FW: RE: x86_64 port

[Simon Marlow]

On 07 March 2005 16:18, David Brown wrote:

> On Mon, Mar 07, 2005 at 11:47:31AM -0000, Simon Marlow wrote:
> 
>> $ cat bug.c
>> register void * R1 __asm__("%r13");
>> 
>> extern void g(void);
>> static void f(void) {
>>  R1 = g;
>>  goto *R1;
>> }
>> $ gcc -S -O bug.c
>> $
>> 
>> And take a look at the generated assembly for the function f:
>> 
>> f:
>> .LFB2:
>>         movl    $g, %eax
>>         jmp     *%rax
>> 
>> Note that the assignment to the global variable R1 has been lost.  It
>> works fine on x86 though: change the register variable to %esi and
>> try it.
> 
> Hmm.  On gcc 3.3.5 that I have, it discards the assignment on x86 as
> well. 

Yes, looks like it fails with 3.4.1 and 3.4.3 I have here, but 3.2.2
works.

Now I'm quite surpised that this hasn't affected us on x86.  Very
strange.

Cheers,
	Simon