[PATCH] Powerpc/trampline: consider __NO_FPRS__

[Ryan Arnold]

On Fri, Jun 18, 2010 at 3:32 AM, Sebastian Andrzej Siewior
<sebastian@breakpoint.cc> wrote:
> 2010-06-18  Sebastan Andrzej Siewior  <bigeasy@linutronix.de>
>
>        * sysdeps/powerpc/powerpc32/dl-trampoline.S: Put __NO_FPRS__ around
>        floating point opcodes.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  sysdeps/powerpc/powerpc32/dl-trampoline.S |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/sysdeps/powerpc/powerpc32/dl-trampoline.S b/sysdeps/powerpc/powerpc32/dl-trampoline.S
> index 6a158c3..bd815c7 100644
> --- a/sysdeps/powerpc/powerpc32/dl-trampoline.S
> +++ b/sysdeps/powerpc/powerpc32/dl-trampoline.S
> @@ -137,6 +137,7 @@ _dl_prof_resolve:
>        stw r9,40(r1)
>        stw r10,44(r1)
>        stw r0,8(r1)
> +#ifndef __NO_FPRS__
>  # Save the floating point registers
>        stfd fp1,48(r1)
>        stfd fp2,56(r1)
> @@ -146,6 +147,7 @@ _dl_prof_resolve:
>        stfd fp6,88(r1)
>        stfd fp7,96(r1)
>        stfd fp8,104(r1)
> +#endif
>  # XXX TODO: store vmx registers
>  # Load the extra parameters.
>        addi r6,r1,16
> @@ -169,6 +171,7 @@ _dl_prof_resolve:
>        lwz r4,20(r1)
>        lwz r3,16(r1)
>         lwz r0,12(r1)
> +#ifndef __NO_FPRS__
>  # Load the floating point registers.
>        lfd fp1,48(r1)
>        lfd fp2,56(r1)
> @@ -178,6 +181,7 @@ _dl_prof_resolve:
>        lfd fp6,88(r1)
>        lfd fp7,96(r1)
>        lfd fp8,104(r1)
> +#endif
>  # ...unwind the stack frame, and jump to the PLT entry we updated.
>        addi r1,r1,320
>        bctr
> --
> 1.6.6.1

The currently blessed method for achieving what you want is to clone
this code and move a copy with FPU support into the powerpc32/fpu/
directory and strip the FPR save out of the powerpc32/dl-trampoline.S
code.  This, of course, introduces code bloat of asm files which is
... undesirable.

Ryan S. Arnold