This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Porposal: Floating-Point Options


On Thu, 16 Jun 2005, Geoffrey Keating wrote:

> Although it does do some of this, -ffloat-store also has some rather nasty
> side-effects, because of what it is actually documented to do:
> 
> > @item -ffloat-store
> > @opindex ffloat-store
> > Do not store floating point variables in registers, and inhibit other
> > options that might change whether a floating point value is taken from a
> > register or memory.

But is this actually a useful thing for users to be able to control, other 
than for its effects in avoiding excess precision?  If not - if the real 
uses of it are for the same purpose as gcc.c-torture/execute/ieee/ieee.exp 
uses it on x86, x86_64 -m32 and m68k, to avoid excess precision - then we 
can just repurpose this option and make it a no-op on systems which 
naturally don't need excess precision, and users using -ffloat-store right 
now to avoid excess precision will find their code gets improved 
correctness.

-- 
Joseph S. Myers               http://www.srcf.ucam.org/~jsm28/gcc/
    jsm@polyomino.org.uk (personal mail)
    joseph@codesourcery.com (CodeSourcery mail)
    jsm28@gcc.gnu.org (Bugzilla assignments and CCs)


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]