neil@xxxxxxxxxxxxxxx said:
> b) Exponents have a wider range, so overflows or underflows that
> would happen on doubles don't necessarily happen on long
> doubles.
Yes, I had figured that too, see my second reply to the PR.
> d) Despite many claims to the contrary that you will read on the
> net, and on GCC lists, there is no double-rounding problem.
The famous "paranoia" test program finds a number of rounding
flaws eg on Linux. I've extracted the failing tests for
multiplication - see attachment.
The tests succeed on NetBSD. If I set the FPCW to its initial
value, ie 64-bit rounding (by enabling the "#if 0" part),
the tests fail. With -mfpmath=sse, the tests succeed.
So doubles are still not rounded correctly if the FPU is used
in extended precision mode.
best regards
Matthias
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para_part.c
Description: para_part.c
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