Re: [loongson-PATCH-v2 20/23] add gcc 4.4 support for MIPS and loongson

[Wu Zhangjin <wuzhangjin@gmail.com>]

On Wed, 2009-05-27 at 11:22 +0200, Arnaud Patard wrote:
> wuzhangjin@gmail.com writes:
> Hi,
> 
> > From: Wu Zhangjin <wuzj@lemote.com>
> >
> > the gcc 4.4 support for MIPS mostly refer to this PATCH:
> > http://www.nabble.com/-PATCH--MIPS:-Handle-removal-of-%27h%27-constraint-in-GCC-4.4-td22192768.html
> > but have been tuned a little.
> >
> > because only gcc 4.4 have loongson-specific support, so, we need to
> > choose the suitable -march argument for gcc <= 4.3 and gcc >= 4.4, and
> > we also need to consider use -march=loongson2e and -march=loongson2f for
> > loongson2e and loongson2f respectively. this is handled by adding two
> > new kernel options: CPU_LOONGSON2E and CPU_LOONGSON2F(thanks for the
> > solutin provided by ZhangLe).
> >
> > I have tested it on FuLoong(2f) in 32bit and 64bit with gcc-4.4 and
> > gcc-4.3. so, basically, it works.
> >
> > Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
> > ---
> >  arch/mips/Makefile               |    9 +++++-
> >  arch/mips/include/asm/compiler.h |   10 ++++++
> >  arch/mips/include/asm/delay.h    |   58 +++++++++++++++++++++++++------------
> >  3 files changed, 57 insertions(+), 20 deletions(-)
> >
> > diff --git a/arch/mips/Makefile b/arch/mips/Makefile
> > index a25c2e5..1ee5504 100644
> > --- a/arch/mips/Makefile
> > +++ b/arch/mips/Makefile
> > @@ -120,7 +120,14 @@ cflags-$(CONFIG_CPU_R4300)	+= -march=r4300 -Wa,--trap
> >  cflags-$(CONFIG_CPU_VR41XX)	+= -march=r4100 -Wa,--trap
> >  cflags-$(CONFIG_CPU_R4X00)	+= -march=r4600 -Wa,--trap
> >  cflags-$(CONFIG_CPU_TX49XX)	+= -march=r4600 -Wa,--trap
> > -cflags-$(CONFIG_CPU_LOONGSON2)	+= -march=r4600 -Wa,--trap
> > +
> > +# only gcc >= 4.4 have the loongson-specific support
> > +cflags-$(CONFIG_CPU_LOONGSON2)	+= -Wa,--trap
> > +cflags-$(CONFIG_CPU_LOONGSON2E)	+= $(shell if [ $(call cc-version) -lt 0440 ] ; then \
> > +	echo $(call cc-option,-march=r4600); else echo $(call cc-option,-march=loongson2e); fi ;)
> > +cflags-$(CONFIG_CPU_LOONGSON2F)	+= $(shell if [ $(call cc-version) -lt 0440 ] ; then \
> > +	echo $(call cc-option,-march=r4600); else echo $(call cc-option,-march=loongson2f); fi ;)
> > +
> 
> why not using something like that ? :
>         cflags-$(CONFIG_LOONGSON2E) += \
>                 $(call cc-option,-march=loongson2e,$(call cc-option,-march=r4600))
>         cflags-$(CONFIG_LOONGSON2F) += \
>                 $(call cc-option,-march=loongson2f,$(call cc-option,-march=r4600))
> 

applied.

Documentation/kbuild/makefiles.txt:

  cc-option is used to check if $(CC) supports a given option, and not
  supported to use an optional second option.

thx!
Wu Zhangjin