Building gcc for MIPS: mabi=64 and -mips3 instead of -mips4?

[Gokhan Kisacikoglu]

> Is there any way to build gcc (3.0.4) so that the mabi=64 libraries (MIPS)
> are
> built for -mips3 instead of -mips4?  The system libs (/usr/lib64) are all
> mips3.
> 

I'd say change configure the CC flags, it should be able to pick up
properly...


> Second question:  Is it important that they match?  The linker gives a
> warning
> if they don't.

I am not sure...

> 
> What's the minimum processor needed for -mips4?  The name seems to imply
> R4000, but the gcc man page says r8000 is the default cpu-type.  Does this
> mean it will issue instructions that can only be run on an r8000 or that it
> will
> just schedule for an r8000?

>From the manual page of CC;

     -mipsn  Specifies the Instruction Set Architecture (ISA).  n can be
             one of the following:

             1   Generates code using the instruction set of the
                 R2000/R3000 RISC architecture, and searches for mips1
                 libraries/objects at link-time.  This defaults to -o32.

             2   Generates code using the MIPS II instruction set (MIPS
I +
                 R4000 specific extensions), and searches for mips2
                 libraries/objects at link-time.  This defaults to -o32.

             3   Generates code using the full MIPS III instruction set,
                 and searches for mips3 libraries/objects at link-time. 
If
                 -n32 or -64 are not specified, this defaults to -64 on
                 R8000-based systems and -n32 on all other systems.

             4   Generates code using the full MIPS IV instruction set
                 which is supported on R10000, R5000 and R8000 systems,
and
                 searches for mips4 libraries/objects at link-time. 
This
                 is the default on R8000 systems.  If -n32 or -64 are
not
                 specified, this defaults to -64 on R8000-based systems
and
                 -n32 on all other systems.

I think it specializes the code to run only on the specific
architecture...

Hope these help,
Gokhan