Help with reload

Help with reload

[Revital1 Eres]

Hello,

I have a question regarding code generation for a new target I'm working
on.
I am using GCC 4.6.

In reload pass  the following first instruction is replaced with the
second one after spilling reg 182 to the stack.  The problem is that
the generated new instruction does not have a valid address format and
I'm not sure why it was considered as a valid replacement.
Any help on how to resolve this is appreciated.

(insn 282 150 151 13 jctrans.c:109 (set (reg:SI 12 r12)
        (mem/s:SI (plus:SI (reg/v/f:SI 182 [ incomp ])
                (const_int 8 [0x8])) [6 *incomp_85 S4 A32])) -1 (nil))

(insn 282 150 151 13 jctrans.c:109 (set (reg:SI 12 r12)
        (mem/s:SI (plus:SI (mem/c:SI (plus:SI (reg/f:SI 63 r63)
                        (const_int -12 [0xfffffff4])) [56 %sfp+-12 S4 A32])
                (const_int 8 [0x8])) [6 *incomp_85 S4 A32])) -1 (nil))

Thanks,
Revital

Re: Help with reload

[Jeff Law]

On 06/22/10 08:52, Revital1 Eres wrote:
> Hello,
>
> I have a question regarding code generation for a new target I'm working
> on.
> I am using GCC 4.6.
>
> In reload pass  the following first instruction is replaced with the
> second one after spilling reg 182 to the stack.  The problem is that
> the generated new instruction does not have a valid address format and
> I'm not sure why it was considered as a valid replacement.
> Any help on how to resolve this is appreciated.
>
> (insn 282 150 151 13 jctrans.c:109 (set (reg:SI 12 r12)
>          (mem/s:SI (plus:SI (reg/v/f:SI 182 [ incomp ])
>                  (const_int 8 [0x8])) [6 *incomp_85 S4 A32])) -1 (nil))
>
> (insn 282 150 151 13 jctrans.c:109 (set (reg:SI 12 r12)
>          (mem/s:SI (plus:SI (mem/c:SI (plus:SI (reg/f:SI 63 r63)
>                          (const_int -12 [0xfffffff4])) [56 %sfp+-12 S4 A32])
>                  (const_int 8 [0x8])) [6 *incomp_85 S4 A32])) -1 (nil))
>    

What's happening is pseudo 182 is not getting a hard reg, and is thus on 
the stack (see reg_equiv_mem).  Reload will substitute the MEM for the 
unassigned pseudo.

Check your GO_IF_LEGITIMATE_ADDRESS.  You might also look at your 
REGNO_OK_FOR_BASE_P and whether or not it handles a strict & non-strict 
variant properly.

Jeff