Enable 32-bit Alignment

[H.J. Lu]

On Tue, Jul 03, 2007 at 07:12:55PM -0500, Menezes, Evandro wrote:
> After iterating with HJ and Alan, here's another spin of the patch.
> 
> 2007-06-29	Evandro Menezes <evandro.menezes@amd.com>
> 
> 	* config/tc-i386.c (handle_align_code, i386_align_code): new
> function 
> 	  to help alignment > 15 bytes, enable alignment up to 31 bytes,
> 
> 	  always use variable-length NOP for K8 too.
> 	* config/tc-i386.h (MAX_MEM_FOR_RS_ALIGN_CODE): change limit to
> 31 bytes.
> 	* testsuite/gas/i386/i386.exp: replace NOP test-case, add new
> one and 
> 	  remove K8-specific one.
> 	* testsuite/gas/i386/nops-3-i686.d: new NOP test-case.
> 	* testsuite/gas/i386/nops-4.s: idem
> 	* testsuite/gas/i386/nops-4-i686.d: idem
> 	* testsuite/gas/i386/x86-64-nops-1-k8.d: removed.

Can you add nops-4.d and x86-64-nops-4.d?

I'd like to see some further changes:

1. For N byte alignment padding up to 15 bytes:
   a. On 32bit,
      i. Use (N - 1) 66 prefixes + 90 by default.
      ii. When Pentium Pro or newer is specified, use (N - X) 66
          prefixes + new nop insn with X bytes.
      iii. For Pentum or older, use the old padding.
   b. On 64bit, use (N - X) 66 prefixes + new nop insn with X bytes.
2.  For alignment padding between 16 and 30 bytes, use 2 x (< 15byte nops).
3.  For 31 byte alignment padding, use 2 x (15byte nops) + 1byte nop.

Will it be a problem on AMD?

Thanks.


H.J.