Though I suppose another view might be: can you judge the assignment to be successful, if you can never get the value you assigned, back, without it having been corrupted.

Yes - how do we conclusively determine whether the bug is in the assigning, or in the retrieving ?
I've been approaching this in a number of different ways, using POSIX, Inline::C and pack/unpack and it's always the same result.
On the x86 perl, whenever I check the value of the (supposed) SNAN, the output tells me that it's a QNAN. Yet the x64 perl always produces expected results.
It's very strange that identical code that behaves fine on x64 perl breaks on x86 perl - given that both of those perls have an ivtype of "long long" and an nvtype of "double".

Just now I've built x86 latest blead (5.25.2) with SvNVX() modified such that the addition of -0.0 is removed.
But it has made no difference.

However, I notice that the SvNVX macro that adds -0.0 is in an #ifdef PERL_DEBUG_COW block and I don't know if PERL_DEBUG_COW is defined.
I suspect that it's not defined because the test suite still produces the same results.

I should just file the bug report and let 'em work it out.

Cheers,
Rob

In reply to Re^9: unintentional conversion of signaling NaN to quiet NaN by syphilis
in thread unintentional conversion of signaling NaN to quiet NaN by pryrt

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