On Tue, Jul 19, 2011 at 10:46 AM, Richard Guenther
<richard.guent...@gmail.com> wrote:

>>>>>>>> TARGET_MEM_REF only works on ptr_mode.   This patch allows 32bit 
>>>>>>>> address
>>>>>>>> in x32 mode.  OK for trunk?
>>>>>>>
>>>>>>> Do you perhaps have a testcase to help in analyzing the problem?
>>>>>>>
>>>>>>
>>>>>> See:
>>>>>>
>>>>>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49780
>>>>>
>>>>> I don't think that tree-ssa-address/addr_for_mem_ref is correct when
>>>>> REALLY_EXPAND is false. It constructs RTX "template" in pointer_mode,
>>>>> which is not necessary valid and is rejected from
>>>>> ix86_validate_address_p. When really expanding the expression, we have
>>>>> a conversion at the end:
>>>>>
>>>>>  gen_addr_rtx (pointer_mode, sym, bse, idx, st, off, &address, NULL, 
>>>>> NULL);
>>>>>  if (pointer_mode != address_mode)
>>>>>    address = convert_memory_address (address_mode, address);
>>>>>  return address;
>>>>>
>>>>> This is in fact your r175912 change in the fix for PR47383 - you need
>>>>> to do something with template as well...
>>>>>
>>>>
>>>> Since TARGET_MEM_REF only works on ptr_mode, I don't think
>>>> we can change template.  We just need to accept TARGET_MEM_REF
>>>> in ptr_mode and fix it up later.
>>>
>>> No, a template is used to get some insight into the supported address
>>> structure. If there is a mismatch, this approach fails, we can as well
>>> give the compiler whatever fake template we want.

I have investigated other Pmode != ptr_mode targets, and none of them
check the mode of a register in TARGET_LEGITIMATE_ADDRESS_P (or
equivalent GO_IF_LEGITIMATE_ADDRESS). All it matters is only if there
is a register and regno of the register.

Attached patch simply removes these two checks, as it seems they are
not needed. This also follows how other Pmode != ptr_mode targets.

2011-07-19  Uros Bizjak  <ubiz...@gmail.com>

        PR target/49780
        * config/i386/i386.c (ix86_legitimate_address_p): Remove checks that
        base and index registers are in Pmode.

Patch was bootstrapped and regression tested on x86_64-pc-linux-gnu
{,-m32}. Can you please re-test it on x32?

BTW: I still think that template should return the same address
structure as expansion, but this won't crash the compiler anymore.

Uros.
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c  (revision 176433)
+++ config/i386/i386.c  (working copy)
@@ -11653,10 +11653,6 @@ ix86_legitimate_address_p (enum machine_
        /* Base is not a register.  */
        return false;
 
-      if (GET_MODE (base) != Pmode)
-       /* Base is not in Pmode.  */
-       return false;
-
       if ((strict && ! REG_OK_FOR_BASE_STRICT_P (reg))
          || (! strict && ! REG_OK_FOR_BASE_NONSTRICT_P (reg)))
        /* Base is not valid.  */
@@ -11682,10 +11678,6 @@ ix86_legitimate_address_p (enum machine_
        /* Index is not a register.  */
        return false;
 
-      if (GET_MODE (index) != Pmode)
-       /* Index is not in Pmode.  */
-       return false;
-
       if ((strict && ! REG_OK_FOR_INDEX_STRICT_P (reg))
          || (! strict && ! REG_OK_FOR_INDEX_NONSTRICT_P (reg)))
        /* Index is not valid.  */

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