Re: arm-elf MULTILIBS_DEFAULT

[Ralf Corsepius <corsepiu at faw dot uni-ulm dot de>]

Am Don, 2003-02-27 um 11.36 schrieb Richard Earnshaw:
> > Hi,
> > 
> > I am trying to extend the multilib being used for arm-rtems (more less
> > is identical to arm-*-elf).
> > 
> > To do so, I introduced a gcc/config/arm/t-rtems containing this:
> > MULTILIB_OPTIONS     = marm/mthumb msoft-float/mhard-float
> > MULTILIB_DIRNAMES    = arm thumb soft fpu
> > MULTILIB_EXCEPTIONS  =
> > MULTILIB_MATCHES =
> > 
> > Resulting into this multilibs:
> > # /opt/rtems/bin/arm-rtems-gcc -print-multi-lib
> > .;
> > thumb;@mthumb
> > fpu;@mhard-float
> > thumb/fpu;@mthumb at mhard-float
> > 
> > [Note this assumes '.' to imply -msoft-float -marm]
> > 
> > However, when trying to link an arbitrary fp-application using
> > -msoft-float I end up with the linker complaining about FP-stuff:
> > 
> > # /opt/rtems/bin/arm-rtems-gcc -msoft-float tmp.c
> > /opt/rtems/lib/gcc-lib/arm-rtems/3.2.2/../../../../arm-rtems/bin/ld:
> > ERROR: /opt/rtems/lib/gcc-lib/arm-rtems/3.2.2/libgcc.a(_df_to_sf.o) uses
> > hardware FP, whereas a.out uses software FP
> > ..
> > 
> > If I understand correctly, this indicates that the arm-elf default flags
> > do not match with arm-elf's MULTILIB_DEFAULTS (from arm-elf.h).
> > 
> > What am I missing? 
> > 
> >
> You need to ensure that the compiler driver passes the correct flags to 
> the assembler when the default multilib  variant is selected.  You do this 
> in rtems-elf.h (take a look at the way netbsd-elf.h does it).

Thanks for the hint, Richard.

Below is the patch I am currently using and which AFAIS seems to
implement the desired behavior.

Ralf

Attachment: gcc-3.2.2-arm-rtems-rc-20030227-1.diff
Description: Text document