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Re: [PATCH] Perform constant folding of math builtins
"Kaveh R. Ghazi" <ghazi@caip.rutgers.edu> writes:
| > From: Gabriel Dos Reis <gdr@integrable-solutions.net>
| >
| > "Kaveh R. Ghazi" <ghazi@caip.rutgers.edu> writes:
| >
| > | Assuming I remembered everything correctly, these are mathematical
| > | identities. But I'm not sure which if any are valid/invalid in the
| > | presence of NaNs, etc.
| >
| > Well, I'm not sure we want to restart the discussion about what
| > -funsafe-transformations should mean, but if we were to consider all
| > those mentioned transformations (which are valid under appropriate
| > conditions) I think we ought to clearly state what we want
| > -funsae-transformation to do.
| > -- Gaby
|
| The descriptions of the various fast math flags in invoke.texi
| (including -funsafe-math-optimizations if that's what you meant) are
| all pretty explicit and clear IMHO.
I don't think I agree with you that the documentation is explicit and
clear. For example, it doesn't appear to me as explicit and clear
that the description of "-ffast-mast" does consider the divergences in
IEEE-754 and ISO rules, notably between IEEE-754 and LIA-1, or
divergences between IEEE-754 specifications and ISO C specifications.
Ditto for "-funsafe-math-optimizations".
| If an FP expert would comment on that, I'd be grateful.
I can't find why the above strikes me as excluding me from the set of
"FP expert". Oh, well.
-- Gaby