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Re: Serious bug
- To: tim at wagner dot princeton dot edu
- Subject: Re: Serious bug
- From: Craig Burley <burley at gnu dot org>
- Date: Fri, 25 Sep 1998 12:55:14 -0400 (EDT)
- CC: kabatek at chemie dot uni-halle dot de, oliva at dcc dot unicamp dot br, egcs-bugs at cygnus dot com, egcs at cygnus dot com, egcs-patches at cygnus dot com
>"but a few programs rely on the precise definition of IEEE floating
>point. Use `-ffloat-store' for such programs."
>
>So -ffloat-store does not work as documented, since some constructs
>still manage to disobey IEEE behavior even with it on.
Actually, it does work as documented, if you take into account the
entire writeup on the option, instead of just looking at the last
few words. It starts off saying "Do not store floating point variables..."
(though perhaps that should be emphasized as "floating-point
@emph{variables}...").
Nevertheless, good documentation should, IMO, not easily suffer this
sort of misreading, so I propose the following patch.
Also, perhaps it's worth considering providing -ffloat-store-all,
to store intermediate results as well, which will *really* slow
down some programs. :)
tq vm, (burley)
Fri Sep 25 12:51:28 1998 Craig Burley <burley@melange.gnu.org>
* invoke.texi (-ffloat-store): Clarify that this option
does not affect intermediate results -- only variables.
*** g77-e/gcc/invoke.texi.~1~ Mon Jul 13 08:39:33 1998
--- g77-e/gcc/invoke.texi Fri Sep 25 12:50:25 1998
*************** precision than a @code{double} is suppos
*** 2190,2194 ****
x86 architecture. For most programs, the excess precision does only
good, but a few programs rely on the precise definition of IEEE floating
! point. Use @samp{-ffloat-store} for such programs.
@item -fno-default-inline
--- 2190,2195 ----
x86 architecture. For most programs, the excess precision does only
good, but a few programs rely on the precise definition of IEEE floating
! point. Use @samp{-ffloat-store} for such programs, after modifying
! them to store all pertinent intermediate computations into variables.
@item -fno-default-inline