Hi Vladimir,
I've some regressions on ARM after this SP elimination patch, and they
are execution failures. Here is the list:
g++.dg/cilk-plus/AN/array_test_ND_tplt.cc -O3 -fcilkplus
gcc.c-torture/execute/va-arg-22.c -O2
gcc.dg/atomic/c11-atomic-exec-5.c -O0
gfortran.dg/direct_io_12.f90 -O[23]
gfortran.dg/elemental_dependency_1.f90 -O2
gfortran.dg/matmul_2.f90 -O2
gfortran.dg/matmul_6.f90 -O2
gfortran.dg/mvbits_7.f90 -O3
gfortran.dg/unlimited_polymorphic_1.f03 -O3
I reduced and looked at var-arg-22.c and the issue is that in
lra_eliminate_regs_1 (called by get_equiv_with_elimination) we
transformed sfp + 0x4c in sp + 0xfc because of a bad sp offset. What
we try to do here is to change the pseudo 195 of the insn 118 below :
(insn 118 114 112 8 (set (reg:DI 195)
(unspec:DI [
(mem:DI (plus:SI (reg/f:SI 215)
(const_int 8 [0x8])) [7 MEM[(struct A35 *)_12
+ 64B]+8 S8 A8])
] UNSPEC_UNALIGNED_LOAD)) v2.c:49 146 {unaligned_loaddi}
(expr_list:REG_EQUIV (mem/c:DI (plus:SI (reg/f:SI 192)
(const_int 8 [0x8])) [7 a35+8 S8 A32])
(nil)))
with its equivalent (x arg of lra_eliminate_regs_1):
(mem/c:DI (plus:SI (reg/f:SI 102 sfp)
(const_int 76 [0x4c])) [7 a35+8 S8 A32])
lra_eliminate_regs_1 is called with full_p = true (it is not really
clear for what it means), but in the PLUS switch case, we have offset
= 0xb (given by ep->offset) and as lra_get_insn_recog_data
(insn)->sp_offset value is 0, we will indeed add 0xb to the original
0x4c offset.
So, here I don't get if it is the sp_offset value of the
lra_insn_recog_data element which is not well updated or if lra_
eliminate_regs_1 has to be called with update_p and not full_p (which
fixed the value in that particular case). Is it more obvious for you
?
Thanks
Yvan
On 3 December 2013 16:39, Vladimir Makarov <[email protected]> wrote:
> On 12/3/2013, 6:54 AM, Marcus Shawcroft wrote:
>>
>> On 2 December 2013 23:44, Vladimir Makarov <[email protected]> wrote:
>>
>>> If somebody with the rights approves, I can commit it tomorrow.
>>>
>>> 2013-12-02 Vladimir Makarov <[email protected]>
>>>
>>> * config/aarch64/aarch64.c (aarch64_frame_pointer_required):
>>> Check
>>> LR_REGNUM.
>>> (aarch64_can_eliminate): Don't check elimination source when
>>> frame_pointer_requred is false.
>>>
>>
>>
>> This is fine with me, go ahead and commit it. Thanks /Marcus
>>
> Committed as rev. 205637 with changelog fix of a typo found by Jeff.
>
