new ppc32 GOT/PLT support

[Richard Henderson]

On Wed, May 18, 2005 at 12:03:53AM +0930, Alan Modra wrote:
>    /* Get address of the 'b _DYNAMIC@local'...  */
> +  asm ("bcl 20,31,0f;"
>         "b _DYNAMIC@local;"
>         "0:"
> +       : "=l" (branchaddr));
>  
>  /* So now work out the difference between where the branch actually points,
>     and the offset of that location in memory from the start of the file.  */
> +  runtime_dynamic = ((Elf32_Addr) branchaddr
> +		     + ((Elf32_Sword) (*branchaddr << 6 & 0xffffff00) >> 6));

This is simply

	asm ("bcl 20,31,0f\n"
	     "0: mflr %0\n"
	     "   addis %0,%0,_DYNAMIC-0b@ha\n"
	     "   addi %0,%0,_DYNAMIC-0b@l"
	  : "=b"(runtime_dynamic) : : "lr");

> +# ifdef HAVE_ASM_PPC_REL16
> +	bcl	20,31,1f
> +1:	mflr	r7
> +	addis	r7,r7,_GLOBAL_OFFSET_TABLE_-1b@ha
> +	addi	r7,r7,_GLOBAL_OFFSET_TABLE_-1b@l
> +# else
>  	bl      _GLOBAL_OFFSET_TABLE_@local-4
>  	mflr    r7
> +# endif

All this ifdefery is so common, perhaps a sysdep.h macro is in order...



r~