[Bug target/55295] [SH] Add support for fipr instruction

[olegendo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55295

--- Comment #7 from Oleg Endo <olegendo at gcc dot gnu.org> 2013-03-06 01:05:14 UTC ---
(In reply to comment #5)
> > 
> > I'm also noticing that -ffast-math is inhibiting fmac emission in some cases:
> > 
> > Compiled with: -O3 -mfused-madd -ffast-math
> > 
> > testfunc:
> > .LFB1:
> >     .cfi_startproc
> >     mov.l    .L3,r1
> >     lds.l    @r1+,fpscr
> >     fldi1    fr0         ; what is a 1.0 doing here?
> >     add    #-4,r1
> >     add    #4,r1
> >     fadd    fr4,fr0     ; v+1 ??
> >     fmul    fr5,fr0     ; (v+1)*v2 ?? That's not what the code does...
> >     rts    
> >     lds.l    @r1+,fpscr
> > 
> > What's going on there? That doesn't even look correct...
> 
> The transformation is legitimate, although unlucky, since using fmac would be
> better in this case.
> 

I've opened a new PR 56547 for this issue.