the mantissa doesn't matter).
According to the VAX trap.cs I've looked at (both my own source tree
and current), this will turn into a SIGILL.

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