> It's the encoding of 1.0f (single precision). The point is that we want
> something we can safely compare with 0.0f using floating-point instructions.
> "Safe" means "without generating any kind of exception", so a subnormal
> representation like 0x00000001 isn't acceptable. 1.0f seems as good a
> value as any.
>
> Yes, this is OK. Your split looks good, but I don't see any reason
> for the !CANNOT_CHANGE_MODE_CLASS condition.
>
> Couple of minor suggestions:
>
> - There is no need for the double quotes around the { ... }.
> Plain { ... } is better. (Support for plain { ... } was
> added a few years ago, so you can still see some older code
> that uses "{ ... }". But { ... } is better for new code.)
>
> - It's generally better to restrict match_dups to things
> that depend on the operands of the original insn.
> In the above, it'd be better to replace (match_dup 4)
> with (const_int 0) and then not set operands[4] in the
> C code. (match_dup 3) is OK as an exception because
> read-rtl.c doesn't support hex constants yet...
Thanks, learned a lot from your detailed explanation.
--
Best Regards.
