Re: Has anyone successfully bootstrapped gcc-4.6.3 on m68k?

[Vincent Rivière <vincent.riviere@freesbee.fr>]

On 30/05/2012 02:58, t-rexky wrote:
> The NEXTSTEP assembler is a very heavily modified gas-1.38 and the
> .const directive indeed changes the output section.

Ok, it is unlikely that the .text and .const sections have a fixed 
distance, so PC-relative jump tables can't work.

ASM_OUTPUT_ADDR_VEC_ELT may be for you:
http://gcc.gnu.org/onlinedocs/gccint/Dispatch-Tables.html#index-ASM_005fOUTPUT_005fADDR_005fVEC_005fELT-4612

As I suggested previously, alternatively the following should do the trick:
#define JUMP_TABLES_IN_TEXT_SECTION 1

But this is not the right solution, because the jump tables will stay in 
the .text segment instead of going to the .const segment as expected.

> I am trying to figure out exactly what has changed in gcc, since the
> jump tables  worked just fine with gcc-3.4.6 and the exact same
> target configuration I am using.

Look at the assembly output from gcc-3.4.6 and see the difference in the 
generated jump table code.

Since .const is a nonstandard keyword, it may not be used in many places 
in your gcc-4.6 source tree. Try to grep for it, and you will find where 
it has specifically be patched. There are probably other useful macros 
there.

--
Vincent Rivière