Re: [MUSL] microMIPS32R2 O32 port

[Szabolcs Nagy <nsz@port70.net>]

* Jaydeep Patil <Jaydeep.Patil@imgtec.com> [2017-04-12 11:54:10 +0000]:
> Hi Rich,
> 
> We can reuse existing MIPS code for microMIPS. There are places where we read from $ra must be compiled for MIPS.
> Please refer to https://github.com/JaydeepIMG/musl-1/tree/micromips32r2_v2 for modifications.
> 

is micromips a different encoding for mips instructions
that works on some cpus but not others?

does it require musl changes because micromips does not
support all mips instructions just a subset?

> Thanks,
> Jaydeep
> 
> >-----Original Message-----
> >From: Rich Felker [mailto:dalias@aerifal.cx] On Behalf Of Rich Felker
> >Sent: 07 April 2017 PM 07:50
> >To: musl@lists.openwall.com
> >Subject: Re: [musl] [MUSL] microMIPS32R2 O32 port
> >
> >On Fri, Apr 07, 2017 at 06:47:57AM +0000, Jaydeep Patil wrote:
> >> Hi Rich,
> >>
> >> microMIPS is an Application Specific Extension (ASE) to MIPS cores.
> >> Both microMIPS and MIPS can co-exist. MIPS code can call microMIPS and
> >> vice-versa. microMIPS is a compressed ISA and contains both 16 and
> >> 32-bit instructions for code size benefit.
> >
> >In that case I'm confused what the benefit of compiling the asm files as
> >micromips rather than plain mips is. Is it just to save 10 bytes here and there?
> >
> >Rich