RFC: powerpc-rtems multilibs

Joel Sherrill joel.sherrill at OARcorp.com
Thu Apr 4 12:14:47 UTC 2002

To me it would be OK.  

We MIGHT benefit more from
include 4xx or 8xx or 7xx variants if gcc makes a speed 
difference for those CPUs.  But that is a separate issue


Ralf Corsepius wrote:
> Hi,
> Currently, powerpc-rtems-gcc-3-0.4 uses these multilib-variants:
> # powerpc-rtems-gcc --print-multi-lib
> .;@mrelocatable-lib at mno-eabi@mstrict-align
> nof;@msoft-float at mrelocatable-lib@mno-eabi at mstrict-align
> le;@mlittle at mrelocatable-lib@mno-eabi at mstrict-align
> ca;@mcall-aix at mrelocatable-lib@mno-eabi at mstrict-align
> und;@fleading-underscore at mrelocatable-lib@mno-eabi at mstrict-align
> le/und;@mlittle at fleading-underscore@mrelocatable-lib at mno-eabi@mstrict-align
> nof/le;@msoft-float at mlittle@mrelocatable-lib at mno-eabi@mstrict-align
> nof/ca;@msoft-float at mcall-aix@mrelocatable-lib at mno-eabi@mstrict-align
> nof/und;@msoft-float at fleading-underscore@mrelocatable-lib at mno-eabi@mstrict-align
> nof/le/und;@msoft-float at mlittle@fleading-underscore at mrelocatable-lib@mno-eabi at mstrict-align
> My question is: Do these actually give sense for RTEMS or can some of
> them be eliminated rsp. shall others be added?
> Remember that we can set the conventions/standards to be used by
> RTEMS-gcc, so "sticking to some arbitrary defaults", as
> powerpc-rtems-gcc currently does, might be worth reconsideration.
> AFAIS, currently, only nof (==softfloat) and "default" are used by the
> public BSPs. Little endian does not seem to be used, however would give
> sense if the ppc-ports support it (AFAIS, they at least claim to do so,
> but there doesn't seem to exist a BSP which actually uses it.)
> How about "call-aix" and "fleading-underscore"?
> I don't know what these actually do, but they don't seem to be used by
> I.e. I am in favor of removing the "ca" and "und" multilib variants,
> unless there is a technical reason to keep them. This would
> significantly reduce the size of powerpc-rtems-gcc and the time required
> to build multilibs.
> Opinions, comments?
> Ralf

Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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