[Bug target/53513] SH Target: Add support for fschg and fpchg insns

[kkojima at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53513

--- Comment #9 from Kazumoto Kojima <kkojima at gcc dot gnu.org> ---
Although it seems that (1)-(5) in #3 are interesting points, they
are almost optimizations.  I guess that programs with frequent FP
mode switchings are simply rare in real world and would be a bit
special or even pathological in the first place.
I like the idea of mode switching without __fpscr_values even if it
requires more instructions on SH4.  Now SH4 is a fairy old core and
is not for heavy FP computations anyway.  I think that it won't impact
the real working set.
It looks to me that Christian's patch is the way to go.