This is the mail archive of the crossgcc@sourceware.org mailing list for the crossgcc project.

See the CrossGCC FAQ for lots more information.

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: More ARM binutils fuckage

On Sat, Dec 23, 2006 at 02:17:23PM +0000, Martin Guy wrote:

> >I use a bog-standard gcc 4.1.0 to cross-compile all my ARM kernels
> >with, which allows me to build both old-ABI and EABI kernels.  (These
> >days I build all kernels in EABI mode with old-ABI compat.)
> 
> There is a speed penalty to keeping old-ABI compat on.
> 
> With old-ABI compat enabled, you lose the speed advantage that the
> system call change was designed to achieve: it still has to inspect
> the instruction stream to see whether each system call is a new-ABI
> (SWI 0, syscall number in r7) or old-abi (SWI 0x900000+n) one, and
> peeking the SWI instruction to figure out which convention was used
> accesses the code segment thorough the data cache, causing a cache
> flush.

ITYM cache miss.


> So if you *can* turn old-ABI compat off, it is well to do so

Sure, if your userland is all-EABI (which mine is), you can turn it
off.

--
For unsubscribe information see http://sourceware.org/lists.html#faq
Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]