Re: problem about the tool chain for R3000

["guo guo" <sunnyboyguo@gmail.com>]

Dear Daney,
Thank you very much.
Under nptl directory, there are 6 places use rdhwr instruction. What's
difference between rdhwr and move instructions?
Could I use move or other r3000 instructions to replace rdhwr?

And I didn't find ll/sc instructions in libc-2.5.90.so. maybe gcc
avoid them for R3000 chip.

Best regards,
Tony


2007/8/29, David Daney <ddaney@avtrex.com>:
> guo guo wrote:
> > Dear All,
> >
> > I'm trying to build tool chain with gcc4.2, binutils2.17 and glibc2.5
> > for mips r3000 chip.
> > During configure gcc I add ?Cmabi=32 ?Cmarch=r3000 ?Cmtune=r3000. and
> > during building glibc, I add CFLAGS= -O2 ?Cmabi=32 ?Cmarch=r3000
> > ?Cmtune=r3000,
> > Then I dissembled the libc-2.5.90.so to check the instructions. I
> > found it has two instructions rdhwr(0x7c03e83b) and sync(0x0000000f)
> > that don't belongs to mips r3000.
>
> The rdhwr and sync are used by the NPTL pthread library and must be
> emulated by the linux kernel.  Probably you will see ll and sc in there
> as well.  If you use glibc2.3.x with Linux threads then the rdhwr will
> not be generated.
>
>  Probably if you did not use libpthread you would not need any of the
> thread synchronization primitives that cause ll,sc, and sync to be
> generated.
>
> But if you want libpthread and your CPU does not support the
> instructions, you will have to emulate them.
>
>
> David Daney
>