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Re: PATCH [5/n] X32: Supprot 32bit address
On Fri, Jul 15, 2011 at 3:03 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Jul 15, 2011 at 5:49 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> On Sun, Jul 10, 2011 at 12:20 AM, H.J. Lu <hongjiu.lu@intel.com> wrote:
>>
>>> TARGET_MEM_REF only works on ptr_mode. ?That means base and index parts
>>> of x86 address operand in x32 mode may be in ptr_mode. ?This patch
>>> supports 32bit base and index parts in x32 mode. ?OK for trunk?
>>>
>>> Thanks.
>>>
>>>
>>> H.J.
>>> ---
>>> 2011-07-09 ?H.J. Lu ?<hongjiu.lu@intel.com>
>>>
>>> ? ? ? ?* config/i386/i386.c (ix86_simplify_base_index_disp): New.
>>> ? ? ? ?(ix86_decompose_address): Support 32bit address in x32 mode.
>>> ? ? ? ?(ix86_legitimate_address_p): Likewise.
>>> ? ? ? ?(ix86_fixup_binary_operands): Likewise.
>>
>> Why don't you handle translations in TARGET_LEGITIMIZE_ADDRESS (or
>> maybe also LEGITIMIZE_RELOAD_ADDRESS) ?
>>
>
> It is because ix86_decompose_address is also called from:
>
> predicates.md: ?ok = ix86_decompose_address (op, &parts);
> predicates.md: ?ok = ix86_decompose_address (op, &parts);
> predicates.md: ?ok = ix86_decompose_address (XEXP (op, 0), &parts);
> predicates.md: ?ok = ix86_decompose_address (XEXP (op, 0), &parts);
> predicates.md: ?ok = ix86_decompose_address (XEXP (op, 0), &parts);
Yes, but you should legitimize the address created by reload before it
enters into predicates.
So, the questions are:
+ (set (reg:SI 40 r11)
+ (plus:SI (plus:SI (mult:SI (reg:SI 1 dx)
+ (const_int 8))
+ (subreg:SI (plus:DI (reg/f:DI 7 sp)
+ (const_int CONST1)) 0))
+ (const_int CONST2)))
+
+ We translate it into
+
+ (set (reg:SI 40 r11)
+ (plus:SI (plus:SI (mult:SI (reg:SI 1 dx)
+ (const_int 8))
+ (reg/f:SI 7 sp))
+ (const_int [CONST1 + CONST2])))
If the first form of the address is not OK (it does not represent the
hardware operation), then it should not enter into the insn stream.
This means, that it should be fixed ("legitimized") to second form by
appropriate function (it looks that LEGITIMIZE_RELOAD_ADDRESS should
fix it, since the incorrect address is generated by IRA/reload). After
this operation, various predicates, based on ix86_decompose_address
will start to work, since they will decompose valid memory addresses.
Uros.